CN111836373A - A kind of access method and system of unlicensed carrier cell - Google Patents

Abstract

The application discloses an access method and a system of an unauthorized carrier cell, wherein the method comprises the following steps: for a cell working on an unlicensed carrier, a base station broadcasts, through a system message, the positions of an initial activated downlink bandwidth Block (BWP) and an initial activated uplink BWP of the cell, and the position of a Physical Random Access Channel (PRACH) resource in the initial activated uplink BWP, wherein the initial activated downlink BWP and the initial activated uplink BWP are located in different sub-bands, and only one PRACH is configured in the frequency domain of the initial activated uplink BWP; and the User Equipment (UE) in an idle state learns the positions of the initial activation downlink BWP and the initial activation uplink BWP and the position of the PRACH resource according to the monitored system message, executes listen-before-talk (LBT) operation when the network needs to be accessed, initiates random access by using the PRACH in the initial activation uplink BWP, and monitors and receives a random access response message returned by the base station at the initial activation downlink BWP. By adopting the invention, the access time delay of the UE can be reduced.

Description

A kind of access method and system of unlicensed carrier cell

technical field

The present application relates to the field of communication technologies, and in particular, to a method and system for accessing an unlicensed carrier cell.

Background technique

Each 5G cell is configured with an initially activated uplink bandwidth block (BandWidth Part, BWP) and an initially activated downlink BWP. The base station sends system broadcast messages in the initially activated downlink BWP frequency band, and various public search spaces are configured on the initial activated downlink BWP, and the UE monitors these search spaces to obtain the downlink control information sent by the network; configure in the initial activated uplink BWP frequency band There are Random Access Channel (PRACH) resources that the UE uses to trigger random access. The idle state UE obtains the starting position and bandwidth of the initially activated uplink and downlink BWP by reading the system broadcast message.

For a 5G cell operating on the asymmetric spectrum of the TDD frequency band, the center frequency of the initial activation of the uplink BWP and the initial activation of the downlink BWP is the same, but the bandwidth can be different, that is to say, the two BWPs overlap in the frequency domain. The base station can configure up to 4 downlink BWPs and 4 uplink BWPs for the connected UE. Each downlink BWP is bound to an uplink BWP to form a BWP pair. At any time, only one BWP pair is active. The UE only receives/transmits data in the currently activated downlink/uplink BWP pair. In a cell in TDD mode, the network also configures a default downlink BWP (Default DLBWP) and a default uplink BWP for the connected UE. Usually, the default downlink BWP has a small bandwidth, which can reduce the power consumption of the connected UE. When the UE has no data to transmit or receive, it will fall back from the currently activated downlink BWP to the default downlink BWP to reduce the power consumption of the terminal. When there is data to transmit, it will switch to other downlink BWPs.

In the current 5G technology research, the 5G network can be deployed on the unlicensed spectrum, and the 5G cell (New Radio-Unlicenced cell, NR-U cell) working in the unlicensed spectrum can be an independent cell, that is, with a 5G cell working on the licensed spectrum. The cells in the spectrum are similar, and can independently send system broadcast messages, independently accept the access of the UE, and transmit uplink and downlink data for the UE. Since the channel is shared, in order to ensure fair coexistence with the WiFi system, 5G base stations and terminals operating in the unlicensed spectrum must perform LBT (Listen Before Talk, listen before talk) operation before transmitting data. The so-called LBT "listen before talk" "Say" means that when a wireless device (including base station and UE) working in an unlicensed spectrum is ready to send data, it must first monitor the status of the wireless channel, and only when it detects that the wireless channel is idle can it occupy the channel to transmit data. If the channel is busy , the wireless channel cannot be used, and it needs to wait for the next transmission opportunity. The wireless device monitors the wireless channel status in units of sub-bands with a bandwidth of 20MHz. According to the monitoring results, data can be sent on the idle (unoccupied) sub-bands, and on the busy (occupied) sub-bands. Unable to send data. The bandwidths of the initially activated uplink BWP and the initially activated downlink BWP of a 5G cell operating in an unlicensed spectrum are both about 20MHz, which is equivalent to one LBT monitoring subband.

In the process of implementing the present invention, the inventor found that: the above-mentioned existing resource allocation scheme of unlicensed carrier cells has the problem of large UE access delay. Based on the above solution, when the positions of the initial activated uplink BWP and the initial activated downlink BWP of the NR-U cell overlap, the base station shall send periodic system broadcast information, downlink reference signals and downlink PDCCH on the initial activated downlink BWP. Operational limitation, only one device transmits on the same subband at any time. During this time, the UE cannot trigger random access on the PRACH resource of the initial activated uplink BWP. Only within the time interval of the base station transmission, the UE can Random access is triggered, which limits the access opportunity of the UE, resulting in an increase in the access delay of the UE, as shown in FIG. 1 .

SUMMARY OF THE INVENTION

The present application provides a method and system for accessing an unlicensed carrier cell, which can effectively reduce UE access delay.

An embodiment of the present invention provides an access method for an unlicensed carrier cell, including:

For a cell operating on an unlicensed carrier, the base station broadcasts the initial activated downlink bandwidth block BWP and the location of the initial activated uplink BWP, and the location of the PRACH resource in the initial activated uplink BWP through a system message, wherein, The initial activation of the downlink BWP and the initial activation of the uplink BWP are located in different subbands, and only one PRACH is configured in the frequency domain of the initial activation of the uplink BWP;

The user equipment UE in the idle state learns the location of the initially activated downlink BWP and the initially activated uplink BWP, and the location of the PRACH resource according to the monitored system message, and performs a listen first when it needs to access the network. The LBT operation is described later, using the PRACH in the initially activated uplink BWP to initiate random access, and monitoring and receiving the random access response message returned by the base station in the initially activated downlink BWP.

Preferably, the method further comprises:

The base station configures a default downlink BWP and a default uplink BWP for the UE in the connected state in the cell, wherein the default downlink BWP and the default uplink BWP are located in different subbands.

Preferably, the method further comprises:

If PRACH resources are configured in the default uplink BWP of the UE in the connected state, when the currently activated downlink BWP of the UE in the connected state is the default downlink BWP, the UE in the connected state is notified to receive data Then, if the uplink is out of synchronization, an LBT operation is performed, and a random access is initiated by using the PRACH in the default uplink BWP, where only one PRACH is configured in the frequency domain of the default uplink BWP.

Preferably, the method further comprises:

The position of the initial activated uplink BWP of the local cell and the position of the PRACH resource in the initial activated uplink BWP are exchanged between adjacent base stations through the Xn interface;

The base station determines, according to the result of the interaction, whether there is: the local unlicensed carrier cell and the adjacent unlicensed carrier cell have the same PRACH resource location, and if so, determine according to the preset conflict resolution entity selection strategy. Whether the local base station is the current PRACH resource conflict resolution entity, and if so, triggers the reconfiguration of the PRACH resources of the corresponding local cell according to the principle that the frequency domain locations of the PRACH in the initial activated uplink BWP of the adjacent cells are not the same , and use the Xn interface to notify the adjacent base station of the adjusted frequency domain position of the PRACH.

The embodiment of the present invention also proposes an access system for an unlicensed carrier cell, including:

The base station is used to broadcast the location of the initial activated downlink bandwidth block BWP and the initial activated uplink BWP of the cell, and the location of the PRACH resource of the physical random access channel in the initial activated uplink BWP through system messages for a cell operating on an unlicensed carrier , wherein the initially activated downlink BWP and the initially activated uplink BWP are located in different subbands, and only one PRACH is configured in the frequency domain of the initial activated uplink BWP;

The user equipment UE is configured to learn the positions of the initially activated downlink BWP and the initially activated uplink BWP, and the PRACH resource position according to the monitored system message when it is in an idle state, and when it is necessary to access the network , perform a listen-before-talk LBT operation, use the PRACH in the initially activated uplink BWP to initiate random access, and monitor and receive the random access response message returned by the base station in the initially activated downlink BWP.

Preferably, the base station is further configured to configure a default downlink BWP and a default uplink BWP for the UE in the connected state in the cell, wherein the default downlink BWP and the default uplink BWP are located in different locations. Subband.

Preferably, the UE is further configured to, if the default uplink BWP configured in the connected state has PRACH resources, when the activated downlink BWP in the connected state is the default downlink BWP, it is notified to perform After the data is received, if the uplink is out of synchronization, an LBT operation is performed, and a random access is initiated by using the PRACH in the default uplink BWP, where only one PRACH is configured in the frequency domain of the default uplink BWP.

Preferably, the base station is further configured to exchange the position of the initial activated uplink BWP of the local cell and the position of the PRACH resource in the initial activated uplink BWP with the adjacent base station through the Xn interface; according to the result of the interaction, determine whether Exist: the local unlicensed carrier cell and the adjacent unlicensed carrier cell have the same PRACH resource location, if there is, determine whether the current base station is the current PRACH resource conflict resolution entity according to the preset conflict resolution entity selection strategy, If yes, trigger to reconfigure the PRACH resources of the corresponding local cell according to the principle that the frequency domain positions of the PRACHs in the initially activated uplink BWP of the adjacent cells are different, and use the Xn interface to reconfigure the PRACH resources after adjustment. The frequency domain position of the adjacent base station is notified. .

It can be seen from the above technical solutions that in the method and system for accessing an unlicensed carrier cell proposed in this application, the network side needs to configure the initial activation of the downlink BWP and the initial activation of the uplink BWP on different subbands, and the frequency of the initial activation of the uplink BWP is required. Only one PRACH is configured in the domain. In this way, the base station sends downlink broadcast information, reference signal and downlink control information and the UE triggers random access operations at the same time, thereby increasing the random access opportunity of the idle UE and effectively shortening the network access delay of the terminal.

Description of drawings

1 is a schematic diagram of the access delay analysis of UE in an existing unlicensed carrier cell;

2 is a schematic flowchart of a method according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a system structure according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and examples.

An embodiment of the present invention provides an embodiment of a method for accessing an unlicensed carrier cell. As shown in FIG. 2 , the method includes:

Step 201: For a cell working on an unlicensed carrier, the base station broadcasts the location of the initial activated downlink bandwidth block BWP and the initial activated uplink BWP of the cell, and the location of the PRACH resource of the physical random access channel in the initial activated uplink BWP through a system message. , wherein the initially activated downlink BWP and the initially activated uplink BWP are located in different subbands, and only one PRACH is configured in the frequency domain of the initially activated uplink BWP.

Here, the division of the subbands can be implemented by the method of the existing system, that is, when the bandwidth of the NR-U cell is greater than 20MHz, it is divided into several subbands with a bandwidth of 20MHz.

One of the different technical features of this step from the existing solution is that the initial activated downlink BWP and the initial activated uplink BWP are located in different subbands. The activation of downlink BWP is configured on different subbands, so that the operations of the base station sending downlink broadcast information, reference signals and downlink control information and the UE triggering random access are no longer mutually exclusive, but do not affect each other, and can be performed at the same time, thereby increasing the number of The timing of random access of the UE in the idle state is reduced, the network access delay of the terminal is effectively shortened, and the user experience is improved.

In addition, another technical feature here that is different from the existing solution is: when configuring PRACH resources in the initially activated uplink BWP, the frequency division multiplexing (FDM) method is not used in the frequency domain, that is, at any time, the uplink is initially activated at any time. There is at most one PRACH in the BWP band. In this way, in the case where the terminal of the unlicensed carrier cell must perform the LBT operation before transmitting data, the PRACH resources are wasted due to the fact that multiple UEs cannot initiate random access at the same time.

Step 202: The user equipment UE in the idle state learns the locations of the initially activated downlink BWP and the initially activated uplink BWP, and the location of the PRACH resource according to the monitored system message, and executes the process when it needs to connect to the network. Listen first and then talk LBT operation, initiate random access by using the PRACH in the initially activated uplink BWP, and monitor and receive the random access response message returned by the base station in the initially activated downlink BWP.

As described in the background art, in order to reduce the power consumption of the terminal, when the UE in the connected state of the unlicensed carrier cell does not transmit or receive data, it will fall back from the currently activated downlink BWP to the default downlink BWP. When there is data to be transmitted, the Then switch to other downlink BWPs. For the above scenario, in order to further shorten the network access delay when the terminal needs to transmit data and the uplink is out of synchronization, the default downlink BWP and the default uplink BWP can be configured on different subbands, that is:

The base station configures a default downlink BWP and a default uplink BWP for the UE in the connected state in the cell, wherein the default downlink BWP and the default uplink BWP are located in different subbands.

Preferably, if PRACH resources are configured in the default uplink BWP, when the connected state UE needs to transmit data again after falling back to the default downlink BWP and the uplink is out of synchronization, the PRACH resources in the default uplink BWP can be used to initiate random access. Enter, specifically:

If PRACH resources are configured in the default uplink BWP of the UE in the connected state, when the currently activated downlink BWP of the UE in the connected state is the default downlink BWP, the UE in the connected state is notified to receive data Then, if the uplink is out of synchronization, an LBT operation is performed, and a random access is initiated by using the PRACH in the default uplink BWP, where only one PRACH is configured in the frequency domain of the default uplink BWP.

In the above method, by configuring the default downlink BWP and the default uplink BWP on different subbands, after the UE in the connected state falls back to the default downlink BWP, the base station sends the downlink information and the UE triggers the random access operation at the same time. Therefore, the opportunity for random access of the UE is increased, and the network access delay of the terminal is effectively shortened.

Further, the inventor found when implementing the present invention: in the existing solution, the UE of adjacent cells may send a preamble (preamble) on the PRACH at the same frequency domain position at the same time in the existing solution, so that the inter-cell co-channel interference will be increased, Thus, the decoding success rate of the PRACH channel is affected. In response to this problem, further, in this embodiment of the present application, adjacent base stations can exchange information on the subband where the initial activated uplink BWP of the local cell is located through the Xn interface. is triggered to adjust the frequency domain position of the PRACH in the initial activated uplink BWP of the corresponding cell, so that the PRACH in the initial activated uplink BWP of the adjacent cell occupies different frequency domain resources to reduce inter-cell co-channel interference. The following methods are specifically adopted to achieve the above objectives:

The position of the initial activated uplink BWP of the local cell and the position of the PRACH resource in the initial activated uplink BWP are exchanged between adjacent base stations through the Xn interface;

The base station determines, according to the result of the interaction, whether there is: the local unlicensed carrier cell and the adjacent unlicensed carrier cell have the same PRACH resource location, and if so, determine according to the preset conflict resolution entity selection strategy. Whether the local base station is the current PRACH resource conflict resolution entity, and if so, triggers the reconfiguration of the PRACH resources of the corresponding local cell according to the principle that the frequency domain locations of the PRACH in the initial activated uplink BWP of the adjacent cells are not the same , and use the Xn interface to notify the adjacent base station of the adjusted frequency domain position of the PRACH.

In practical applications, those skilled in the art can set the conflict resolution entity selection strategy according to actual needs, for example, the base station corresponding to the smallest or largest cell ID can be selected as the conflict resolution entity, but it is not limited to this and will not be repeated here.

Corresponding to the above method embodiments, the present application proposes an embodiment of an access system for an unlicensed carrier cell. As shown in FIG. 3 , the system includes:

The base station is used to broadcast the location of the initial activated downlink bandwidth block BWP and the initial activated uplink BWP of the cell, and the location of the PRACH resource of the physical random access channel in the initial activated uplink BWP through system messages for a cell operating on an unlicensed carrier , wherein the initially activated downlink BWP and the initially activated uplink BWP are located in different subbands, and only one PRACH is configured in the frequency domain of the initial activated uplink BWP;

The user equipment UE is configured to learn the positions of the initially activated downlink BWP and the initially activated uplink BWP, and the PRACH resource position according to the monitored system message when it is in an idle state, and when it is necessary to access the network , perform a listen-before-talk LBT operation, use the PRACH in the initially activated uplink BWP to initiate random access, and monitor and receive the random access response message returned by the base station in the initially activated downlink BWP.

Preferably, the base station is further configured to configure a default downlink BWP and a default uplink BWP for the UE in the connected state in the cell, wherein the default downlink BWP and the default uplink BWP are located in different locations. Subband.

Preferably, the UE is further configured to, if the default uplink BWP configured in the connected state has PRACH resources, when the activated downlink BWP in the connected state is the default downlink BWP, it is notified to perform After the data is received, if the uplink is out of synchronization, an LBT operation is performed, and a random access is initiated by using the PRACH in the default uplink BWP, where only one PRACH is configured in the frequency domain of the default uplink BWP.

Preferably, the base station is further configured to exchange the position of the initial activated uplink BWP of the local cell and the position of the PRACH resource in the initial activated uplink BWP with the adjacent base station through the Xn interface; according to the result of the interaction, determine whether Exist: the local unlicensed carrier cell and the adjacent unlicensed carrier cell have the same PRACH resource location, if there is, determine whether the current base station is the current PRACH resource conflict resolution entity according to the preset conflict resolution entity selection strategy, If yes, trigger to reconfigure the PRACH resources of the corresponding local cell according to the principle that the frequency domain positions of the PRACHs in the initially activated uplink BWP of the adjacent cells are different, and use the Xn interface to reconfigure the PRACH resources after adjustment. The frequency domain position of the adjacent base station is notified.

It can be seen from the above embodiment that the above technical solution configures the initial activated uplink BWP and the initial activated downlink BWP of the unlicensed carrier cell on different subbands, so that the base station sends the downlink broadcast information, reference signal and downlink control information with the UE. The operations of triggering random access are no longer mutually exclusive, and can be performed simultaneously, which increases the chance of random access of the UE in the idle state, and effectively shortens the network access delay of the terminal. In addition, by configuring the PRACH of the same-frequency neighboring cell on different subbands, or in different frequency domain positions of the same subband, the UEs in the neighboring cells will not transmit PRACH at the same time and in the same frequency domain position, effectively The uplink co-channel interference between cells is reduced, and the PRACH decoding success rate of the base station is improved.

Two specific implementation examples are provided below, and the specific implementation of this application is further elaborated:

Example 1 is as follows,

Cell 1 of the 5G base station works on an unlicensed carrier with a bandwidth of 40MHz and occupies 2 subbands, namely sub-band 0 and sub-band 1. UE1 is covered by cell 1 and is in an idle state. UE2 has established RRC with cell 1. connect.

1) The base station configures the initial activated downlink BWP of cell 1 on sub-band 0, the initial activated uplink BWP is configured on sub-band 1, and configures PRACH resources in the frequency domain of the initial activated uplink BWP;

2) The base station configures the default downlink BWP of UE2 in sub-band 0, the corresponding uplink BWP is configured in sub-band 1, and configures PRACH resources in the uplink BWP;

3) UE 1 learns the positions of the initial activated downlink BWP and the initial activated uplink BWP, and the PRACH resource position by reading the system broadcast message of cell 1;

4) At time t1, cell 1 initially activates the downlink BWP to send the downlink reference signal, UE1 wants to access the network to send data, it performs LBT monitoring on sub-band 1, and finds that the channel is idle, then UE1 selects the available uplink BWP in the initial activation. PRACH, initiate random access, and then establish an RRC connection with cell 1 after completing the access.

5) At time t2, since UE2 has no data for a period of time, its currently activated downlink BWP is the default downlink BWP. At this time, UE2 loses synchronization in uplink, and the network has data from UE2 arriving, and sends the PDCCH order command on its default downlink BWP. , UE2 immediately performs LBT monitoring on the subband where the corresponding uplink BWP is located after receiving the instruction, finds that the channel is idle, initiates random access on the PRACH configured in the BWP, completes uplink synchronization and receives downlink data.

Embodiment 2 is as follows:

Three 5G cells working on unlicensed carriers are deployed in an area, they are adjacent to each other, each cell has a bandwidth of 60MHz and occupies 3 subbands, namely sub-band 0, sub-band 1 and sub-band 2.

1) The initial activated downlink BWPs of the three cells are all configured on sub-band 0, the initial activated uplink BWPs are all configured on sub-band 2, and the location of the PRACH configured in the frequency domain of the initial activated uplink BWP of cell 1 is in sub-band Within the initial 5M bandwidth from low to high of 2, the PRACH position of cell 2 is within the second 5M bandwidth from low to high of sub-band 2, and the PRACH position of cell 3 is the same as that of cell 1;

2) The subband numbers where the respective initial activated uplink BWPs are located between the three cells are exchanged through the base station Xn interface, and the configuration position of the PRACH in the subband;

3) After information exchange, cell 3 finds that its PRACH frequency domain location configured in sub-band 2 is the same as that of cell 1. In order to avoid uplink co-channel interference caused by two cells transmitting PRACH in the same frequency domain location, cell 3 Decided to change its PRACH position to sub-band 2 from low to high within the third 5M bandwidth;

5) After the configuration modification, cell 3 sends the updated configuration to cells 1 and 2 through the Xn interface.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the present application. within the scope of protection.

Claims (8)

1. An access method for an unlicensed carrier cell, comprising:

for a cell working on an unlicensed carrier, a base station broadcasts, through a system message, the positions of an initial activated downlink bandwidth Block (BWP) and an initial activated uplink BWP of the cell, and the position of a Physical Random Access Channel (PRACH) resource in the initial activated uplink BWP, wherein the initial activated downlink BWP and the initial activated uplink BWP are located in different sub-bands, and only one PRACH is configured in the frequency domain of the initial activated uplink BWP;

and the User Equipment (UE) in an idle state learns the positions of the initial activation downlink BWP and the initial activation uplink BWP and the position of the PRACH resource according to the monitored system message, executes listen-before-talk (LBT) operation when a network needs to be connected, initiates random access by using the PRACH in the initial activation uplink BWP, and monitors and receives a random access response message returned by the base station at the initial activation downlink BWP.

2. The method of claim 1, wherein: the method further comprises:

and the base station configures a default downlink BWP and a default uplink BWP for the UE in a connected state in the cell, wherein the default downlink BWP and the default uplink BWP are positioned in different sub-bands.

3. The method of claim 2, wherein: the method further comprises:

if the default uplink BWP of the UE in the connected state is configured with PRACH resource, when the currently activated downlink BWP of the UE in the connected state is the default downlink BWP, the UE in the connected state is notified to receive data, and if the uplink is out of synchronization, performs LBT operation, and initiates random access by using the PRACH in the default uplink BWP, wherein only one PRACH is configured in the frequency domain of the default uplink BWP.

4. The method of claim 1, wherein: the method further comprises:

the method comprises the following steps that the positions of the initial activation uplink BWP of a local cell and the position of PRACH resources in the initial activation uplink BWP are interacted between adjacent base stations through an Xn interface;

the base station judges whether the following conditions exist according to the interaction result: the PRACH resource positions of a local unauthorized carrier cell and an adjacent unauthorized carrier cell are the same, if the PRACH resource positions of the local unauthorized carrier cell and the adjacent unauthorized carrier cell are the same, whether the base station is the current PRACH resource conflict solution entity is determined according to a preset conflict solution entity selection strategy, if the PRACH resource conflict solution entity exists, the PRACH resource of the corresponding local cell is triggered to be reconfigured according to the principle that the PRACH frequency domain positions in the initial activation uplink BWP of the adjacent cell are different, and the adjusted PRACH frequency domain position is notified to the adjacent base station by utilizing an Xn interface.

5. An access system for an unlicensed carrier cell, comprising:

a base station, configured to broadcast, through a system message, positions of an initial activated downlink bandwidth block BWP and an initial activated uplink BWP of a cell operating on an unlicensed carrier, and a position of a PRACH resource of a physical random access channel within the initial activated uplink BWP, where the initial activated downlink BWP and the initial activated uplink BWP are located in different subbands, and only one PRACH is configured in a frequency domain of the initial activated uplink BWP;

user Equipment (UE) is configured to learn, when the UE is in an idle state, locations of the initially activated downlink BWP and the initially activated uplink BWP and a location of the PRACH resource according to the monitored system message, perform listen-before-talk (LBT) operation when a network needs to be connected, initiate random access by using the PRACH in the initially activated uplink BWP, and monitor and receive a random access response message returned by the base station at the initially activated downlink BWP.

6. The system of claim 5, wherein:

the base station is further configured to configure a default downlink BWP and a default uplink BWP for the UE in the connected state in the cell, where the default downlink BWP and the default uplink BWP are located in different sub-bands.

7. The system of claim 6, wherein: the UE is further configured to, if there is a PRACH resource in the default uplink BWP configured in the connected state, perform LBT operation and initiate random access using the PRACH in the default uplink BWP if uplink desynchronization is performed after the activated downlink BWP in the connected state is notified of data reception when the activated downlink BWP is the default downlink BWP, where only one PRACH is configured in the frequency domain of the default uplink BWP.

8. The system of claim 5, wherein: the base station is further configured to interact with an adjacent base station through an Xn interface between the base station and the adjacent base station, where the location of the uplink BWP of the local cell is initially activated and the location of the PRACH resource within the uplink BWP is initially activated; and judging whether the following conditions exist according to the interaction result: the PRACH resource positions of a local unauthorized carrier cell and an adjacent unauthorized carrier cell are the same, if the PRACH resource positions of the local unauthorized carrier cell and the adjacent unauthorized carrier cell are the same, whether the base station is the current PRACH resource conflict solution entity is determined according to a preset conflict solution entity selection strategy, if the PRACH resource conflict solution entity exists, the PRACH resource of the corresponding local cell is triggered to be reconfigured according to the principle that the PRACH frequency domain positions in the initial activation uplink BWP of the adjacent cell are different, and the adjusted PRACH frequency domain position is notified to the adjacent base station by utilizing an Xn interface.

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