HK1139273B - Method for connecting mobile station to base station, mobile station, base station, multi-carrier mobile communication system, and random access channel mapping method - Google Patents

Description

Mobile station, base station, connection processing method between them, multi-carrier mobile communication system, and random access channel mapping method

The present invention is a divisional application of the present invention entitled "method for processing connection between mobile station and base station, mobile station, base station, multi-carrier mobile communication system, and mapping method for random access channel" filed by sharp corporation on 31/5/2007 with application number 200780020184.6.

Technical Field

The present invention relates to a connection processing method between a mobile station and a base station, a mobile station, a base station, a multi-carrier mobile communication system, and a random access channel mapping method.

Background

Currently, rat (radio Access technology) as a radio Access technology is standardized as a third-Generation cellular mobile communication system by W-CDMA (wireless-code division Multiple Access, non-patent document 1) specified by 3GPP (3rd Generation Partnership Project), and services are started in sequence.

Further, an evolution of a third-generation RAT (Evolved Universal Radio Access, hereinafter referred to as EUTRA) and an evolution of a third-generation RAT Access Network (Evolved Universal Radio Access Network, hereinafter referred to as EUTRAN) are being studied. In EUTRA, an ofdma (orthogonal Frequency division multiplexing access) system is proposed as a communication system (non-patent document 2).

The EUTRA, which is the next-generation communication standard, is based on the 3G (third generation) technology, and is expected to follow the 3G technology in many parts basically by increasing the capacity and speed of mobile communication by using OFDM or the like, but there are many problems to be solved that cannot be solved by the 3G technology.

The Random Access (RACH) sequence of the uplink (uplink) in EUTRA is an important step for the mobile station and the base station to perform connection processing (for example, the importance of which is pointed out in non-patent document 3), and the step or meaning is greatly different between the 3G technology and the EUTRA standard.

That is, in the 3G technology, a Random Access Channel (RACH) is a Channel that a mobile station can transmit to a base station at an arbitrary timing and is used for establishing an uplink) is not orthogonal to a data Channel, and therefore, interference occurs between the RACH and the data Channel. Therefore, before the base station becomes a receivable state, the mobile station side must perform control called power ramping (for example, refer to pages 45 to 47 of non-patent document 1, "2-2-3 random access") for gradually increasing the transmission power.

Here, uplink random access in the W-CDMA system is briefly described with reference to fig. 22. Fig. 22 is a flowchart showing an uplink random access procedure (RACH transmission procedure) in the W-CDMA scheme.

A mobile station that performs initial transmission, i.e., a mobile station after power-on or in intermittent reception, first has to transmit a Random Access Channel (RACH) to a base station in order to establish an uplink with the base station. Since the RACH is used before dedicated uplink resources are allocated, the transmission frequency and timing may be the same as those of other mobile stations. In this case, the transmission signal is degraded by interference between other stations, and the base station cannot correctly receive the RACH.

Therefore, as shown in fig. 22, the mobile station first randomly selects a data signal sequence called RACH Preamble (Preamble) and specifying the transmitting mobile station, and transmits the data signal sequence to the base station (step S20). When an ack (acknowledgement) indicating that transmission is permitted is replied to the RACH preamble from the base station (step S21), actual data transmission called a RACH message (message) is started. (step S22). When ACK is not returned from the base station (step S21) or nack (notacknowledgement) is returned, the transmission power of the RACH preamble is increased (step S25), and the RACH preamble is transmitted again. Whether the number of retransmissions defined in advance is full is confirmed (step S23), the same process is repeated, and even if the predetermined number of transmissions is full, if ACK cannot be received from the base station, it is determined that RACH transmission has failed (step S24), and the series of steps is ended.

On the other hand, in the mobile communication system (EUTRA system) using OFDM, since the RACH is orthogonal to the data channel, basically no interference occurs between the RACH and the data channel, and the power ramp wave as described above is not required.

However, instead, in OFDM communication, it is necessary to perform transmission timing correction (processing for establishing time synchronization based on transmission timing correction information from a base station) in a mobile station and communication resource allocation processing based on base station scheduling, taking into account the influence of multipath. These processes are specific processes when OFDM is used, and 3G technology cannot be cited. Therefore, a new connection processing technique of the mobile station and the base station is required to be established.

Non-patent document 1: the two worshipings in Chuan are: "W-CDMA Mobile communication mode", first edition issue, pill-good company, 6 months and 25 days, which is flat to 13 years

Non-patent document 2: 3GPP TR (Technical Report)25.814, v1.4.1(2006-5), Physical Layer accessories for evolved UTRA. http:// www.3gpp.org/ftp/Specs/html-info/25814.htm)

Non-patent document 3: "E-UTRA Random Access" 3GPP TSG RAN WG1Meeting #43, Seoul, Korea, 7-11 November, 2005

In the connection processing of the uplink for enabling data transmission between the mobile station and the base station in EUTRA, no standard can be determined as to which channel is used at all. In particular, the state of the mobile station in relation to the base station may change constantly, and if it is not clear which communication channel is used in which case, the connection processing cannot be performed.

Also, the transmission procedure from the mobile station to the base station or the transmission procedure from the base station to the mobile station is not uniformly determined, and for example, if 2 kinds of information (for example, an uplink synchronization request and a resource allocation request transmitted from the mobile station to the base station) are transmitted in different orders, it is possible to transmit the 2 kinds of information at the same time (in parallel). Therefore, in order to flexibly adapt to such a change in transmission, it is important to study the contents of connection processing.

In addition, in the uplink connection processing in the EUTRA standard, it is important to improve the resource utilization efficiency of OFDM communication and to consume resources usable for data communication and the like performed in parallel at the same time without waste. In particular, what kind of mapping of the synchronous RACH/non-synchronous RACH to the communication resource is an important issue.

Disclosure of Invention

The present invention has been made in view of such a consideration, and an object thereof is to realize a new connection process between a mobile station and a base station according to the EUTRA standard, which can flexibly adapt to an actual state of the mobile station or an actual transmission procedure and can effectively utilize communication resources.

(1) The connection processing method of the present invention is a connection processing method between a mobile station and a base station, and is characterized in that: the following two channels are set: a random access channel having a guard time, which is used in a state where time synchronization of an uplink is not established between a mobile station and a base station; and 2 kinds of channels of synchronous random access channel, it is used in the state of establishing the time synchronism of the up link between mobile station and base transceiver station, and, as the mobile station sends the information used for requesting the time synchronism of the up link or channel selected for information used for requesting the allocation of the communication resource to the base transceiver station, set up said random access channel with guard time, said synchronous random access channel and 3 channels of the control channel in the up link, in the mobile station, according to having time synchronism and having allocation of the communication resource of the up link while producing the transmission data, carry on the connection processing between base transceiver station and the mobile station from any one in said 3 channels.

In the connection processing method of the present invention, 2 types of channels are provided, including a random access channel (asynchronous RACH) having a guard time used in a state where time synchronization of an uplink is not established between a mobile station and a base station, and a synchronous random access channel (synchronous RACH) used in a state where time synchronization of an uplink is established between a mobile station and a base station. Since the RACH is originally a channel transmitted by the mobile station to the base station at an arbitrary timing, it is widely considered that time synchronization with the base station is not established at this time. The case of voice call is assumed to be only such a case. However, in the case of packet communication, the RACH may be transmitted from the mobile station to the base station in a state where time synchronization is achieved with the base station. For example, in a state where an uplink is established with the base station, that is, in a state where the transmission timing offset is corrected, new uplink data transmission is necessary after data transmission and before the resource is invalidated, that is, during a period in which the correction of the transmission timing offset is valid, and the mobile station transmits the RACH to the base station. In this case, for example, if the RACH is transmitted at a timing such that the frame or subframe of the resource to be synchronized matches the beginning of the OFDM symbol, the RACH coincides with the reception timing of the base station. Therefore, the RACH at this time is referred to as a synchronous RACH. When the asynchronous RACH is mapped to a subcarrier and transmitted to the base station, it is necessary to set a redundant period of an inherent code multiplied by the RACH to be longer, for example, in order to reduce the influence of multipath. Therefore, by effectively using the synchronous RACH, communication resources can be effectively utilized. In the connection processing method according to the present invention, as a channel that may be used in the uplink, a control channel that can be commonly used by a plurality of mobile stations is assumed (for example, an Uplink Shared Control Channel (USCCH) corresponds to this) in addition to the synchronous RACH and the asynchronous RACH. This Channel is a Channel in which the transmission timing for resource transmission allocated from the base station is corrected (uplink synchronization), and can be used for the mobile station to transmit a Quality information Indicator (CQI), HARQ (hybrid auto Repeat Request), ACK/NACK, and the like to the base station. For example, when transmission data is newly generated after resources are allocated from the base station, a case may be considered in which a new resource allocation request is transmitted using the currently allocated resources and the Uplink Shared Control Channel (USCCH). Therefore, the Uplink Shared Control Channel (USCCH) is also a channel that is likely to be used for connection processing of the uplink. As a result, there are channels that can potentially be used for uplink connection processing, including an asynchronous RACH and a synchronous RACH as channels used before resource allocation, and an Uplink Shared Control Channel (USCCH) as a channel used after resource allocation, for a total of 3 channels. In addition, regardless of the specific name of "control channel commonly available", in the following description, for convenience of description, the Uplink Shared Control Channel (USCCH) is described (without limitation). In the present invention, the synchronous RACH, the asynchronous RACH, and the USCCH are adaptively used in a separated manner, particularly in consideration of the resource utilization efficiency, the uplink resource allocation state of the mobile station, and the uplink time synchronization state. That is, the mobile station state when the transmission data is generated in the mobile station is classified by cases according to the presence or absence of time synchronization and the presence or absence of resource allocation, and is further classified by cases after adding, if necessary, the type of information for requesting resource allocation to be transmitted from the mobile station to the base station (that is, the request signal as scheduling information of the resource, the type of signal used for scheduling information request may be specifically classified by cases considering the type of signal used for scheduling information request since various signals such as a signal for notifying the presence or absence of transmission data, a signal for notifying the amount of transmission data, a signal for notifying the type or rate of transmission data, and a signal for notifying the amount of transmission buffer can be used). This makes it possible to establish an optimum uplink connection processing method that is suitable for the EUTRA standard and flexibly compatible with consideration given to the resource utilization efficiency, the specific state of the mobile station, and the like.

(2) Further, a connection processing method according to the present invention is characterized in that: the method includes the steps of dividing the mobile station into a 1 st state in which uplink is asynchronous and no communication resource is allocated, a 2 nd state in which uplink is synchronous and no communication resource is allocated, a 3rd state in which uplink is asynchronous and communication resource is allocated, and a 4 th state in which uplink is synchronous and communication resource is allocated according to the synchronization state of an uplink and the allocation state of communication resource when data transmission occurs in the mobile station, and performing connection processing between the mobile station and the base station on any one of the 3 channels according to the divided states.

When data to be transmitted to a mobile station is generated, a connection processing procedure to be adopted by the mobile station to a base station is roughly divided into 4 states (1 st to 4 th states) depending on whether or not time synchronization/non-synchronization is established or whether or not resource information is transmitted from the base station, with attention paid to the fact that the connection processing procedure differs depending on whether or not uplink time synchronization is established or not, and resource allocation. Specifically, for example, since there are 3 states of a Detached (Detached) state, an Idle (Idle) state, and an Active (Active) state as the mobile station state in EUTRA, it is considered which of the states is classified into which one is distinguished by the case, and it is determined that the best channel is used in each state. The Detached (Detached) state is a state in which the base station does not recognize the presence of the mobile station after the power of the mobile station is turned on or after the mobile station is transferred to a different RAT; the Idle (Idle) state is a state in which the base station recognizes the presence of the mobile station but does not perform data communication, the base station allocates a minimum downlink resource for credit to the mobile station, and the mobile station performs intermittent reception using the allocated resource; the so-called Active state is a state in which the base station recognizes the presence of the mobile station, and the base station and the mobile station perform data communication.

(3) Further, a connection processing method according to the present invention is characterized in that: the mobile station transmits information requesting time synchronization of the uplink to the base station using a random access channel having a guard time, transmits information requesting allocation of the communication resource using a control channel in the uplink in a state where the communication resource is allocated, and transmits the information using a synchronous random access channel in a state where the communication resource is not allocated.

This makes it possible to clarify the basic steps (sequence) of the uplink connection processing suitable for EUTRA.

(4) The connection processing method of the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink and allocation information of communication resources using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink and the allocation information of the communication resources according to the request of the mobile station; in the 2 nd state, the mobile station notifies the base station of the presence or absence of untransmitted data by using a random access channel having a guard time, requests the base station of allocation information of a communication resource for the transmission of the untransmitted data, and the base station notifies the mobile station of the allocation information of the communication resource in accordance with the request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies the base station of the presence or absence of untransmitted data by using a control channel in an uplink, requests the base station of allocation information of communication resources for the transmission of the untransmitted data, and the base station notifies the mobile station of the allocation information of the communication resources in accordance with the request of the mobile station.

According to this configuration, the mobile station can include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1 RACH transmission. Also, since a control channel (USCCH) commonly available to a plurality of mobile stations can be used to request resource information by notifying the base station of the presence or absence of transmission data, the synchronous RACH is not necessarily used. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(5) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink and allocation information of communication resources using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink and the allocation information of the communication resources according to the request of the mobile station; in the 2 nd state, the mobile station notifies a base station of a transmission data amount by using a random access channel having a guard time, requests allocation information of a communication resource for data transmission to the base station, and the base station notifies the mobile station of the allocation information of the communication resource corresponding to the transmission data amount in accordance with the request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies the base station of the transmission data amount by using a control channel in an uplink and requests the base station of allocation information of a communication resource for data transmission, and the base station notifies the mobile station of the allocation information of the communication resource corresponding to the transmission data amount of the mobile station in accordance with the request of the mobile station.

According to this configuration, the mobile station can include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1 RACH transmission. Also, since a control channel (USCCH) commonly available to a plurality of mobile stations can be used to request resource information by notifying the base station of the presence or absence of transmission data, the synchronous RACH is not necessarily used. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(6) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 2 nd state, the mobile station notifies the base station of the transmission data amount by using a synchronous random access channel, requests the base station of allocation information of communication resources for data transmission, and the base station notifies the mobile station of the allocation information of communication resources corresponding to the transmission data amount in accordance with the request of the mobile station.

This configuration is effective in the case where the mobile station cannot include both an uplink synchronization request (request for transmission timing information) and a resource allocation request in 1 RACH transmission, and a control channel (USCCH) commonly available to a plurality of mobile stations cannot be used for the resource allocation request, and the synchronous RACH can be used for requesting resource information by notifying the base station of the transmission data amount. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state and the 2 nd state.

(7) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 2 nd state, the mobile station notifies the base station of the transmission data amount by using a synchronous random access channel, requests the base station of allocation information of communication resources for data transmission, and the base station notifies the mobile station of the allocation information of communication resources corresponding to the transmission data amount according to the request of the mobile station; in the 3rd state, a mobile station requests a base station for time synchronization information of an uplink using a random access channel having a guard time, the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station, in the 4 th state, the mobile station notifies the base station of a transmission data amount by using a control channel in the uplink, requests the base station for allocation information of a communication resource for data transmission, and the base station notifies the mobile station of the allocation information of the communication resource corresponding to the transmission data amount according to the request of the mobile station.

This configuration is effective in the case where the mobile station cannot include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1-time RACH transmission, and a control channel (USCCH) commonly available to a plurality of mobile stations can be used to request resource information by notifying the base station of the amount of transmission data, and the synchronous RACH can also be used to request resource information by notifying the base station of the amount of transmission data. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(8) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink using a random access channel having a guard time when transmitting data composed of a constant transmission interval and a fixed transmission rate, the base station notifying the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 2 nd state, the mobile station requests the base station for allocation information of communication resources that guarantee a prescribed transmission interval and transmission rate by notifying the base station of the data type and transmission rate using a synchronous random access channel, and the base station notifies the mobile station of the allocation information of the communication resources according to the request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies the base station of the data type and the transmission rate by using a control channel in an uplink, requests the base station of allocation information of communication resources that guarantee a predetermined transmission interval and transmission rate, and the base station notifies the mobile station of the allocation information of the communication resources in accordance with the request of the mobile station.

This structure is effective under the condition that the mobile station cannot include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1-time RACH transmission, and a control channel (USCCH) commonly available to a plurality of mobile stations can be used to request resource information by notifying the base station of the data type and transmission rate of data to be transmitted. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(9) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, when transmitting data composed of a constant transmission interval and a variable transmission rate, a mobile station requests a base station for time synchronization information of an uplink using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink in accordance with the request of the mobile station; in the 2 nd state, the mobile station requests the base station for allocation information of communication resources that guarantee a prescribed transmission interval and a current transmission rate by notifying the base station of a data type and the current transmission rate using a synchronous random access channel, the base station notifying the mobile station of the allocation information of the communication resources according to the request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies the base station of the data type and the current transmission rate by using a control channel in an uplink, requests the base station of allocation information of communication resources that guarantee a prescribed transmission interval and the current transmission rate, and the base station notifies the mobile station of the allocation information of the communication resources in accordance with the request of the mobile station.

This configuration is effective under the condition that the mobile station cannot include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1-time TRACH transmission, a control channel (USCCH) commonly available to a plurality of mobile stations can be used to request resource information by notifying the base station of the data type and transmission rate of data to be transmitted, and the synchronous RACH can be used to request resource information by notifying the base station of the data type and transmission rate of data to be transmitted, and to transmit transmission data at a variable transmission rate in a predetermined transmission period. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(10) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 2 nd state, the mobile station requests a base station for allocation information of a communication resource corresponding to a data buffer amount by notifying a data buffer amount accumulated in the mobile station using a synchronous random access channel, and the base station notifies the mobile station of the allocation information of the communication resource in response to a request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies a data buffer amount stored in the mobile station by using a control channel in an uplink, requests a base station of allocation information of a communication resource corresponding to the data buffer amount, and the base station notifies the mobile station of the allocation information of the communication resource in response to the request of the mobile station.

This configuration is effective under the condition that both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) cannot be included in 1-time RACH transmission, a control channel (USCCH) commonly available to a plurality of mobile stations can be used to request resource information by notifying the base station of the amount of data buffer not transmitted in the mobile station, and a synchronous RACH can be similarly used to request resource information by notifying the base station of the amount of data buffer not transmitted in the mobile station. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(11) Further, a connection processing method according to the present invention is characterized in that: the random access channel having the guard time and the synchronous random access channel are time-division allocated in all frequency bands at different predetermined times.

The case where the asynchronous RACH and the synchronous RACH are mapped (allocated) to resources defined by the time axis and the frequency axis is shown. That is, the synchronous RACH and the non-synchronous RACH are mapped to different subframes for the time axis and mapped to the entire frequency band for the frequency axis. In this case, since it is possible to fixedly determine which subframe period of the 1 frame period the synchronous RACH/asynchronous RACH is allocated to, an effect is obtained that the base station easily detects the received synchronous RACH/asynchronous RACH using its fixed configuration.

(12) Further, a connection processing method according to the present invention is characterized in that: the random access channel with guard time and the synchronous random access channel are respectively allocated in different frequency bands within the same specified time in a frequency division mode.

Has the following effects: by allocating the synchronous RACH and the asynchronous RACH to different frequency bands in the common subframe period, that is, by multiplexing in the TTI in the divided band, both the synchronous RACH and the asynchronous RACH can be transmitted using the same resource as when either the synchronous RACH or the asynchronous RACH is allocated in all frequency bands in one subframe period, and the resource can be effectively used. Further, by appropriately changing the frequency band occupied by each RACH in accordance with the frequency of use of each RACH, it is possible to arrange a RACH having a higher frequency of use without any problem (without collision in the frequency band). Therefore, resources can be more efficiently utilized.

(13) Further, a connection processing method according to the present invention is characterized in that: the random access channel with the guard time is allocated in all frequency bands within a subframe period, and the synchronous random access channel is allocated in a time division manner in a plurality of predetermined periods and in a manner that the frequency bands in the predetermined periods do not overlap, with the frequency bands of one resource unit being periodically shifted in frequency band.

In this way, since the synchronous RACH is arranged uniformly in the time axis direction, when a data transmission request is generated by the synchronous RACH, the synchronous RACH can be mapped to a resource (subcarrier) immediately without waiting for a long time. Therefore, it is possible to suppress the processing delay before the synchronous RACH is transmitted.

(14) Further, a connection processing method according to the present invention is characterized in that: the random access channel having the guard time and the synchronous random access channel are arranged in the same frequency band at the same predetermined time.

In this way, a mapping scheme is adopted in which the synchronous RACH/asynchronous RACH shares a common subframe period and a common frequency band. Since the synchronous RACH and the asynchronous RACH are time-division configured as necessary within one subframe period, it is difficult to wastefully occupy resources.

(15) Further, a connection processing method according to the present invention is characterized in that: the base station transmits uplink time synchronization information or communication resource allocation information to the mobile station using a downlink control channel.

In this way, the base station transmits a Channel for transmitting timing information (synchronization information) or scheduling information (resource allocation information) to the mobile station, and uses a Control Channel (for example, Downlink Shared Control Channel (DSCCH)) commonly usable by a plurality of mobile stations. Thus, transmission timing information or scheduling information can be transmitted without resetting the control channel.

(16) Further, a mobile station according to the present invention includes: a control signal analysis unit configured to analyze uplink time synchronization information or communication resource allocation information of a communication resource included in a control signal from a base station; a scheduling unit configured to perform control of allocating transmission data to a communication resource of an uplink, based on an analysis result of the allocation information of the communication resource generated by the control signal analysis unit; and a transmission timing adjustment unit which performs control for adjusting the transmission timing of the uplink to be synchronized with the reception timing of the base station based on the analysis result of the time synchronization information of the uplink generated by the control signal analysis unit, and performs connection processing with the base station based on the presence or absence of time synchronization of the uplink and the presence or absence of communication resource allocation when transmission data is generated, from any one of the synchronous random access channel, the random access channel having the guard time, and the control channel in the uplink.

With this structure, the following functions can be exerted: that is, a control signal analysis function that analyzes a control signal transmitted from a base station and extracts transmission timing information or scheduling information; a scheduling control function for adaptively and separately using synchronous RACH/asynchronous RACH/control channels according to the state of a mobile station and the like, and mapping resources according to scheduling information from a base station; and a transmission timing control function for correcting the transmission timing based on the transmission timing information from the base station. Thereby, a mobile station apparatus suitable for the EUTRA standard can be provided.

(17) Further, a mobile station of the present invention is characterized in that: and selecting one of the synchronous random access channel, the random access channel with the guard time, and the control channel in the uplink, by using the scheduling unit or according to an instruction from a base station.

With this configuration, the mobile station can perform control for adaptively and separately using the synchronous RACH/asynchronous RACH/control channel in accordance with the state of the mobile station, for example, autonomously or in accordance with an instruction from the base station (for example, by inserting instruction information into scheduling information).

(18) Further, a base station according to the present invention includes: a channel detection unit that detects at least one of a synchronous random access channel for notifying request information from a mobile station, a random access channel having a guard time, and a control channel in an uplink; a transmission timing information generating unit that generates time synchronization information of an uplink; a scheduling information generating unit for generating allocation information of communication resources; and a transmission unit configured to transmit the uplink time synchronization information or the communication resource allocation information of the communication resource to a mobile station as a control signal of a downlink control channel.

According to this structure, the following functions can be performed: that is, the channel detection function receives a signal transmitted from a mobile station, and detects at least one of a synchronous random access channel (synchronous RACH), an asynchronous random access channel (asynchronous RACH), and a control channel (USCCH) in an uplink which can be commonly used by the mobile stations, which are included in the received signal; a function of generating transmission timing information (information for acquiring time synchronization) based on the influence of multipath in a received signal; a function of allocating resources to each mobile station (a resource information generation function); and a function of transmitting the transmission timing information and the resource information included in the control channel. Thereby, a base station suitable for the EUTRA standard can be provided.

(19) Further, a communication system according to the present invention is characterized in that: the mobile station apparatus is configured by any one of the mobile stations and the base station.

Thus, a mobile communication system compliant with the EUTRA standard can be constructed in which an uplink can be established by a new connection process between the mobile station and the base station.

(20) A random access channel allocation method according to the present invention is a communication resource allocation method for a random access channel in an uplink of a mobile communication system using an orthogonal frequency division multiplexing system, the method including: a random access channel having a guard time and a synchronous random access channel are arranged in a common predetermined time.

The synchronous RACH/non-synchronous RACH is a hybrid allocation method in a common prescribed time, suitable for the EUTRA standard. The use efficiency of resources can be improved by effectively using the synchronous RACH (unprotected time).

(21) Further, a random access channel allocation method according to the present invention is characterized in that: the random access channel having the guard time and the synchronous random access channel are time-division allocated in all frequency domains at different predetermined times.

The synchronous RACH and the non-synchronous RACH are mapped to different subframes for a time axis and to the entire frequency band for a frequency axis. In this case, since it is possible to fixedly determine which subframe period of the 1 frame period the synchronous RACH or the non-synchronous RACH is allocated, the base station can easily detect the received synchronous RACH/non-synchronous RACH by using the fixed configuration.

(22) Further, a random access channel allocation method according to the present invention is characterized in that: the random access channel with guard time and the synchronous random access channel are respectively allocated in different frequency bands within the same specified time in a frequency division mode.

With this structure, the following effects are obtained: by allocating the synchronous RACH/non-RACH to different frequency bands in a common subframe period (that is, by multiplexing the divided frequency bands), both the synchronous RACH and the non-synchronous RACH can be transmitted using the same resource as that used when only one of the synchronous RACH and the non-synchronous RACH is allocated to all frequency bands in one subframe period, and the resource can be effectively used. Further, by appropriately changing the frequency band occupied by each RACH in accordance with the frequency of use of each RACH, it is possible to arrange a RACH having a higher frequency of use without any problem (without collision in the frequency band). Therefore, resources can be more efficiently utilized.

(23) Further, a random access channel allocation method according to the present invention is characterized in that: the random access channel with the guard time is allocated in all frequency bands within a subframe period, and the synchronous random access channel is allocated in a time division manner in a plurality of predetermined periods and in a manner that the frequency bands in the predetermined periods do not overlap, with the frequency bands of one resource unit being periodically shifted in frequency band.

With this configuration, since the synchronous RACH is arranged uniformly in the time axis direction, when a data transmission request is generated by the synchronous RACH, the synchronous RACH can be mapped to a resource (subcarrier) immediately without waiting for a long time. Therefore, it is possible to suppress the processing delay before the synchronous RACH is transmitted.

(24) Further, a random access channel allocation method according to the present invention is characterized in that: and configuring the random access channel with the guard time and the synchronous random access channel in the same frequency band at the same predetermined time.

As described above, in the present invention, a mapping scheme is adopted in which the synchronous RACH/asynchronous RACH shares a common subframe period and a common frequency band. That is, within one subframe period, the synchronous RACH and the non-synchronous RACH are time-division configured as necessary. This has the effect that it is difficult to occupy resources wastefully.

(25) Further, an uplink connection method according to the present invention is an uplink connection processing method from a mobile station to a base station, comprising: comprises the following steps: a 1 st step in which when transmission data to a base station occurs in a mobile station, at least one of the mobile station and the base station determines whether the state of the mobile station is a 1 st state in which uplink is asynchronous and no communication resource is allocated, a 2 nd state in which uplink is synchronous and no communication resource is allocated, a 3rd state in which uplink is asynchronous and communication resource is allocated, or a 4 th state in which uplink is synchronous and communication resource is allocated; and a 2 nd step of performing an uplink connection process from the mobile station to the base station using any one of 3 channels, which are a random access channel having a guard time, synchronous random access information, and a control channel in an uplink, according to the determination result of the state of the mobile station in the 1 st step.

This makes it possible to realize an uplink connection process according to the EUTRA standard.

(26) A connection processing method according to the present invention is a connection processing method between a mobile station and a base station, in which a random access channel having a guard time and a control channel in an uplink used in a state where time synchronization of the uplink is established are provided as a channel selected as information for requesting time synchronization of the uplink or information for requesting allocation of communication resources to be transmitted from the mobile station to the base station, and either one of the channel is selected according to whether time synchronization of the uplink and whether communication resource allocation is performed when data transmission occurs in the mobile station.

In the connection processing method of the present invention, a random access channel (non-synchronous RACH) having a guard time is set, which is used in a state where uplink time synchronization is not established between a mobile station and a base station. Since the RACH is originally a channel transmitted by the mobile station to the base station at an arbitrary timing, it is widely considered that time synchronization with the base station is not established at that time. The case of voice communication can only be assumed to be this case. The asynchronous RACH is mapped to a subcarrier and transmitted to a base station, in order to reduce the influence of multipath. It is necessary to set a guard time, for example, to extend a redundancy period of the unique code by which RACH is multiplied. In the connection processing method according to the present invention, as a channel that may be used in the uplink, a control channel that can be commonly used by a plurality of mobile stations is assumed in addition to the asynchronous RACH (for example, the Uplink Shared Control Channel (USCCH) corresponds to this). This Channel is a Channel in which the transmission timing for resource transmission allocated from the base station is corrected (uplink synchronization), and can be used for the mobile station to transmit a Quality information Indicator (CQI), HARQ (hybrid auto Repeat Request), ACK/NACK, and the like to the base station. For example, when transmission data is newly generated after resources are allocated from the base station, a case may be considered in which a new resource allocation request is transmitted using the currently allocated resources and the Uplink Shared Control Channel (USCCH). Therefore, the Uplink Shared Control Channel (USCCH) is also a channel that is likely to be used for connection processing of the uplink. In the present invention, the synchronous RACH, the asynchronous RACH, and the USCCH are adaptively used separately, particularly in consideration of the resource utilization efficiency, the uplink resource allocation state of the mobile station, and the uplink time synchronization state. That is, the mobile station distinguishes the state of the mobile station at the time of generating transmission data on a case-by-case basis according to the presence or absence of time synchronization and the presence or absence of resource allocation, and further distinguishes the state of the mobile station at the time of generating transmission data on a case-by-case basis (that is, the request signal as scheduling information of resources may be a signal notifying the presence or absence of transmission data, a signal notifying the amount of transmission data, a signal notifying the type or rate of transmission data, a signal notifying the amount of transmission buffer, or other various signals, and therefore, the type of the signal used for the scheduling information request may be specifically distinguished on a case-by-case basis). This makes it possible to establish an optimal uplink connection processing method that is suitable for the EUTRA standard and flexibly adaptable in consideration of the resource utilization efficiency, the specific state of the mobile station, and the like.

(27) Further, a connection processing method according to the present invention is characterized in that: in a mobile station, a 1 st state in which uplink is asynchronous and no communication resource is allocated, a 2 nd state in which uplink is synchronous and no communication resource is allocated, a 3rd state in which uplink is asynchronous and there is communication resource allocation, and a 4 th state in which uplink is synchronous and there is communication resource allocation are classified as appropriate on the basis of a synchronization state of an uplink and an allocation state of communication resources at the time of occurrence of transmission data, and a connection process between the mobile station and a base station is performed on any one of the channels on the basis of the classified states as appropriate.

When data to be transmitted to a mobile station is generated, a connection processing procedure to be adopted by the mobile station to a base station is roughly divided into 4 states (1 st to 4 th states) depending on whether or not time synchronization/non-synchronization is established or whether or not resource information is transmitted from the base station, with attention paid to the fact that the connection processing procedure differs depending on whether or not uplink time synchronization is established or not, and resource allocation. Specifically, for example, as the mobile station state in EUTRA, there are 3 states of a Detached (Detached) state, an Idle (Idle) state, and an Active (Active) state, and thus, it is considered which of the states is classified into which one is distinguished by the case, and it is determined that the best channel is used in each state. The Detached (Detached) state is a state in which the base station does not recognize the presence of the mobile station after the power of the mobile station is turned on or after the mobile station is transferred to a different RAT; the Idle (Idle) state is a state in which the base station recognizes the presence of the mobile station but does not perform data communication, the base station allocates a minimum downlink resource for credit to the mobile station, and the mobile station performs intermittent reception using the allocated resource; the so-called Active state is a state in which the base station recognizes the presence of the mobile station, and the base station and the mobile station perform data communication.

(28) Further, a connection processing method according to the present invention is characterized in that: the mobile station transmits information requesting time synchronization of the uplink to the base station using a random access channel having a guard time, transmits information requesting allocation of the communication resource using a control channel in the uplink in a state where the communication resource is allocated, and transmits the information using a random access channel having a guard time in a state where the communication resource is not allocated.

This makes it possible to clarify the basic steps (sequence) of the uplink connection processing suitable for EUTRA.

(29) The connection processing method of the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink and allocation information of communication resources using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink and the allocation information of the communication resources according to the request of the mobile station; in the 2 nd state, the mobile station notifies the base station of the presence or absence of untransmitted data by using a random access channel having a guard time, requests the base station of allocation information of a communication resource for the transmission of the untransmitted data, and the base station notifies the mobile station of the allocation information of the communication resource in accordance with the request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies the base station of the presence or absence of untransmitted data by using a control channel in an uplink, requests the base station of allocation information of a communication resource for the transmission of the untransmitted data, and the base station notifies the mobile station of the allocation information of the communication resource in accordance with the request of the mobile station.

According to this configuration, the mobile station can include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1 RACH transmission. Also, a control channel (USCCH) commonly available to a plurality of mobile stations may be used to request resource information by informing a base station of the presence or absence of transmission data. In this case, the present invention makes clear the optimum channel to be used in the uplink connection processing for each of the 1 st state to the 4 th state.

(30) Further, a connection processing method according to the present invention is characterized in that: in the 1 st state, a mobile station requests a base station for time synchronization information of an uplink and allocation information of communication resources using a random access channel having a guard time, and the base station notifies the mobile station of the time synchronization information of the uplink and the allocation information of the communication resources according to the request of the mobile station; in the 2 nd state, the mobile station notifies a base station of a transmission data amount by using a random access channel having a guard time, requests allocation information of a communication resource for data transmission to the base station, and the base station notifies the mobile station of the allocation information of the communication resource according to the transmission data amount in accordance with a request of the mobile station; in the 3rd state, a mobile station requests time synchronization information of an uplink to a base station by using a random access channel with guard time, and the base station notifies the mobile station of the time synchronization information of the uplink according to the request of the mobile station; in the 4 th state, the mobile station notifies the base station of the transmission data amount by using a control channel in an uplink and requests the base station of allocation information of a communication resource for data transmission, and the base station notifies the mobile station of the allocation information of the communication resource corresponding to the transmission data amount in accordance with the request of the mobile station.

According to this configuration, the mobile station can include both an uplink synchronization request (request for transmission timing information) and a resource allocation request (request for scheduling information) in 1 RACH transmission. Also, a control channel (USCCH) commonly available to a plurality of mobile stations may be used to request resource information by informing a base station of the presence or absence of transmission data. In this case, the present invention makes clear the optimum channel to be used for the uplink connection processing for each of the 1 st state to the 4 th state.

(31) Further, a connection processing method according to the present invention is characterized in that: a mobile station adapted to the connection processing method according to any one of claims 26 to 30, comprising: a control signal analysis unit which extracts and analyzes time synchronization information of an uplink or allocation information of communication resources included in a control signal from a base station; a scheduling unit configured to perform control of allocating transmission data to a communication resource of an uplink, based on an analysis result of the allocation information of the communication resource generated by the control signal analysis unit; and a transmission timing adjustment unit that performs control for adjusting the transmission timing of the uplink to be synchronized with the reception timing of the base station, based on the analysis result of the time synchronization information of the uplink generated by the control signal analysis unit, and selects one of the random access channel having the guard time and the control channel in the uplink, based on whether or not there is time synchronization of the uplink and whether or not there is communication resource allocation when transmission data is generated, and performs a connection process with the base station.

With this structure, the following functions can be exerted: that is, a control signal analysis function that analyzes a control signal transmitted from a base station and extracts transmission timing information or scheduling information; a scheduling control function for adaptively and separately using an asynchronous RACH/control channel according to the state of a mobile station and the like, and mapping resources according to scheduling information from a base station; and a transmission timing control function for correcting the transmission timing based on the transmission timing information from the base station. Thereby, a mobile station apparatus suitable for the EUTRA standard can be provided.

(32) Further, a mobile station of the present invention is characterized in that: selecting one of the random access channel having the guard time or the control channel in the uplink line by the scheduling section or according to an instruction from a base station.

With this configuration, the mobile station can autonomously perform control for adaptively using the asynchronous RACH/control channel separately according to the state of the mobile station or the like, or according to an instruction from the base station (for example, by inserting instruction information into the scheduling information).

(33) Further, a base station according to the present invention includes: a channel detection unit for detecting at least one of a random access channel having a guard time and a control channel in an uplink for notifying request information from a mobile station; a transmission timing information generating unit that generates time synchronization information of an uplink; a scheduling information generating unit for generating allocation information of communication resources; and a transmission unit configured to transmit the uplink time synchronization information or the communication resource allocation information of the communication resource to a mobile station as a control signal of a downlink control channel.

With this structure, the following functions can be exerted: that is, the channel detection function receives a signal transmitted from a mobile station, and detects at least one of an asynchronous random access channel (asynchronous RACH) and a control channel (USCCH) in an uplink which can be commonly used by each mobile station, which are included in the received signal; a function of generating transmission timing information (information for acquiring time synchronization) based on the influence of multipath in a received signal; a function of allocating resources to each mobile station (a resource information generation function); and a function of transmitting the transmission timing information and the resource information included in the control channel. Thereby, a base station suitable for the EUTRA standard can be provided.

(34) Further, a communication system according to the present invention is characterized in that: the mobile station apparatus is configured by any one of the mobile stations and the base station.

Thus, a mobile communication system compliant with the EUTRA standard can be constructed in which an uplink can be established by a new connection process between the mobile station and the base station.

Effects of the invention

In the present invention, a new method is adopted in which 2 types of non-synchronized RACH (protected time)/synchronized RACH (unprotected time) are prepared as Random Access Channels (RACH) used before resource allocation, and in consideration of the fact that there is a case where a mobile station transmits a new resource allocation request after resource allocation, a control channel (a channel for communication using allocated resources, for example, USCCH) commonly usable by a plurality of mobile stations is used, and the 3 channels are adaptively and separately used in accordance with the state of the mobile station classified according to the presence or absence of time synchronization and the presence or absence of resource allocation (in consideration of the type of data for requesting resource information transmitted from the mobile station to the base station), in addition to the usable channels, whereby the actual state of the mobile station or the actual transmission procedure can be flexibly adapted, and a random access channel according to the EUTRA standard, which can effectively use communication resources, can be realized, A new connection process between the mobile station and the base station.

That is, in the uplink connection process between the mobile station and the base station in EUTRA, it is possible to specify which channel is used in which case, considering the effective use of resources, communication quality, and the like comprehensively. Therefore, an optimal connection process is realized in the multi-carrier communication system of the EUTRA standard.

Further, even when there are 2 types of information to be simultaneously transmitted (specifically, even when there is a case where the mobile station simultaneously transmits an uplink synchronization request and a resource allocation request to the base station and, correspondingly, returns transmission timing information and resource information from the base station at the same time), an optimal used channel is determined in consideration of the above case, and therefore, the method can be flexibly adapted.

Furthermore, by effectively using the synchronous RACH without guard time, the resource utilization efficiency of OFDM communication can be improved, and wasteful consumption of resources that can be used for simultaneous parallel data communication and the like can be suppressed.

When mapping (allocating) the synchronous RACH/asynchronous RACH to the communication resources of the OFCM defined by the time axis and the frequency axis, by using various mapping schemes (that is, a subframe division scheme, a band division scheme within a common subframe, a scheme in which synchronous RACHs are distributed and arranged in a manner that bands are different from each other within 1 frame and equally distributed on the time axis, and a scheme in which both RACHs are allocated to a common subframe), it is possible to use the mapping with rich changes appropriately, and thus, resources can be used more efficiently.

According to the present invention, the contents of the uplink connection processing including the RACH sequence in EUTRA can be specified specifically and objectively, and particularly, an optimum uplink channel use method for EUTRA can be provided.

Drawings

Fig. 1 is a resource allocation diagram for explaining a line in the EUTRA standard (using OFDM).

Fig. 2 is an example of resource mapping for a downlink in the EUTRA standard (using OFDM).

Fig. 3 is an example of resource mapping for an uplink in the EUTRA standard (using OFDM).

Fig. 4 is a sequence diagram showing an example of the RACH sequence in the EUTRA standard (an example in which transmission timing information and resource information are transmitted in different sequences).

Fig. 5 is a sequence diagram of an example of the RACH sequence in the EUTRA standard (an example of simultaneous transmission of transmission timing information and resource information).

Fig. 6 is an example of mapping of unsynchronized RACHs to resource elements in a radio frame.

Fig. 7 is an example diagram showing a mapping of synchronous RACH to resource units in a radio frame.

Fig. 8 is a diagram for classifying the contents of each of 7 embodiments of the present invention according to the request method of usable channels and resources.

Fig. 9 is a block diagram showing an example of the configuration of a mobile station.

Fig. 10 is a block diagram showing an example of the configuration of a base station.

Fig. 11 is an example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 12 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 13 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 14 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 15 is a diagram showing an example of channel mapping between the synchronous RACH and the asynchronous RACH (an example in which the asynchronous RACH and the synchronous RACH are arranged in different TTIs).

Fig. 16 is a diagram showing another example of channel mapping between the synchronous RACH and the asynchronous RACH (an example in which the asynchronous RACH and the synchronous RACH are arranged in different frequency domains in a common TTI).

Fig. 17 is a diagram showing another example of channel mapping of the synchronous RACH/asynchronous RACH (an example in which the asynchronous RACH is mapped to the entire frequency band of one TTI, and the synchronous RACH is distributed on the frequency axis in units of frequency bands of resource elements and is equally (periodically) time-division arranged on the time axis).

Fig. 18 is a diagram showing another example of channel mapping between the synchronous RACH and the asynchronous RACH (an example of TTI and frequency domain configuration shared by the asynchronous RACH and the synchronous RACH).

Fig. 19 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 20 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 21 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

Fig. 22 is a flowchart showing an uplink random access procedure (RACH transmission procedure) in the W-CDMA scheme.

Description of the symbols

30-receiving part

32-channel demodulation section

34-control signal analysis section

36-decoding part

38-channel measurement section

40-transmitting part

42-channel demodulation section

44-coding part

46-scheduling part

47-Transmission timing adjustment Unit

48-control part (upper layer)

50-mobile station

70-base station

72-receiving part

74-channel detection section

76-scheduling part

78-Transmission timing information generating part

80-DSCCH generating unit

82-transmitting part

AN1, AN2, AN3, AN 4-antenna

Detailed Description

Before the detailed description of the embodiments, the principles of the technology adopted in EUTRA, the basic technical contents adopted in the present invention, and the like are briefly described.

Fig. 1 is a diagram for explaining resource allocation in the EUTRA standard (using OFDM). As illustrated, the radio frames of EUTRA are defined by a time axis and a frequency axis. The usable frequency band coincides with the frequency band occupied by all subframes. The radio frame is divided into a plurality of Resource blocks RB (hereinafter, also referred to as RB) in the downlink. The Resource Block (RB) is a unit for the base station to allocate communication resources to mobile stations existing in the same cell. The Resource Block (RB) is defined by a predetermined frequency bandwidth (Bch) composed of a plurality of subcarriers and a subframe Interval (TTI: Transmission Timing Interval, hereinafter referred to as TTI. In the uplink, a Resource Block (RB) is referred to as a Resource Unit (RU). Therefore, in the present specification, terms such as resource block IRB) are used for the downlink, and terms such as Resource Unit (RU) are used for the uplink.

Fig. 2 is an example diagram showing a resource mapping of a downlink in the EUTRA standard (using OFDCM). BW denotes a frequency bandwidth, and Bch denotes a frequency bandwidth of a Resource Block (RB). In fig. 2, Resource Blocks (RBs) are allocated to mobile stations 1(MS1) to 4(MS4) located in a cell under the control of a base station. In fig. 2, a downlink common pilot channel (D-CPICH), a Downlink Shared Control Channel (DSCCH), and a Downlink Shared Data Channel (DSDCH) are used.

Here, the downlink common pilot channel (D-CPICH) is a channel for measuring the quality of the downlink radio link. The downlink shared control channel is a channel used for transmission power control, reception data modulation scheme, notification of scheduling information, and the like. Also, a Downlink Shared Data Channel (DSDCH) is a channel used for transmission of downlink user data. In addition, even a mapping structure of a downlink channel different from that of the present drawing does not affect the present invention. For example, the DSDCH may include a DSCCH mapping structure therein.

Fig. 3 is an illustration of resource mapping of an uplink in the EUTRA standard (using OFDM). In fig. 3, as in fig. 2, Resource Units (RUs) are allocated to mobile stations 1(MS1) to 4(MS4) located in a cell governed by a base station

In fig. 3, the Uplink Shared Control Channel (USCCH) is a channel for notifying the base station of quality information indicators CQI, harq, ACK/NACK, information on transmission data, and the like of the downlink data channel.

The uplink common pilot channel (U-CPICH) is a channel used by the base station to estimate the quality of an uplink radio transmission path. An Uplink Shared Data Channel (USDCH) is a channel for transmitting uplink user data.

The Random Access Channel (RACH) is a channel used for the mobile station to perform an uplink resource allocation request at the start of transmission.

In this example, an example is shown in which RACH is allocated to all frequency Bands (BW) in a certain TTI (TTI-3 in the figure), but even if a plurality of to arbitrary Resource Units (RUs) are allocated, a plurality of to arbitrary subframe intervals (TTIs) can be allocated. Even if the mapping structure of the uplink channel is different from that shown in the figure, the present invention is not affected. For example, the mapping structure of the USCCH may be included in the USDCH.

Next, a change of the RACH procedure in the EUTRA standard is described. Fig. 4 is a sequence diagram showing an example of the RACH sequence (transmission timing channel and resource information are transmitted in different sequences) in the EUTRA standard. In fig. 4, the mobile station transmits an RACH Preamble (RACH Preamble) and an uplink resource allocation request (transmission request), and the base station returns uplink transmission timing information (transmission timing correction information) and uplink resource allocation information (resource information), respectively, in response to the transmission request.

In fig. 4, in a mobile station to which uplink resources are not allocated, when uplink data transmission occurs, the mobile station randomly selects one Resource Unit (RU) allocated as the RACH, and transmits a RACH preamble in the selected Resource Unit (RU) (step S1). The base station having received the RACH preamble calculates a deviation of the transmission timing of the mobile station from the timing actually received, and transmits correction information (uplink transmission timing information) of the transmission timing to the mobile station (step S2).

The mobile station adjusts the transmission timing based on the correction information and continuously transmits the "transmission request" (step S3). The "transmission request" is an uplink resource allocation request transmitted to the base station together with control information on transmission data. In this specification, terms such as "resource allocation request", "transmission resource" and the like are mixed, but they are used with the same meaning.

The base station schedules a necessary uplink resource based on the control information in the received transmission resource, and transmits uplink resource allocation information allocated according to the scheduling to the mobile station (step S4).

Through the above steps, the uplink synchronization is established and the resource for the mobile station to transmit data is allocated. Therefore, the mobile station starts data transmission using the allocated uplink resource (step S5).

Fig. 5 is a sequence diagram showing another example of the RACH sequence in the EUTRA standard (an example in which uplink transmission timing information and uplink resource allocation information are simultaneously transmitted). In fig. 5, in a mobile station where uplink resources are not allocated, when uplink data transmission occurs, the mobile station randomly selects one Resource Unit (RU) allocated as the RACH, and transmits the RACH preamble and the transmission request including the selected Resource Unit (RU) (step S10).

The base station having received the RACH preamble and the transmission resource calculates a deviation of the transmission timing of the mobile station from the actually received timing, and transmits correction information of the transmission timing (uplink transmission timing information) to the mobile station (step S11). Then, the uplink resources required for the scheduling are scheduled based on the information in the transmission request, and the uplink resource allocation information allocated based on the scheduling is transmitted to the mobile station (step S12). Here, the transmission timing correction information (uplink transmission timing information) and the uplink resource allocation information are simultaneously transmitted from the base station.

Then, the mobile station adjusts the transmission timing based on the correction information of the transmission timing (uplink transmission timing information), and starts data transmission using the allocated uplink resource (step S13).

In the present invention, 2 types of Random Access Channels (RACHs) that can be transmitted by the mobile station at an arbitrary timing are prepared, and the RACHs are used separately according to the actual state of the mobile station.

Hereinafter, the non-synchronous RACH/synchronous RACH will be briefly described. The asynchronous RACH is a RACH used in a state where uplink transmission timing is not corrected without acquiring uplink timing correction information from the base station. In contrast, the synchronous RACH is a RACH used in a state in which uplink transmission timing is corrected.

The following may exist: that is, the RACH is a channel originally transmitted from the mobile station to the base station at an arbitrary timing, and therefore, it is generally considered that time synchronization with the base station is not established at this time (in a voice call, this is assumed to be the case only), but the RACH is transmitted from the mobile station to the base station in a state where time synchronization with the base station is achieved at the time of packet communication. For example, after data is transmitted in a state where an uplink is established with the base station (a state where transmission timing offset is corrected), a new uplink data transmission is necessary before the link fails (that is, during a period in which the correction of the transmission timing offset is valid), and the mobile station transmits the RACH to the base station. Therefore, the RACH at this time may be referred to as a synchronous RACH.

When the asynchronous RACH is mapped to a subcarrier and transmitted to the base station, it is necessary to set a guard time (to extend a redundant period of an inherent code multiplied by the RACH) in order to reduce the influence of multipath, but the synchronous RACH does not require a guard time. Therefore, by effectively using the synchronous RACH, communication resources can be effectively utilized.

Fig. 6 is an example of mapping of unsynchronized RACHs to resource elements in a radio frame. As shown in the figure, the non-synchronized RACH is accompanied by a guard time, and the non-synchronized RACH including the guard time occupies one subframe interval (TTI ═ 0.5ms).

Fig. 7 is an example diagram showing a mapping of synchronous RACH to resource units in a radio frame. As shown in the figure, since the synchronous RACH does not require a guard time and ensures synchronization, the minimum time width of the synchronous RACH coincides with the time width of the OFDM symbol. That is, there is no redundant guard time, and the time width is greatly shortened. Accordingly, a portion in which a subframe interval (TTI ═ 0.5ms) is free may be allocated to a data channel or a control channel. In this way, if the synchronous RACH can be effectively used, communication resources can be effectively utilized.

Further, the RACH is a channel used before resource allocation (resource allocation request), but even after resource allocation, a new resource allocation request may be required to be transmitted, and in this case, it is considered that, for example, the uplink shared control channel USCCH (a channel for transmission using allocated resources) may be used instead of the RACH.

Therefore, in the connection processing method according to the present invention, as a channel that may be used in the uplink, a control channel that can be commonly used by a plurality of mobile stations is assumed in addition to the synchronous RACH and the asynchronous RACH (for example, the Uplink Shared Control Channel (USCCH) corresponds to this).

The USCCH is a channel (uplink-synchronized) in which transmission timing for transmission is corrected using resources allocated from the base station, and is used for the mobile station to transmit a quality information indicator (CQI), HARQ (hybrid ARQ), ACK/NACK, and the like to the base station. As described above, when retransmission of data occurs after resources are once allocated from the base station, a case is considered in which a new resource allocation request is transmitted using the Uplink Shared Control Channel (USCCH) while using currently allocated resources. Therefore, the Uplink Shared Control Channel (USCCH) is also a channel that is likely to be used for connection processing of the uplink.

Therefore, as a result, there are channels potentially usable for the uplink connection processing, the asynchronous RACH and the synchronous RACH as channels used before resource allocation, and the Uplink Shared Control Channel (USCCH) as channels used after resource allocation, for which there are 3 channels in total. Note that, although the specific name of "control channel commonly available" is not used, for convenience of description in the present specification, the control channel is described as an Uplink Shared Control Channel (USCCH) (not limited to the channel of the name, but the control channel may be used when the use of another control channel is recognized in EUTRA).

In the present invention, the synchronous RACH, the asynchronous RACH, and the USCCH are adaptively used in a separated manner, particularly in consideration of the resource utilization efficiency, the uplink resource allocation state of the mobile station, and the uplink time synchronization state. That is, the mobile station distinguishes the state of the mobile station at the time of generating transmission data on a case-by-case basis according to the presence or absence of time synchronization and the presence or absence of resource allocation, and also distinguishes the state of the mobile station at the time of generating transmission data on a case-by-case basis (that is, since various signals such as a signal for notifying the presence or absence of transmission data, a signal for notifying the amount of transmission data, a signal for notifying the type or speed of transmission data, and a signal for notifying transmission buffer can be used as a request signal of scheduling information of resources, the mobile station may specifically distinguish the mobile station on a case-by-case basis in consideration of the type of a signal used for scheduling information request), and when transmission data actually occurs, the mobile station appropriately selects one of the 3 channels on a case-by-case basis of the state of the mobile station distinguished.

That is, in the following embodiments, the environment condition for performing the connection processing is set assuming a real scene of the OFDM mobile communication specifically. Then, under this condition setting, the optimum used channel is determined for each of the above 4 cases. The basic conditions set in the following embodiments are as follows.

(a) Condition mode 1 (embodiment 1, embodiment 2)

(1) The uplink synchronization request signal and the resource allocation request signal may be transmitted simultaneously.

(2) The synchronous RACH is not used.

(3) The USCCH may be used for resource allocation requests.

(b) Condition mode 2 (embodiment 3)

(1) The uplink synchronization request signal and the resource allocation request signal cannot be transmitted (separately) at the same time.

(2) The USCCH is not used.

(3) The synchronous RACH may be used for resource allocation requests.

(c) Condition mode 3 (embodiments 4 to 7)

(1) The uplink synchronization request signal and the resource allocation request signal cannot be transmitted (separately) at the same time.

(2) The synchronous RACH may be used for resource allocation requests.

(3) The USCCH may also be used for resource allocation requests.

Here, the condition mode 3 is the most important condition, and when considered in accordance with the condition mode 3, the basic usage of the uplink is as follows. That is, the asynchronous RACH is used for the request of the timing correction information. In addition, when a resource allocation request is made, the USCCH is used when there is a resource, and the synchronous RACH is used when there is no resource.

The following briefly explains the classification of contents shown in the following description of embodiments (embodiments 1 to 7). Fig. 8 is a diagram for classifying the contents of each of the 7 embodiments of the present invention according to the request method of usable channels and resources.

In fig. 8, (1) to (7) shown on the left side respectively represent embodiments 1 to 7. The center shows the channels that can be used for resource requests. The right side shows a resource request method (a type of data used for the request, and the like). Namely as follows.

(1) In embodiment 1, the resource allocation request is executed by transmitting information for making the mobile station aware of the presence or absence of transmission data to the base station using the asynchronous RACH and the USCCH.

(2) In embodiment 2, the resource allocation request is executed by transmitting information for making the mobile station know the data amount of transmission data to the base station using the asynchronous RACH and the USCCH.

(3) In embodiment 3, the resource allocation request is executed by transmitting information for making the mobile station know the data amount of transmission data to the base station using the asynchronous RACH and the synchronous RACH.

(4) In embodiment 4, the resource allocation request is executed by transmitting information for making the mobile station know the data amount of transmission data to the base station using the asynchronous RACH, the synchronous RACH, and the USCCH.

(5) In embodiment 5, the resource allocation request is executed by transmitting information for making the mobile station know the type of transmission data or a fixed transmission rate to the base station using the asynchronous RACH, the synchronous RACH, and the USCCH.

(6) In embodiment 6, the resource allocation request is executed by transmitting information for making the mobile station know the type of transmission data or the variable transmission rate to the base station using the asynchronous RACH, the synchronous RACH, and the USCCH.

(7) In embodiment 7, the resource allocation request is executed by transmitting the amount of data buffer not transmitted by the mobile station to the base station using the asynchronous RACH, the synchronous RACH, and the USCCH.

The following embodiments classify the states of the mobile stations according to the uplink synchronization/non-synchronization and the presence/absence of uplink information, and examine and determine which channel is the most suitable channel for each case. That is, in the present invention, as states when a mobile station in EUTRA transmits a transmission request, there are 4 types of (1) no uplink resource information/uplink asynchronous, (2) no uplink resource information/uplink synchronous, (3) uplink resource information/uplink asynchronous, and (4) uplink resource information/uplink synchronous.

Here, "no uplink resource information" indicates a state in which no uplink resource for transmitting a transmission request by the USCCH is allocated to the mobile station. For example, this corresponds to an Idle (Idle) state in EUTRA. Alternatively, the Active state corresponds to a case where resources can be allocated by only transmitting a transmission request once (in this case, there is no resource for newly generated transmission data) for the reason that the transmission rate of transmission data is constant or the like. Alternatively, the Active state corresponds to a case where the mobile station starts the next transmission (in this case, there is no resource for newly generated transmission data) before the mobile station transitions to the Idle state after the mobile station finishes transmitting certain transmission data.

The "uplink resource information" indicates a state in which an uplink resource for transmitting a transmission request from the USCCH is allocated to the mobile station. For example, the Active state in EUTRA corresponds to a case where resources necessary for data transmission must be appropriately allocated for the reason of increasing or decreasing the transmission rate or the transmission buffer amount.

The "uplink asynchronous" is a state in which the mobile station does not receive the correction information before correcting the deviation of the transmission timing or within a certain time period by the correction information, and the mobile station is considered to be out of the uplink synchronous when the validity period of the correction information is expired.

The "uplink synchronization" is a state in which the mobile station corrects the transmission timing deviation based on the correction information, and the correction information is in the valid period.

Also, in the following embodiments, the actual state of the mobile station is considered as appropriate. That is, as specific states of the mobile station in EUTRA, 3 states of "Detached (Detached) state", "Idle (Idle) state", and "Active (Active) state" are considered.

The "Detached (Detached) state" is a state in which the base station does not recognize the presence of the mobile station for the reason that the mobile station is turned on or after the mobile station is changed to a different RAT (radio access technology).

The "Idle (Idle) state" is a state in which the base station recognizes the presence of the mobile station, but does not perform data communication, the base station assigns the mobile station a minimum downlink resource for credit, and the mobile station performs intermittent reception using the assigned resource.

The "Active state" is a state in which the base station recognizes the presence of the mobile station and the base station and the mobile station perform data communication.

In view of the above, embodiments of the present invention will be described below in detail.

(embodiment mode 1)

Embodiment 1 of the present invention will be described below. Fig. 9 is a block diagram showing an example of the structure of a mobile station. The mobile station 50 corresponds to EUTRA (OFDM usage), and as shown in the figure, the mobile station 50 includes AN antenna AN1, a receiving unit 30, a channel demodulating unit 32, a control signal analyzing unit 34, a decoding unit 36, and a channel measuring unit 38 as a receiving system, and includes AN antenna AN2, a transmitting unit 40, a channel demodulating unit 42, AN encoding unit 44, a scheduling unit 46, and a transmission timing adjusting unit 47 as a transmitting system. The operations of the respective units are collectively controlled by the control unit 48 as an upper layer.

Next, the operation of the mobile station of fig. 9 will be described. The signal from the base station is received by the receiving section 30 via AN antenna AN 1. The received signal is sent to the channel demodulation unit 32, and demodulation processing is performed according to the type or content of the received signal. The demodulated received signal is sent to each processing unit (reference numerals 34 to 38) corresponding to the type of the received channel.

That is, the control channel is transmitted to the control signal analysis unit 34, the data channel is transmitted to the decoding unit 36, and the measurement channel is transmitted to the channel measurement unit 38. Here, the "control channel" is a DSCCH or a report information channel, the "data channel" is a DSDCH or the like, and the measurement channel is a D-CPICH or the like. The control signal analysis unit 34 extracts control data, downlink channel information, a transmission timing channel, and scheduling information from the control channel.

The downlink channel information includes information necessary for decoding and demodulation, and is supplied to each of the decoding unit 36 and the channel decoding unit 32. The transmission timing channel is transmitted to the transmission timing adjustment unit 47. The scheduling information is transmitted to the scheduling unit 46.

The decoding unit 36 extracts user data from the data channel based on the downlink channel information. The channel measuring unit 38 takes out the measured quality from the measurement channel. The control data, the user data, and the measurement quality are transmitted to the control unit 48, which is an upper layer.

Further, the user data and the control data are input to the encoding unit 44 and encoded upon a transmission request from the control unit 48 (upper layer). The encoded user data and control data are input to the channel modulation section 42 and modulated. The channel information required for coding and modulating the user data and the control data is specified by the scheduling unit 46.

Then, each transmission data is mapped to an appropriate uplink channel (RACH, USCCH, USDCH, etc.) based on the scheduling information transmitted from the scheduling unit 46. The transmission unit 40 adjusts the transmission timing to synchronize with the reception timing of the base station, based on the correction information obtained from the transmission timing adjustment unit. The components of the other mobile stations are not related to the present invention and therefore are omitted.

Fig. 10 is a block diagram showing an example of the configuration of a base station. The base station 70 corresponds to EUTRA (OFDM usage), and as shown in the figure, includes AN antenna AN3, a receiving unit 72, a channel detecting unit 74, a scheduling unit 76, a transmission timing information generating unit 78, a DSCCH (downlink shared control channel) generating unit 80, and a transmitting unit 82.

The channel detector 74 detects a RACH (synchronous RACH, asynchronous RACH) or a USCCH (uplink shared control channel) from the received signal, and detects a transmission timing information request and a resource allocation request from the mobile station. The scheduling unit 76 generates scheduling information (resource allocation information), and the transmission timing information generating unit 78 generates transmission timing information (transmission timing correction information). The DSCCH generating unit 80 forms a transmission frame including the DSCCH, and the transmitting unit 82 maps scheduling information and transmission timing information to the DSCCH and transmits the DSCCH from the antenna AN4 to the mobile station.

Fig. 11 is an example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station. In fig. 11, the upper stage is a base station, and UL indicates an uplink viewed from the base station (a line from the base station to the mobile station), and DL indicates a downlink viewed from the base station (a line from the mobile station to the base station). In addition, the middle section of fig. 11 is a mobile station, UL is an uplink viewed from the mobile station (a line from the mobile station to the base station), and DL is a downlink viewed from the mobile station (a line from the base station to the mobile station). The lower frame number in fig. 11 indicates the common sequence number of the transmission frame. This is the same for the subsequent figures of fig. 12.

The communication procedure of the connection processing shown in fig. 11 is most suitable for the case where the following conditions (1) to (3) are satisfied.

(1) The RACH preamble and the transmission request may be simultaneously included in one RACH transmission.

(2) The USCCH has a function of transmitting data and is used for a resource allocation request.

(3) The synchronous RACH is not used.

At this time, the mobile station uses the "asynchronous RACH" for a transmission request (resource allocation request) from the "state of no uplink resource information/uplink asynchronous" and the "state of no uplink resource information/uplink synchronous". Further, as long as transmission data continues, "USCCH" is used for each transmission request from the "state where uplink resource information and uplink synchronization are present".

The transmission procedure of fig. 11 will be described in detail below. At the initial transmission, that is, when there is no uplink information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronous RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request after the initial transmission is transmitted after receiving the transmission timing information and the scheduling information. That is, when there is uplink resource information and uplink synchronization, the mobile station allocates uplink resources based on the transmission timing information and the scheduling information, and therefore, the use of the asynchronous RACH, which may cause interference between other stations, and the efficiency of resource utilization may be low. Therefore, the USCCH is best suited for sending requests (frames 6, 11 in the figure). The mobile station transmits data using the USDCH based on the scheduling information (frames 5 and 10 in the figure) notified from the base station by the DSCCH. In addition, the USCCH and the USDCH may also be transmitted simultaneously.

The mobile station uses the USCCH to notify the base station of information indicating "transmission data present" every time when there is transmission data, and uses the USCCH to notify the base station of information indicating "no transmission data" every time when there is no transmission data. Instead of notifying "no transmission data", it may be possible to notify "transmission data is present" without notifying "transmission data is not present".

When new transmission data is generated after transmission data ends or before uplink synchronization is released, that is, when there is no uplink resource information and uplink synchronization, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronized RACH is now best (frame 21 in the figure).

Further, the base station allocates uplink resources to the mobile station after the execution of the handover or the like, but if the transmission timing of the mobile station is not corrected, that is, if there is uplink resource information/uplink asynchronous, the USCCH cannot be used until the timing information is received from the base station. Therefore, the non-synchronized RACH is now best (frame 31 in the figure).

(embodiment mode 2)

Embodiment 2 of the present invention will be described below. The mobile station and the base station may have the same configuration as that of embodiment 1. Fig. 12 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station. The communication procedure of fig. 12 is suitable for the case where the following conditions (1) to (3) are satisfied.

(1) The RACH preamble and the transmission request may be simultaneously included in one RACH transmission.

(2) The USCCH has a function of notifying the amount of transmission data and is used for a resource allocation request.

(3) The synchronous RACH cannot be used.

At this time, the mobile station uses the "asynchronous RACH" for transmission requests from the "state of no uplink resource information/uplink asynchronous" and the "state of no uplink resource information/uplink synchronous". When transmission data is generated, the "USCCH" is used for a transmission request from the "state where uplink resource information and uplink synchronization are present".

Next, the transmission procedure of fig. 12 is explained in detail. At the initial transmission, that is, when there is no uplink resource information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronous RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request after the initial transmission is transmitted after receiving the transmission timing information and the scheduling information. That is, when there is uplink resource information and uplink synchronization, the mobile station allocates uplink resources based on the transmission timing information and the scheduling information, and therefore, the efficiency of using asynchronous RACH resources, which may cause interference between other stations, is low. Therefore, the USCCH is best suited for sending requests (frames 6, 14 in the figure). As a transmission request, the mobile station includes the total amount of data transmitted from this station in the USCCH and transmits the USCCH only once (frame 6 in the figure). Then, every time a new transmission data amount is generated, the total amount of data to be transmitted is included in the USCCH as a transmission request and transmitted only once (frame 14 in the figure). Except when the request notification is transmitted, data is transmitted using the USDCH based on scheduling information (frames 10 and 11 in the figure) notified from the base station by the DSCCH. In addition, at this time, USCCH and USDCH can also be transmitted simultaneously.

Further, the USCCH cannot be used because no uplink resource is allocated when new transmission data occurs after transmission data ends or before uplink synchronization is released, that is, when there is no uplink resource information and uplink synchronization. Therefore, the non-synchronized RACH is now best (frame 21 in the figure).

Further, the base station allocates uplink resources to the mobile station after the execution of the handover or the like, but if the transmission timing of the mobile station is not corrected, that is, if there is uplink resource information/uplink asynchronous, the USCCH cannot be used until the timing information is received from the base station. Therefore, the non-synchronized RACH is now best (frame 31 in the figure).

(embodiment mode 3)

Embodiment 3 of the present invention will be described below. The mobile station may have the same configuration as that of embodiment 1. Fig. 13 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station. The communication procedure of fig. 13 is suitable for the case where the following conditions (1) to (3) are satisfied.

(1) The RACH preamble and the transmission request cannot be included in the same RACH transmission.

(2) The USCCH is not used for resource allocation requests.

(3) The synchronous RACH has a function of notifying the transmission data amount, and is used for a resource allocation request.

At this time, the mobile station uses the "asynchronous RACH" for a transmission request (resource allocation request) from the "state of no uplink resource information and uplink asynchronous". Then, the "synchronous RACH" is used for a transmission request from the "state without uplink resource information and uplink synchronization". In addition, under the above conditions, it is not necessary to consider the state of uplink resource information/uplink synchronization and the state of uplink resource information/uplink asynchronization.

The transmission procedure of fig. 13 is explained in detail below. At the initial transmission, that is, when there is no uplink resource information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronous RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request is transmitted after receiving only the transmission timing information. That is, in the state where there is no uplink resource information and uplink synchronization, the mobile station corrects uplink synchronization based on the transmission timing information, and therefore the synchronous RACH is most suitable for a transmission request (frames 6 and 12 in the figure).

As a transmission request, the mobile station includes the amount of data transmitted from this in the synchronous RACH and transmits the data only once (frame 6 in the figure). Since there is no resource allocation for transmission request, the mobile station includes the amount of data to be transmitted in the synchronous RACH and transmits the data only once every time transmission data occurs (frame 12 in the figure). Fig. 13 shows that the base station performs scheduling based on the total data amount a reported in frame 6, the DSCCH reports scheduling information of the mobile station (frame 10 in the figure), and the USDCH transmits data based on the scheduling information (frame 11 in the figure).

In the present embodiment, since the USCCH is not used for a transmission request, there are no states of uplink resource information/uplink synchronization and uplink resource information/uplink non-synchronization, and the mobile station does not consider the above 2 states.

In the present embodiment, since the asynchronous RACH and the synchronous RACH are used in combination, how to map the 2 channels to a radio frame (communication resource) (that is, a channel mapping method) becomes a problem.

Therefore, a channel mapping method of the synchronous RACH/non-synchronous RACH will be described below. Fig. 15 to 18 are diagrams showing examples of channel mapping of synchronous RACH and asynchronous RACH, respectively. In each figure, the guard band in the asynchronous RACH is omitted. In the figure, for simplicity, the time axis of the synchronous RACH is described as occupying all 1 TTI, but the time axis may be actually mapped to an arbitrary OFDM symbol, and the number of the time axes may be an arbitrary number of OFDM symbols within 1 TTI.

In fig. 15, the non-synchronous RACH and the synchronous RACH are each configured at different TTIs (subframe periods). The non-synchronous RACH and the synchronous RACH are mapped to the full Band (BW) for the frequency axis and to different TTIs for the time axis. In the figure, the synchronous RACH is configured after the non-synchronous RACH, but the reverse is also possible.

Further, the frames may be arranged in different frames, or may be arranged continuously. The present mapping method has an advantage that since the transmission timing of each RACH in 1 frame period can be fixedly determined, the reception process in the base station is easily performed.

In fig. 16, the non-synchronous RACH and the synchronous RACH configure different frequency bands within the same TTI (subframe period). For the time axis, the non-synchronous RACH and the synchronous RACH are mapped within the same TTI. In the frequency axis, the synchronous RACH and the asynchronous RACH are arranged so as not to overlap each other in units of the frequency bandwidth (Bch) of the Resource Unit (RU) (that is, the frequency bands are different, and two channels are multiplexed in a common TTI).

In the present mapping method, since both the asynchronous RACH and the synchronous RACH can be included in a common TTI, communication resources can be reduced as compared with the case where each channel is allocated to a different TTI. That is, when only the non-synchronized RACH is allocated to the TTI, there is an advantage that allocation of both channels is completed with the same resource. Also, by changing the division ratio of the frequency band according to the use frequency of each RACH, resources can be more effectively utilized. Further, by appropriately changing the frequency domain allocated to each RACH in accordance with the frequency of use of each RACH, the resource utilization efficiency is further improved. For example, when the frequency of use of the synchronous RACH is high, the ratio of the asynchronous RACH to the synchronous RACH is set to 4: 6, for example, so that the collision probability when using the synchronous RACH is reduced, resulting in effective use of resources.

In fig. 17, the asynchronous RACH is mapped in 1 TTI, and the synchronous RACH is mapped in time division in units of the frequency domain width (Bch) of the resource element. That is, the asynchronous RACH is arranged in all frequency bands within 1 subframe period, and the synchronous RACH is arranged in a time division manner within a plurality of subframe periods, and the frequency bands in the respective subframe periods are periodically arranged in a 1 frame period while shifting the frequency band in units of the frequency band (Bch) of one resource element without overlapping. The configuration of the synchronous RACH may be configured with consecutive TTIs or with a plurality of TTI intervals, but the configuration must be equally configured within 1 frame.

According to the mapping of fig. 17, since the synchronous RACHs are equally arranged in the time axis direction, when a data transmission request by the synchronous RACH is generated, the synchronous RACH can be mapped to a resource (subcarrier) immediately without waiting for a long time. Therefore, it is possible to suppress the processing delay before the synchronous RACH is transmitted.

In fig. 18, the non-synchronous RACH and the synchronous RACH are configured within the same TTI. The non-synchronous RACH and the synchronous RACH each share the same frequency band and TTI. That is, both channels are configured in the same frequency band during the same subframe. The synchronous RACH and the non-synchronous RACH are time-division configured as necessary during one subframe. This has the effect of making it difficult to occupy resources wastefully. For example, the uplink resource occupied for the synchronous RACH is not required.

The channel mapping method in fig. 15 to 18 can be specified for each cell based on report information from the base station, even if it is defined in advance in the mobile communication system. The channel mapping method shown in fig. 15 to 18 is also applicable to the following embodiments.

(embodiment mode 4)

Embodiment 4 of the present invention will be described below. The mobile station and the base station may have the same configuration as that of embodiment 1. Fig. 14 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station. The communication procedure of fig. 14 is suitable for the case where the following conditions (1) to (3) are satisfied.

(1) The RACH preamble and the transmission request cannot be included in the same RACH transmission.

(2) The USCCH has a function of notifying the amount of transmission data and is used for a resource allocation request.

(3) The synchronous RACH has a function of notifying the transmission data amount, and is used for a resource allocation request.

At this time, the mobile station uses the "asynchronous RACH" for a transmission request from the "state of no uplink resource information and uplink asynchronous". Then, the "synchronous RACH" is used for a transmission request from the "state without uplink resource information and uplink synchronization". Further, the "USCCH" is used for a transmission request from the "state where uplink resource information and uplink synchronization are present".

Next, the transmission procedure of fig. 14 will be described in detail. At the initial transmission, that is, when there is no uplink resource information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronous RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request (resource allocation request) is transmitted after receiving only the transmission timing information. That is, when there is no uplink resource information and uplink synchronization, the mobile station corrects uplink synchronization based on the transmission timing information, and therefore the synchronous RACH is optimal (frame 6 in the figure). As a transmission request, the mobile station transmits the amount of data transmitted from this time in one transmission in the synchronous RACH (frame 6 in the figure).

Further, it is necessary to similarly notify the amount of data to be transmitted every time transmission data occurs, but in this case, since uplink resources are allocated, it is not necessary to use the synchronous RACH. That is, the USCCH is most suitable for transmission request when there is uplink resource information and uplink synchronization (frame 12 in the figure).

The mobile station transmits data using the USDCH based on the scheduling information (frame 10 in the figure) notified from the base station by the DSCCH (frames 11 and 12 in the figure). Thereafter, every time new transmission data is generated, the amount of data to be transmitted is included in the USCCH and transmitted once. In addition, at this time, USCCH and USDCH can also be transmitted simultaneously.

When new transmission data is generated after transmission data ends and before uplink synchronization is released, that is, when there is no uplink resource information and uplink synchronization, uplink resources are not allocated, and therefore USCCH cannot be used. Therefore, the synchronous RACH is best at this time (frame 21 in the figure).

Further, the base station allocates uplink resources to the mobile station after the execution of the handover or the like, but if the transmission timing of the mobile station is not corrected, that is, if there is uplink resource information and uplink asynchronous, the USCCH and the synchronous RACH cannot be used until the timing information is received from the base station. Therefore, the non-synchronized RACH is now best (frame 3 in the figure).

The method shown in fig. 15 to 18 in embodiment 3 can be used for channel mapping of the asynchronous RACH and the synchronous RACH in embodiment 4.

(embodiment 5)

Embodiment 5 of the present invention will be described below. The mobile station and the base station may have the same configurations as those of embodiment 1. Fig. 19 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station.

The communication procedure of fig. 19 is optimal in a case where transmission data (for example, voice communication) composed of a constant transmission cycle and a fixed transmission rate is transmitted, and in particular, is optimal in a case where the following conditions (1) to (3) are satisfied.

(1) The RACH preamble and the transmission request cannot be included in the same RACH transmission.

(2) The USCCH has a function of notifying a data type and a transmission rate, and is used for a resource allocation request.

(3) The synchronous RACH has a function of notifying a data type and a transmission rate, and is used for a resource allocation request.

At this time, the mobile station uses the "asynchronous RACH" for a transmission request from the "state of no uplink resource information and uplink asynchronous". Then, "USCCH" is used for a transmission request from "state with uplink resource information and uplink synchronization". Further, the "synchronous RACH" is used for a transmission request from the "state without uplink resource information and uplink synchronization".

Next, the transmission procedure of fig. 19 is explained in detail. At the initial transmission, that is, when there is no uplink resource information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronous RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request is transmitted after receiving only the transmission timing information. That is, in the state where there is no uplink resource information and uplink synchronization, the mobile station corrects uplink synchronization based on the transmission timing information, and therefore the synchronous RACH is most suitable for a transmission request (frame 6 in the figure). As a transmission request, the mobile station transmits the type and transmission rate of data transmitted from this station once in the synchronous RACH (frame 6 in the figure).

Here, when the type of data is configured by a constant transmission cycle and a fixed transmission rate, the base station performs scheduling for allocating uplink resources at a constant cycle, and notifies the mobile station of scheduling information using the DSCCH (frame 10 in the figure). The mobile station transmits the scheduling information using the uplink resource allocated at a constant cycle (frames 11 and 14 in the figure). In this case, a case where the base station allocates an uplink resource for transmission request transmission from the USCCH to the mobile station and a case where the uplink resource is not allocated are considered. By allocating uplink resources, it is possible to immediately change according to communication increase or the like, and in addition, there is a waste of resources when the transmission rate is not changed. The opposite is true when not allocated. Here, both cases are shown.

When there is resource allocation for a transmission request, i.e., when there is uplink resource information and uplink synchronization, the USCCH is most suitable for a transmission request (frame 11 in the figure). In addition, at this time, USCCH and USDCH can also be transmitted simultaneously. When there is no resource allocation for transmission request, that is, when there is no uplink resource information and uplink synchronization, the USCCH can be used because no uplink resource is allocated. Therefore, the synchronous RACH is most suitable for transmitting a request (frame 21 in the figure).

Further, the base station allocates uplink resources to the mobile station after the execution of the handover or the like, but if there is uplink resource information and uplink asynchronous timing that are not corrected in the transmission timing of the mobile station, the USCCH and the synchronous RACH cannot be used until the timing information is received from the base station. Therefore, the non-synchronized RACH is now best (frame 31 in the figure).

The method shown in fig. 15 to 18 in embodiment 3 can be used for channel mapping of the non-synchronous RACH and the synchronous RACH in embodiment 5.

(embodiment mode 6)

Embodiment 6 of the present invention will be described below. The mobile station and the base station may have the same configurations as those of embodiment 1. Fig. 20 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station. The conditions assumed by the communication procedure of fig. 20 are the same as those of embodiment 5. However, the steps of fig. 20 are particularly suitable for the case of transmitting transmission data composed of a constant transmission period and a variable transmission rate (for example, variable bit rate image communication).

That is, in the step of fig. 20, the mobile station uses the "asynchronous RACH" for a transmission request from the "state without uplink resource information and uplink asynchronous". Then, "USCCH" is used for a transmission request from "state with uplink resource information and uplink synchronization". Further, the "synchronous RACH" is used for a transmission request from the "state without uplink resource information and uplink synchronization".

Next, the transmission procedure of fig. 20 is explained in detail. At the initial transmission, that is, when there is no uplink resource information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronized RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request is transmitted after receiving only the transmission timing information. That is, in the state where there is no uplink resource information and uplink synchronization, the mobile station corrects uplink synchronization based on the transmission timing information, and therefore the synchronous RACH is most suitable for a transmission request (frame 6 in the figure).

As a transmission request, the mobile station transmits the type and transmission rate of data transmitted from this station once in the synchronous RACH (frame 6 in the figure). Here, when the type of data is composed of a constant transmission cycle and a variable transmission rate, the base station performs scheduling for allocating uplink resources at a constant cycle, and notifies the mobile station of scheduling information using the DSCCH (frame 10 in the figure). The mobile station transmits the scheduling information using the uplink resource allocated at a constant period (frames 11 and 13 in the figure).

In this case, the base station may allocate uplink resources for transmitting a transmission request to the mobile station on the USCCH, or may not allocate uplink resources. By allocating uplink resources, it is possible to immediately change according to an increase in communication or the like, and it is a waste of resources when the transmission rate is not changed. The opposite is true when no allocation is made. Here, both cases are shown.

When there is resource allocation for transmitting a request, that is, when there is uplink resource information and uplink synchronization, the USCC is adapted to transmit a request (frame 1 in the figure). In addition, at this time, USCCH and USDCH can also be transmitted simultaneously. When there is no resource allocation for transmission request, that is, when there is no uplink resource information and uplink synchronization, the USCCH cannot be used because no uplink resource is allocated. Therefore, the synchronous RACH is suitable for transmitting a request (frame 21 in the figure).

Further, the base station allocates uplink resources to the mobile station after the execution of the handover or the like, but if the transmission timing of the mobile station is not corrected, that is, if there is uplink resource information and uplink asynchronous, the USCCH and the synchronous RACH cannot be used until the timing information is received from the base station. Therefore, the non-synchronized RACH is now best (frame 31 in the figure).

The channel mapping of the non-synchronous RACH and the synchronous RACH in embodiment 6 can also use any of the methods shown in fig. 15 to 18 in embodiment 3.

(embodiment 7)

Embodiment 7 of the present invention will be described below. The mobile station and the base station may have the same configuration as that of embodiment 1. Fig. 21 is another example diagram showing a series of steps (and contents thereof) of an uplink connection process between a mobile station and a base station. The communication procedure of fig. 21 is optimal when the following conditions (1) to (3) are satisfied.

(1) The RACH preamble and the transmission request cannot be included in the same RACH transmission.

(2) The USCCH has a function of notifying the buffer amount of data that is not transmitted by the mobile station, and is used for a resource allocation request.

(3) The synchronous RACH has a function of notifying the buffer amount of data not transmitted by the mobile station, and is used for a resource allocation request.

At this time, the mobile station uses the asynchronous RACH for a transmission request from a state of no uplink resource information and uplink asynchronous. The USCCH is used for a transmission request from a state where uplink resource information and uplink synchronization are present. The synchronous RACH is used for a transmission request from a state in which no uplink resource information and uplink synchronization are present.

The transmission procedure of fig. 21 is explained in detail below. At the initial transmission, that is, when there is no uplink resource information and uplink asynchronous, the USCCH cannot be used because no uplink resource is allocated. Therefore, the non-synchronous RACH is optimal at the initial transmission (frame 1 in the figure).

The transmission request is transmitted after receiving only the transmission timing information. That is, in the state where there is no uplink resource information and uplink synchronization, the mobile station corrects uplink synchronization based on the transmission timing information, and therefore the synchronous RACH is suitable for a transmission request (frame 6 in the figure). As a first transmission request, the mobile station transmits the data buffer amount currently stored in the synchronous RACH in one time (frame 6 in the figure).

Fig. 21 shows that the base station performs scheduling based on the data buffer amount B1 reported by the frame 6, the mobile station scheduling information (frame 10 in the figure) is reported by the DSCCH, and data is transmitted by the USDCH based on the scheduling information (frame 11 in the figure).

In the first and subsequent transmission requests, the mobile station must notify the base station of the data buffer amount each time before the data buffer amount becomes zero, but at this time, the mobile station does not need to use the synchronous RACH because the uplink resource is not allocated. Therefore, in the state where uplink resource information and uplink synchronization exist, the USCCH of the transmission request other than the first time is optimal (frame 11 in the figure). In addition, at this time, USCCH and USDCH can also be transmitted simultaneously.

When new transmission data occurs after the data buffer amount is zero and before the uplink synchronization is released, that is, when there is no uplink resource information and uplink synchronization, uplink resources are not allocated, and therefore the USCCH cannot be used. Therefore, the synchronous RACH is best at this time (frame 21 in the figure).

Further, the base station allocates uplink resources to the mobile station after the execution of the handover or the like, but when there is uplink resource information/uplink asynchronous state in which the transmission timing of the mobile station is not corrected, the USCCH and the synchronous RACH cannot be used simultaneously until the timing information is received from the base station. Therefore, the non-synchronized RACH is now best (frame 31 in the figure).

The method shown in fig. 15 to 18 in embodiment 3 can be used for channel mapping of the non-synchronous RACH and the synchronous RACH in embodiment 7.

The present invention has been described above with reference to the embodiments, but the present invention is not limited thereto, and various modifications and applications can be made within the scope of the technical idea of the present invention.

For example, in the resource allocation state, the control channel when the mobile station transmits a new resource allocation request to the base station is not necessarily limited to the Uplink Shared Control Channel (USCCH), and if the control channel is a control channel that can be used commonly by the mobile station and can transmit information such as the type of data, other control information may be used, and depending on the situation, a plurality of control channels may be used separately or in combination.

In addition, the channel mapping method of the synchronous RACH/asynchronous RACH shown in fig. 15 to 18 may be adaptively used according to the situation of the mobile station, thereby improving the resource utilization efficiency. Further, it is also considered that the allocation cycle of the TTI used for allocation of the synchronous RACH or the non-synchronous RACH is changed depending on the case where the number of subcarriers is large or the case where the number of subcarriers is small.

As described above, according to the present invention, it is possible to flexibly adapt to an actual mobile station state or an actual transmission procedure change, and it is possible to realize a new connection process between a mobile station and a base station according to the EUTRA standard, which can effectively utilize communication resources.

That is, in the uplink connection process between the mobile station and the base station in EUTRA, it is possible to specify which communication channel is used in which case, comprehensively considering the effective use of resources, communication quality, and the like. Therefore, an optimal connection process is realized in the multi-carrier communication system of the EUTRA standard.

Further, even if there are cases where 2 types of information are simultaneously transmitted (specifically, even if there are cases where the mobile station simultaneously transmits an uplink synchronization request and a resource allocation request to the base station), the optimum used channel is determined in consideration of the cases, and therefore, the method can be flexibly adapted.

Furthermore, by effectively using the synchronous RACH without guard time, the resource utilization efficiency of OFDM communication can be improved, and wasteful consumption of resources usable for data communication and the like performed simultaneously and in parallel can be suppressed.

When the synchronous RACH/asynchronous RACH is mapped (allocated) to an OFDM communication resource defined by the time axis and the frequency axis, by using various mapping schemes (that is, a subframe division scheme, a band division scheme within a common subframe, a scheme in which synchronous RACHs are distributed uniformly on the time axis at different bands within 1 frame, and a scheme in which both RACHs are allocated to a common subframe) separately, it is possible to use a mapping that is rich in changes appropriately, and thus, it is possible to further effectively use resources.

According to the present invention, the contents of the uplink connection processing including the RACH sequence in EUTRA can be specified specifically and objectively, and particularly, an optimum uplink channel use method for EUTRA can be provided.

As described above, the present invention can flexibly adapt to an actual mobile station state or an actual transmission procedure change, and can achieve an effect of realizing a new connection process between a mobile station and a base station according to the EUTRA standard, which can effectively utilize communication resources. Therefore, the connection processing method between the mobile station and the base station is suitable for the mobile station (including a mobile phone terminal, a PDA terminal, a portable personal computer terminal), the base station, the multicarrier mobile communication system, and the mapping method of the random access channel.

Claims (3)

1. A processing method in a mobile station, wherein a control channel in an uplink from the mobile station to a base station and a random access channel having a guard time are provided as channels used by the mobile station to request allocation information of communication resources for transmitting data to the base station, the mobile station acquires correction information from the base station in order to correct a deviation of transmission timing of the uplink and corrects the deviation of transmission timing based on the correction information, and the mobile station requests the base station for the allocation information of the communication resources for transmitting data during a period in which the correction information is valid,

the period includes the following states: a state in which a communication resource for transmitting the control channel in the uplink is allocated to the mobile station; and a state in which the mobile station is not allocated communication resources for transmitting the control channel in the uplink,

the mobile station is adapted to perform, at the mobile station,

requesting, from the base station, allocation information of a communication resource for the mobile station to transmit data using the control channel in the uplink when the communication resource for transmitting the control channel in the uplink is allocated to the mobile station in the period,

and requesting, from the base station, allocation information of a communication resource for the mobile station to transmit the transmission data using the random access channel having the guard time, when the mobile station is not allocated a communication resource for transmitting the control channel in the uplink during the period.

2. A processing apparatus in a mobile station, wherein a control channel and a random access channel having a guard time in an uplink from the mobile station to a base station are provided as channels used by the mobile station to request allocation information of communication resources for transmitting data to the base station, comprising: means for causing the mobile station to acquire correction information from the base station in order to correct the variation in the transmission timing of the uplink, means for causing the mobile station to correct the variation in the transmission timing based on the correction information, and means for causing the mobile station to request allocation information of communication resources for the transmission data from the base station during a period in which the correction information is valid,

the period includes the following states: a state in which a communication resource for transmitting the control channel in the uplink is allocated to the mobile station; and a state in which the mobile station is not allocated communication resources for transmitting the control channel in the uplink,

the apparatus for causing the mobile station to request allocation information of a communication resource for the transmission data to the base station during a period in which the correction information is valid includes:

means for causing the mobile station to request, from the base station, allocation information of a communication resource for the mobile station to transmit data using the control channel in the uplink when the communication resource for transmitting the control channel in the uplink is allocated to the mobile station in the period; and

and a controller configured to cause the mobile station to request, from the base station, allocation information of a communication resource for the mobile station to transmit the transmission data, using the random access channel having the guard time, when the communication resource for transmitting the control channel in the uplink is not allocated to the mobile station in the period.

3. A communication system comprising a mobile station and a base station, wherein a control channel in an uplink from the mobile station to the base station and a random access channel having a guard time are provided as channels used by the mobile station to request allocation information of communication resources for transmitting data to the base station, the mobile station acquires correction information from the base station to correct a variation in transmission timing of the uplink and corrects the variation in transmission timing based on the correction information, and the mobile station requests the base station for the allocation information of the communication resources for transmitting data during a period in which the correction information is valid,

the period includes the following states: a state in which a communication resource for transmitting the control channel in the uplink is allocated to the mobile station; and a state in which the mobile station is not allocated communication resources for transmitting the control channel in the uplink,

the mobile station is adapted to perform, at the mobile station,

requesting, from the base station, allocation information of a communication resource for the mobile station to transmit data using the control channel in the uplink when the communication resource for transmitting the control channel in the uplink is allocated to the mobile station in the period,

requesting, from the base station, allocation information of a communication resource for the mobile station to transmit data using the random access channel having the guard time when a communication resource for transmitting the control channel in the uplink is not allocated to the mobile station in the period,

the base station detects the request by the mobile station.