CN102325382B - Accidental access method and equipment - Google Patents

Abstract

The embodiment of the invention discloses a kind of accidental access method and equipment, relate to wireless communication technology field, for solving the problem of how to carry out Stochastic accessing in carrier aggregation system.In the present invention, terminal by PRACH resource, sends described random access leader sequence to base station on auxiliary community; Terminal is according to the information of the carrier identification information of described auxiliary community and/or described PRACH resource, determine the random access radio network temporary mark RA-RNTI that described random access leader sequence is corresponding, the public search space in main plot detects the physical downlink control channel PDCCH using this RA-RNTI scrambling; According to the described PDCCH detected, receive the Physical Downlink Shared Channel PDSCH carrying accidental access response corresponding to described random access leader sequence, and according to the uplink timing advance TA in described accidental access response, uplink synchronous adjustment is carried out to described auxiliary community.Adopt the present invention, achieve carrier aggregation system Zhong Fu community or the Stochastic accessing simultaneously in multiple community.

Description

Random access method and equipment

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a random access method and apparatus.

Background

A random access procedure (random access procedure) is divided into contention random access and non-contention random access, and is used to establish uplink synchronization between a terminal (UE) and a base station.

The contention random access is triggered by a Media Access Control (MAC) layer of the UE, a random access preamble sequence (preamble) sent by the UE may be randomly selected in a specific preamble sequence group, and a Physical Random Access Channel (PRACH) resource used for sending the preamble may also be a resource randomly selected in a specific plurality of resources, so that when a plurality of UEs select the same PRACH resource and preamble sequence at the same time, contention exists. The trigger reasons for contention random access include: radio Resource Control (RRC) connection establishment (i.e., initial access)/RRC reestablishment, Uplink (UL) data arrival but UL out-of-sync, no Dedicated-scheduling request (D-SR) resource configured, and failure of the D-SR after reaching the maximum transmission number (RA-SR).

Non-contention random access, which is triggered by a physical downlink control channel command (pdcch) or RRC signaling sent by a base station and allocates a dedicated preamble and PRACH resource, so that there is no contention, and the triggering reasons include: the UE has Downlink (DL) data arrival but UL out-of-step, cell switching, UL data volume increase, a newly added cell is needed, Timing Advance (TA) of the newly added cell is different from that of a cell which is synchronized, and positioning is needed.

In a Long Term Evolution (LTE) system, 5 prach (preamble) structures are defined, and each structure has a different length in a time domain, as shown in table 1, occupies 6 Physical Resource Blocks (PRBs), that is, 72 subcarriers, in a frequency domain. For a Frequency Division Duplex (FDD) system, there is at most one PRACH in one subframe; for a Time Division Duplex (TDD) system, there are at most 6 PRACH channels in a subframe for frequency division multiplexing. According to the transmission density of the PRACH and the random access preamble sequence format (preamblefmat), the FDD system defines 64 PRACH configurations, and notifies the PRACH configuration used by the UE through a higher layer signaling, so that the preamblefmat transmitted by the UE and the subframe in which the PRACH can be transmitted can be determined, as shown in table 2. The TDD system also defines 58 PRACH configurations, and the PRACH configuration used by the UE is signaled by a higher layer, as shown in tables 3 and 4, where table 3 shows the combinations between different preamblefumormats and different PRACH transmission densities, and table 4 shows the available PRACH resources in the next radio frame for each preamblefumormat and transmission density combination in table 3, and thus the PRACH configurations used by the UE are signaled by a higher layer, and the PRACH configurations used by the UE are indicated by table 3 and table 4A vector of four parameters represents a specific physical resource location of the PRACH mapping, where f_RAIs a frequency-domain resource index and,is a radio frame index, representing PThe RACH will occur in every radio frame either even or odd,is a field index, which indicates that the PRACH is positioned in the first half frame or the second half frame of the wireless frame,indicating the starting point of Preamble for the uplink subframe number index, starting counting from 0, and because the PRACH in Format4 must be located in the special time slot (UpPTS), under the configurationIndicated by (#). Because there are 7 configurations of uplink and downlink subframes in the frame structure of the TDD system, the specific time-frequency domain resource locations that can be used for sending the PRACH are different under different uplink and downlink configurations.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

Fig. 1 shows a non-contention random access procedure, and fig. 2 shows a contention random access procedure. Wherein:

message 0(Msg 0): the method is only suitable for non-competitive random access or competitive random access triggered by a base station; the loaded content at least comprises:

ra-preamble index (random access preamble): indicating a dedicated preamble number;

ra-PRACH-maskindex (prachmaksdex): indicating a PRACH resource number, i.e. indicating one of the PRACH resources in table 2 or table 4;

message 1(Msg 1): the method is suitable for both non-competitive random access and competitive random access; a process of sending a preamble to a base station for UE through PRACH;

for non-competitive random access, a preamble sequence and PRACH resources are both exclusive to UE and are configured in Msg 0; there is therefore no competition;

for competitive random access, a preamble sequence is a sequence randomly selected by the UE in a determined preamble group according to the configuration of the UE; for the FDD system, the UE selects, according to the PRACH configuration, a PRACH resource of a first available PRACH resource subframe among a plurality of PRACH-transmittable subframes shown in table 2, to be used for transmitting a preamble; for the TDD system, according to the PRACH configuration, the UE randomly selects one (equal probability) of PRACH resources of three consecutive subframes from a first available subframe having PRACH resources among the PRACH time-frequency domain resources shown in table 4; therefore, when different UEs select the same PRACH resource and preamble sequence, there is contention;

message 2(Msg 2): the method is suitable for both non-competitive random access and competitive random access, and does not support hybrid automatic repeat request (HARQ), namely, no retransmission; the UE receives a Random Access Response (RAR) sent by the base station; the RAR is scheduled by a PDCCH scrambled by a random access radio network temporary identifier (RA-RNTI) and transmitted on a Physical Downlink Shared Channel (PDSCH), the PDSCH can comprise RARs of a plurality of UEs, and the RAR of each UE comprises a TA adjusting value and an uplink scheduling signaling (ULgrant) for scheduling uplink transmission (for competitive random access, namely scheduling message 3(Msg3) transmission of the UE);

the UE which sends the preamble needs to monitor a PDCCH scrambled by RA-RNTI in a RAR receiving window defined by a system, if the PDCCH is detected and the RAR contains the preamble identification sent by the RAR, the UE considers that the RAR is successfully received and applies TA carried in the RAR; otherwise, the RAR is considered to be failed to receive, and random access is initiated again after a period of time delay;

if the random access is non-competitive random access, the random access is considered to be successful, and the random access process is finished;

if the random access is the contention random access, the random access process cannot be considered to be successful temporarily, because contention may exist, and Msg3 needs to be sent further;

the RA-RNTI corresponds to PRACH resources, one PRACH resource only corresponds to one RA-RNTI, and RA-RNTI is 1+ t _ id +10 f _ id, wherein: t _ id is the number of the first subframe corresponding to the PRACH resource, and the value is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and is numbered according to the ascending order of the frequency domain, and the value is more than or equal to 0 and less than 6;

message 3(Msg 3): only suitable for competitive random access, supports HARQ, namely allows retransmission; the UE transmits the Msg3 on frequency domain resources of a corresponding Physical Uplink Shared Channel (PUSCH) according to the ULgrant in the RAR in the Msg 2; for initial access, namely RRC connection establishment/RRC reestablishment, the Msg3 includes a radio resource control connection request (RRCConnectionRequest) generated by an RRC layer and a terminal non-access stratum identity (UENASidentifier); for other situations, such as uplink desynchronization, the Msg3 at least includes a Cell radio network temporary identifier (C-RNTI) of the UE;

before the maximum Msg3 transmission times are reached, if the base station cannot receive the Msg3, HARQ feedback cannot be conducted, the UE defaults that the HARQ feedback is Negative Acknowledgement (NACK), synchronous retransmission can be conducted automatically, and when the Msg3 reaches the maximum retransmission times and is not successful, the UE can find that random access fails and delay a period of time to initiate competitive random access again.

Message 4(Msg 4): and the method is only suitable for contention random access, supports an HARQ mechanism, and only the UE which detects the self UE identification in the Msg4 carries out HARQ feedback. Msg4 is transmitted on the PDSCH channel by PDCCH scheduling; for the condition that the random access triggering reason is RRC connection establishment/RRC reestablishment, the PDCCH is scrambled by using a temporary cell radio network temporary identifier (TC-RNTI), and for other scenes, the PDCCH is scrambled by using the C-RNTI;

if the Msg3 contains the C-RNTI of the UE, either of the following two cases occurs, and the contention is considered successful:

first, PRACH is the UE's MAC self-trigger and PDCCH scheduling Msg4 is addressed based on this C-RNTI and contains the ULgrant for the new transmission;

second, PRACH is a base station triggered, but contended RACH, and the PDCCH scheduling Msg4 is addressed based on this C-RNTI.

If the random access trigger reason is RRC connection establishment/RRC reestablishment and the PDCCH of the Msg4 is scheduled to be addressed based on TC-RNTI, if a terminal contention resolution identity media access control cell (UEContentionResolutionIdentityMACCE) is contained in the Msg4 and the UEContentionResolutionIdentityin the MACCE is consistent with a Common Control Channel Service Data Unit (CCCSDU) in the Msg3, the contention is considered to be successful and the TC-RNTI is upgraded to C-RNTI; otherwise, the contention is considered to be failed.

For a long term evolution advanced (LTE-a) system, in order to support a system bandwidth wider than that of the LTE system, some frequency spectrums allocated to the existing system may be aggregated, and the aggregated frequency spectrums may be aggregated into a large bandwidth for a long term evolution multi-carrier system, that is, a carrier aggregation technique. At this time, uplink and downlink carriers in the system may be configured asymmetrically, that is, a user may occupy N1 ≧ 1 carrier for downlink transmission, and N2 ≧ 1 carrier for uplink transmission, as shown in fig. 3.

In a Carrier Aggregation (CA) system of LTE-a release 10(Rel-10), an uplink direction only supports continuous carrier aggregation, and each UE is allocated one primary cell (Pcell) by a base station, where one cell includes one downlink carrier and one uplink carrier for an FDD system, and one carrier becomes one cell for a TDD system. Random access for CA-capable UEs in LTE-ARel-10 only occurs on Pcell. Unlike the LTE-ARel-10 system, the LTE-a release 11(Rel-11) system needs to support a more complex carrier aggregation scenario, including carrier aggregation in different uplink frequency bands and a carrier aggregation deployment scheme in which a macro base station (macro enb) and a Remote Radio Head (RRH) are mixed. Examples of carrier aggregation deployment scenarios in which macro base stations and RRHs are mixed are shown in fig. 4A and 4B.

For fig. 4A, frequency F1 is used by the macro base station, providing macro coverage, and frequency F2 is used by the RRHs, providing higher throughput for hot spot areas. The UE moving at high speed operates on the frequency of F1, ensuring continuous traffic. The frequencies of F1 and F2 are different, for example, F1 is located at 800MHz or 2GHz frequency band, and F2 is located at 3.5GHz frequency band. F2 may be carrier aggregated with F1 within the geographic area covered by the F2 RRH. For fig. 4B, the frequencies F1 and F2 are used by the macro base station, and for the frequency band reason, F2 has a smaller coverage area than F1, so that RRHs are deployed at the cell edge of F2 for coverage extension. In the region where the F1 and the F2 cover the overlap, F1 and F2 may perform carrier aggregation.

Since the propagation characteristics of wireless signals in different frequency bands are different, if the UE transmits signals to the base station on the component carriers located in two frequency bands at a longer distance, the arrival times of the two signals at the base station will be different. Further, according to the examples shown in fig. 4A and 4B, if the UE is in a geographical area covered by Macro and RRH in common and carrier aggregation of F1 and F2 is performed, since F1 is used for the Macro base station and F2 is used for the RRH, signals on two frequencies pass through different propagation paths, resulting in a difference in arrival times of the signals transmitted simultaneously by the UE on F1 and F2 at the base station.

Therefore, in carrier aggregation in different frequency bands or a carrier aggregation deployment scenario in which a macro base station and an RRH are mixed, TA adjustment is also required to be performed on a secondary cell (Scell, serving cell) through random access, so as to ensure uplink synchronization between the Scell and the base station. In the current standardization discussion, there is no specific implementation scheme for how to perform random access on the Scell and how to perform random access simultaneously on multiple cells in a carrier aggregation system.

Disclosure of Invention

The embodiment of the invention provides a random access method and equipment, which are used for solving the problem that random access on a Scell and multiple cells simultaneously perform random access in a carrier aggregation system.

A random access method in a carrier aggregation system, the method comprising:

a terminal determines a random access preamble sequence to be sent on a cell which needs to perform random access on a current subframe and a Physical Random Access Channel (PRACH) resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

the terminal determines a random access radio network temporary identifier RA-RNTI corresponding to the random access leader sequence sent on the cell according to the carrier identification information of the cell and the information of the PRACH resource used by the random access leader sequence sent on the cell, and detects a physical downlink control channel PDCCH scrambled by the RA-RNTI in a public search space of a main cell of the terminal;

and the terminal receives a Physical Downlink Shared Channel (PDSCH) carrying a random access response corresponding to the random access preamble sequence sent by the cell according to the detected PDCCH, and performs uplink synchronization adjustment on the cell according to an uplink Timing Advance (TA) in the random access response.

A random access method in a carrier aggregation system, the method comprising:

a terminal determines a random access preamble sequence to be sent on a cell which needs to perform random access on a current subframe and a Physical Random Access Channel (PRACH) resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

the terminal determines a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent by the cell according to the information of the PRACH resource used by the random access preamble sequence sent by the cell, and detects a physical downlink control channel PDCCH scrambled by the RA-RNTI in a public search space of a main cell of the terminal;

and the terminal receives a Physical Downlink Shared Channel (PDSCH) carrying a random access response corresponding to the random access preamble sequence sent on the cell according to the detected carrier identification information indicated by the carrier identification indication field in the PDCCH, and performs uplink synchronization adjustment on the cell according to an uplink Timing Advance (TA) in the random access response.

A random access processing method in a carrier aggregation system comprises the following steps:

a base station receives a random access preamble sequence sent by a terminal on a Physical Random Access Channel (PRACH) resource of a cell;

a base station determines a random access radio network temporary identifier RA-RNTI corresponding to a random access leader sequence received on a cell according to carrier identification information of the cell receiving the random access leader sequence and information of PRACH resources for transmitting the random access leader sequence on the cell, and transmits a physical downlink control channel PDCCH scrambled by using the RA-RNTI in a public search space of the set cell so as to receive a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access leader sequence by a scheduling terminal;

and the base station sends the PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink timing advance TA.

A random access processing method in a carrier aggregation system comprises the following steps:

a base station receives a random access preamble sequence sent by a terminal on a Physical Random Access Channel (PRACH) resource of a cell;

a base station determines a random access radio network temporary identifier RA-RNTI corresponding to a random access leader sequence received on a cell according to information of PRACH resources of the random access leader sequence transmitted on the cell receiving the random access leader sequence, and transmits a PDCCH scrambled by using the RA-RNTI and carrying a carrier identifier indication domain in a public search space of the set cell so as to schedule a terminal to receive a PDSCH carrying a random access response of the random access leader sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence;

and the base station sends the PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink timing advance TA.

A terminal, the terminal comprising:

a sending unit, configured to determine a random access preamble sequence to be sent in a cell where a random access needs to be performed in a current subframe, and a physical random access channel PRACH resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

a detecting unit, configured to determine, according to carrier identifier information of the cell and information of the PRACH resource used by the random access preamble sequence sent by the cell, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent by the cell, and detect, in a common search space of a main cell of the terminal, a physical downlink control channel PDCCH scrambled by using the RA-RNTI;

and a synchronization unit, configured to receive, according to the detected PDCCH, a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell, and perform uplink synchronization adjustment on the cell according to an uplink timing advance TA in the random access response.

A terminal, the terminal comprising:

a sending unit, configured to determine a random access preamble sequence to be sent in a cell where a random access needs to be performed in a current subframe, and a physical random access channel PRACH resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

a detecting unit, configured to determine, according to information of the PRACH resource used by the random access preamble sequence sent on the cell, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent on the cell, and detect, in a common search space of a main cell of the terminal, a physical downlink control channel PDCCH scrambled by using the RA-RNTI;

and a synchronization unit, configured to receive, according to the detected carrier identifier information indicated by the carrier identifier indication field in the PDCCH, a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell, and perform uplink synchronization adjustment on the cell according to an uplink timing advance TA in the random access response.

A base station, the base station comprising:

a receiving unit, configured to receive a random access preamble sequence sent by a terminal on a physical random access channel PRACH resource of a cell;

a scheduling unit, configured to determine a random access radio network temporary identifier RA-RNTI corresponding to a random access preamble sequence received in a cell according to carrier identifier information of the cell receiving the random access preamble sequence and information of PRACH resource on the cell for transmitting the random access preamble sequence, and send a physical downlink control channel PDCCH scrambled by using the RA-RNTI in a common search space of the set cell, so that a scheduling terminal receives a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence;

and a sending unit, configured to send, to the terminal, the PDSCH carrying the random access response, where the random access response includes an uplink timing advance TA.

A base station, the base station comprising:

a receiving unit, configured to receive a random access preamble sequence sent by a terminal on a physical random access channel PRACH resource of a cell;

the scheduling unit is used for determining a random access radio network temporary identifier (RA-RNTI) corresponding to a random access leader sequence received on a cell according to information of PRACH resources of the random access leader sequence transmitted on the cell receiving the random access leader sequence, transmitting a Physical Downlink Control Channel (PDCCH) scrambled by using the RA-RNTI and carrying a carrier identifier indication domain in a public search space of the set cell, and receiving a Physical Downlink Shared Channel (PDSCH) carrying a random access response of the random access leader sequence by a scheduling terminal; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence;

and a sending unit, configured to send, to the terminal, the PDSCH carrying the random access response, where the random access response includes an uplink timing advance TA.

A random access method in a carrier aggregation system, the method comprising:

a terminal determines a random access preamble sequence sent on an auxiliary cell needing random access and a Physical Random Access Channel (PRACH) resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the secondary cell;

the terminal detects a physical downlink control channel PDCCH which is scrambled by using a random access radio network temporary identifier RA-RNTI and corresponds to the random access response of the auxiliary cell in a public search space of a main cell of the terminal;

the terminal receives a Physical Downlink Shared Channel (PDSCH) carrying a random access response corresponding to the auxiliary cell according to the detected PDCCH;

before a terminal determines a random access leader sequence sent by an auxiliary cell needing random access and a PRACH resource used for sending the random access leader sequence, the terminal receives a special random access leader sequence number and a PRACH resource number sent by a base station through a PDCCH (physical Downlink control) command or a Radio Resource Control (RRC) signaling, wherein the special random access leader sequence number is used for indicating the random access leader sequence used by the auxiliary cell, the PRACH resource number is used for indicating the PRACH resource used for sending the random access leader sequence by the auxiliary cell, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal;

the terminal receives the PDCCH command on a secondary cell or a primary cell of the terminal, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command correspondingly triggers non-competitive random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command correspondingly triggers non-competitive random access of a cell indicated by a carrier indication domain in the PDCCH command.

A random access processing method in a carrier aggregation system comprises the following steps:

a base station receives a random access preamble sequence sent by a terminal on a Physical Random Access Channel (PRACH) resource of an auxiliary cell needing random access;

a base station sends a Physical Downlink Control Channel (PDCCH) which is scrambled by using a random access radio network temporary identifier (RA-RNTI) and corresponds to a random access response of an auxiliary cell in a public search space of a main cell of the terminal so as to schedule the terminal to receive a Physical Downlink Shared Channel (PDSCH) carrying the random access response corresponding to the auxiliary cell; the base station sends a PDSCH carrying a random access response corresponding to the secondary cell to the terminal;

before a base station receives a random access preamble sequence sent by a terminal on a PRACH resource of an auxiliary cell needing random access, the base station sends a special random access preamble sequence number and a PRACH resource number to the terminal through a PDCCH (physical Downlink control channel) command or a Radio Resource Control (RRC) signaling, wherein the special random access preamble sequence number is used for indicating a random access preamble sequence used by the auxiliary cell, the PRACH resource number is used for indicating the PRACH resource used by the auxiliary cell for sending the random access preamble sequence, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal;

the base station sends the PDCCH command on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command correspondingly triggers the non-contention random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command correspondingly triggers the non-contention random access of a cell indicated by a carrier indication domain in the PDCCH command.

In one scheme provided by the embodiment of the invention, a terminal determines a random access preamble sequence to be sent on a cell where random access is required to be performed on a current subframe and a PRACH resource used for sending the random access preamble sequence, and sends the random access preamble sequence to a base station on the cell through the PRACH resource; then, according to the carrier identification information of the cell and the information of the PRACH resource used by the random access preamble sequence sent by the cell, determining RA-RNTI corresponding to the random access preamble sequence sent by the cell, detecting a PDCCH scrambled by using the RA-RNTI in a public search space of a main cell of the terminal, receiving a PDSCH carrying a random access response corresponding to the random access preamble sequence sent by the cell according to the detected PDCCH, and performing uplink synchronization adjustment on the cell according to an uplink TA in the random access response. Therefore, the method can realize the random access of the terminal side in the auxiliary cell or a plurality of cells in the carrier aggregation system.

Correspondingly, a base station receives a random access preamble sequence sent by a terminal on PRACH resources of a cell, determines RA-RNTI corresponding to the random access preamble sequence received on the cell according to carrier identification information of the cell receiving the random access preamble sequence and information of PRACH resources for transmitting the random access preamble sequence on the cell, and sends PDCCH scrambled by using the RA-RNTI in a public search space of a set cell so as to schedule the terminal to receive PDSCH carrying random access response corresponding to the random access preamble sequence and send PDSCH carrying the random access response to the terminal, wherein the random access response comprises uplink TA. Therefore, by adopting the method, the base station side can realize the random access of the auxiliary cell or a plurality of cells in the carrier aggregation system.

In another scheme provided by the embodiment of the invention, a terminal determines a random access preamble sequence to be sent on a cell where random access is required to be performed on a current subframe and a PRACH resource used for sending the random access preamble sequence, and sends the random access preamble sequence to a base station on the cell through the PRACH resource; then, according to the information of the PRACH resource used by the random access preamble sequence sent by the cell, determining RA-RNTI corresponding to the random access preamble sequence sent by the cell, and detecting a PDCCH scrambled by the RA-RNTI in a public search space of a main cell of the terminal; and receiving a PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell according to the detected carrier identification information indicated by the carrier identification indication field in the PDCCH, and performing uplink synchronization adjustment on the cell according to an uplink TA in the random access response. Therefore, the method can realize the random access of the terminal side in the auxiliary cell or a plurality of cells in the carrier aggregation system.

Correspondingly, a base station receives a random access preamble sequence sent by a terminal on PRACH resources of a cell, determines RA-RNTI corresponding to the random access preamble sequence received on the cell according to information of PRACH resources of the random access preamble sequence transmitted on the cell receiving the random access preamble sequence, and sends a PDCCH which is scrambled by using the RA-RNTI and carries a carrier identifier indication domain in a public search space of the set cell so as to schedule the terminal to receive a PDSCH carrying random access response of the random access preamble sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence; and then the base station sends the PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink TA. Therefore, by adopting the method, the base station side can realize the random access of the auxiliary cell or a plurality of cells in the carrier aggregation system.

Drawings

Fig. 1 is a flow chart of non-contention random access in the prior art;

fig. 2 is a flow chart of contention random access in the prior art;

fig. 3 is a schematic diagram of a spectrum aggregation system in the prior art;

fig. 4A is a schematic view of a mixed deployment scenario of a macro base station and an RRH in the prior art;

fig. 4B is a schematic view of a hybrid deployment scenario of another macro base station and an RRH in the prior art;

fig. 5 is a schematic flow chart of a terminal side method provided in an embodiment of the present invention;

fig. 6 is a schematic flow chart of a base station side method according to an embodiment of the present invention;

fig. 7 is a flowchart illustrating another terminal-side method according to an embodiment of the present invention;

fig. 8 is a schematic flow chart of another base station-side method according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a terminal according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a base station according to an embodiment of the present invention.

Detailed Description

In order to solve the problem how a terminal performs random access in a secondary cell or multiple cells simultaneously in a carrier aggregation system, embodiments of the present invention provide a random access method in a carrier aggregation system corresponding to a terminal side and a random access processing method corresponding to a base station side.

Referring to fig. 5, a random access method in a carrier aggregation system provided in an embodiment of the present invention includes the following steps:

step 50: a terminal determines a random access preamble sequence to be sent on a cell which needs to perform random access on a current subframe and PRACH resources used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

step 51: the terminal determines RA-RNTI corresponding to the random access leader sequence sent on the cell according to the carrier identification information of the cell and the information of the PRACH resource used by the random access leader sequence sent on the cell, and detects the PDCCH scrambled by the RA-RNTI in the public search space of the main cell of the terminal;

step 52: and the terminal receives a PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell according to the detected PDCCH, and performs uplink synchronization adjustment on the cell according to an uplink TA in the random access response.

Further, before the terminal determines a random access preamble sequence to be sent on a cell in which random access is required to be performed in a current subframe and a PRACH resource to be used for sending the random access preamble sequence in step 50, the terminal receives a dedicated random access preamble sequence number and a PRACH resource number, which are sent by a base station through a PDCCH order or a Radio Resource Control (RRC) signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence to be used by the cell in which random access is required, the PRACH resource number is used to indicate a PRACH resource to be used by the cell in which random access is required to be performed and to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal. In step 50, the terminal sends the random access leader sequence indicated by the special random access leader sequence number to the base station on the PRACH resource indicated by the PRACH resource number.

Specifically, the terminal may receive the PDCCH order in a secondary cell or a primary cell of the terminal; when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers the non-competitive random access of the cell in which the PDCCH command is transmitted; when the PDCCH command adopts cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers the non-contention random access of the cell indicated by the carrier indication domain in the PDCCH command.

In step 51, the terminal may determine an RA-RNTI corresponding to the random access preamble sequence sent on the cell according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

Specifically, the carrier identification information is: a carrier number (cell _ index) maintained by the terminal, or a system-level number defined for the cell in the system (i.e., a unique number defined for the cell within the system), or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell (i.e., a unique number defined for the cell within the cell set corresponding to the primary cell of the terminal).

Preferably, when the random access procedure of the cell is non-contention random access, the carrier identification information may be a carrier number (cell _ index) maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell; and when the random access process of the cell is competitive random access, the carrier identification information is a system-level number defined to the cell in a system.

When the carrier identification information is a carrier number maintained by the terminal, the terminal receives the PDSCH in the primary cell of the terminal in step 52. In other cases, the terminal receives the PDSCH in the primary cell of the terminal or the cell transmitting the random access preamble sequence, and specifically, which cell receives the PDSCH may be agreed in advance.

In the method, the cell is a secondary cell of the terminal, and may be a primary cell. In particular, when a plurality of cells are defined in the system as a group sharing one TA, the cell may also refer to one cell defined/configured in advance in a cell group sharing one TA.

Referring to fig. 6, an embodiment of the present invention further provides a random access processing method in a carrier aggregation system, including the following steps:

step 60: a base station receives a random access preamble sequence sent by a terminal on PRACH resources of a cell;

step 61: a base station determines RA-RNTI corresponding to a random access leader sequence received on a cell according to carrier identification information of the cell receiving the random access leader sequence and information of PRACH resources for transmitting the random access leader sequence on the cell, and transmits a PDCCH scrambled by using the RA-RNTI in a public search space of the set cell so as to schedule a terminal to receive a PDSCH carrying random access response corresponding to the random access leader sequence;

step 62: and the base station sends the PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink TA.

Further, in step 60, before the base station receives the random access preamble sequence sent by the terminal on the PRACH resource of the cell, the base station may send a dedicated random access preamble sequence number and a PRACH resource number to the terminal through a PDCCH order or an RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by a cell that needs to perform random access, the PRACH resource number is used to indicate a PRACH resource used by the cell that sends the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal. In step 60, the base station may receive the random access preamble sequence indicated by the dedicated random access preamble sequence number only on the PRACH resource indicated by the PRACH resource number on the cell configured with the non-contention random access by the terminal.

Specifically, the base station sends the PDCCH order on an auxiliary cell or a primary cell of a terminal that needs to perform random access; when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers non-contention random access of a cell for transmitting the PDCCH command; when the PDCCH command adopts cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers the non-contention random access of the cell indicated by the carrier indication domain in the PDCCH command.

In step 61, the base station sends the PDCCH scrambled by the RA-RNTI in the common search space of the set cell, and the specific implementation may be as follows:

when the base station configures the terminal to adopt non-competitive random access, the base station sends the PDCCH scrambled by the RA-RNTI in a public search space of a main cell configured with the terminal adopting non-competitive random access; or,

and when the base station does not configure the terminal to adopt non-competitive random access, the base station sends the PDCCH scrambled by using the RA-RNTI in the common search space of all the cells.

In step 61, the base station may determine an RA-RNTI corresponding to the random access preamble sequence received on the cell according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

In step 62, the base station transmits the random access response of the random access preamble sequence corresponding to the same RA-RNTI on the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI at the same time.

Specifically, the carrier identification information is a carrier number maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell.

Preferably, when the random access procedure of the cell is non-contention random access, the carrier identification information may be a carrier number (cell _ index) maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell; and when the random access process of the cell is competitive random access, the carrier identification information is a system-level number defined to the cell in a system.

In step 62, when the carrier identification information is a carrier number maintained by the terminal and the random access is non-contention random access, the base station sends the PDSCH in the primary cell of the terminal corresponding to the received random access preamble sequence.

Under other conditions, the base station sends the PDSCH in a primary cell of a terminal corresponding to the received random access preamble sequence; or, the base station sends the PDSCH in the cell where the received random access preamble sequence is located, and specifically, it may be predetermined in which cell the PDSCH is sent.

In the method, the cell is a secondary cell of the terminal, and certainly can be a primary cell of the terminal. In particular, when a plurality of cells are defined in the system as a group sharing one TA, the cell may also refer to one cell defined/configured in advance in a cell group sharing one TA.

In order to solve the problem how a terminal performs random access in a secondary cell or a plurality of cells simultaneously in a carrier aggregation system, embodiments of the present invention provide another random access method in a carrier aggregation system corresponding to a terminal side and a random access processing method corresponding to a base station side.

Referring to fig. 7, a random access method in a carrier aggregation system provided in an embodiment of the present invention includes the following steps:

step 70: a terminal determines a random access preamble sequence to be sent on a cell which needs to perform random access on a current subframe and PRACH resources used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

step 71: the terminal determines RA-RNTI corresponding to the random access leader sequence sent on the cell according to the information of the PRACH resource used by the random access leader sequence sent on the cell, and detects the PDCCH scrambled by the RA-RNTI in a public search space of a main cell of the terminal;

step 72: and the terminal receives a PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell according to the detected carrier identification information indicated by the carrier identification indication field in the PDCCH, and performs uplink synchronization adjustment on the cell according to an uplink TA in the random access response.

Further, in step 70, before the terminal determines a random access preamble sequence to be sent on a cell in which random access is to be performed in a current subframe and a PRACH resource to be used for sending the random access preamble sequence, the terminal receives a dedicated random access preamble sequence number and a PRACH resource number, which are sent by a base station through a PDCCH order or an RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence to be used by the cell in which random access is to be performed, the PRACH resource number is used to indicate a PRACH resource to be used for sending the random access preamble sequence by the cell, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal. In step 70, the terminal sends the random access preamble sequence indicated by the special random access preamble sequence number to the base station on the PRACH resource indicated by the PRACH resource number.

Specifically, the terminal may receive the PDCCH order in a secondary cell or a primary cell of the terminal; when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers the non-competitive random access of the cell in which the PDCCH command is transmitted; when the PDCCH command adopts cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers the non-contention random access of the cell indicated by the carrier indication domain in the PDCCH command.

In step 72, the terminal receives, according to the detected carrier identifier information indicated by the carrier identifier indication field in the PDCCH, the PDSCH carrying the random access response corresponding to the random access preamble sequence sent in the cell, specifically: and the terminal receives the PDCCH carrying the carrier identification information consistent with the carrier identification information of the cell which sends the random access leader sequence, the dispatched PDSCH and further obtains the random access response corresponding to the random access leader sequence sent on the cell from the PDSCH.

Specifically, the carrier identification information is a carrier number maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell.

Preferably, when the random access procedure of the cell is non-contention random access, the carrier identification information may be a carrier number (cell _ index) maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell; and when the random access process of the cell is competitive random access, the carrier identification information is a system-level number defined to the cell in a system.

When the carrier identification information is a carrier number maintained by the terminal, the terminal receives the PDSCH in the primary cell of the terminal in step 72. In other cases, the terminal receives the PDSCH in the primary cell of the terminal or the cell transmitting the random access preamble sequence, and specifically, which cell receives the PDSCH may be agreed in advance.

The carrier identification indication field is the reuse of original bits in the PDCCH or newly added bits. When the PDCCH adopts a Downlink Control Information (DCI) format1A, one or any combination of a hybrid automatic repeat request (HARQ) process number indication field, a redundancy version indication field, and a downlink allocation index indication field may be reused as a carrier identifier indication field in the PDCCH.

In the method, the cell is a secondary cell of the terminal, and may be a primary cell. In particular, when a plurality of cells are defined in the system as a group sharing one TA, the cell may also refer to one cell defined/configured in advance in a cell group sharing one TA.

Referring to fig. 8, an embodiment of the present invention further provides a random access processing method in a carrier aggregation system, including the following steps:

step 80: a base station receives a random access preamble sequence sent by a terminal on PRACH resources of a cell;

step 81: a base station determines RA-RNTI corresponding to a random access leader sequence received on a cell according to information of PRACH resources of the random access leader sequence transmitted on the cell receiving the random access leader sequence, and transmits a PDCCH which is scrambled by using the RA-RNTI and carries a carrier identifier indication domain in a public search space of the set cell so as to schedule a terminal to receive a PDSCH carrying random access response of the random access leader sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence;

step 82: and the base station sends the PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink TA.

Further, before the base station receives the random access preamble sequence sent by the terminal on the PRACH resource of the cell in step 80, the base station may send a dedicated random access preamble sequence number and a PRACH resource number to the terminal through a PDCCH order or an RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by a cell that needs to perform random access, the PRACH resource number is used to indicate a PRACH resource used by the cell that sends the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal. In step 80, the base station may receive the random access preamble sequence indicated by the dedicated random access preamble sequence number only on the PRACH resource indicated by the PRACH resource number on the cell configured with the non-contention random access by the terminal.

Specifically, the base station sends the PDCCH order on an auxiliary cell or a primary cell of a terminal that needs to perform random access; when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers non-contention random access of a cell for transmitting the PDCCH command; when the PDCCH command adopts cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers the non-contention random access of the cell indicated by the carrier indication domain in the PDCCH command.

In step 81, the base station sends, in a common search space of a set cell, a PDCCH scrambled with the RA-RNTI and having a carrier identity indicator field, and the specific implementation may be as follows:

when the base station configures the terminal to adopt non-competitive random access, the base station sends the PDCCH which is scrambled by the RA-RNTI and is provided with the carrier identifier indication domain in a public search space of a main cell configured with the terminal adopting non-competitive random access; or,

and when the base station is not configured with the terminal and adopts non-competitive random access, the base station sends the PDCCH which is scrambled by the RA-RNTI and provided with the carrier identifier indication domain in the public search space of all the cells.

In step 82, the base station transmits the random access response of the random access preamble sequence corresponding to the same RA-RNTI and received on the cell with the same carrier identification information on the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI and carrying the carrier identification indication field indicating the carrier identification information of the cell.

Specifically, the carrier identification information is a carrier number maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell.

Preferably, when the random access procedure of the cell is non-contention random access, the carrier identification information may be a carrier number (cell _ index) maintained by the terminal, or a system-level number defined for the cell in the system, or a primary cell-level number defined for the cell in a cell set corresponding to the same primary cell; and when the random access process of the cell is competitive random access, the carrier identification information is a system-level number defined to the cell in a system.

And when the carrier identification information is a carrier number maintained by the terminal and the random access is non-competitive random access, the base station sends the PDSCH in a main cell of the terminal corresponding to the received random access leader sequence. Under other conditions, the base station sends the PDSCH in a primary cell of a terminal corresponding to the received random access preamble sequence; or, the base station sends the PDSCH in the cell where the received random access preamble sequence is located, and specifically, it may be predetermined in which cell the PDSCH is sent.

The carrier identification indication field is the reuse of original bits in the PDCCH or newly added bits. When the PDCCH adopts DCI format1A, one or any combination of a HARQ process number indication field, a redundancy version indication field, and a downlink allocation index indication field may be reused as a carrier identifier indication field in the PDCCH.

In the method, the cell is a secondary cell of the terminal, and certainly can be a primary cell of the terminal. In particular, when a plurality of cells are defined in the system as a group sharing one TA, the cell may also refer to one cell defined/configured in advance in a cell group sharing one TA.

The present invention is described in detail below:

in the LTE-ACA system, when the UE aggregates multiple cells, the UE performs random access on the Scell or performs random access on multiple cells simultaneously in the following manner:

the UE end:

step 1: the UE determines a preamble sequence which is sent on the Scell and needs to be randomly accessed and a PRACH resource used for sending the preamble, and sends the determined preamble sequence on the Scell through the determined PRACH channel resource;

the PRACH configuration on each Scell may be the same as or different from the Pcell;

if the Scell is non-competitive random access, the method also comprises the step that the UE receives an exclusive preamble sequence and PRACH resources which are configured to the UE by the base station through a PDCCHorder or RRC signaling before the step;

the pdcch order corresponding to the Scell may be sent on the Scell, or may also be sent on the Pcell or other scells (pdcch ue dedicated search space transmission on the Pcell or other scells, cross-carrier scheduling needs to be configured);

preferably, in order to avoid that the base station cannot judge which UE it comes from when receiving the preamble sequence, and therefore cannot determine the Pcell of the UE, the random access on the Scell should be triggered in a PDCCHorder manner;

step 2: the UE detects a PDCCH scrambled by RA-RNTI corresponding to Scell random access response in a public search space of the Pcell and receives a PDSCH which is scheduled by the PDCCH and bears the Scell random access response;

the PDSCH may be transmitted in Pcell or Scell, and the specific manner may be pre-agreed by the UE and the base station (if the PDCCH has a carrier indication field, for example, in method 2, the PDSCH scheduled by the PDCCH is not required to be transmitted on the carrier indicated by the carrier indication field);

the PDSCH may include random access responses of a plurality of UEs that simultaneously send preambles on the same PRACH resource (same time-frequency domain location) on the Scell; that is, the random access response of the UE on the Scell corresponding to the same RA-RNTI is transmitted simultaneously in the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI;

the method comprises the following steps: the UE distinguishes Scell corresponding to the PDCCH scrambled by the RA-RNTI sent in the Pcell public search space through the RA-RNTI related to the carrier information;

specifically, the carrier information may be carrier identification information (cell _ sign), that is, RA-RNTI is associated with the cell _ sign, for example, RA-RNTI is 1+ t _ id +10 × f _ id +60 × -cell _ sign, where: t _ id is the number of a first subframe corresponding to the PRACH resource, the value of t _ id is more than or equal to 0 and less than 10, f _ id is the number of the PRACH resource in one subframe, the values of f _ id is more than or equal to 0 and less than 6 according to the ascending sequence number of a frequency domain, cell _ sign is the carrier identification of the current Scell, the value of cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system;

the cell _ sign of each Scell may be a carrier number maintained by the UE (i.e., each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; preferably, the cell _ sign is a carrier identifier specific to the system (i.e. a specific number defined for a cell in the system, and a uniform number for all cells in the system), or a carrier identifier specific to the Pcell (i.e. a specific number defined for the cell in a cell set corresponding to the same primary cell, and a uniform number for Scell corresponding to UE of the same Pcell); preferably, when the random access process of the Scell is non-contention random access, the carrier identifier may be a carrier number maintained by the UE (that is, each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; when the random access process of the Scell is competitive random access, the carrier identifier needs to be a carrier identifier exclusive to the system;

and when the cell _ sign is the carrier number maintained by the UE, requiring the PDSCH carrying the Scell random access response to be sent in the Pcell.

For example: the UE0 is configured with 2 Scell, namely Scell-1 and Scell-2, the UE0 simultaneously transmits the same preamble on Scell-1 and Scell-2 by using the same PRACH time-frequency domain resource, the UE0 determines RA-RNTI-1 corresponding to the random access response on Scell-1 according to t _ id and f _ id corresponding to the PRACH resource on Scell-1 and cell _ sign of Scell-1, detects the PDCCH scrambled by RA-RNTI-1 in the public search space of Pcell, and receives the PDSCH scheduled by the PDCCH (which can be transmitted on Pcell or Scell, and is agreed in advance by the UE and the base station, namely one of the transmission modes is specified in the standard), so as to obtain the random access response of Scell-1; the UE0 determines RA-RNTI-2 corresponding to the random access response on the Scell-2 according to t _ id and f _ id corresponding to the PRACH resource on the Scell-2 and the cell _ sign of the Scell-2, detects a PDCCH scrambled by the RA-RNTI-2 in a public search space of the Pcell, and receives a PDSCH scheduled by the PDCCH to obtain the random access response of the Scell-2; in the above process, in multiple UEs that simultaneously transmit preamble sequences on the same PRACH resource on Scell-1 and Scell-2, the random access response of the UE corresponding to the same RA-RNTI is simultaneously carried in the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI, that is, if UE1 simultaneously transmits a preamble sequence (different from the preamble of UE 0) on the PRACH resource that UE0 transmits a preamble sequence on Scell-1, and UE2 simultaneously transmits a preamble sequence (different from the preamble of UE 0) on the PRACH resource that UE0 transmits a preamble sequence on Scell-2:

if the cell _ sign of the Scell is a system-specific or Pcell-specific carrier identity, i.e. the carrier identity of Scell-1 maintained by UE1 is consistent with the carrier identity of Scell-1 maintained by UE0, and the carrier identity of Scell-2 maintained by UE2 is consistent with the carrier identity of Scell-2 maintained by UE0, as shown in Table 5, then UE1 determines the RA-RNTI corresponding to the random access response on Scell-1 and the RA-RNTI corresponding to UE0Scell-1 according to the t _ id and f _ id corresponding to the PRACH resource on Scell-1 and the cell _ sign of Scell-1 maintained by UE1, as RA-RNTI-1, UE2 determines the RA-RNTI corresponding to the random access response on Scell-2 and the cell _ sign of Scell-2 maintained by UE2 and the RA-RNTI-2 corresponding to the RA-RNTI 0 Scell-RNTI 2, is RA-RNTI-2, therefore, the random access response of UE1 is also carried in the RA-RNTI-1 scrambled PDCCH scheduled PDSCH, the random access response of UE2 is also carried in the RA-RNTI-2 scrambled PDCCH scheduled PDSCH, UE1 uses RA-RNTI-1 to detect PDCCH in the common search space of Pcell, and UE2 uses RA-RNTI-2 to detect PDCCH in the common search space of Pcell;

	UE0	UE1	UE2
				Pcell	0	0	0
Scell-1	1√	1√	1

Scell-2

2√

2

2√

TABLE 5

Where √ denotes that the preamble is transmitted simultaneously on the same PRACH resource.

If the cell _ sign of the Scell is the carrier number maintained by the UE, i.e. the number of Scell-1 maintained by the UE1 is not consistent with the number of Scell-1 maintained by the UE0, but is consistent with the number of Scell-2 maintained by the UE0, and the number of Scell-2 maintained by the UE2 is not consistent with the number of Scell-2 maintained by the UE0, but is consistent with the number of Scell-1 maintained by the UE0, as shown in Table 6, the UE1 is RA-RNTI-2 according to t _ id and f _ id corresponding to PRACH resource on Scell-1, and RA-RNTI corresponding to RA-RNTI on Scell-1 determined by cell _ index of Scell-1 maintained by the UE1 is RA-RNTI-2, the UE2 is RA-RNTI corresponding to t _ id and f _ id corresponding to PRACH resource on Scell-2, and RA-RNTI corresponding to RA-RNTI 0 determined by cell _ index of Scell-2 maintained by the UE2, is RA-RNTI-1, therefore, the random access response corresponding to Scell-1 of UE1 is carried in the PDCCH scheduled PDSCH scrambled by RA-RNTI-2 together with the random access response corresponding to Scell-2 of UE0, the random access response corresponding to Scell-2 of UE2 is carried in the PDCCH scheduled PDSCH scrambled by RA-RNTI-1 together with the random access response corresponding to Scell-1 of UE0, UE1 detects the PDCCH in the common search space of Pcell using RA-RNTI-2, and UE2 detects the PDCCH in the common search space of Pcell using RA-RNTI-1; because the PDSCH scheduled by the PDCCH scrambled by the same RA-RNTI bears the random access response of different UE on different Scell, the PDSCH can be transmitted only on Pcell;

	UE0	UE1	UE2
				Pcell	0	0	0
Scell-1	1√	2√	2
				Scell-2	2√	1	1√

TABLE 6

Where √ denotes that the preamble is transmitted simultaneously on the same PRACH resource

The method 2 comprises the following steps: the UE determines a Scell corresponding to the PDCCH scrambled by the RA-RNTI sent in a Pcell public search space through a carrier indication domain in the PDCCH scrambled by the RA-RNTI;

the information indicated by the carrier indication field is a random access response of which Scell is correspondingly carried by the PDSCH scheduled by the PDCCH, and the indication information may be cell _ sign;

the cell _ sign of each Scell may be a carrier number maintained by the UE (i.e., each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; preferably, the cell _ sign is a carrier identifier specific to the system (i.e. a specific number defined for a cell in the system, and a uniform number for all cells in the system), or a carrier identifier specific to the Pcell (i.e. a specific number defined for the cell in a cell set corresponding to the same primary cell, and a uniform number for Scell corresponding to UE of the same Pcell); preferably, when the random access process of the Scell is non-contention random access, the carrier identifier may be a carrier number maintained by the UE (that is, each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; when the random access process of the Scell is competitive random access, the carrier identifier needs to be a carrier identifier exclusive to the system;

when the cell _ sign is a carrier number maintained by the UE, requiring the PDSCH carrying the Scell random access response to be sent in the Pcell;

the random access response of the UE on the Scell corresponding to the same RA-RNTI and Scellsign is transmitted simultaneously in the PDSCH scheduled by the PDCCH corresponding to the Scellsign and the carrier indication domain scrambled by the RA-RNTI;

the carrier indication field in the PDCCH scrambled by the RA-RNTI can be newly added extra bits or reuse original bits;

preferably, in order not to increase blind detection, the PDCCH scrambled by RA-RNTI may adopt DCI _ format1A, and at this time, one of them may be reused:

HARQ process number (HARQ processsnumber) indication field, 3 bits for FDD system and 4 bits for TDD system; and/or the presence of a gas in the gas,

redundancy version (redundancy) indication field, 2 bits for both FDD and TDD; and/or the presence of a gas in the gas,

for a TDD system, a downlink allocation index (downlink assignment index) indication field, 2 bits;

for example: the UE0 is configured with 2 scells, which are Scell-1 and Scell-2, respectively, and the UE0 simultaneously transmits the same preamble on Scell-1 and Scell-2 by using the same PRACH time frequency domain resource, so that the UE0 determines that the two scells correspond to the same RA-RNTI according to t _ id and f _ id corresponding to the PRACH resource on Scell-1 and Scell-2, detects the PDCCH scrambled by the RA-RNTI in the common search space of the Pcell to obtain 2 PDCCHs scrambled by the RA-RNTI, and determines the PDSCH scheduled by each PDCCH (which may be transmitted on the Pcell or on the Scell, and the UE and the base station have a predetermined convention, that is, one of the transmission modes is specified in the standard) according to the carrier indication domain in the 2 PDCCHs: that is, the carrier indication field in PDCCH1 corresponds to cell _ sign of Scell-1 maintained by UE0, so that it is determined that the random access response of Scell-1 is carried on the PDSCH scheduled by PDCCH1, and UE0 obtains the random access response of Scell-1 from the PDSCH scheduled by PDCCH 1; the carrier indication domain in the PDCCH2 corresponds to cell _ sign of Scell-2 maintained by the UE0, so that the random access response of Scell-2 is determined to be carried on the PDSCH scheduled by the PDCCH2, and the UE0 obtains the random access response of Scell-2 from the PDSCH scheduled by the PDCCH 2; in the above process, the random access responses of multiple UEs that simultaneously transmit preamble sequences on the same PRACH resource on Scell-1 and Scell-2 are transmitted in the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI corresponding to the same carrier indication domain, that is, if UE1 simultaneously transmits a preamble sequence (different from the preamble of UE 0) on the PRACH resource where UE0 transmits the preamble sequence on Scell-1, UE2 simultaneously transmits a preamble sequence (different from the preamble of UE 0) on the PRACH resource where UE0 transmits the preamble sequence on Scell-2, UE1 and UE2 also use the same RA-RNTI as UE0 to detect 2 PDCCHs in the common search space of Pcell, and obtain a random access response in the PDSCH scheduled by the PDCCH that is consistent with the Scell number where the preamble sequence is transmitted by itself according to the carrier indication domain in each PDCCH, specifically:

if the cell _ sign of the Scell is a system-specific or Pcell-specific carrier identity, that is, the carrier identity of Scell-1 maintained by the UE1 is consistent with the carrier identity of Scell-1 maintained by the UE0, and the carrier identity of Scell-2 maintained by the UE2 is consistent with the carrier identity of Scell-2 maintained by the UE0, as shown in table 5: the cell _ sign of the Scell-1 maintained by the UE1 corresponds to the carrier indication field in the PDCCH1, so that the random access response corresponding to the Scell-1 of the UE1 and the random access response corresponding to the Scell-1 of the UE0 are carried on the PDSCH scheduled by the PDCCH1, and the UE1 obtains the random access response corresponding to the Scell-1 from the PDSCH scheduled by the PDCCH 1; the cell _ sign of the Scell-2 maintained by the UE2 corresponds to the carrier indicator field in the PDCCH2, so that the random access response corresponding to the Scell-2 of the UE2 and the random access response corresponding to the Scell-2 of the UE0 are carried on the PDSCH scheduled by the PDCCH2, and the UE2 obtains the random access response corresponding to the Scell-2 from the PDSCH scheduled by the PDCCH 2;

if the cell _ sign of the Scell is the UE-specific carrier number, i.e. the number of Scell-1 maintained by the UE1 is not consistent with the number of Scell-1 maintained by the UE0, but is consistent with the number of Scell-2 maintained by the UE0, and the number of Scell-2 maintained by the UE2 is not consistent with the number of Scell-2 maintained by the UE0, but is consistent with the number of Scell-1 maintained by the UE0, as shown in table 6: cellindex of Scell-1 maintained by UE1 corresponds to a carrier indication domain in PDCCH2, so that a random access response corresponding to Scell-1 of UE1 and a random access response corresponding to Scell-2 of UE0 are carried on a PDSCH scheduled by PDCCH2, and UE1 obtains a random access response corresponding to Scell-1 from the PDSCH scheduled by PDCCH 2; cellindex of Scell-2 maintained by UE2 corresponds to a carrier indication domain in PDCCH1, so that a random access response corresponding to Scell-2 of UE2 and a random access response corresponding to Scell-1 of UE0 are carried on a PDSCH scheduled by PDCCH1, and UE2 obtains a random access response corresponding to Scell-2 from the PDSCH scheduled by PDCCH 1; because the PDSCH scheduled by the PDCCH scrambled by the same RA-RNTI bears the random access response of different UE on different Scell, the PDSCH can be transmitted only on Pcell;

in addition, the random access method on the Scell may also be applicable to random access on the Pcell, and the random access method is also applicable when the Pcell of the UE and at least one Scell perform random access simultaneously. Particularly, the random access method is also applicable when a plurality of cells are defined in a system as a group sharing one TA, and the Scell may refer to one cell or Pcell predefined/configured in a cell group sharing one TA.

A base station end:

step 1: the base station receives a preamble sequence on the PRACH channel resource on the Scell;

the PRACH configuration on each Scell may be the same as or different from the Pcell;

if the Scell is non-competitive random access, before the step, the base station sends configuration information to the Scell of the UE through PDCCHorder or RRC signaling, and configures dedicated preamble sequences and PRACH resources of the UE; the pdcch order corresponding to the Scell may be sent on the Scell, or may also be sent on the Pcell or other scells (pdcch ue dedicated search space transmission on the Pcell or other scells, cross-carrier scheduling needs to be configured); if the base station is configured with non-competitive random access, only the configured PRACH resource on the Scell configured with non-competitive random access needs to receive a preamble sequence;

step 2: a base station sends a PDCCH scrambled by RA-RNTI corresponding to Scell random access response in a public search space of a Pcell, and sends a PDSCH which is scheduled by the PDCCH and bears the Scell random access response;

the PDSCH may be transmitted in Pcell or Scell, and the specific manner may be predetermined by the UE and the base station;

the PDSCH may include random access responses of a plurality of UEs that simultaneously send preambles on the same PRACH resource on the Scell; that is, the random access response of the UE on the Scell corresponding to the same RA-RNTI is transmitted simultaneously in the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI;

the method comprises the following steps: a base station scrambles a PDCCH (physical downlink control channel) of a random access response of a corresponding Scell, which is sent in a Pcell public search space, by adopting RA-RNTI (random access-radio network temporary identifier) related to carrier information;

specifically, the carrier information may be carrier identification information (cell _ sign), that is, RA-RNTI is associated with the cell _ sign, for example, RA-RNTI is 1+ t _ id +10 × f _ id +60 × -cell _ sign, where: t _ id is the number of a first subframe corresponding to the PRACH resource, the value of t _ id is more than or equal to 0 and less than 10, f _ id is the number of the PRACH resource in one subframe, the values of f _ id is more than or equal to 0 and less than 6 according to the ascending sequence number of a frequency domain, cell _ sign is the carrier identification of the current Scell, the value of cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system;

the cell _ sign of each Scell may be a carrier number maintained by the UE (i.e., each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; preferably, the cell _ sign is a carrier identifier specific to the system (i.e. a specific number defined for a cell in the system, and a uniform number for all cells in the system), or a carrier identifier specific to the Pcell (i.e. a specific number defined for the cell in a cell set corresponding to the same primary cell, and a uniform number for Scell corresponding to UE of the same Pcell); preferably, when the random access process of the Scell is non-contention random access, the carrier identifier may be a carrier number maintained by the UE (that is, each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; when the random access process of the Scell is competitive random access, the carrier identifier needs to be a carrier identifier exclusive to the system;

when the cell _ sign is a carrier number maintained by the UE, requiring the PDSCH carrying the Scell random access response to be sent in the Pcell;

particularly, when the base station is not configured with non-contention random access, if the base station receives a preamble sequence, the base station needs to send a PDCCH for scheduling a PDSCH carrying the RAR in a common search space of all cells;

for example: the base station receives the same preamble0 sequence sent by UE0 on the same PRACH resource on Scell-1 and Scell-2, the base station determines RA-RNTI-1 corresponding to the random access response sent on Scell-1 according to t _ id and f _ id corresponding to the PRACH resource of preamble0 received on Scell-1 and cell _ sign of Scell-1, and adopts PDCCH scrambled by RA-RNTI-1 in the public search space of Pcell to schedule and bear PDSCH of the random access response corresponding to the preamble received on Scell-1; the base station determines RA-RNTI-2 corresponding to the random access response sent on the Scell-2 according to t _ id and f _ id corresponding to PRACH resource of preamble0 received on the Scell-2 and cell _ sign of the Scell-2, and adopts PDCCH scrambled by RA-RNTI-2 to schedule and bear PDSCH (the PDSCH can be transmitted on the Pcell or the Scell and is pre-agreed by the UE and the base station, namely one of transmission modes is stipulated in the standard) of the random access response received on the Scell-2 in the public search space of the Pcell; in the above process, if the base station receives multiple preamble sequences simultaneously on the same PRACH resource on Scell-1 and Scell-2, the random access response of the preamble sequence corresponding to the same RA-RNTI is transmitted simultaneously in the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI, that is, if the base station receives the preamble1 sequence from the UE1 on the PRACH resource of the preamble0 sequence received on Scell-1, and receives the preamble2 sequence from the UE2 on the PRACH resource of the preamble0 sequence received on Scell-2, then:

if the cell _ sign of the Scell is a system-specific or Pcell-specific carrier identity, that is, the carrier identity of the Scell-1 maintained by the UE1 is consistent with the carrier identity of the Scell-1 maintained by the UE0, and the carrier identity of the Scell-2 maintained by the UE2 is consistent with the carrier identity of the Scell-2 maintained by the UE0, as shown in table 5: the base station receives the RA-RNTI corresponding to the random access response of preamble1 on Scell-1 and the RA-RNTI corresponding to the random access response of preamble0 on UE0Scell-1, which are determined by cell sign of Scell-1, from the t _ id and f _ id corresponding to the PRACH resource of preamble2 received on Scell-2, and the RA-RNTI corresponding to the random access response of preamble2 on Scell-2 and the RA-RNTI corresponding to the random access response of preamble0 on UE0Scell-2, which are determined by cell sign of Scell-2, from the t _ id and f _ id corresponding to the PRACH resource of preamble1 received on Scell-1, and the RA-RNTI corresponding to the random access response of preamble0 on Scell-2, which are determined by cell sign of Scell-2, which are RA-RNTI-2, so that the base station transmits the random access response of the PDSCH 1 on the random access response of the PDSCH 563268 on the PDCCH which is scrambled by RA-RNTI-1 (namely the PDSCH 0 corresponding to the UE1 on Scell-1), the base station simultaneously transmits the random access response corresponding to the preamble2 of the UE2 on the Scell-2 in the PDSCH (namely the PDSCH carrying the random access response corresponding to the preamble0 of the UE0 on the Scell-2) scheduled by the PDCCH scrambled by RA-RNTI-2;

if the cell _ index of the Scell is the carrier number maintained by the UE, i.e. the number of Scell-1 maintained by the UE1 is not consistent with the number of Scell-1 maintained by the UE0 but is consistent with the number of Scell-2 maintained by the UE0, and the number of Scell-2 maintained by the UE2 is not consistent with the number of Scell-2 maintained by the UE0 but is consistent with the number of Scell-1 maintained by the UE0, as shown in Table 6: the base station receives the t _ id and f _ id corresponding to the PRACH resource of preamble1 received on Scell-1, and the RA-RNTI corresponding to the random access response of preamble1 on Scell-1 and the RA-RNTI corresponding to the random access response of preamble0 on UE0Scell-2 determined by cell _ index of Scell-1, and is RA-RNTI-2, the base station receives the t _ id and f _ id corresponding to the PRACH resource of preamble2 received on Scell-2, and the RA-RNTI corresponding to the random access response of preamble2 on Scell-2 determined by cell _ index of Scell-2 and the RA-RNTI corresponding to the random access response of preamble0 on UE0Scell-1, and is RA-RNTI-1, therefore, the base station transmits the random access response of the PDSCH 3668 on PDSCH 0 scrambled by RA-RNTI-2 (namely, the PDSCH 1 corresponding to preamble0 on Scell-2 carrying UE 7 on Scell-1) in the random access response of the UE 3526, the base station simultaneously transmits the random access response corresponding to the preamble2 of the UE2 on the Scell-2 in the PDSCH (namely the PDSCH carrying the random access response corresponding to the preamble0 of the UE0 on the Scell-1) scheduled by the PDCCH scrambled by RA-RNTI-1; because the PDSCH scheduled by the PDCCH scrambled by the same RA-RNTI bears the random access response of different UE on different Scell, the PDSCH can be transmitted only on Pcell;

the method 2 comprises the following steps: the base station indicates a Scell corresponding to the PDCCH scrambled by the RA-RNTI sent in the Pcell public search space through a carrier indication domain in the PDCCH scrambled by the RA-RNTI;

the information indicated by the carrier indication field is a random access response of the Scell corresponding to the PDSCH scheduled by the PDCCH, and the indication information may be cell _ sign;

the cell _ sign of each Scell may be a carrier number maintained by the UE (i.e., each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; preferably, the cell _ sign is a carrier identifier specific to the system (i.e. a specific number defined for a cell in the system, and a uniform number for all cells in the system), or a carrier identifier specific to the Pcell (i.e. a specific number defined for the cell in a cell set corresponding to the same primary cell, and a uniform number for Scell corresponding to UE of the same Pcell); preferably, when the random access process of the Scell is non-contention random access, the carrier identifier may be a carrier number maintained by the UE (that is, each UE maintains an independent cell _ index), or a system-specific carrier identifier, or a Pcell-specific carrier identifier; when the random access process of the Scell is competitive random access, the carrier identifier needs to be a carrier identifier exclusive to the system;

when the cell _ sign is a carrier number maintained by the UE, requiring the PDSCH carrying the Scell random access response to be sent in the Pcell;

particularly, when the base station is not configured with non-contention random access, if the base station receives a preamble sequence, the base station needs to send a PDCCH for scheduling a PDSCH carrying the RAR in a common search space of all cells;

the random access response of the UE on the Scell corresponding to the same RA-RNTI and Scellsign is transmitted simultaneously in the PDSCH scheduled by the PDCCH corresponding to the Scellindex and the carrier indication domain scrambled by the RA-RNTI;

the carrier indication field in the PDCCH scrambled by the RA-RNTI can be newly added extra bits or reuse original bits;

preferably, in order not to increase blind detection, the PDCCH scrambled by RA-RNTI may adopt DCIformat1A, and at this time, one of them may be reused:

HARQ process number (HARQ processsnumber) indication field, 3 bits for FDD system and 4 bits for TDD system; and/or the presence of a gas in the gas,

redundancy version (redundancy) indication field, 2 bits for both FDD and TDD; and/or the presence of a gas in the gas,

for a TDD system, a downlink allocation index (downlink assignment index) indication field, 2 bits;

for example: the base station receives the same preamble0 sequence sent by the UE0 on the same PRACH resource on Scell-1 and Scell-2, then the base station determines that two scells correspond to the same RA-RNTI according to t _ id and f _ id corresponding to the PRACH resource on Scell-1 and Scell-2, sends 2 PDCCHs scrambled with the RA-RNTI in the common search space of the Pcell, sets the carrier indication field in the PDCCH corresponding to the preamble0 response on Scell-1 to the value corresponding to the carrier identifier of Scell-1, transmits the random access response of the preamble0 received on Scell-1 in the PDSCH scheduled by the PDCCH, sets the carrier indication field in the PDCCH corresponding to the preamble0 response on Scell-2 to the value corresponding to the carrier identifier of Scell-2, and transmits the random access response of the preamble0 received on Scell-2 in the PDSCH scheduled by the PDCCH (the above can be transmitted on the Pcell, or may be transmitted on Scell, where UE and base station agree in advance, that is, one of the transmission modes is specified in the standard); in the above process, if the base station receives preamble sequences from multiple UEs on the same PRACH resource on Scell-1 and Scell-2 at the same time, then the random access response of the preamble corresponding to the same Scell carrier identity (corresponding to the carrier indicator field in the PDCCH) is transmitted in the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI having the carrier indicator field corresponding to the Scell carrier identity at the same time, that is, if the base station receives the preamble1 sequence from the UE1 on the PRACH resource of the preamble0 sequence on Scell-1 and receives the preamble2 sequence from the UE2 on the PRACH resource of the preamble0 sequence on Scell-2, then:

if the cell _ sign of the Scell is a system-specific or Pcell-specific carrier identity, that is, the carrier identity of Scell-1 maintained by the UE1 is consistent with the carrier identity of Scell-1 maintained by the UE0, and the carrier identity of Scell-2 maintained by the UE2 is consistent with the carrier identity of Scell-2 maintained by the UE0, as shown in table 5: the base station simultaneously transmits a random access response corresponding to preamble1 of UE1 on Scell-1 in a PDSCH scheduled by a PDCCH with a carrier indication field corresponding to cell _ sign of Scell-1 (namely, a PDSCH carrying a random access response corresponding to preamble0 of UE0 on Scell-1), and simultaneously transmits a random access response corresponding to preamble2 of UE2 on Scell-2 in a PDSCH scheduled by a PDCCH with a carrier indication field corresponding to cell _ sign of Scell-2 (namely, a PDSCH carrying a random access response corresponding to preamble0 of UE0 on Scell-2);

if the cell _ sign of the Scell is the UE-specific carrier number, i.e. the number of Scell-1 maintained by the UE1 is not consistent with the number of Scell-1 maintained by the UE0, but is consistent with the number of Scell-2 maintained by the UE0, and the number of Scell-2 maintained by the UE2 is not consistent with the number of Scell-2 maintained by the UE0, but is consistent with the number of Scell-1 maintained by the UE0, as shown in table 6: the base station simultaneously transmits a random access response corresponding to a preamble1 of UE1 on Scell-1 in a PDSCH (namely, a PDSCH carrying a random access response corresponding to a preamble0 of UE0 on Scell-2) scheduled by a PDCCH with a carrier indication domain corresponding to celldex of Scell-2, and simultaneously transmits a random access response corresponding to a preamble2 of UE2 on Scell-2 in a PDSCH (namely, a PDSCH carrying a random access response corresponding to a preamble0 of UE0 on Scell-1) scheduled by a PDCCH with a carrier indication domain corresponding to celldex of Scell-1; because the PDSCH scheduled by the PDCCH scrambled by the same RA-RNTI bears the random access response of different UE on different Scell, the PDSCH can be transmitted only on Pcell;

the embodiment of the invention provides a random access method, which can support simultaneous random access on one Scell, or Pcell and Scell, or a plurality of Scells, thereby ensuring that different cells can independently perform TA adjustment when different frequency bands are aggregated in an LTE-A system on the basis of not increasing the blind detection times of a PDCCH by UE.

Referring to fig. 9, an embodiment of the present invention provides a terminal, where the terminal includes:

a sending unit 90, configured to determine a random access preamble sequence to be sent in a cell where a random access needs to be performed in a current subframe, and a physical random access channel PRACH resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

a detecting unit 91, configured to determine a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent in the cell according to the carrier identifier information of the cell and the information of the PRACH resource used by the random access preamble sequence sent in the cell, and detect a physical downlink control channel PDCCH scrambled by using the RA-RNTI in a common search space of a primary cell of the terminal;

a synchronization unit 92, configured to receive, according to the detected PDCCH, a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell, and perform uplink synchronization adjustment on the cell according to an uplink timing advance TA in the random access response.

The terminal further includes:

a receiving unit 93, configured to receive a dedicated random access preamble sequence number and a PRACH resource number that are sent by a base station through a PDCCH order or a radio resource control RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by the cell that needs to perform random access, the PRACH resource number is used to indicate a PRACH resource used by the cell to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal.

The receiving unit 93 is configured to:

and receiving the PDCCH command on an auxiliary cell or a main cell of the terminal, wherein when the PDCCH command does not adopt cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell indicated by a carrier indication domain in the PDCCH command.

The detection unit 91 is configured to:

the RA-RNTI is determined according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

The carrier identification information is: the number of the carrier wave maintained by the terminal, or the number defined to a system level of the cell in the system, or the number defined to a main cell level of the cell in a cell set corresponding to the same main cell.

The synchronization unit 92 is configured to:

and when the carrier identification information is a carrier number maintained by the terminal, receiving the PDSCH in a main cell of the terminal.

The synchronization unit 92 is configured to:

and receiving the PDSCH on the main cell of the terminal or the cell sending the random access preamble sequence.

The cell is a secondary cell of the terminal.

Referring to fig. 10, an embodiment of the present invention provides a base station, where the base station includes:

a receiving unit 101, configured to receive a random access preamble sequence sent by a terminal on a physical random access channel PRACH resource of a cell;

a scheduling unit 102, configured to determine a random access radio network temporary identifier RA-RNTI corresponding to a random access preamble sequence received in a cell according to carrier identifier information of the cell receiving the random access preamble sequence and information of PRACH resource on the cell for transmitting the random access preamble sequence, and send a physical downlink control channel PDCCH scrambled by using the RA-RNTI in a common search space of the set cell, so that a scheduling terminal receives a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence;

a sending unit 103, configured to send the PDSCH carrying the random access response to the terminal, where the random access response includes the uplink timing advance TA.

The base station further comprises:

an indicating unit 104, configured to send a dedicated random access preamble sequence number and a PRACH resource number to a terminal through a PDCCH order or a radio resource control, RRC, signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by a cell that needs to perform random access, the PRACH resource number is used to indicate a PRACH resource used by the cell to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal.

The indication unit 104 is configured to:

the method comprises the steps that the PDCCH command is sent on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the sent PDCCH command correspondingly triggers non-contention random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the sent PDCCH command correspondingly triggers the non-contention random access of the cell indicated by a carrier indication domain in the PDCCH command.

The scheduling unit 102 is configured to:

when the base station configuration terminal adopts non-competitive random access, sending the PDCCH scrambled by using the RA-RNTI in a public search space of a main cell configured with the terminal adopting non-competitive random access;

and when the base station does not configure the terminal to adopt non-competitive random access, sending the PDCCH scrambled by using the RA-RNTI in the common search space of all the cells.

The scheduling unit 102 is configured to:

the RA-RNTI is determined according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

The sending unit 103 is configured to:

and simultaneously transmitting the random access response of the random access leader sequence corresponding to the same RA-RNTI on the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI.

The carrier identification information is a carrier number maintained by the terminal, or a system-level number defined to the cell in the system, or a primary cell-level number defined to the cell in a cell set corresponding to the same primary cell.

The sending unit 103 is configured to:

and when the carrier identification information is a carrier number maintained by the terminal and the random access is non-competitive random access, sending the PDSCH in a main cell of the terminal corresponding to the received random access leader sequence.

The sending unit 103 is configured to:

sending the PDSCH in a main cell of a terminal corresponding to the received random access preamble sequence; or,

and sending the PDSCH on the cell where the received random access preamble sequence is located.

The cell is an auxiliary cell of the terminal.

Still referring to fig. 9, an embodiment of the present invention provides a terminal, including:

a sending unit 90, configured to determine a random access preamble sequence to be sent in a cell where a random access needs to be performed in a current subframe, and a physical random access channel PRACH resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the cell;

a detecting unit 91, configured to determine, according to the information of the PRACH resource used by the random access preamble sequence sent in the cell, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent in the cell, and detect, in a common search space of a primary cell of the terminal, a physical downlink control channel PDCCH scrambled by using the RA-RNTI;

a synchronizing unit 92, configured to receive, according to the detected carrier identifier information indicated by the carrier identifier indication field in the PDCCH, a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell, and perform uplink synchronization adjustment on the cell according to an uplink timing advance TA in the random access response.

The terminal further includes:

a receiving unit 93, configured to receive a dedicated random access preamble sequence number and a PRACH resource number that are sent by a base station through a PDCCH order or a radio resource control RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by the cell that needs to perform random access, the PRACH resource number is used to indicate a PRACH resource used by the cell to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal.

The receiving unit 93 is configured to:

and receiving the PDCCH command on an auxiliary cell or a main cell of the terminal, wherein when the PDCCH command does not adopt cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell indicated by a carrier indication domain in the PDCCH command.

The synchronization unit 92 is configured to:

and receiving the PDCCH carrying the carrier identification information consistent with the carrier identification information of the cell for sending the random access leader sequence, and acquiring the random access response of the random access leader sequence sent by the cell from the scheduled PDSCH.

The carrier identification information is a carrier number maintained by a terminal, or a system-level number defined to the cell in a system, or a primary cell-level number defined to the cell in a corresponding primary cell set.

The synchronization unit 92 is configured to:

and when the carrier identification information is a carrier number maintained by the terminal, receiving the PDSCH in a main cell of the terminal.

The carrier identification indication field is the reuse of original bits in the PDCCH or newly added bits.

When the PDCCH adopts DCI format1A, one or any combination of a hybrid automatic repeat request HARQ process number indication domain, a redundancy version indication domain and a downlink allocation index indication domain is reused as a carrier identification indication domain in the PDCCH.

The synchronization unit 92 is configured to:

and receiving the PDSCH on the main cell of the terminal or the cell sending the random access preamble sequence.

The cell is a secondary cell of the terminal.

Still referring to fig. 10, an embodiment of the present invention provides a base station, including:

a receiving unit 101, configured to receive a random access preamble sequence sent by a terminal on a physical random access channel PRACH resource of a cell;

a scheduling unit 102, configured to determine, according to information of PRACH resources of a random access preamble sequence transmitted on a cell receiving the random access preamble sequence, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence received on the cell, send, in a common search space of a set cell, a PDCCH scrambled with the RA-RNTI and carrying a carrier identifier indicator field, and receive, by a scheduling terminal, a PDSCH carrying a random access response of the random access preamble sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence;

a sending unit 103, configured to send the PDSCH carrying the random access response to the terminal, where the random access response includes the uplink timing advance TA.

The base station further comprises:

an indicating unit 104, configured to send a dedicated random access preamble sequence number and a PRACH resource number to a terminal through a PDCCH order or a radio resource control, RRC, signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by a cell that needs to perform random access, the PRACH resource number is used to indicate a PRACH resource used by the cell to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal.

The indication unit 104 is configured to:

the method comprises the steps that the PDCCH command is sent on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the sent PDCCH command correspondingly triggers non-contention random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the sent PDCCH command correspondingly triggers the non-contention random access of the cell indicated by a carrier indication domain in the PDCCH command.

The scheduling unit 102 is configured to:

when the base station configuration terminal adopts non-competitive random access, sending a PDCCH scrambled by the RA-RNTI and provided with a carrier identifier indication domain in a public search space of a main cell configured with the terminal adopting non-competitive random access;

and when the base station does not configure the terminal to adopt non-competitive random access, sending the PDCCH which is scrambled by using the RA-RNTI and is provided with the carrier identifier indication domain in a common search space of all cells.

The sending unit 103 is configured to:

and simultaneously transmitting the random access response of the random access preamble sequence which corresponds to the same RA-RNTI and is received on the cell with the same carrier identification information on the PDSCH scheduled by the PDCCH of which the carrier identification information of the cell is indicated by the carrier identification indication domain scrambled by the RA-RNTI.

The carrier identification information is a carrier number maintained by the terminal, or a system-level number defined to the cell in the system, or a primary cell-level number defined to the cell in a cell set corresponding to the same primary cell.

The sending unit 103 is configured to:

and when the carrier identification information is a carrier number maintained by the terminal and the random access is non-competitive random access, sending the PDSCH in a main cell of the terminal corresponding to the received random access leader sequence.

The carrier identification indication field is the reuse of original bits in the PDCCH or newly added bits.

When the PDCCH adopts DCI format1A, one or any combination of a hybrid automatic repeat request HARQ process number indication domain, a redundancy version indication domain and a downlink allocation index indication domain is reused as a carrier identification indication domain in the PDCCH.

The sending unit 103 is configured to:

sending the PDSCH in a main cell of a terminal corresponding to the received random access preamble sequence; or,

and sending the PDSCH on the cell where the received random access preamble sequence is located.

The cell is an auxiliary cell of the terminal.

In conclusion, the beneficial effects of the invention include:

in one scheme provided by the embodiment of the invention, a terminal determines a random access preamble sequence to be sent on a cell where random access is required to be performed on a current subframe and a PRACH resource used for sending the random access preamble sequence, and sends the random access preamble sequence to a base station on the cell through the PRACH resource; then, according to the carrier identification information of the cell and the information of the PRACH resource used by the random access preamble sequence sent by the cell, determining RA-RNTI corresponding to the random access preamble sequence sent by the cell, detecting a PDCCH scrambled by using the RA-RNTI in a public search space of a main cell of the terminal, receiving a PDSCH carrying a random access response corresponding to the random access preamble sequence sent by the cell according to the detected PDCCH, and performing uplink synchronization adjustment on the cell according to an uplink TA in the random access response. Therefore, the method can realize the random access of the terminal side in the auxiliary cell or a plurality of cells simultaneously in the carrier aggregation system.

Correspondingly, a base station receives a random access preamble sequence sent by a terminal on PRACH resources of a cell, determines RA-RNTI corresponding to the random access preamble sequence received on the cell according to carrier identification information of the cell receiving the random access preamble sequence and information of PRACH resources for transmitting the random access preamble sequence on the cell, and sends PDCCH scrambled by using the RA-RNTI in a public search space of a set cell so as to schedule the terminal to receive PDSCH carrying random access response corresponding to the random access preamble sequence and send PDSCH carrying the random access response to the terminal, wherein the random access response comprises uplink TA. Therefore, by adopting the method, the base station side can realize the random access in the auxiliary cell or a plurality of cells simultaneously in the carrier aggregation system.

In another scheme provided by the embodiment of the invention, a terminal determines a random access preamble sequence to be sent on a cell where random access is required to be performed on a current subframe and a PRACH resource used for sending the random access preamble sequence, and sends the random access preamble sequence to a base station on the cell through the PRACH resource; then, according to the information of the PRACH resource used by the random access preamble sequence sent by the cell, determining RA-RNTI corresponding to the random access preamble sequence sent by the cell, and detecting a PDCCH scrambled by the RA-RNTI in a public search space of a main cell of the terminal; and receiving a PDSCH carrying a random access response corresponding to the random access preamble sequence sent on the cell according to the detected carrier identification information indicated by the carrier identification indication field in the PDCCH, and performing uplink synchronization adjustment on the cell according to an uplink TA in the random access response. Therefore, the method can realize the random access of the terminal side in the auxiliary cell or a plurality of cells simultaneously in the carrier aggregation system.

Correspondingly, a base station receives a random access preamble sequence sent by a terminal on PRACH resources of a cell, determines RA-RNTI corresponding to the random access preamble sequence received on the cell according to information of PRACH resources of the random access preamble sequence transmitted on the cell receiving the random access preamble sequence, and sends a PDCCH which is scrambled by using the RA-RNTI and carries a carrier identifier indication domain in a public search space of the set cell so as to schedule the terminal to receive a PDSCH carrying random access response of the random access preamble sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence; and then the base station sends the PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink TA. Therefore, by adopting the method, the base station side can realize the random access in the auxiliary cell or a plurality of cells simultaneously in the carrier aggregation system.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (66)

1. A random access method in a carrier aggregation system, the method comprising:

a terminal determines a random access preamble sequence to be sent on a cell which needs to perform random access on a current subframe and a Physical Random Access Channel (PRACH) resource used for sending the random access preamble sequence; sending the random access leader sequence to a base station through the PRACH resource on the cell needing random access on the current subframe;

the terminal determines a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent on the cell which needs to be randomly accessed in the current subframe according to the carrier identification information of the cell which needs to be randomly accessed in the current subframe and the information of the PRACH resource used by the random access preamble sequence sent on the cell which needs to be randomly accessed in the current subframe, and detects a physical downlink control channel PDCCH scrambled by the RA-RNTI in a public search space of a main cell of the terminal;

the terminal receives a Physical Downlink Shared Channel (PDSCH) carrying a random access response corresponding to the random access preamble sequence sent on the cell requiring random access on the current subframe according to the detected PDCCH, and performs uplink synchronization adjustment on the cell requiring random access on the current subframe according to an uplink Timing Advance (TA) in the random access response;

before a terminal determines a random access leader sequence to be sent on a cell needing random access in a current subframe and a PRACH resource used for sending the random access leader sequence, the terminal receives a special random access leader sequence number and a PRACH resource number sent by a base station through a PDCCH (physical Downlink control) command or a Radio Resource Control (RRC) signaling, wherein the special random access leader sequence number is used for indicating the random access leader sequence used by the cell needing random access in the current subframe, the PRACH resource number is used for indicating the PRACH resource used for sending the random access leader sequence by the cell needing random access in the current subframe, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal; the terminal receives the PDCCH command on an auxiliary cell or a main cell of the terminal, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers non-competitive random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers non-competitive random access of a cell indicated by a carrier indication domain in the PDCCH command.

2. The method of claim 1, wherein the determining, by the terminal, the RA-RNTI corresponding to the random access preamble sequence that is transmitted in the cell requiring random access in the current subframe according to the carrier identification information of the cell requiring random access in the current subframe and the information of the PRACH resource used by the random access preamble sequence that is transmitted in the cell requiring random access in the current subframe comprises:

the RA-RNTI is determined according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell needing random access in the current subframe, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

3. The method according to claim 1 or 2, wherein the carrier identification information is: the carrier number maintained by the terminal is defined to a system level number of the cell needing random access in the current subframe, or a primary cell level number of the cell needing random access in the current subframe is defined in a cell set corresponding to the same primary cell.

4. The method of claim 3, wherein the terminal receives the PDSCH in a primary cell of the terminal when the carrier identification information is a carrier number maintained by the terminal.

5. The method of claim 1 or 2, wherein the receiving, by the terminal according to the detected PDCCH, the PDSCH carrying the random access response corresponding to the random access preamble sequence that needs to be transmitted on the cell where the random access is performed in the current subframe, comprises:

and the terminal receives the PDSCH on a main cell of the terminal or the cell which sends the random access preamble sequence.

6. The method of claim 1 or 2, wherein the cell requiring random access in a current subframe is a secondary cell of the terminal.

7. A random access method in a carrier aggregation system, the method comprising:

a terminal determines a random access preamble sequence to be sent on a cell which needs to perform random access on a current subframe and a Physical Random Access Channel (PRACH) resource used for sending the random access preamble sequence; sending the random access leader sequence to a base station through the PRACH resource on the cell needing random access on the current subframe;

the terminal determines a random access radio network temporary identifier (RA-RNTI) corresponding to the random access leader sequence sent on the cell which needs to be randomly accessed in the current subframe according to the information of the PRACH resource used by the random access leader sequence sent on the cell which needs to be randomly accessed in the current subframe, and detects a Physical Downlink Control Channel (PDCCH) scrambled by the RA-RNTI in a public search space of a main cell of the terminal;

the terminal receives a Physical Downlink Shared Channel (PDSCH) carrying a random access response corresponding to the random access leader sequence sent on the cell requiring random access in the current subframe according to the detected carrier identification information indicated by the carrier identification indication field in the PDCCH, and performs uplink synchronization adjustment on the cell requiring random access in the current subframe according to an uplink Timing Advance (TA) in the random access response;

before a terminal determines a random access leader sequence to be sent on a cell needing random access in a current subframe and a PRACH resource used for sending the random access leader sequence, the terminal receives a special random access leader sequence number and a PRACH resource number sent by a base station through a PDCCH (physical Downlink control) command or a Radio Resource Control (RRC) signaling, wherein the special random access leader sequence number is used for indicating the random access leader sequence used by the cell needing random access in the current subframe, the PRACH resource number is used for indicating the PRACH resource used for sending the random access leader sequence by the cell needing random access in the current subframe, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal; the terminal receives the PDCCH command on an auxiliary cell or a main cell of the terminal, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers non-competitive random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command received by the terminal correspondingly triggers non-competitive random access of a cell indicated by a carrier indication domain in the PDCCH command.

8. The method of claim 7, wherein the receiving, by the terminal, the PDSCH carrying the random access response corresponding to the random access preamble sequence that needs to be sent on the cell where the random access is performed in the current subframe according to the detected carrier identifier information indicated by the carrier identifier indicator field in the PDCCH includes:

and the terminal receives the PDCCH carrying the carrier identification information consistent with the carrier identification information of the cell which sends the random access leader sequence, the dispatched PDSCH and acquires the random access response of the random access leader sequence sent by the cell which needs to carry out random access in the current subframe from the PDSCH.

9. The method according to claim 7 or 8, wherein the carrier identification information is a carrier number maintained by the terminal, or a system level number defined for the cell requiring random access in the current subframe, or a primary cell level number defined for the cell requiring random access in the current subframe in a cell set corresponding to the same primary cell.

10. The method of claim 9, wherein a terminal receives the PDSCH in a primary cell of the terminal when the carrier identification information is a carrier number maintained by the terminal.

11. The method of claim 7 or 8, wherein the carrier identity indication field is a reuse of original bits in the PDCCH or a newly added bit.

12. The method of claim 11, wherein when the PDCCH is in DCI format1A, one or any combination of a hybrid automatic repeat request, HARQ, process number indication field, a redundancy version indication field, a downlink allocation index indication field is reused as a carrier identity indication field in the PDCCH.

13. The method of claim 7 or 8, wherein a terminal receives the PDSCH on a primary cell of the terminal or the cell transmitting a random access preamble sequence.

14. The method of claim 7 or 8, wherein the cell requiring random access in a current subframe is a secondary cell of the terminal.

15. A random access processing method in a carrier aggregation system is characterized by comprising the following steps:

a base station receives a random access preamble sequence sent by a terminal on a Physical Random Access Channel (PRACH) resource of a cell;

a base station determines a random access radio network temporary identifier RA-RNTI corresponding to a random access leader sequence received on a cell receiving the random access leader sequence according to carrier identification information of the cell receiving the random access leader sequence and information of PRACH resources transmitted on the cell receiving the random access leader sequence, and transmits a physical downlink control channel PDCCH scrambled by using the RA-RNTI in a public search space of a set cell so as to schedule a terminal to receive a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access leader sequence;

the base station sends a PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink timing advance TA;

before a base station receives a random access preamble sequence sent by a terminal on a PRACH resource of a cell, the base station sends a special random access preamble sequence number and a PRACH resource number to the terminal through a PDCCH (physical Downlink control) command or a Radio Resource Control (RRC) signaling, wherein the special random access preamble sequence number is used for indicating a random access preamble sequence used by the cell needing random access, the PRACH resource number is used for indicating the cell needing random access to send the PRACH resource used by the random access preamble sequence, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal; the base station sends the PDCCH command on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers non-competitive random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers non-competitive random access of a cell indicated by a carrier indication domain in the PDCCH command.

16. The method of claim 15, wherein the sending the PDCCH scrambled with the RA-RNTI in the common search space of the set cell comprises:

when the base station configures the terminal to adopt non-competitive random access, the base station sends the PDCCH scrambled by the RA-RNTI in a public search space of a main cell configured with the terminal adopting non-competitive random access;

and when the base station does not configure the terminal to adopt non-competitive random access, the base station sends the PDCCH scrambled by using the RA-RNTI in the common search space of all the cells.

17. The method of claim 15, wherein the determining, by the base station, the RA-RNTI corresponding to the random access preamble sequence received on the cell receiving the random access preamble sequence according to the carrier identification information of the cell receiving the random access preamble sequence and the information of the PRACH resource on the cell receiving the random access preamble sequence for transmitting the random access preamble sequence comprises:

the RA-RNTI is determined according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell receiving the random access preamble sequence, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

18. A method according to any of claims 15-17, wherein the base station transmits the random access response of the random access preamble sequence corresponding to the same RA-RNTI simultaneously on the PDSCH scheduled by the PDCCH scrambled by that RA-RNTI.

19. The method according to any of claims 15-17, wherein the carrier identification information is a carrier number maintained by the terminal, or a system level number defined for the cell receiving the random access preamble sequence, or a primary cell level number defined for the cell receiving the random access preamble sequence in a cell set corresponding to the same primary cell.

20. The method of claim 19, wherein the base station transmits the PDSCH in a primary cell of the terminal corresponding to the received random access preamble sequence when the carrier identification information is a carrier number maintained by the terminal and random access is non-contention random access.

21. The method of any of claims 15-17, wherein the base station transmitting the PDSCH carrying the random access response to the terminal comprises:

the base station sends the PDSCH in a main cell of a terminal corresponding to the received random access leader sequence; or,

and the base station transmits the PDSCH on the cell receiving the random access preamble sequence.

22. The method according to any of claims 15-17, wherein the cell receiving the random access preamble sequence is a secondary cell of a terminal.

23. A random access processing method in a carrier aggregation system is characterized by comprising the following steps:

a base station receives a random access preamble sequence sent by a terminal on a Physical Random Access Channel (PRACH) resource of a cell;

a base station determines a random access radio network temporary identifier (RA-RNTI) corresponding to a random access preamble sequence received on a cell receiving the random access preamble sequence according to information of PRACH resources of the random access preamble sequence transmitted on the cell receiving the random access preamble sequence, and transmits a Physical Downlink Control Channel (PDCCH) scrambled by using the RA-RNTI and carrying a carrier identifier indication domain in a public search space of a set cell so as to schedule a terminal to receive a Physical Downlink Shared Channel (PDSCH) carrying random access response of the random access preamble sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence;

the base station sends a PDSCH carrying the random access response to the terminal, wherein the random access response comprises an uplink timing advance TA;

before a base station receives a random access preamble sequence sent by a terminal on a PRACH resource of a cell, the base station sends a special random access preamble sequence number and a PRACH resource number to the terminal through a PDCCH (physical Downlink control) command or a Radio Resource Control (RRC) signaling, wherein the special random access preamble sequence number is used for indicating a random access preamble sequence used by the cell needing random access, the PRACH resource number is used for indicating the cell needing random access to send the PRACH resource used by the random access preamble sequence, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal; the base station sends the PDCCH command on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers non-competitive random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command sent by the base station correspondingly triggers non-competitive random access of a cell indicated by a carrier indication domain in the PDCCH command.

24. The method of claim 23, wherein the base station sends the PDCCH scrambled with the RA-RNTI and having the carrier identity indicator field in the common search space of the set cell, and specifically comprises:

when the base station configures the terminal to adopt non-competitive random access, the base station sends the PDCCH which is scrambled by the RA-RNTI and is provided with the carrier identifier indication domain in a public search space of a main cell configured with the terminal adopting non-competitive random access;

and when the base station is not configured with the terminal and adopts non-competitive random access, the base station sends the PDCCH which is scrambled by the RA-RNTI and provided with the carrier identifier indication domain in the public search space of all the cells.

25. The method of claim 23, wherein the base station transmits a random access response of a random access preamble sequence corresponding to the same RA-RNTI and received on a cell with the same carrier identification information simultaneously on a PDSCH scheduled by a PDCCH scrambled by the RA-RNTI and carrying carrier identification indication field indicating carrier identification information of the cell receiving the random access preamble sequence.

26. The method according to any of claims 23-25, wherein the carrier identification information is a carrier number maintained by the terminal, or a system level number defined for the cell receiving the random access preamble sequence, or a primary cell level number defined for the cell receiving the random access preamble sequence in a cell set corresponding to the same primary cell.

27. The method of claim 26, wherein the base station sends the PDSCH in a primary cell of the terminal corresponding to the received random access preamble sequence when the carrier identification information is a carrier number maintained by the terminal and random access is non-contention random access.

28. The method of any of claims 23-25, wherein the carrier identification indication field is a reuse of original bits in the PDCCH or a newly added bit.

29. The method of claim 28, wherein when the PDCCH is in DCI format1A, one or any combination of a hybrid automatic repeat request, HARQ, process number indication field, a redundancy version indication field, a downlink allocation index indication field is reused as a carrier identity indication field in the PDCCH.

30. The method of any of claims 23-25, wherein the base station transmitting the PDSCH carrying the random access response to the terminal comprises:

the base station sends the PDSCH in a main cell of a terminal corresponding to the received random access leader sequence; or,

and the base station transmits the PDSCH on the cell receiving the random access preamble sequence.

31. The method of any of claims 23-25, wherein the cell receiving the random access preamble sequence is a secondary cell of a terminal.

32. A terminal, characterized in that the terminal comprises:

a sending unit, configured to determine a random access preamble sequence to be sent in a cell where a random access needs to be performed in a current subframe, and a physical random access channel PRACH resource used for sending the random access preamble sequence; sending the random access leader sequence to a base station through the PRACH resource on the cell needing random access on the current subframe;

a detecting unit, configured to determine, according to the carrier identifier information of the cell requiring random access in the current subframe and the information of the PRACH resource used by the random access preamble sequence sent in the cell requiring random access in the current subframe, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence sent in the cell requiring random access in the current subframe, and detect, in a common search space of a main cell of the terminal, a physical downlink control channel PDCCH scrambled by using the RA-RNTI;

a synchronization unit, configured to receive, according to the detected PDCCH, a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence that is sent on a cell where random access is to be performed on a current subframe, and perform uplink synchronization adjustment on the cell where random access is to be performed on the current subframe according to an uplink timing advance TA in the random access response;

wherein, this terminal station still includes: a receiving unit, configured to receive a dedicated random access preamble sequence number and a PRACH resource number that are sent by a base station through a PDCCH order or a radio resource control RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by the cell that needs to perform random access in a current subframe, the PRACH resource number is used to indicate a PRACH resource used by the cell that needs to perform random access in the current subframe to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal; the receiving unit is used for: and receiving the PDCCH command on an auxiliary cell or a main cell of the terminal, wherein when the PDCCH command does not adopt cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell indicated by a carrier indication domain in the PDCCH command.

33. The terminal of claim 32, wherein the detection unit is configured to:

the RA-RNTI is determined according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell needing random access in the current subframe, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

34. The terminal according to claim 32 or 33, wherein the carrier identification information is: the carrier number maintained by the terminal is defined to a system level number of the cell needing random access in the current subframe, or a primary cell level number of the cell needing random access in the current subframe is defined in a cell set corresponding to the same primary cell.

35. The terminal of claim 34, wherein the synchronization unit is configured to:

and when the carrier identification information is a carrier number maintained by the terminal, receiving the PDSCH in a main cell of the terminal.

36. The terminal according to claim 32 or 33, wherein the synchronization unit is configured to:

and receiving the PDSCH on the main cell of the terminal or the cell sending the random access preamble sequence.

37. The terminal of claim 32 or 33, wherein the cell requiring random access in a current subframe is a secondary cell of the terminal.

38. A terminal, characterized in that the terminal comprises:

a sending unit, configured to determine a random access preamble sequence to be sent in a cell where a random access needs to be performed in a current subframe, and a physical random access channel PRACH resource used for sending the random access preamble sequence; sending the random access leader sequence to a base station through the PRACH resource on the cell needing random access on the current subframe;

a detecting unit, configured to determine, according to the information of the PRACH resource used by the random access preamble sequence that is sent on the cell where random access is required to be performed on the current subframe, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence that is sent on the cell where random access is required to be performed on the current subframe, and detect, in a common search space of a main cell of the terminal, a physical downlink control channel PDCCH scrambled by using the RA-RNTI;

a synchronization unit, configured to receive, according to carrier identifier information indicated by a detected carrier identifier indication field in the PDCCH, a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence that is sent on a cell to which random access is performed on a current subframe, and perform uplink synchronization adjustment on the cell to which random access is performed on the current subframe according to an uplink timing advance TA in the random access response;

wherein, this terminal station still includes: a receiving unit, configured to receive a dedicated random access preamble sequence number and a PRACH resource number that are sent by a base station through a PDCCH order or a radio resource control RRC signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by the cell that needs to perform random access in a current subframe, the PRACH resource number is used to indicate a PRACH resource used by the cell that needs to perform random access in the current subframe to send the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal; the receiving unit is used for: and receiving the PDCCH command on an auxiliary cell or a main cell of the terminal, wherein when the PDCCH command does not adopt cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the received PDCCH command correspondingly triggers the non-contention random access of a cell indicated by a carrier indication domain in the PDCCH command.

39. The terminal of claim 38, wherein the synchronization unit is configured to:

and receiving the PDCCH carrying the carrier identification information consistent with the carrier identification information of the cell for sending the random access leader sequence, and acquiring the random access response of the random access leader sequence sent by the cell needing random access in the current subframe from the scheduled PDSCH.

40. The terminal according to claim 38 or 39, wherein the carrier identification information is a carrier number maintained by the terminal, or a system level number defined for the cell requiring random access in the current subframe, or a primary cell level number defined for the cell requiring random access in the current subframe in a cell set corresponding to the same primary cell.

41. The terminal of claim 40, wherein the synchronization unit is to:

and when the carrier identification information is a carrier number maintained by the terminal, receiving the PDSCH in a main cell of the terminal.

42. The terminal of claim 38 or 39, wherein the carrier identity indication field is a reuse of original bits in the PDCCH or a newly added bit.

43. The terminal of claim 42, wherein when the PDCCH adopts DCI format1A, one or any combination of a HARQ process number indication field, a redundancy version indication field and a downlink allocation index indication field is reused as a carrier identification indication field in the PDCCH.

44. The terminal according to claim 38 or 39, wherein the synchronization unit is configured to:

and receiving the PDSCH on the main cell of the terminal or the cell sending the random access preamble sequence.

45. The terminal of claim 38 or 39, wherein the cell requiring random access in a current subframe is a secondary cell of the terminal.

46. A base station, comprising:

a receiving unit, configured to receive a random access preamble sequence sent by a terminal on a physical random access channel PRACH resource of a cell;

a scheduling unit, configured to determine, according to carrier identifier information of a cell receiving a random access preamble sequence and information of PRACH resources that the random access preamble sequence transmits in the cell receiving the random access preamble sequence, a random access radio network temporary identifier RA-RNTI corresponding to the random access preamble sequence received in the cell receiving the random access preamble sequence, and send a physical downlink control channel PDCCH scrambled by using the RA-RNTI in a public search space of a set cell, so that a scheduling terminal receives a physical downlink shared channel PDSCH carrying a random access response corresponding to the random access preamble sequence;

a sending unit, configured to send, to a terminal, a PDSCH carrying the random access response, where the random access response includes an uplink timing advance TA;

wherein, this base station still includes: an indicating unit, configured to send a dedicated random access preamble sequence number and a PRACH resource number to a terminal through a PDCCH order or a radio resource control, RRC, signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by a cell that needs to perform random access, the PRACH resource number is used to indicate the cell that needs to perform random access to send a PRACH resource used by the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal; the indication unit is used for: the method comprises the steps that the PDCCH command is sent on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the sent PDCCH command correspondingly triggers non-contention random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the sent PDCCH command correspondingly triggers the non-contention random access of the cell indicated by a carrier indication domain in the PDCCH command.

47. The base station of claim 46, wherein the scheduling unit is configured to:

when the base station configuration terminal adopts non-competitive random access, sending the PDCCH scrambled by using the RA-RNTI in a public search space of a main cell configured with the terminal adopting non-competitive random access;

and when the base station does not configure the terminal to adopt non-competitive random access, sending the PDCCH scrambled by using the RA-RNTI in the common search space of all the cells.

48. The base station of claim 46, wherein the scheduling unit is configured to:

the RA-RNTI is determined according to the following formula:

RA-RNTI + 1+ t _ id +10 f _ id +60 cell _ sign, wherein:

t _ id is the number of the first subframe corresponding to the PRACH resource, and t _ id is more than or equal to 0 and less than 10; f _ id is the number of PRACH resources in a subframe in the frequency domain, and f _ id is more than or equal to 0 and less than 6; the cell _ sign is the carrier identification information of the cell receiving the random access preamble sequence, the cell _ sign is more than or equal to 0 and less than N, and N is the maximum carrier number in the system.

49. The base station according to any of claims 46-48, wherein said transmitting unit is configured to:

and simultaneously transmitting the random access response of the random access leader sequence corresponding to the same RA-RNTI on the PDSCH scheduled by the PDCCH scrambled by the RA-RNTI.

50. A base station according to any of claims 46 to 48, wherein the carrier identification information is a carrier number maintained by the terminal, or a system level number defined for the cell receiving the random access preamble sequence, or a primary cell level number defined for the cell receiving the random access preamble sequence in a cell set corresponding to the same primary cell.

51. The base station of claim 50, wherein the transmitting unit is configured to:

and when the carrier identification information is a carrier number maintained by the terminal and the random access is non-competitive random access, sending the PDSCH in a main cell of the terminal corresponding to the received random access leader sequence.

52. The base station according to any of claims 46-48, wherein said transmitting unit is configured to:

sending the PDSCH in a main cell of a terminal corresponding to the received random access preamble sequence; or,

transmitting the PDSCH on the cell receiving the random access preamble sequence.

53. The base station according to any of claims 46-48, wherein the cell receiving the random access preamble sequence is a secondary cell of the terminal.

54. A base station, comprising:

a receiving unit, configured to receive a random access preamble sequence sent by a terminal on a physical random access channel PRACH resource of a cell;

the scheduling unit is used for determining a random access radio network temporary identifier (RA-RNTI) corresponding to a random access preamble sequence received on a cell receiving the random access preamble sequence according to information of PRACH resources of the random access preamble sequence transmitted on the cell receiving the random access preamble sequence, and transmitting a Physical Downlink Control Channel (PDCCH) scrambled by the RA-RNTI and carrying a carrier identifier indication domain in a public search space of a set cell so as to schedule a terminal to receive a Physical Downlink Shared Channel (PDSCH) carrying random access response of the random access preamble sequence; the carrier identification indication field indicates the carrier identification information of the cell receiving the random access leader sequence;

a sending unit, configured to send, to a terminal, a PDSCH carrying the random access response, where the random access response includes an uplink timing advance TA;

the base station further comprises: an indicating unit, configured to send a dedicated random access preamble sequence number and a PRACH resource number to a terminal through a PDCCH order or a radio resource control, RRC, signaling, where the dedicated random access preamble sequence number is used to indicate a random access preamble sequence used by a cell that needs to perform random access, the PRACH resource number is used to indicate the cell that needs to perform random access to send a PRACH resource used by the random access preamble sequence, and the PDCCH order or the RRC signaling is used to trigger non-contention random access of the terminal; the indication unit is used for: the method comprises the steps that the PDCCH command is sent on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the sent PDCCH command correspondingly triggers non-contention random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the sent PDCCH command correspondingly triggers the non-contention random access of the cell indicated by a carrier indication domain in the PDCCH command.

55. The base station of claim 54, wherein the scheduling unit is configured to:

when the base station configuration terminal adopts non-competitive random access, sending a PDCCH scrambled by the RA-RNTI and provided with a carrier identifier indication domain in a public search space of a main cell configured with the terminal adopting non-competitive random access;

and when the base station does not configure the terminal to adopt non-competitive random access, sending the PDCCH which is scrambled by using the RA-RNTI and is provided with the carrier identifier indication domain in a common search space of all cells.

56. The base station of claim 54, wherein the transmitting unit is configured to:

and simultaneously transmitting the random access response of the random access preamble sequence which corresponds to the same RA-RNTI and is received on the cell with the same carrier identification information on the PDSCH scheduled by the PDCCH of the cell which is scrambled by the RA-RNTI and carries the carrier identification indication domain indicating the carrier identification information of the cell receiving the random access preamble sequence.

57. A base station according to any of claims 54 to 56, wherein the carrier identification information is a carrier number maintained by the terminal, or a system level number defined for the cell receiving the random access preamble sequence, or a primary cell level number defined for the cell receiving the random access preamble sequence in a cell set corresponding to the same primary cell.

58. The base station of claim 57, wherein the transmitting unit is configured to:

and when the carrier identification information is a carrier number maintained by the terminal and the random access is non-competitive random access, sending the PDSCH in a main cell of the terminal corresponding to the received random access leader sequence.

59. The base station of any of claims 54-56, wherein the carrier identification indication field is a reuse of original bits in the PDCCH or a newly added bit.

60. The base station of claim 59, wherein when the PDCCH adopts DCI format1A, one or any combination of a HARQ process number indication field, a redundancy version indication field and a downlink allocation index indication field is reused as a carrier identification indication field in the PDCCH.

61. The base station according to any of claims 54-56, wherein said transmitting unit is configured to:

sending the PDSCH in a main cell of a terminal corresponding to the received random access preamble sequence; or,

transmitting the PDSCH on the cell receiving the random access preamble sequence.

62. The base station of any of claims 54 to 56, wherein the cell receiving the random access preamble sequence is a secondary cell of a terminal.

63. A random access method in a carrier aggregation system, the method comprising:

a terminal determines a random access preamble sequence sent on an auxiliary cell needing random access and a Physical Random Access Channel (PRACH) resource used for sending the random access preamble sequence; sending the random access preamble sequence to a base station through the PRACH resource on the secondary cell;

the terminal detects a physical downlink control channel PDCCH which is scrambled by using a random access radio network temporary identifier RA-RNTI and corresponds to the random access response of the auxiliary cell in a public search space of a main cell of the terminal;

the terminal receives a Physical Downlink Shared Channel (PDSCH) carrying a random access response corresponding to the auxiliary cell according to the detected PDCCH;

before a terminal determines a random access leader sequence sent by an auxiliary cell needing random access and a PRACH resource used for sending the random access leader sequence, the terminal receives a special random access leader sequence number and a PRACH resource number sent by a base station through a PDCCH (physical Downlink control) command or a Radio Resource Control (RRC) signaling, wherein the special random access leader sequence number is used for indicating the random access leader sequence used by the auxiliary cell, the PRACH resource number is used for indicating the PRACH resource used for sending the random access leader sequence by the auxiliary cell, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal;

the terminal receives the PDCCH command on a secondary cell or a primary cell of the terminal, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command correspondingly triggers non-competitive random access of a cell where the PDCCH command is transmitted, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command correspondingly triggers non-competitive random access of a cell indicated by a carrier indication domain in the PDCCH command.

64. The method of claim 63, wherein the receiving, by the terminal, the PDSCH carrying the random access response corresponding to the secondary cell according to the detected PDCCH comprises:

the terminal receives the PDSCH on a primary cell of the terminal.

65. A random access processing method in a carrier aggregation system is characterized by comprising the following steps:

a base station receives a random access preamble sequence sent by a terminal on a Physical Random Access Channel (PRACH) resource of an auxiliary cell needing random access;

a base station sends a Physical Downlink Control Channel (PDCCH) which is scrambled by using a random access radio network temporary identifier (RA-RNTI) and corresponds to a random access response of an auxiliary cell in a public search space of a main cell of the terminal so as to schedule the terminal to receive a Physical Downlink Shared Channel (PDSCH) carrying the random access response corresponding to the auxiliary cell;

the base station sends a PDSCH carrying a random access response corresponding to the secondary cell to the terminal;

before a base station receives a random access preamble sequence sent by a terminal on a PRACH resource of an auxiliary cell needing random access, the base station sends a special random access preamble sequence number and a PRACH resource number to the terminal through a PDCCH (physical Downlink control channel) command or a Radio Resource Control (RRC) signaling, wherein the special random access preamble sequence number is used for indicating a random access preamble sequence used by the auxiliary cell, the PRACH resource number is used for indicating the PRACH resource used by the auxiliary cell for sending the random access preamble sequence, and the PDCCH command or the RRC signaling is used for triggering non-competitive random access of the terminal;

the base station sends the PDCCH command on an auxiliary cell or a main cell of a terminal needing random access, when the PDCCH command does not adopt cross-carrier scheduling, the PDCCH command correspondingly triggers the non-contention random access of a cell for transmitting the PDCCH command, and when the PDCCH command adopts cross-carrier scheduling, the PDCCH command correspondingly triggers the non-contention random access of a cell indicated by a carrier indication domain in the PDCCH command.

66. The method of claim 65, wherein the base station sending the PDSCH carrying the random access response for the secondary cell to the terminal comprises:

and the base station sends the PDSCH on a primary cell of the terminal.