Communication method and communication apparatus

Abstract

The present application provides a communication method, comprising: receiving first information indicating a first time-frequency resource for random access, wherein the first time-frequency resource is a resource for random access on a full-duplex time unit, the first time-frequency resource comprises two or more time-frequency resource units, and any two of the two or more time-frequency resource units do not overlap in a time domain; if a first condition is met, the first time-frequency resource unit is selected as a time-frequency resource for random access; and if the first condition is not met, the second time-frequency resource unit is selected as the time-frequency resource for random access.

Description

Communication method and communication device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 23, 2024, with application number 202410205335.0 and application name “A Communication Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method and a communication device. Background Art

[0003] With the rapid development of the fifth-generation mobile communication technology, new radio (NR), a variety of communication needs have emerged. To meet the needs of emerging services, a full-duplex (FD) solution has been proposed to improve the uplink coverage of the time-division duplex (TDD) system.

[0004] Random access is a step in the process of a terminal device connecting to the network. The terminal device can complete uplink time synchronization with the network device through the random access process. For initial access, the terminal device can establish a radio resource control (RRC) connection with the network device through the random access process, thereby realizing the transmission of uplink and downlink service data. Currently, terminal devices are supported to perform random access (RA) on FD time units. However, during the random access process on FD time units, uplink and downlink transmissions will interfere with each other, affecting transmission performance. Therefore, how to reduce the interference of random access on FD time units has become an urgent problem to be solved.

[0005] Summary of the Invention

[0006] The present application provides a communication method to reduce interference caused by random access of terminal devices on FD time units.

[0007] In the first aspect, a communication method is provided. The method can be executed by a first device, or it can also be executed by other entities, and this application does not limit this. For the convenience of description, the following is an example of execution by the first device. Among them, the first device can be a terminal device, or a chip or circuit in the terminal device (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or system in package (SIP) chip containing a modem core), etc., or a functional module in the terminal device that can call and execute a program, etc.

[0008] The communication method includes:

[0009] A first device receives first information from a second device, where the first information indicates a first time-frequency resource, the first time-frequency resource is used for random access, the first time-frequency resource includes two or more time-frequency resource units, any two of the two or more time-frequency resource units do not overlap in the time domain, the two or more time-frequency resource units include a first time-frequency resource unit and a second time-frequency resource unit, the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, the first time domain resource is located in the first time domain unit, the first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission, and the first frequency domain resource is located in the first subband;

[0010] If the first condition is met, the first device selects the first time-frequency resource unit as the time-frequency resource for random access;

[0011] If the first condition is not met, the first device selects the second time-frequency resource unit as the time-frequency resource for random access.

[0012] Based on the above technical solution, after the first device receives the first information, it can obtain the first time-frequency resource for random access configured by the second device (such as a network device) for the first device. In this technical solution, the first time-frequency resource corresponds to the first time domain resource and the first frequency domain resource. The first time domain resource is located in the first time domain unit. The first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission. The first frequency domain resource is located in the first subband, that is, the first time-frequency resource is located in the FD time unit. The first time-frequency resource includes multiple time-frequency resource units that do not overlap in the time domain (or called sub-time-frequency resources, partial time-frequency resources, etc.). The first device can select a time-frequency resource unit from two or more time-frequency resource units based on the first condition as the time-frequency resource for random access, so that different devices can select different time-frequency resource units as time-frequency resources for random access according to the first condition, so that different devices can use different parts of the first time-frequency resource in a time-division manner, so that the base station can adjust the scheduling strategy of other downlink terminals in the corresponding time period according to the terminal type or terminal status or interference situation corresponding to the different parts of the first time-frequency resource, or understand the terminal type or terminal status or interference situation according to the different parts of the first time-frequency resource used by the terminal to adjust the scheduling strategy of the subsequent communication of this terminal accordingly. This can reduce interference between different devices and achieve the purpose of reducing interference when the terminal equipment performs random access on the FD time unit.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the first condition is that a measurement value is greater than or equal to a first threshold, and the measurement value is measured by the first device.

[0014] Based on the above technical solution, the first condition may be that the measured value of the reference signal is greater than or equal to a first threshold; satisfying the first condition includes: the measured value is greater than or equal to the first threshold. That is, the first device may determine whether the first condition is satisfied based on the measured value obtained by measuring the reference signal and the first threshold, thereby determining the time-frequency resource to be used for random access.

[0015] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the first device receiving second information from a second device, where the second information indicates the first threshold.

[0016] Based on the above technical solution, the first threshold can be indicated by the second device, that is, the second device can indicate the usage of the first time-frequency resource by indicating the first threshold to indicate that the first time-frequency resource is used for random access by different devices.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the first threshold is a reference signal receiving power threshold, and the measured value is the receiving power of the reference signal; or, the first threshold is a reference signal transmitting power threshold, and the measured value is the transmitting power of the reference signal; or, the first threshold is a reference signal path loss threshold, and the measured value is the path loss of the reference signal; or, the first threshold is a distance threshold between the first device and the second device, and the measured value is the distance between the first device and the second device.

[0018] Based on the above technical solution, the first threshold value can be in different forms, and the corresponding measurement value can also be in different forms, thereby improving the flexibility of the solution.

[0019] In conjunction with the first aspect, in certain implementations of the first aspect, the first condition is that the state of the first device is idle or inactive. Satisfying the first condition includes: the state of the first device is idle or inactive.

[0020] In conjunction with the first aspect, in certain implementations of the first aspect, the first condition is that the state of the first device is a connected state. Satisfying the first condition includes: the state of the first device is a connected state.

[0021] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the first device obtains a first association relationship, where the first association relationship is an association relationship between the state of the first device and the two or more time-frequency resource units.

[0022] Based on the above technical solution, the first condition may be that the state of the first device is idle, inactive or connected, that is, the first device can determine the random access time-frequency resources used based on its own state and the association between the state of the first device and more than two time-frequency resource units.

[0023] In conjunction with the first aspect, in certain implementations of the first aspect, the first condition is that the type of the first device is the first type, or the first condition is that the type of the first device is the second type, wherein the first type includes terminals with interference control capabilities, terminals with environmental awareness capabilities, or terminals whose maximum transmit power level is less than or equal to a predetermined threshold. Exemplarily, a terminal with interference control capabilities may be a terminal capable of using a narrower PRACH transmit beam, for example, a beamwidth less than or equal to a given threshold; a terminal with environmental awareness capabilities may be a terminal that senses the locations of surrounding terminals and adjusts the direction of transmitted signals to avoid adjacent terminals. The second type includes terminals without interference control capabilities, terminals without environmental awareness capabilities, or terminals whose maximum transmit power is greater than a predetermined threshold. Exemplarily, a terminal without interference control capabilities may be a terminal that uses a wide PRACH transmit beam, for example, a beamwidth greater than a given threshold; a terminal without environmental awareness capabilities may be a terminal that is unable to sense the locations of surrounding terminals and / or adjust the direction of transmitted signals to avoid adjacent terminals.

[0024] It should be understood that the first type of terminals cause less interference, while the second type of terminals cause greater interference.

[0025] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the first device obtains a second association relationship, where the second association relationship is an association relationship between the type of the first device and the two or more time-frequency resource units.

[0026] Based on the above technical solution, the first condition may be that the type of the first device is the first type or the second type, that is, the first device may determine the random access time-frequency resources used based on its own type and the association between the type of the first device and more than two time-frequency resource units.

[0027] In combination with the first aspect, in certain implementations of the first aspect, the time domain occupied by the first time domain resource is a first time period, the time domain occupied by the first time-frequency resource unit is a first sub-time period, and the time domain occupied by the second time-frequency resource unit is a second sub-time period, wherein the starting point of the first sub-time period is the starting point of the first time period, the end point of the first sub-time period is the starting point of the second sub-time period, and the end point of the second sub-time period is the end point of the first time period.

[0028] In combination with the first aspect, in certain implementations of the first aspect, the method further includes: the first device receives a system message, the system message indicates a synchronization signal block (synchronization signal and PBCH Block, SSB) index, the SSB index is associated with a first random access opportunity set and a second random access opportunity set, the first random access opportunity set belongs to the first time-frequency resource unit, and the second random access opportunity set belongs to the second time-frequency resource unit.

[0029] In combination with the first aspect, in certain implementations of the first aspect, the first random access opportunity set is indicated by a first mask index, and the second random access opportunity set is indicated by a second mask index; or, the first random access opportunity set is located in an odd time slot, and the second random access opportunity set is located in an even time slot; or, the starting time of the first random access opportunity in the first random access opportunity set is an odd orthogonal frequency division multiplexing symbol, and the starting time of the second random access opportunity in the second random access opportunity set is an even orthogonal frequency division multiplexing symbol; or, the index of each random access opportunity in the first random access opportunity set is an odd number, and the index of each random access opportunity in the second random access opportunity set is an even number.

[0030] In combination with the first aspect, in certain implementations of the first aspect, the first time-frequency resource is a physical random access channel (PRACH) resource, and each of the two or more time-frequency resource units is a random access opportunity.

[0031] In the second aspect, a communication method is provided. The method can be executed by a second device, or it can also be executed by other entities, and this application does not limit this. For the convenience of description, the following is an example of execution by the second device. Among them, the second device can be a network device, or a chip or circuit in the network device (such as a modem chip, also known as a baseband chip, or a system-on-chip chip or system-level package chip containing a modem core), etc., or a functional module in the network device that can call and execute a program, etc.

[0032] The communication method includes: a second device determines first information, the first information indicates a first time-frequency resource, the first time-frequency resource is used for random access, the first time-frequency resource includes two or more time-frequency resource units, any two of the two or more time-frequency resource units do not have overlapping parts in the time domain, the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, the first time domain resource is located in the first time domain unit, the first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission, and the first frequency domain resource is located in the first subband; the second device sends the first information to the first device.

[0033] Based on the above technical solution, the second device (such as a network device) can configure the first time-frequency resource for random access to the first device (such as a terminal device) through the first information. In this technical solution, the first time-frequency resource corresponds to the first time domain resource and the first frequency domain resource. The first time domain resource is located in the first time domain unit. The first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission. The first frequency domain resource is located in the first subband, that is, the first time-frequency resource is located in the FD time unit. The first time-frequency resource includes multiple time-frequency resource units that do not overlap in the time domain (or called sub-time-frequency resources, partial time-frequency resources, etc.), so that the first device can select a time-frequency resource unit from two or more time-frequency resource units as a time-frequency resource for random access, so that different devices can select different time-frequency resource units as time-frequency resources for random access, so that different devices can use different parts of the first time-frequency resource in time-sharing, so that the base station can adjust the downlink scheduling strategy according to the terminal type or interference situation corresponding to the different parts of the first time-frequency resource, or understand the terminal type or interference situation according to the different parts of the first time-frequency resource used by the terminal to adjust the scheduling strategy of the terminal's subsequent communication accordingly. This can reduce interference between different devices and achieve the purpose of reducing interference caused by random access of terminal equipment on the FD time unit.

[0034] In combination with the second aspect, in certain implementations of the second aspect, the second device sends second information to the first device, the second information indicates a first threshold, the first threshold and the measurement value are used by the first device to select one of the two or more time-frequency resource units as a time-frequency resource for random access, and the measurement value is measured by the first device.

[0035] Based on the above technical solution, the first threshold can be indicated by the second device, that is, the second device can indicate the usage of the first time-frequency resource by indicating the first threshold to indicate that the first time-frequency resource is used for random access by different devices.

[0036] In combination with the second aspect, in certain implementations of the second aspect, the first threshold is a reference signal receiving power threshold, and the measured value is the receiving power of the reference signal; or, the first threshold is a reference signal transmitting power threshold, and the measured value is the transmitting power of the reference signal; or, the first threshold is a reference signal path loss threshold, and the measured value is the path loss of the reference signal; or, the first threshold is a distance threshold between the first device and the second device, and the measured value is the distance between the first device and the second device.

[0037] Based on the above technical solution, the first threshold value can be in different forms, and the corresponding measurement value can also be in different forms, thereby improving the flexibility of the solution.

[0038] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: the second device sends third information to the first device, the third information indicates a first association relationship, and the first association relationship is an association relationship between the state of the first device and the two or more time-frequency resource units.

[0039] Based on the above technical solution, the second device can indicate the association between the status of the first device and the two or more time-frequency resource units through the third information, so that the first device can determine the random access time-frequency resources to be used based on its own status.

[0040] In combination with the second aspect, in certain implementations of the second aspect, the two or more time-frequency resource units include a first time-frequency resource unit and a second time-frequency resource unit, the time domain occupied by the first time domain resource is a first time period, the time domain occupied by the first time-frequency resource unit is a first sub-time period, and the time domain occupied by the second time-frequency resource unit is a second sub-time period.

[0041] In combination with the second aspect, in certain implementations of the second aspect, the second device receives a preamble code from the first device on the first time-frequency resource unit; the second device sends first scheduling information to a third device that performs physical downlink shared channel PDSCH transmission in the first sub-time period, and the first scheduling information includes at least one of the following information: the PDSCH transmission power, the downlink resources for transmitting the PDSCH, the beam for transmitting the PDSCH, a repeated transmission indication, a modulation and coding strategy MCS or a precoding strategy, wherein the PDSCH transmission power is greater than or equal to the second threshold, the distance between the downlink resources for transmitting the PDSCH and the first time-frequency resource unit is greater than or equal to the third threshold, and the repeated transmission indication is used to indicate that the PDSCH can be repeatedly transmitted and the MCS is less than or equal to the fourth threshold.

[0042] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: the second device receives a preamble code from the first device on the second time-frequency resource unit; the second device sends second scheduling information to a fourth device that performs physical downlink shared channel PDSCH transmission in the second sub-time period, and the second scheduling information includes at least one of the following information: the PDSCH transmission power, the downlink resources for transmitting the PDSCH, the beam for transmitting the PDSCH, a repeated transmission indication, or a modulation and coding strategy MCS, wherein the PDSCH transmission power is less than a second threshold, the distance between the downlink resources for transmitting the PDSCH and the first time-frequency resource unit is less than a third threshold, and the repeated transmission indication is used to indicate that the PDSCH cannot be repeatedly transmitted and the MCS is greater than or equal to the fourth threshold.

[0043] Based on the above technical solution, the first device sends a preamble code in different time domain resources according to the first condition. That is, devices that meet the first condition and those that do not meet the first condition can use the first time-frequency resource in a time-division manner, which can provide a priori information for the second device to estimate and control interference, so that the second device can differentially schedule users performing downlink communication in the time domain corresponding to the first time-frequency resource. For example, when the second device schedules downlink users in the time period corresponding to the first time-frequency resource unit or the second time-frequency resource unit for random access of edge users (or users with high PRACH transmit power), the scheduling strategy adopted includes user selection, resource allocation, power control, MCS adjustment, transmit precoding (downlink beam), etc. For example, when the first device uses the first time-frequency resource unit for random access, the first device is a high-interference terminal. Therefore, for downlink users using the first time-frequency resource unit, the second device can allocate higher PDSCH transmit power to them, allocate downlink resources away from the first time-frequency resource unit, schedule devices far away from the first device, use a beam with low spatial correlation with the SSB beam corresponding to the first time-frequency resource, lower the MCS, enable repeated transmission, etc., to reduce interference.

[0044] As an example and not a limitation, when the first condition is that the measurement value is greater than or equal to a first threshold, and the first threshold is the received power of the reference signal, if the first device determines that the first condition is met, then the first device is a terminal that causes low interference; or, if the first device determines that the first condition is not met, then the first device is a terminal that causes high interference.

[0045] When the first condition is that the measured value is greater than or equal to the first threshold, and the first threshold is the transmission power of the reference signal, the path loss, or the distance between the terminal device and the network device, if the first device determines that the first condition is met, then the first device is a terminal that causes low interference; or, if the first device determines that the first condition is not met, then the first device is a terminal that causes large interference.

[0046] When the first condition is that the state of the first device is idle or inactive, if the first device determines that the first condition is met, the first device is a terminal that causes low interference; or, if the first device determines that the first condition is not met, the first device is a terminal that causes high interference.

[0047] When the first condition is that the state of the first device is a connected state, if the first device determines that the first condition is met, the first device is a terminal causing high interference; or if the first device determines that the first condition is not met, the first device is a terminal causing low interference.

[0048] When the first condition is that the type of the first device is the first type, if the first device determines that the first condition is met, the first device is a terminal causing low interference; or, if the first device determines that the first condition is not met, the first device is a terminal causing high interference.

[0049] When the first condition is that the type of the first device is the second type, if the first device determines that the first condition is met, the first device is a terminal causing large interference; or, if the first device determines that the first condition is not met, the first device is a terminal causing low interference.

[0050] For a terminal that causes large interference, if the first device selects the first time-frequency resource unit or the second time-frequency resource unit for random access, since the first device is a high-interference terminal, the second device can allocate higher PDSCH transmission power to the downlink user when scheduling the downlink user on the time-frequency resource unit selected by the first device, allocate downlink resources far away from the first time-frequency resource unit, schedule users that are far away from the first device, use a beam with low spatial correlation of the SSB beam corresponding to the first time-frequency resource, lower the MCS, enable repeated transmission, etc., to reduce interference.

[0051] For a terminal that causes low interference, if the first device selects the first time-frequency resource unit or the second time-frequency resource unit for random access, since the first device is a low-interference terminal, the second device does not need to consider the interference caused by the first device when scheduling downlink users on the time-frequency resource unit selected by the first device. Alternatively, the second device may allocate low PDSCH transmission power to it, allocate downlink resources close to the first time-frequency resource unit, schedule users that are close to the first device, use a beam with high spatial correlation with the SSB beam corresponding to the first time-frequency resource, increase the MCS, disable repeated transmission, and so on.

[0052] For the first device #1 (for example, a device located at the edge of a cell) being a terminal causing large interference, and the first device #2 (for example, a device located at the center of the cell) being a terminal causing low interference, if the second device configures the first time-frequency resource in the middle of the uplink subband (farthest from the downlink subband below the uplink subband, and / or farthest from the downlink subband above the uplink subband), or the second device configures the first time-frequency resource at the top of the uplink subband (for example, the first frequency domain unit includes an uplink subband and a downlink subband, and the uplink subband is located above the downlink subband), or the second device configures the first time-frequency resource at the bottom of the uplink subband (for example, the first frequency domain unit includes an uplink subband and a downlink subband, and the uplink subband is located below the downlink subband), and the first device #1 selects the first time-frequency resource unit for random access, the first device #2 selects the second time-frequency resource unit for random access, and the second device schedules the random access response (random access response) of the first device #1 response, RAR) is farther away from the first time-frequency resource than the RAR of the first device #2 scheduled, and the message 5 (message 5, Msg5) and message 3 (message 3, Msg3) of the first device #1 scheduled by the second device are closer to the middle of the uplink subband than the Msg5 and Msg3 of the first device #2 scheduled.

[0053] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: the second device sends a system message to the first device, the system message indicates a synchronization signal block SSB index, the SSB index is associated with a first random access opportunity set and a second random access opportunity set, the first random access opportunity set belongs to the first time-frequency resource unit, and the second random access opportunity set belongs to the second time-frequency resource unit.

[0054] In combination with the second aspect, in certain implementations of the second aspect, the first random access opportunity set is indicated by a first mask index, and the second random access opportunity set is indicated by a second mask index; or, the first random access opportunity set is located in an odd time slot, and the second random access opportunity set is located in an even time slot; or, the starting time of the first random access opportunity in the first random access opportunity set is an odd orthogonal frequency division multiplexing symbol, and the starting time of the second random access opportunity in the second random access opportunity set is an even orthogonal frequency division multiplexing symbol; or, the index of each random access opportunity in the first random access opportunity set is an odd number, and the index of each random access opportunity in the second random access opportunity set is an even number.

[0055] In a third aspect, a communication method is provided. The method can be performed by a first device, or it can also be performed by other entities, and this application does not limit this. For the sake of convenience, the following is an example of execution by the first device. Among them, the first device can be a terminal device, or a chip or circuit in the terminal device (such as a modem chip, also known as a baseband chip, or a system-on-chip chip or system-level package chip containing a modem core), or a functional module in the terminal device that can call and execute a program.

[0056] The communication method includes: receiving fourth information, the fourth information indicating a first parameter corresponding to a first time-frequency resource, the first time-frequency resource corresponding to a first time domain resource and a first frequency domain resource, the first time domain resource being located in a first time domain unit, the first frequency domain unit corresponding to the first time domain unit including a frequency domain resource for uplink transmission and a frequency domain resource for downlink transmission, the first frequency domain resource being located in the first frequency domain unit, and the first parameter including at least one of the following parameters: a format of a first preamble code, a first receiving power, or a first transmitting power; and receiving fifth information, the fifth information indicating a second parameter corresponding to a second time-frequency resource, the second time-frequency resource corresponding to a second time domain resource and a second frequency domain resource, the second time domain resource being located in a second time domain unit, the second frequency domain unit corresponding to the second time domain unit including a frequency domain resource for uplink transmission, the second frequency domain resource being located in the second frequency domain unit, and the second parameter including at least one of the following parameters: a format of a second preamble code, a second receiving power, or a second transmitting power; the length of the format of the first preamble code is greater than the length of the format of the second preamble code, the first receiving power is less than the second receiving power, and the first transmitting power is greater than the second transmitting power.

[0057] Based on the above technical solution, different preamble code formats and / or powers are configured for the first time-frequency resource and the second time-frequency resource. For example, the length of the preamble code format configured for the first time-frequency resource is greater than the format of the preamble code configured for the second time-frequency resource. For another example, the target receiving power configured for the first time-frequency resource is less than the target receiving power configured for the second time-frequency resource, so that the terminal device has lower transmission power on the first time-frequency resource and causes lower interference. At the same time, the long preamble code format takes a longer time and can also complete more power accumulation, so as to improve the random access performance of the terminal device on the first time-frequency resource.

[0058] In a fourth aspect, a communication method is provided. The method can be performed by a second device, or it can also be performed by other entities, and this application does not limit this. For the sake of convenience, the following is an example of execution by a second device. Among them, the second device can be a network device, or a chip or circuit in a network device (such as a modem chip, also known as a baseband chip, or a system-on-chip chip or system-level package chip containing a modem core), etc., or a functional module in a network device that can call and execute a program, etc.

[0059] The communication method includes: sending fourth information, the fourth information indicating a first parameter corresponding to a first time-frequency resource, the first time-frequency resource corresponding to a first time domain resource and a first frequency domain resource, the first time domain resource being located in a first time domain unit, the first frequency domain unit corresponding to the first time domain unit including a frequency domain resource for uplink transmission and a frequency domain resource for downlink transmission, the first frequency domain resource being located in the first frequency domain unit, and the first parameter including at least one of the following parameters: a format of a first preamble code, a first receiving power, or a first transmitting power; sending fifth information, the fifth information indicating a second parameter corresponding to a second time-frequency resource, the second time-frequency resource corresponding to a second time domain resource and a second frequency domain resource, the second time domain resource being located in a second time domain unit, the second frequency domain unit corresponding to the second time domain unit including a frequency domain resource for uplink transmission, the second frequency domain resource being located in the second frequency domain unit, and the second parameter including at least one of the following parameters: a format of a second preamble code, a second receiving power, or a second transmitting power; the length of the format of the first preamble code is greater than the length of the format of the second preamble code, the first receiving power is less than the second receiving power, and the first transmitting power is greater than the second transmitting power.

[0060] The technical effects of the method shown in the above fourth aspect and its possible design can refer to the technical effects in the third aspect and its possible design.

[0061] In a fifth aspect, a communication device is provided. The communication device is configured to implement the first or third aspect above, and any one of the embodiments thereof. Specifically, the communication device includes a processor and a memory, the memory being configured to store a computer program; the processor being configured to retrieve and execute the computer program from the memory, causing the communication device to implement the first or third aspect above, and any one of the embodiments thereof.

[0062] In one implementation, the communication device is a terminal device, and the transceiver unit may be a transceiver or an input / output interface. The processing unit may be at least one processor. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0063] In another implementation, the communication device may be a chip, chip system, or circuit in a terminal device. In this case, the transceiver unit may be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; and the processing unit may be at least one processor, processing circuit, or logic circuit.

[0064] In a sixth aspect, a communication device is provided. The communication device is configured to execute the second aspect or the fourth aspect, and any one of the embodiments thereof. Specifically, the communication device includes a processor and a memory, the memory being configured to store a computer program; the processor being configured to retrieve and execute the computer program from the memory, causing the network device to execute the second aspect or the fourth aspect, and any one of the embodiments thereof.

[0065] In one implementation, the communication device is a network device, and the transceiver unit may be a transceiver or an input / output interface. The processing unit may be at least one processor. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0066] In another implementation, the communication device may be a chip, chip system, or circuit in a network device. In this case, the transceiver unit may be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; and the processing unit may be at least one processor, processing circuit, or logic circuit.

[0067] In a seventh aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed, the method of any one of the implementation modes of the first to fourth aspects is executed.

[0068] In an eighth aspect, a computer program product comprising instructions is provided. When the computer program product is executed, the method provided in any one of the implementations of the first to fourth aspects is executed.

[0069] In a ninth aspect, a chip is provided, which includes a processor and a communication interface. The processor reads instructions through the communication interface and executes the method provided by any one of the implementation methods of the first to fourth aspects above.

[0070] Optionally, as an implementation method, the chip also includes a memory, the memory stores a computer program or instructions, and the processor is used to execute the computer program or instructions stored in the memory. When the computer program or instructions are executed, the processor is used to execute the method provided by any one of the implementation methods of the first and second aspects above.

[0071] In a tenth aspect, a communication system is provided, comprising the communication device of the fifth aspect and the communication device of the sixth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] FIG1 is a schematic diagram of a communication system suitable for use in the present application.

[0073] FIG2 is a schematic diagram showing the time-frequency division of the TDD solution.

[0074] FIG3 (a) and (b) show schematic diagrams of the time-frequency division of the SBFD scheme.

[0075] FIG4 is a schematic diagram showing the time-frequency division of the SFFD scheme.

[0076] FIG5 shows a schematic flow chart of a four-step random access process.

[0077] FIG6 shows a schematic flow chart of a two-step random access process.

[0078] FIG7 is a schematic diagram showing configuration of PRACH in a UL time slot.

[0079] FIG8 (a) and (b) show schematic diagrams of PRACH time-frequency resources.

[0080] Figures 9(a) to 9(c) show schematic diagrams of the association relationship between RO and SSB.

[0081] FIG10 (a) and (b) show the interference of the SBFD random access process.

[0082] FIG11 is a schematic diagram showing interference between terminal devices in PRACH transmission under different situations.

[0083] FIG12 (a) and (b) show a schematic diagram of a method for reducing interference.

[0084] FIG13 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0085] FIG14 is a schematic diagram of a resource configuration provided in an embodiment of the present application.

[0086] Figure 15 (a) and (b) show the time division method of the first time-frequency resource.

[0087] FIG16 is a schematic diagram of RO selection provided in an embodiment of the present application.

[0088] FIG17 is another schematic diagram of RO selection provided in an embodiment of the present application.

[0089] FIG18 is another schematic diagram of RO selection provided in an embodiment of the present application.

[0090] FIG19 is a scheduling diagram provided in an embodiment of the present application.

[0091] Figure 20 is another scheduling diagram provided in an embodiment of the present application.

[0092] Figure 21 is a schematic flowchart of another communication method provided in an embodiment of the present application.

[0093] FIG22 is another schematic diagram of resource configuration provided in an embodiment of the present application.

[0094] Figure 23 is a schematic block diagram of a communication device provided in an embodiment of the present application.

[0095] Figure 24 is a schematic diagram of another communication device provided in an embodiment of the present application.

[0096] Figure 25 is a schematic diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0097] In order to facilitate understanding of the embodiments of the present application, the following points are first explained.

[0098] First, in this application, "used to indicate" can include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A.

[0099] The information indicated by the indication information is called the information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, wherein there is an association between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, it is also possible to use the arrangement order of each piece of information agreed in advance (such as specified in the protocol) to achieve the indication of specific information, thereby reducing the indication overhead to a certain extent. At the same time, it is also possible to identify the common parts of each piece of information and indicate them uniformly to reduce the indication overhead caused by indicating the same information separately.

[0100] Second, "at least one" shown in the present application refers to one or more, and "multiple" refers to more than two (including two). In addition, in the embodiments of the present application, "first", "second" and various digital numbers (for example, "#1", "#2", etc.) are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each process below does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. It should be understood that the objects described in this way can be interchangeable under appropriate circumstances so as to be able to describe solutions other than the embodiments of the present application. In addition, in the embodiments of the present application, words such as "S310" are only for the convenience of description and are not used to limit the order of execution of steps.

[0101] Third, in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0102] Fourth, the term "storage" used in the embodiments of this application may refer to storage in one or more memories. The one or more memories may be provided separately or integrated into an encoder or decoder, a processor, or a communication device. The one or more memories may also be partially provided separately and partially integrated into a decoder, a processor, or a communication device. The type of memory may be any form of storage medium, and this application is not limited thereto.

[0103] Fifth, in the implementation of this application, "protocol" may refer to a standard protocol in the field of communications, for example, it may include the NR protocol and related protocols used in future communication systems, and this application does not limit this.

[0104] Sixth, in the embodiments of the present application, the terms “of”, “corresponding, relevant”, “corresponding” and “associate” can sometimes be used interchangeably. It should be noted that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0105] Seventh, in the embodiments of the present application, "under the circumstances", "when", and "if" can sometimes be used interchangeably. It should be pointed out that when the distinction between them is not emphasized, the meanings they intend to express are consistent.

[0106] Eighth, the term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0107] Ninth, in this document, "message", "information", or "information element (IE)" can be used interchangeably. There is no limitation on the name of the message or information, as long as it can achieve the corresponding function.

[0108] The technical solution in this application will be described below with reference to the accompanying drawings.

[0109] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR) and future communication systems, vehicle-to-other devices (V2X), where V2X may include vehicle to network (V2N), vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (V2P), etc., long term evolution-vehicle (LTE-V), Internet of Vehicles, machine type communication (MTC), Internet of Things (IoT), etc. things, IoT), long term evolution-machine (LTE-M), machine to machine (M2M), etc.

[0110] Figure 1 is a schematic diagram of a communication system applicable to the present application. As shown in Figure 1 , communication system 100 includes at least one network device, such as network device 110 shown in Figure 1 ; communication system 100 may also include at least one terminal device, such as terminal device 120 and / or terminal device 130 shown in Figure 1 . Network device 110 and terminal device 120 or terminal device 130 can communicate via a wireless link, thereby exchanging information. It will be appreciated that network devices and terminal devices may also be referred to as communication devices or communication apparatuses.

[0111] A network device is a network-side device with wireless transceiver functions. A network device may be a device in a radio access network (RAN) that provides wireless communication functions for terminal devices, and is called a RAN device. The RAN may be a cellular system related to the 3rd Generation Partnership Project (3GPP), such as a 5G mobile communication system, or a future-oriented evolution system. The RAN may also be an open radio access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. For example, the network device may be a base station, an evolved NodeB (eNodeB), a next-generation NodeB (gNB) in a 5G mobile communication system, a base station that is subsequently evolved by 3GPP, a transmission reception point (TRP), an access node in a WiFi system, a wireless relay node, a wireless backhaul node, etc. In communication systems using different radio access technologies (RATs), the names of devices with base station functions may be different. For example, in an LTE system, it may be referred to as an eNB or eNodeB, and in a 5G system or an NR system, it may be referred to as a gNB. This application does not limit the specific name of the base station. The network device may include one or more co-sited or non-co-sited transmitting and receiving points. For another example, the network device may include at least one of the following items: one or more centralized units (CU), one or more distributed units (DU), and one or more radio units (RU). In different systems, CU (or CU-CP and CU-UP), DU, or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an ORAN system, CU may also be referred to as O-CU (Open CU), DU may also be referred to as O-DU (Open DU), CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. Any of the CU (or CU-CP, CU-UP), DU, and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. For example, the functions of the CU may be implemented by one entity or different entities.For example, the functions of the CU are further divided, that is, the control plane and user plane are separated and implemented through different entities, namely the control plane CU entity (i.e., CU-CP entity) and the user plane CU entity (i.e., CU-UP entity). The CU-CP entity and CU-UP entity can be coupled with the DU to jointly complete the functions of the access network device. For example, the CU is responsible for processing non-real-time protocols and services, and implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, and implementing the functions of the radio link control (RLC) layer, media access control (MAC) layer, and physical (PHY) layer. In this way, some functions of the wireless access network device can be implemented through multiple network function entities. These network function entities can be network elements in hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). The network device may also include an active antenna unit (AAU). The AAU implements some physical layer processing functions, RF processing, and related functions of the active antenna. Since the information of the RRC layer will eventually become the information of the PHY layer, or be converted from the information of the PHY layer, therefore, under this architecture, high-level signaling, such as RRC layer signaling, can also be considered to be sent by DU, or, sent by DU+AAU. It can be understood that the network device can be a device including one or more of a CU node, a DU node, and an AAU node. In addition, the CU can be divided into a network device in the access network (radio access network, RAN), or the CU can be divided into a network device in the core network (core network, CN), and this application does not limit this. For example, in the vehicle to everything (V2X) technology, the access network device can be a road side unit (RSU). Multiple access network devices in the communication system can be base stations of the same type or different types. The base station can communicate with the terminal device, or it can communicate with the terminal device through a relay station. In the embodiments of the present application, the apparatus for implementing the network device function may be the network device itself, or may be an apparatus capable of supporting the network device in implementing the function, such as a chip system or a combination of devices or components capable of implementing the access network device function, which may be installed in the network device. In the embodiments of the present application, the chip system may be composed of a chip or may include a chip and other discrete components.

[0112] A terminal device is a user-side device with wireless transceiver capabilities. It can be a fixed device, mobile device, handheld device (such as a mobile phone), wearable device, in-vehicle device, or a wireless device built into any of the above devices (such as a communication module, modem, or chip system). Terminal devices are used to connect people, objects, and machines, and can be used in a wide range of scenarios, such as cellular communications, device-to-device (D2D) communications, vehicle-to-everything (V2X) communications, machine-to-machine / machine-type communications (M2M / MTC) communications, the Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, drones, robots, and other scenarios. Exemplarily, the terminal device can be a handheld terminal in cellular communication, a communication device in D2D, an Internet of Things device in MTC, a surveillance camera in intelligent transportation and smart cities, or a communication device on a drone, etc. The terminal device may sometimes be referred to as user equipment (UE), user terminal, user device, user unit, user station, terminal, access terminal, access station, UE station, remote station, mobile device or wireless communication device, etc. The terminal device may also be a terminal device in an IoT system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection. In an embodiment of the present application, IoT technology can achieve massive connections, deep coverage, and terminal power saving through, for example, narrowband (NB) technology. In an embodiment of the present application, the device for realizing the function of the terminal device may be a terminal device, or a device that can support the terminal device to realize the function, such as a chip system or a combination device or component that can realize the function of the terminal device. The device can be installed in the terminal device.

[0113] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0114] For example, the communication system 100 may further include an application function (AF) network element, which is a control plane network function provided by the operator network and is used to provide application layer information; the communication system 100 may further include a session management function (SMF) network element, which is a control plane network function provided by the operator network. In the embodiment of the present application, when the communication system 100 includes the AF network element and the SMF network element, the AF can send service-related information to the network device via the SMF.

[0115] To facilitate understanding of the embodiments of the present application, the basic concepts involved in the present application are first explained.

[0116] 1. TDD: In a TDD system, time domain resources are divided into uplink and downlink. For example, a possible uplink / downlink configuration in a TDD system is DDDSU, where D represents a downlink timeslot, where every symbol in a downlink timeslot is a downlink symbol; U represents an uplink timeslot, where every symbol in an uplink timeslot is an uplink symbol; and S represents a special timeslot, which includes at least flexible symbols.

[0117] In the widely used TDD system, the downlink usually occupies most of the time resources, which results in poor uplink coverage and large latency, and cannot meet the needs of emerging services (such as VR, AR, etc.).

[0118] For example, as shown in Figure 2, the horizontal direction represents the time domain and the vertical direction represents the frequency domain. This includes a set of time-frequency resources for downlink transmission (e.g., downlink data or downlink control information) and a set of time-frequency resources for uplink transmission (e.g., uplink data or uplink control information). The time domain range occupied by the time-frequency resources for downlink transmission is called a downlink time slot (DL slot), and the time domain range occupied by the time-frequency resources for uplink transmission is called an uplink time slot (UL slot).

[0119] 2. SBFD: To meet the needs of emerging services, the SBFD solution was proposed. In the SBFD solution, a carrier (e.g., a component carrier (CC)) is divided into multiple overlapping or non-overlapping subbands, and the transmission directions of different subbands can be different. For example, a carrier may include a first subband and a second subband that are non-overlapping, and the first and second subbands have different transmission directions.

[0120] It should be noted that the first subband and the second subband refer to two types of subbands with different transmission directions, and do not mean that a carrier contains only two subbands. For example, a carrier includes subband #1 and subband #2, where the transmission directions of subband #1 and subband #2 are different. Alternatively, a carrier includes subband #1, subband #2, and subband #3, where the transmission directions of subband #1 and subband #3 are the same, and the transmission directions of subband #1 and subband #2 are different.

[0121] In this application, SBFD includes subband overlapping full duplex and subband non-overlapping full duplex.

[0122] For ease of understanding, the time-frequency division method in the SBFD scheme is briefly introduced below with reference to (a) and (b) in FIG3 .

[0123] As shown in (a) and (b) of Figure 3, the horizontal direction represents the time domain, the vertical direction represents the frequency domain, DL represents downlink resources, which are used for downlink data or control information transmission, and UL represents uplink resources, which are used for uplink data or control information transmission. The time period that includes only downlink resources is called a downlink time slot or a downlink symbol, the time period that includes only uplink resources is called an uplink time slot or an uplink symbol, and the time period that includes both downlink and uplink resources is called an SBFD time slot or an SBFD symbol. In this application, an SBFD time slot, an SBFD symbol, or a time period that includes both downlink and uplink resources may be referred to as an SBFD time unit.

[0124] 3. SBFD time unit: includes uplink frequency resources and downlink frequency resources, wherein the uplink frequency resources are used for uplink transmission and the downlink frequency resources are used for downlink transmission. It can be understood that the SBFD time unit includes subbands for uplink transmission and downlink transmission, and the base station can use the subbands on the SBFD time unit to perform SBFD operation. In the embodiment of the present application, when the time unit is a symbol, the SBFD time unit is an SBFD symbol. When the time unit is a time slot, or a subframe, or a half-frame, or a frame, or a mini-subframe, or a mini-time slot, or a transmission occasion (TO), the SBFD time unit may refer to a time unit containing an SBFD symbol.

[0125] It should be noted that the frequency domain resources on the SBFD time unit of the present application may include a downlink (DL) subband and an uplink (UL) subband. In order to avoid cross-link interference between downlink transmission on the DL subband and uplink transmission on the UL subband, a guard band may be defined between the DL subband and the UL subband. The present application does not limit whether there is a guard band between the DL subband and the UL subband, and if the guard band exists, whether transmission can be performed on the guard band. In addition, the present application does not limit whether the DL subband and the UL subband can overlap (e.g., the DL subband and the UL subband can not overlap at all, or the DL subband and the UL subband can partially overlap, or the DL subband and the UL subband can completely overlap).

[0126] For example, regarding the configuration of SBFD, depending on whether a timeslot contains both SBFD symbols and non-SBFD symbols, there are the following two possible configuration modes:

[0127] 1) SBFD is configured at the time slot level, that is, all symbols contained in a time slot are configured as SBFD symbols or all as non-SBFD symbols.

[0128] 2) SBFD is configured at the symbol level, that is, a portion of the symbols contained in a time slot can be configured as SBFD symbols, and the other portion can be configured as non-SBFD symbols.

[0129] Among them, SBFD symbols can be considered as symbols configured with SBFD, and non-SBFD symbols can be considered as symbols not configured with SBFD. This application does not limit the configuration of SBFD.

[0130] 4. Single Frequency Full Duplex (SFFD): Indicates that the entire CC can be used for both transmission and reception within a symbol or time slot. For example, a typical SFFD time-frequency partitioning scheme is shown in Figure 4. The horizontal direction represents the time domain, and the vertical direction represents the frequency domain. It includes a set of time-frequency resources used for both downlink and uplink data or control information transmission.

[0131] 5. Subband: A partial frequency band in a carrier, that is, one or more continuous PRBs in the frequency domain. In this application, the subband used for uplink transmission is called an uplink subband, and the subband used for downlink transmission is called a downlink subband. The subband can also be understood as a frequency resource. Currently, the base station supports FD (such as the above-mentioned SBFD and SFFD), that is, it can simultaneously transmit on the uplink subband and receive on the downlink subband in one time slot. The terminal device only supports half-duplex (HF) SBFD, that is, it can only transmit on the uplink subband or only receive on the downlink subband in one time slot.

[0132] 6. Time-frequency resources: In the embodiment of the present application, data or information can be carried by time-frequency resources, which can include resources in the time domain (i.e., time-domain resources) and resources in the frequency domain (i.e., frequency-domain resources).

[0133] In the time domain, the time domain resources may include one or more time domain units (or, may also be referred to as time units), and a time unit may include several time domain resources. A time domain unit is, for example, a radio frame (RF), and the time domain resources included in the time domain unit are, for example, a subframe, a frame, a half subframe or a half frame, a slot, a mini-slot, a partial slot, or an orthogonal frequency division multiplexing OFDM symbol, etc. Alternatively, a time domain unit may also be a collection of one or more time domain resources, for example, a time domain unit is one or more OFDM symbols in a time slot, for example, the number of the one or more is 6, 7, 12 or 14, etc. One or more time units may be continuous or discrete in time. In addition, the duration of a time slot may be related to a sub-carrier space (SCS) interval. For example, when the subcarrier spacing is 15kHz, the duration of a time slot is 1 millisecond (ms); when the subcarrier spacing is 30kHz, the duration of a time slot is 0.5ms; when the subcarrier spacing is 60kHz, the duration of a time slot is 0.25ms. Similarly, when the subcarrier spacing is 15*2 μ kHz, the length of a time slot is 2 -μ ms, μ = 0, 1, 2, .... μ is a non-negative integer.

[0134] In the frequency domain, frequency domain resources can include one or more frequency domain units. A frequency domain unit can be a resource element (RE), a resource block (RB), a subchannel, a resource pool, a bandwidth, a bandwidth part (BWP), a carrier (CC), a channel, or an interlace RB, etc.

[0135] 7. Random access (RA): In a communication system, a terminal completes uplink time synchronization with a base station through a random access procedure, and establishes an RRC connection with the base station through the random access procedure. After the terminal and the base station establish an RRC connection, uplink and downlink service data can be transmitted. In addition, generally, before initiating uplink random access, the terminal also detects and receives the downlink synchronization signal sent by the base station to complete downlink time synchronization and frequency synchronization. The downlink synchronization signal generally includes the primary synchronization signal (PSS) and the secondary synchronization signal (SSS). Exemplarily, the PSS and SSS are carried in the synchronization broadcast block (synchronization signal and PBCH Block, SSB).

[0136] There are two types of random access procedures: Type-1 random access and Type-2 random access. The Type-1 random access is also known as a four-step random access procedure, and the Type-2 random access is also known as a two-step random access procedure. Depending on whether there is a conflict in the transmission of preambles between terminal devices, the Type-1 RA procedure and / or the Type-2 RA procedure include a contention-based random access (CBRA) procedure and a contention-free random access (CFRA) procedure. The CBRA and CFRA processes are basically the same. For ease of description, the following uses CBRA as an example to introduce the Type-1 RA procedure and the Type-2 RA procedure.

[0137] Figure 5 shows a schematic flow chart of a four-step random access. The execution subject of the method shown in Figure 5 can be a first communication device and a second communication device, wherein the first communication device can be a terminal device, or a chip or circuit in the terminal device, or a functional module in the terminal device that can call and execute a program, and the second communication device can be a network device, or a chip or circuit in the network device, or a CU or DU in the network device, or a functional module in the network device that can call and execute a program. As shown in Figure 5, the method includes the following steps.

[0138] S510: The first communication device sends a random access preamble to the second communication device.

[0139] Correspondingly, the second communication device receives the random access preamble code sent by the first communication device.

[0140] The first communication device randomly selects a random access opportunity (RACH occasion, RO) associated with the SSB index based on the received system message and the selected SSB index. The RO can be understood as the time-frequency resource used by the first communication device for random access. The second communication device preconfigures the association between the RO and the SSB index, and a certain RO is used to send the Preamble, that is, message 1 (Msg1).

[0141] After determining the time-frequency resource (RO), the first communication device selects a preamble sequence from the selected RO and sends it. It should be understood that up to 64 preambles can be transmitted simultaneously on an RO, and the first communication device can select one of the 64 preamble sequences to send. The first communication device then sends the preamble sequence to the second communication device, and the preamble sequence is carried by the PRACH.

[0142] S520: The second communication device sends a random access response (RAR) to the first communication device.

[0143] Accordingly, the first communication device receives the RAR from the second communication device.

[0144] After receiving the Preamble, the second communication device sends a random access response (RAR) message to the terminal, which is message 2 (Msg2). The random access response message includes scheduling information for allocating message 3 (Msg3), such as RAR uplink grant information.

[0145] After sending Msg1, the first communications device initiates a random access response window and listens for Msg2 sent by the network within the window. If the first communications device successfully detects its own RAR, random access is successful. Following the RAR, the first communications device then sends Msg3, which primarily serves as an RRC connection establishment request. If the first communications device does not receive its own RAR, random access fails. The first communications device re-initiates random access according to the fallback parameters specified by the second communications device until the maximum number of random access attempts is reached.

[0146] S530: The first communication device sends Msg3 to the second communication device.

[0147] Accordingly, the second communication device receives Msg3 from the first communication device.

[0148] Exemplarily, the first communication device sends Msg3 based on RAR, and the main function of Msg3 is to send an RRC connection establishment request. Among them, Msg3 is sent in the time-frequency resources specified by Msg2 and is carried by the PUSCH channel.

[0149] S540: The second communication device sends message 4 (message 4, Msg4) to the first communication device.

[0150] Accordingly, the first communication device receives Msg4 from the second communication device.

[0151] Msg4 is mainly used for conflict resolution. When multiple first communication devices access at the same time, it is necessary to determine which first communication device is selected for access in this random access. Specifically, after sending Msg3, the first communication device listens for and receives Msg4 sent by the second communication device. Msg4 carries a conflict resolution identifier and the air interface parameter configuration for the first communication device. If the first communication device successfully receives Msg4, the random access is successful, otherwise the random access fails. If successful, the first communication device continues to send Msg5. Msg5 is mainly used to send an RRC establishment completion command. If it fails, the first communication device re-initiates the random access process according to the fallback parameters indicated by the second communication device until the maximum number of random access times is reached.

[0152] It should be noted that FIG5 is only a schematic diagram provided for the convenience of explaining the four-step random access process and does not constitute any limitation on the protection scope of the present application. For a specific description of the four-step random access process, reference may be made to the introduction in the current related art.

[0153] Figure 6 shows a schematic flow chart of a two-step random access process. The execution subject of the method shown in Figure 6 can be a first communication device and a second communication device, wherein the first communication device can be a terminal device, or a chip or circuit in the terminal device, or a functional module in the terminal device that can call and execute a program, and the second communication device can be a network device, or a chip or circuit in the network device, or a CU or DU in the network device, or a functional module in the network device that can call and execute a program. As shown in Figure 6, the method includes the following steps.

[0154] S610: The first communication device sends a message A (MsgA) to the second communication device.

[0155] Accordingly, the second communication device receives the message A from the first communication device.

[0156] The MsgA includes a preamble part and a physical uplink shared channel (PUSCH) part. The preamble part is sent on the PRACH resource (such as the RO mentioned above), and the PUSCH resource can carry L2 or L3 information, such as a BFR MAC CE or an RRC connection establishment request message.

[0157] S620: The second communication device sends a message B (MsgB) to the first communication device.

[0158] Accordingly, the first communication device receives the message B from the second communication device.

[0159] The MsgB message may include a success RAR (success RAR) or a fallback RAR (fallback RAR).

[0160] Exemplarily, when the first communication device receives the fallback RAR, the first communication device needs to fall back to the four-step random access process and send Msg3 to the second communication device, that is, perform step S530 of FIG. 5 .

[0161] Optionally, in addition to the above-mentioned fallback process from two-step random access to four-step random access, if the second communication device chooses to perform a two-step random access process when triggering random access, after the preamble of the two-step random access process reaches the maximum number of transmissions, the first communication device can also fallback to the four-step random access process to attempt access, thereby increasing the access success rate of the first communication device and ensuring the access performance of the first communication device.

[0162] 8. Access opportunity (RACH occasion, RO): As mentioned above, the UE sends a preamble sequence on the RO. An RO can be considered as a time-frequency resource for transmitting the preamble. One RO can support code division multiplexing transmission of multiple preamble sequences, and one NR cell supports multiple ROs. Unlike LTE, NR introduces multi-beam operation, so the random access process of NR is based on beam transmission. For example, for UEs in the initial access phase, its transmission is mainly based on the SSB beam. For UEs in the connected state, it can also be based on the CSI-RS beam. NR can support the base station to send SSBs in multiple beam directions. For example, in frequency range 1 (FR1), it can support up to 8 SSBs. The UE can select one of the SSBs and use the SSB beam to send PRACH. Regarding how the UE selects the SSB to send PRACH, for example, if the base station does not configure the RSRP threshold value, the UE can select any SSB to send PRACH; otherwise, it can select any SSB among the SSB(s) that exceed the RSRP threshold value to send PRACH.

[0163] 9. PRACH configuration: PRACH can be configured in the UL time slot through the RACH configuration general (RACH-ConfigGeneric) information element. New and old terminals can use the PRACH in the UL time slot for random access at the same time.

[0164] Figure 7 shows a schematic diagram of configuring PRACH on the UL time slot. As shown in Figure 7, the horizontal axis represents the time domain, including the SBFD time slot and the UL time slot, the vertical axis represents the frequency domain, and the dotted box in the UL time slot can represent the PRACH resource. Exemplarily, the UE can use the PRACH for random access. For example, the UE obtains the period, frame number, subframe number, time slot number, number of ROs in the time slot, etc. of the PRACH in the time domain according to the parameter prach-ConfigurationIndex carried in RACH-ConfigGeneric (such as Table 6.3.3.2-2 to 6.3.3.2-4 in the existing protocol (such as TS38211)), thereby determining the time domain position of the PRACH. For another example, the UE can obtain the starting position and frequency division multiplexing number of the PRACH in the frequency domain according to the parameters msg1-FrequencyStart and msg1-FDM carried in RACH-ConfigGeneric, thereby determining the frequency domain position of the PRACH.

[0165] FIG8 (a) and (b) show schematic diagrams of PRACH time-frequency resources. As shown in FIG8 (a), the three topmost blocks in the figure can represent the radio frame where the PRACH is located, and the time domain distance between two adjacent blocks is the PRACH period. The middle layer represents the 10 subframes contained in a radio frame where the PRACH is located, for example, subframes 0-9, where subframes 4 and subframe 9 represent the subframes where the PRACH is located. The bottom layer represents the time slot structure of subframe 4 where the PRACH is located, and the time slot structure includes 2 PRACH slots (for example, PRACH slot#1 and PRACH slot#2). Each small block is an RO, that is, each PRACH slot contains 6 ROs. As shown in FIG8 (b), the horizontal axis represents the time domain and the vertical axis represents the frequency domain. Each block represents an RO, and the number of ROs can be 1, 2, 4 or 8. For example, 4 ROs can be arranged starting from the frequency domain position specified by msg1-FrequencyStart.

[0166] 9. RO is associated with SSB: During the Msg1 transmission process of step S510 above, the UE can select an RO to transmit the Preamble sequence based on the index of the SSB. Therefore, in the NR standard, in addition to specifying the PRACH position, the RO-SSB mapping relationship is also specified (one SSB index can be associated with multiple ROs, or multiple SSB indexes are associated with one RO). For example, the network device can configure the mapping relationship of N SSBs to 1 RO through the high-level parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB. When N is less than 1, 1 SSB is associated with 1 / N ROs; when N is greater than 1, N SSBs are associated with 1 RO (1 SSB is associated with 1 / N ROs).

[0167] Figure 9 (a) to (c) show schematic diagrams of the association relationship between RO and SSB. As shown in Figure 9 (a), when N=1 / 2, one SSB is associated with 2 ROs. As shown in Figure 9 (b), when N=2, one RO is associated with 2 SSBs. Therefore, when one SSB index is associated with multiple ROs, the UE can select one of the multiple ROs and select the preamble sequence to be transmitted on the RO. Furthermore, after determining the association relationship between RO and SSB, the UE starts RO-SSB mapping in the order of frequency domain first, then time domain, first same time slot, then same frame, and finally different frames. As shown in Figure 9 (c), where the horizontal axis represents the time domain and the vertical axis represents the frequency domain, the SSB set used by the base station can be {SSB i , SSB i+1 , SSB i+2 , SSB i+3}, msg1-FDM=4 and N=1 / 4, 1 SSB is associated with 4 ROs, and the RO set is recorded as {RO0, RO1, RO2, RO3}. 16 ROs complete a complete RO-SSB mapping cycle. The mapping order of RO-SSB can be arranged from the frequency domain corresponding to a certain RO time domain position, that is, SSB i The corresponding RO0-RO3 occupies the first RO time domain position of the PRACH time slot at the beginning of the same frame, corresponding to the four RO positions in the frequency domain, SSB i+1 The corresponding RO0-RO3 occupies the second RO time domain position of the starting PRACH time slot, corresponding to the 4 RO positions in the frequency domain, SSB i+1 The corresponding RO0-RO3 occupies the second RO time domain position of the PRACH time slot at the beginning of the same frame, corresponding to the four RO positions in the frequency domain, SSB i+2 The corresponding RO0-RO3 occupies the first RO time domain position of the second PRACH time slot of the same frame, corresponding to the four RO positions in the frequency domain, SSB i+3 The corresponding RO0-RO3 occupy the second RO time domain position of the second PRACH time slot of the same frame, corresponding to the four RO positions in the frequency domain.

[0168] 10. Interference during SBFD random access: Currently, random access is supported on SBFD symbols / timeslots, including the transmission of Msg1 or MsgA. However, the following issues may arise when supporting the transmission of Msg1 or MsgA on SBFD symbols / timeslots:

[0169] 1) As shown in Figure 10(a), uplink transmissions within the uplink subband of SBFD symbols / timeslots will generate cross-link interference (CLI), i.e., UE-UE interference, on downlink transmissions within the downlink subbands of the current cell or neighboring cells. This results in poor downlink transmission performance in SBFD symbols / timeslots, especially for users in poor coverage areas such as cell edges. To ensure the success rate of random access, users increase their transmit power, which leads to stronger UE-UE interference.

[0170] 2) As shown in Figure 10(b), uplink transmissions within the uplink subband of SBFD symbols / timeslots are subject to CLI (CLI) caused by downlink transmissions within the downlink subband of the own cell or neighboring cells, resulting in poor uplink transmission performance in SBFD symbols / timeslots. Supporting PRACH transmissions in SBFD symbols / timeslots can lead to reduced UE random access success rates, particularly for users in poor coverage areas such as cell edges.

[0171] The degree of interference between terminal devices caused by terminal devices in different situations is different. For example, the interference between terminal devices caused by terminal devices is related to parameters such as the PRACH resource location, the number of access terminal devices, the density of terminal devices, and the application scenario. For ease of understanding, Figure 11 briefly introduces the different losses and benefits of initial access of terminal devices to PRACH resources on SBFD time slots (hereinafter referred to as SBFD-PRACH resources) in different situations. As can be seen from Figure 11, when the frequency distance between PRACH and downlink resources is greater than the threshold, the degree of interference between terminal devices is low; when the frequency distance between PRACH and downlink resources is less than or equal to the threshold, the degree of interference between terminal devices is high.

[0172] The above, in combination with Figure 1, briefly introduces the scenarios in which the communication method provided in the embodiment of the present application can be applied, as well as the basic concepts that may be involved in the embodiment of the present application, and introduces the interference between terminal devices in the basic concepts. A method for reducing CLI interference between terminal devices in PRACH transmission is: prohibiting terminal devices with limited coverage (such as cell edge terminal devices using a larger transmission power to transmit preamble) from using SBFD-PRACH resources for random access, thereby avoiding high CLI interference caused by terminal devices whose reference signal RSRP is less than a certain threshold using high power to send Preamble.

[0173] For ease of understanding, the method for reducing CLI interference between terminal devices in PRACH transmission will be introduced below in conjunction with (a) and (b) in Figure 12.

[0174] As shown in (a) of Figure 12, the greater the transmission power of the cell edge terminal device, the greater the possibility of causing severe CLI interference. If, as shown in (b) of Figure 12, the terminal device with RSRP less than a certain threshold causes a high degree of CLI interference between terminal devices, the terminal device is not allowed to use SBFD-PRACH resources.

[0175] However, this method of reducing CLI interference between terminal devices during PRACH transmission has the following problems:

[0176] 1) Since coverage-limited UEs (e.g., UEs supporting SBFD) are prohibited from using SBFD-PRACH resources for random access, coverage-limited UEs use PRACH in the UL time slot for random access, which in turn makes it impossible for the base station to identify different UEs (e.g., identify whether a UE supports SBFD) by whether the UE accesses on the SBFD-PRACH.

[0177] 2) UEs with limited coverage of this interference reduction method cannot use SBFD-PRACH, which may result in waste of SBFD-PRACH resources and reduce resource utilization efficiency.

[0178] In order to solve the problems existing in the above-mentioned method of reducing CLI interference between terminal devices, the present application proposes a communication method, so as to improve the transmission performance of the terminal device while reducing the CLI interference between the terminal devices.

[0179] It should be understood that the communication method provided in the embodiments of the present application can be applied to a system that communicates using a multi-antenna technology, for example, the communication system 100 shown in Figure 1. The communication system may include at least one network device and at least one terminal device.

[0180] It should also be understood that the embodiments shown below do not specifically limit the specific structure of the execution subject of the method provided in the embodiments of the present application, as long as it is possible to communicate according to the method provided in the embodiments of the present application by running a program that records the code of the method provided in the embodiments of the present application. For example, the execution subject of the method provided in the embodiments of the present application can be a first device, which can be a terminal device, or a chip or circuit in the terminal device (such as a modem chip, also known as a baseband chip, or a system-on-chip chip or system-level package chip containing a modem core), or a functional module in the terminal device that can call and execute a program; for example, the execution subject of the method provided in the embodiments of the present application can be a second device, which can be a network device, or a chip or circuit in the network device (such as a modem chip, also known as a baseband chip, or a system-on-chip chip or system-level package chip containing a modem core), or a functional module in the network device that can call and execute a program.

[0181] For the convenience of description, the following description takes the first device as a terminal device and the second device as a network device as an example.

[0182] FIG13 is a schematic flow chart of a communication method provided in an embodiment of the present application, comprising the following steps:

[0183] S1310, the network device sends first information to the terminal device, and correspondingly, the terminal device receives the first information from the network device.

[0184] Specifically, the first information indicates a first time-frequency resource. The first time-frequency resource is used for random access. The first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource. The first time domain resource is located in a first time domain unit. The first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission. The first frequency domain resource is located in the first subband. The first subband and the second subband may partially or completely overlap or not overlap at all.

[0185] In this embodiment, the terminal device is mainly considered to be a terminal device supporting SBFD or SFFD, that is, the terminal device is a terminal device that can use the first frequency domain unit corresponding to the first time domain unit, including the first sub-band for uplink transmission and the second sub-band for downlink transmission for uplink and downlink communications, or the terminal device is a terminal device that can use the first time-frequency resource for random access.

[0186] Exemplarily, the first time domain unit is an FD time unit, that is, the first frequency domain unit corresponding to the first time domain unit includes uplink frequency domain resources and downlink frequency domain resources. For example, the first time domain unit is an SBFD symbol or an SBFD time slot. Alternatively, the first time domain unit is an SFFD time unit, that is, on the first time domain unit, the entire carrier includes uplink frequency domain resources and downlink frequency domain resources (e.g., on the first time domain unit, the entire carrier can be used for both transmission and reception).

[0187] It should be understood that the above-mentioned first time domain unit being an SBFD time unit or an SFFD time unit is merely an example and does not constitute any limitation on the scope of protection of this application. Other time domain units including uplink frequency domain resources and downlink frequency domain resources can also be understood as the first time domain unit involved in this embodiment.

[0188] For example, the first time-frequency resource may be a PRACH resource dedicated to an SBFD time unit or an SFFD time unit. Optionally, the first time-frequency resource may be referred to as an SBFD-PRACH resource. For ease of understanding, the first time-frequency resource may be referred to as an SBFD-PRACH resource hereinafter.

[0189] As an example and not a limitation, the first information may further indicate a second time-frequency resource, which is also used for random access. The second time-frequency resource includes a second time domain resource and a second frequency domain resource, the second time domain resource corresponds to the second frequency domain resource, the second part of the second time domain resource is located in a second time domain unit, the second frequency domain unit corresponding to the second time domain unit is used for uplink transmission, and the second frequency domain resource is located in the second frequency domain unit.

[0190] Exemplarily, the second time domain unit is a UL time unit, that is, the second time domain unit includes uplink frequency domain resources. For example, the second time domain unit is a UL time slot or a UL symbol.

[0191] It should be understood that the above-mentioned second time domain unit being the UL time unit is only an example and does not constitute any limitation to the protection scope of this application. Other time domain units including uplink frequency domain resources can also be understood as the second time domain unit involved in this embodiment.

[0192] Exemplarily, the second time-frequency resource may be a PRACH resource dedicated to a non-SBFD time slot. Optionally, the second time-frequency resource may be called a UL-PRACH resource.

[0193] In this embodiment, there is no limitation on the names of the time-frequency resources as long as they can realize the corresponding functions. For example, the first time-frequency resource mentioned above can also be called resource #1, and the second time-frequency resource can also be called resource #2.

[0194] It should be noted that, in this embodiment, the first time-frequency resource and / or the second time-frequency resource can be used in the random access process of the four-step random access shown above, or in the random access process of the two-step random access shown above, and can be used for both CBRA and CFRA.

[0195] For ease of understanding, the resource situation configured by the network device for the terminal device through the first information in this embodiment is briefly introduced in conjunction with Figure 14.

[0196] As can be seen from Figure 14, the network device indicates the location of SBFD-PRACH resources and UL-PRACH resources to the terminal device. The dotted box in Figure 14 represents PRACH resources, among which the PRACH resources located in the SBFD time slot are PRACH resources exclusive to the SBFD time slot, namely, SBFD-PRACH resources; the PRACH resources located in the UL time slot are PRACH resources exclusive to the non-SBFD time slot, namely, UL-PRACH resources.

[0197] In this embodiment, there is no limitation on the specific form of the first information. Information that can indicate the above-mentioned first time-frequency resource is within the protection scope of this application. For example, the format of the first information can refer to the description of the information indicating parameters such as the PRACH resource location and usage format in the current related technology, which will not be repeated here.

[0198] Specifically, the first time-frequency resource in this embodiment includes more than two time-frequency resource units, and there is no overlapping part between any two of the more than two time-frequency resource units in the time domain.

[0199] For example, the two or more time-frequency resource units include a first time-frequency resource unit and a second time-frequency resource unit, and there is no overlapping part between the first time-frequency resource unit and the second time-frequency resource unit in the time domain.

[0200] For example, the two or more time-frequency resource units include a first time-frequency resource unit, a second time-frequency resource unit, and a third time-frequency resource unit, and there is no overlapping part in the time domain between any two of the first time-frequency resource unit, the second time-frequency resource unit, and the third time-frequency resource unit.

[0201] It should be understood that in this embodiment, there is no limitation on the number of time-frequency resource units included in the first time-frequency resource, and it can be greater than or equal to two. For ease of understanding, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit. The time-frequency resource unit can be understood as a random access opportunity, or the time-frequency resource unit can be understood as a random access opportunity set.

[0202] As an example but not limitation, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit as shown in (a) and (b) of Figure 15.

[0203] As can be seen from Figure 15(a), the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit located in consecutive adjacent positions. For example, the time domain occupied by the first time domain resource is the first time period, the time domain occupied by the first time-frequency resource unit is the first sub-time period, and the time domain occupied by the second time-frequency resource unit is the second sub-time period, wherein the starting point of the first sub-time period is the starting point of the first time period, the end point of the first sub-time period is the starting point of the second sub-time period, and the end point of the second sub-time period is the end point of the first time period.

[0204] As can be seen from FIG15( b ), the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit located in non-contiguous positions.

[0205] It should be understood that (a) and (b) in Figure 15 are only examples and do not constitute any limitation on the scope of protection of this application. It is sufficient that there is no overlapping part between the first time-frequency resource unit and the second time-frequency resource unit in the time domain, and no examples will be given here one by one.

[0206] Furthermore, in this embodiment, after receiving the above-mentioned first information, the terminal device can obtain a first time-frequency resource that can be used for random access based on the first information. In order to reduce interference between terminal devices, the terminal device can select a time-frequency resource unit from two or more time-frequency resource units included in the first time-frequency resource based on the first condition as the time-frequency resource for random access to improve transmission performance. The method flow shown in Figure 13 also includes:

[0207] S1320: The terminal device selects a time-frequency resource for random access according to the first condition.

[0208] Specifically, in this embodiment, the terminal device can select one of two or more time-frequency resource units as the time-frequency resource for random access according to the first condition.

[0209] For example, the two or more time-frequency resource units include a first time-frequency resource unit and a second time-frequency resource unit.

[0210] If the first condition is met, the terminal device selects the first time-frequency resource unit as the time-frequency resource for random access; if the first condition is not met, the terminal device selects the second time-frequency resource unit as the time-frequency resource for random access.

[0211] It should be understood that in this embodiment, terminal devices that meet the first condition and those that do not meet the first condition can use different time-frequency resource units included in the first time-frequency resource in a time-division manner, thereby reducing interference between terminal devices.

[0212] In this embodiment, the first condition mentioned above includes but is not limited to the following two possible implementations:

[0213] As a possible implementation manner, the first condition is that the measurement value is greater than or equal to a first threshold, and the measurement value is obtained by measurement by the terminal device.

[0214] In this implementation, the network device may indicate the first threshold through the second information. That is, in addition to configuring the first time-frequency resource through the first information, the network device may also indicate the selection rule of the SBFD-PRACH resource through the second information, in order to reduce CLI interference between terminal devices and improve transmission performance. In this implementation, the method flow shown in FIG13 further includes:

[0215] S1321, the network device sends second information to the terminal device, and correspondingly, the terminal device receives the second information from the network device.

[0216] Specifically, the second information indicates a first threshold, wherein the first threshold includes at least one of the following thresholds:

[0217] Reference signal received power RSRP threshold, reference signal transmit power threshold, reference signal path loss threshold, or distance threshold between terminal equipment and network equipment, etc.

[0218] If the first threshold is a reference signal received power threshold, the measured value is the reference signal received power; or,

[0219] If the first threshold is a reference signal transmit power threshold, the measured value is the transmit power of the reference signal; or

[0220] If the first threshold is a reference signal path loss threshold, the measured value is the path loss of the reference signal; or,

[0221] If the first threshold is a distance threshold between the terminal device and the network device, the measured value is the distance between the terminal device and the network device.

[0222] It should be noted that if the measured value is the received power of the reference signal, the larger the measured value, the smaller the path loss, that is, the smaller the required transmission power, and the smaller the interference to the terminal device. Conversely, the smaller the measured value, the greater the path loss, that is, the greater the required transmission power, and the greater the interference to the terminal device.

[0223] In addition, if the measured value is the reference signal transmit power, path loss, or the distance between the terminal device and the network device, a larger measured value indicates greater interference to the terminal device, and conversely, a smaller measured value indicates less interference to the terminal device. When the measured value is path loss, it corresponds to the difference between the transmit power and receive power of the reference signal. A larger difference indicates a greater path loss, which means more transmit power is required and greater interference is caused.

[0224] That is to say, the time-frequency resource unit selected by the terminal device according to the first condition is also related to the threshold type. For example, when the first threshold is the reference signal receiving power threshold, the terminal device determines that the time-frequency resource unit selected to meet the first condition is the second time-frequency resource unit. Then when the first threshold is the reference signal transmission power, the path loss threshold, or the distance between the terminal device and the network device, the terminal device determines that the time-frequency resource unit selected to meet the first condition is the first time-frequency resource unit.

[0225] Optionally, in this implementation, the second information indicating the first threshold may directly indicate the value of the first threshold.

[0226] For example, in this implementation, the second information indicates that the first threshold is 10 dBm or dBw, and the threshold type is a reference signal received power or transmit power threshold. For another example, in this implementation, the second information indicates that the first threshold is 10 dB, and the threshold type is a path loss threshold. It should be understood that the specific value of the first threshold indicated by the second information is merely an example and does not constitute any limitation on the scope of protection of this application. For example, this embodiment does not impose any limitation on the unit of the first threshold.

[0227] Optionally, in this implementation, the second information indicating the first threshold may indirectly indicate the value of the first threshold.

[0228] For example, in this implementation, the second information indicates an index value of the first threshold, and the terminal device can determine the first threshold based on the index value of the first threshold. Exemplarily, the preset thresholds are stored in a table, and the second information can indicate the index of the table, thereby indicating the threshold.

[0229] It should be understood that the implementation of the second information is merely an example and does not limit the scope of protection of this application. Other information that can indicate the first threshold value is also within the scope of protection of this application. In addition, the first threshold value can also be predefined without the need for additional indication from the network device.

[0230] By way of example and not limitation, the first information and the second information may be carried in a single message, or they may be carried in different messages. For example, the first information and the second information may be different fields carried in a system message, or the first information may be carried in a system message, and the second information may be newly added signaling in addition to the system message.

[0231] The second information can be sent before or after the first information. This embodiment does not impose any restrictions on the timing of sending the first information and the second information. It should be understood that this embodiment does not impose any restrictions on how the network device sends the first information and the second information to the terminal device.

[0232] In addition, the above-mentioned first condition that the measured value is greater than or equal to the first threshold is only an example and does not constitute any limitation on the scope of protection of this application. The first condition is related to the comparison result of the measured value and the first threshold. For example, the first condition is that the measured value is greater than the first threshold; for example, the first condition is that the measured value is less than or equal to the first threshold; for example, the first condition is that the measured value is less than the first threshold, etc., and examples will not be given one by one here.

[0233] Furthermore, in this implementation mode, after the terminal device receives the above-mentioned first information and second information, it can determine the first time-frequency resource that can be used for random access based on the first information, and determine the RO resource position for sending the preamble code from the first time-frequency resource according to the second information, in order to reduce interference between terminal devices (such as CLI). Then the above-mentioned step S1320 in which the terminal device selects the time-frequency resource for random access according to the first condition specifically includes: the terminal device selects one of the two or more time-frequency resource units included in the first time-frequency resource as the time-frequency resource for random access according to the measurement value and the first threshold.

[0234] Optionally, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit, and the terminal device selects the first time-frequency resource unit or the second time-frequency resource unit as the time-frequency resource for random access according to the measurement value and the first threshold, specifically including:

[0235] If the measured value is greater than or equal to the first threshold, the terminal device selects the first time-frequency resource unit as the time-frequency resource for random access; if the measured value is less than the first threshold, the terminal device selects the second time-frequency resource unit as the time-frequency resource for random access.

[0236] For example, a terminal device with a smaller measurement value has a greater path loss, requires a larger power, and is more likely to cause strong interference. The first time-frequency resource unit can be used as a time-frequency resource for random access so that the network device can adjust the PDSCH to reduce interference; while a terminal device with a larger measurement value is more likely to cause weak interference, and the second time-frequency resource unit can be used as a time-frequency resource for random access (or there is no constraint, and a time-frequency resource within the first time-frequency resource is arbitrarily selected as a time-frequency resource for random access).

[0237] As another possible implementation, the first condition is that the state of the terminal device is idle or inactive, or the first condition is that the state of the terminal device is connected. The idle state can be understood as the RRC idle state (RRC_IDLE), and the inactive state can be understood as the RRC inactive state (RRC_INACTIVE).

[0238] In this implementation, it can be understood that the state of the terminal device is idle or inactive, and the RO and preamble used for random access are not controlled by the network device, which is more likely to cause large interference; while the state of the terminal device is connected, and the RO and preamble used for random access are controlled by the network device and are less likely to cause large interference. Specifically, the terminal device can select one from the two or more time-frequency resource units included in the first time-frequency resource as a time-frequency resource for random access based on the first association relationship and the state of the terminal device, wherein the first association relationship is the association relationship between the state of the terminal device and the two or more time-frequency resource units.

[0239] Optionally, the first association relationship is indicated by a network device. For example, the method flow shown in FIG13 in this implementation further includes:

[0240] S1322: The network device sends third information to the terminal device. Correspondingly, the terminal device receives the third information from the network device.

[0241] Specifically, the third information indicates a first association relationship. For example, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit, and the first association relationship is that an idle terminal device or an inactive terminal device is associated with the first time-frequency resource unit, and a connected terminal device is associated with the second time-frequency resource unit.

[0242] By way of example and not limitation, the first information and the third information may be carried in one message, or they may be carried in different messages. For example, the first information and the third information may be different fields carried in a system message, or the first information may be carried in a system message, and the third information may be newly added signaling in addition to the system message.

[0243] The third information may be sent before or after the first information, and this embodiment does not impose any restrictions on the timing of sending the first information and the third information. It should be understood that this embodiment does not impose any restrictions on how the network device sends the first information and the third information to the terminal device.

[0244] Optionally, the first association relationship is predefined.

[0245] Furthermore, in this implementation mode, after the terminal device receives the above-mentioned first information and obtains the first association relationship, it can determine the first time-frequency resource that can be used for random access based on the first information, and determine the RO resource position for sending the preamble code from the first time-frequency resource according to the first association relationship, in order to reduce interference between terminal devices (such as CLI). Then the above-mentioned step S1320 in which the terminal device selects the time-frequency resource for random access according to the first condition specifically includes: the terminal device selects one of the two or more time-frequency resource units included in the first time-frequency resource as the time-frequency resource for random access according to the first association relationship and the status of the terminal device.

[0246] Optionally, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit, and the terminal device selects the first time-frequency resource unit or the second time-frequency resource unit as the time-frequency resource for random access according to the first association relationship and the state of the terminal device, specifically including:

[0247] If the state of the terminal device is idle or inactive, the terminal device selects the first time-frequency resource unit as the time-frequency resource for random access; if the state of the terminal device is connected, the terminal device selects the second time-frequency resource unit as the time-frequency resource for random access.

[0248] For example, a terminal device in an idle or inactive state has a greater path loss, requires a greater power, and is more likely to cause strong interference. The first time-frequency resource unit can be used as a time-frequency resource for random access so that the network device can adjust the PDSCH to reduce interference; while a terminal device in a connected state is more likely to cause weak interference, the second time-frequency resource unit can be used as a time-frequency resource for random access (or there is no constraint, and a time-frequency resource within the first time-frequency resource is arbitrarily selected as a time-frequency resource for random access).

[0249] As another possible implementation, the first condition is that the terminal device is of the first type, or the first condition is that the terminal device is of the second type, wherein the interference caused by the first type of terminal is small, and the interference caused by the second type of terminal is large.

[0250] As an example and not a limitation, the first type includes terminals with interference control capabilities, terminals with environmental perception capabilities, or terminals with a maximum transmit power level less than or equal to a predetermined threshold. For example, a terminal with interference control capabilities may be a terminal that can use a narrower PRACH to transmit a beam, for example, a beam width less than or equal to a given threshold; a terminal with environmental perception capabilities may be a terminal that senses the positions of surrounding terminals and adjusts the direction of transmitted signals to avoid adjacent terminals. The second type includes terminals without interference control capabilities, terminals without environmental perception capabilities, or terminals with a maximum transmit power greater than a predetermined threshold. For example, a terminal without interference control capabilities may use a wide PRACH to transmit a beam, for example, a beam width greater than a given threshold; a terminal without environmental perception capabilities may be a terminal that is unable to sense the positions of surrounding terminals and / or adjust the direction of transmitted signals to avoid adjacent terminals.

[0251] Specifically, the terminal device can select one from two or more time-frequency resource units included in the first time-frequency resource as a random access time-frequency resource based on the second association relationship and the status of the terminal device, wherein the second association relationship is the association relationship between the type of the terminal device and the two or more time-frequency resource units.

[0252] Optionally, the second association relationship is indicated by a network device. For example, the method flow shown in FIG13 in this implementation further includes:

[0253] S1323: The network device sends sixth information to the terminal device. Correspondingly, the terminal device receives the sixth information from the network device.

[0254] Specifically, the sixth information indicates a second association relationship. For example, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit, and the first association relationship is that the first type of terminal device is associated with the second time-frequency resource unit, and the second type of terminal device is associated with the first time-frequency resource unit.

[0255] By way of example and not limitation, the first information and the sixth information may be carried in one message, or they may be carried in different messages. For example, the first information and the sixth information may be different fields carried in a system message, or the first information may be carried in a system message, and the sixth information may be newly added signaling in addition to the system message.

[0256] The sixth information may be sent before or after the first information, and this embodiment does not impose any restrictions on the timing of sending the first information and the sixth information. It should be understood that this embodiment does not impose any restrictions on how the network device sends the first information and the sixth information to the terminal device.

[0257] Optionally, the second association relationship is predefined.

[0258] Furthermore, in this implementation mode, after the terminal device receives the above-mentioned first information and obtains the second association relationship, it can determine the first time-frequency resource that can be used for random access based on the first information, and determine the RO resource position for sending the preamble code from the first time-frequency resource according to the second association relationship, in order to reduce interference between terminal devices (such as CLI). Then the above-mentioned step S1320 in which the terminal device selects the time-frequency resource for random access according to the first condition specifically includes: the terminal device selects one of the two or more time-frequency resource units included in the first time-frequency resource as the time-frequency resource for random access according to the second association relationship and the type of the terminal device.

[0259] Optionally, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit, and the terminal device selects the first time-frequency resource unit or the second time-frequency resource unit as the time-frequency resource for random access according to the second association relationship and the type of the terminal device, specifically including:

[0260] If the type of the terminal device is the first type, the terminal device selects the first time-frequency resource unit as the time-frequency resource for random access; if the type of the terminal device is the second type, the terminal device selects the second time-frequency resource unit as the time-frequency resource for random access.

[0261] Exemplarily, in this embodiment, the terminal device may select a time-frequency resource (e.g., RO) for random access associated with the SSB index based on a comparison result between a measurement value and a first threshold (or based on the state of the terminal device and the first association relationship, or based on the type of the terminal device and the second association relationship) according to the system message received from the network device and the index of the selected SSB. In this embodiment, the network device configures the association relationship between the RO and the SSB index.

[0262] For example, the SSB index selected by the terminal device in this embodiment is associated with the first random access opportunity set and the second random access opportunity set.

[0263] The random access opportunities included in the first random access opportunity set and the second random access opportunity set are located in a certain frame. In this communication system, the starting frame is the first frame, and the first frame is numbered 0. Alternatively, any frame is designated as the starting frame, and the starting frame is numbered 0. After the starting frame is determined, the time slot or symbol in which the random access opportunity is located can be determined.

[0264] For example, in this embodiment, the indexes of different random access opportunities are numbered based on the number of random access opportunities, or based on the periodic time. Therefore, after determining the starting point of the periodic time or the number of random access opportunities, the index of the random access opportunity can be determined.

[0265] Optionally, the first random access opportunity set associated with the SSB index selected by the terminal device in this embodiment belongs to the above-mentioned first time-frequency resource unit; the second random access opportunity set associated with the SSB index selected by the terminal device in this embodiment belongs to the above-mentioned second time-frequency resource unit, that is, in this embodiment, the terminal device can determine the time-frequency resource for random access based on the size relationship between the measurement value and the first threshold (or based on the state of the terminal device and the first association relationship, or based on the type of the terminal device and the second association relationship), and the time-frequency resource for random access is a random access opportunity corresponding to the SSB index.

[0266] As an example and not a limitation, in this embodiment, based on the comparison result of the measured value and the first threshold (or based on its own state and the first association relationship, or based on the type of the terminal device and the second association relationship), the RO is selected from the random access opportunity sets associated with different SSB indexes for random access, including but not limited to the following possible methods:

[0267] Mode 1.1: The comparison result between the measurement value and the first threshold value and the association relationship with the RO are indicated in a PRACH mask manner.

[0268] When the first threshold indicated by the second information is the RSRP threshold, the terminal device compares the RSRP measurement value of the SSB or other reference signal with the first threshold, and determines the RO resource location for random access based on the magnitude relationship. As shown in Figure 16, in the case shown in method 1.1, the terminal device compares the measured RSPR of the SSB beam with the first threshold:

[0269] If the RSRP measurement value is greater than or equal to the first threshold, a RO is randomly selected from the RO set indicated by mask index 1 associated with the selected SSB beam;

[0270] If the RSRP measurement value is less than the RSRP measurement value of the first threshold, a RO is randomly selected from the RO set indicated by mask index 2 associated with the selected SSB beam.

[0271] Method 1.2: The association between the terminal device status and the RO is indicated in a PRACH mask manner.

[0272] When the first association relationship is that the idle or inactive terminal device is associated with the first time-frequency resource unit, the connected terminal device is associated with the second time-frequency resource unit. As shown in Figure 16, in the case shown in method 1.2, the terminal device selects the RO according to the terminal device's state:

[0273] If the terminal device is in idle or inactive state, a RO is randomly selected from the RO set indicated by mask index 1 associated with the selected SSB beam;

[0274] If the state of the terminal device is connected, an RO is randomly selected from the RO set indicated by mask index 2 associated with the selected SSB beam.

[0275] Method 1.3: The association between the terminal device type and the RO is indicated in a PRACH mask manner.

[0276] When the second association relationship is that the first type of terminal device is associated with the second time-frequency resource unit, the second type of terminal device is associated with the first time-frequency resource unit. As shown in Figure 16, in the case shown in method 1.3, the terminal device selects the RO according to the type of the terminal device:

[0277] If the type of the terminal device is the second type, a RO is randomly selected from the RO set indicated by mask index 1 associated with the selected SSB beam;

[0278] If the type of the terminal device is the first type, an RO is randomly selected from the RO set indicated by mask index 2 associated with the selected SSB beam.

[0279] Mode 2.1: Indicate the comparison result between the measurement value and the first threshold value and the association relationship with the RO in the form of odd-even time slots or start symbols.

[0280] When the first threshold indicated by the second information is the RSRP threshold, the terminal device compares the RSRP measurement value of the SSB or other reference signal with the first threshold, and determines the RO resource location for random access based on the magnitude relationship. As shown in Figure 17, in the case shown in method 2.1, the terminal device compares the measured RSPR of the SSB beam with the first threshold:

[0281] If the RSRP measurement value is greater than or equal to the first threshold, randomly selecting an RO from the set of ROs in odd time slots associated with the selected SSB beam;

[0282] If the RSRP measurement value is less than the RSRP measurement value of the first threshold, randomly select an RO from the RO set associated with the selected SSB beam and in the even time slot; or

[0283] If the RSRP measurement value is greater than or equal to a first threshold, randomly selecting an RO from a set of ROs associated with the selected SSB beam starting from an odd OFDM symbol;

[0284] If the RSRP measurement value is less than the RSRP measurement value of the first threshold, a RO is randomly selected from a set of ROs associated with the selected SSB beam and starting from an even-numbered OFDM symbol.

[0285] Method 2.2: The association between the terminal device status and the RO is indicated in the form of odd and even time slots or start symbols.

[0286] When the first association relationship is that the idle or inactive terminal device is associated with the first time-frequency resource unit, the connected terminal device is associated with the second time-frequency resource unit. As shown in Figure 17, in the case shown in method 2.2, the terminal device selects the RO according to the terminal device's state:

[0287] If the terminal device is in idle or inactive state, a RO is randomly selected from the set of ROs in odd time slots associated with the selected SSB beam;

[0288] If the terminal device is in the connected state, a RO is randomly selected from the set of ROs in even time slots associated with the selected SSB beam; or

[0289] If the state of the terminal device is idle or inactive, a RO is randomly selected from the set of ROs associated with the selected SSB beam starting from odd OFDM symbols;

[0290] If the state of the terminal device is connected, an RO is randomly selected from the set of ROs associated with the selected SSB beam starting from an even OFDM symbol.

[0291] Method 2.3: Indicate the association between the terminal device type and the RO in the form of odd-even time slots or starting symbols.

[0292] When the second association relationship is that the first type of terminal device is associated with the second time-frequency resource unit, the second type of terminal device is associated with the first time-frequency resource unit. As shown in Figure 17, in the case shown in method 2.3, the terminal device selects the RO according to the type of the terminal device:

[0293] If the type of the terminal device is the second type, randomly selecting an RO from the set of ROs in odd time slots associated with the selected SSB beam;

[0294] If the type of the terminal device is the first type, randomly selecting an RO from the set of ROs in even time slots associated with the selected SSB beam; or

[0295] If the type of the terminal device is the second type, randomly selecting an RO from a set of ROs associated with the selected SSB beam and starting from an odd-numbered OFDM symbol;

[0296] If the type of the terminal device is the first type, an RO is randomly selected from a set of ROs associated with the selected SSB beam starting from an even-numbered OFDM symbol.

[0297] Method 3.1: Indicate the comparison result between the measurement value and the first threshold value and the association relationship with the RO in the form of TDM-RO index. Among them, the FDM-ROs at the same time have the same TDM-RO index, which can be numbered in the time domain according to the granularity of the RO.

[0298] When the first threshold indicated by the second information is the RSRP threshold, the terminal device compares the RSRP measurement value of the SSB or other reference signal with the first threshold, and determines the RO resource position for random access based on the magnitude relationship. As shown in Figure 18, in the case shown in mode 3, the terminal device compares the measured RSPR of the SSB beam with the first threshold:

[0299] If the RSRP measurement value is greater than or equal to the first threshold, a RO is randomly selected from the RO set whose RO index is an odd number at the time associated with the selected SSB beam;

[0300] If the RSRP measurement value is less than the RSRP measurement value of the first threshold, a RO is randomly selected from a set of ROs whose RO index is an even number at the time associated with the selected SSB beam.

[0301] Method 3.2: The TDM-RO index is used to indicate the relationship between the terminal device status and the RO.

[0302] When the first association relationship is that the idle or inactive terminal device is associated with the first time-frequency resource unit, the connected terminal device is associated with the second time-frequency resource unit. As shown in Figure 18, in the case shown in method 3.2, the terminal device selects the RO according to the terminal device's state:

[0303] If the terminal device is in idle or inactive state, a RO is randomly selected from the set of ROs whose RO index is an odd number at the time associated with the selected SSB beam;

[0304] If the state of the terminal device is connected, an RO is randomly selected from the set of ROs whose RO index is an even number at the time associated with the selected SSB beam.

[0305] Method 3.3: Use TDM-RO index to indicate the association between the terminal device type and RO.

[0306] When the second association relationship is that the first type of terminal device is associated with the second time-frequency resource unit, the second type of terminal device is associated with the first time-frequency resource unit. As shown in Figure 18, in the case shown in method 3.3, the terminal device selects the RO according to the type of the terminal device:

[0307] If the type of the terminal device is the second type, a RO is randomly selected from a set of ROs whose RO index is an odd number at the time associated with the selected SSB beam;

[0308] If the type of the terminal device is the first type, an RO is randomly selected from a set of ROs whose RO index is an even number at the time associated with the selected SSB beam.

[0309] It should be noted that the above-mentioned methods 1.1 to 3.3 are only examples and do not constitute any limitation on the scope of protection of this application. Other methods of selecting RO based on the comparison result of the measurement value and the first threshold (or based on the status of the terminal device and the first association relationship, or based on the type of the terminal device and the second association relationship) are also within the scope of protection of this application, and will not be illustrated one by one here.

[0310] In addition, it should be noted that if the terminal device determines that there is no RO meeting the requirements of the above solution in the first time-frequency resource, the terminal device may not use the first time-frequency resource for initial random access.

[0311] As can be seen from the above, in this embodiment, the network device can indicate the location of the first time-frequency resource (e.g., SBFD-PRACH resource) to the terminal device through the first information. Optionally, the first information can also be used to indicate the location of the second time-frequency resource (e.g., the above-mentioned UL-PRACH resource) (for example, the dotted box in Figure 14 represents the PRACH resource). The network device can then indicate the first threshold (e.g., RSRP threshold) through the second information.

[0312] A terminal device whose predefined measurement value is greater than or equal to a first threshold (e.g., a terminal device at the center of a cell served by the network device) uses a first time-frequency resource unit, while a terminal device whose measurement value is less than the threshold (e.g., a terminal device at an edge of a cell served by the network device) uses a second time-frequency resource unit; or

[0313] It is predefined that a terminal device in an idle state or an inactive state uses a first time-frequency resource unit, and a terminal device in a connected state uses a second time-frequency resource unit; or,

[0314] It is predefined that a first type of terminal device uses a first time-frequency resource unit, while a second type of terminal device uses a second time-frequency resource unit.

[0315] It should be noted that the above description only uses the example of selecting the first time-frequency resource unit or the second time-frequency resource unit according to the first condition. In this embodiment, the terminal device can also select a time-frequency resource unit from two or more time-frequency resource units as the random access time-frequency resource according to the first condition. For example, the first time-frequency resource includes time-frequency resource unit #1, time-frequency resource unit #2, and time-frequency resource unit #3. The above-mentioned first threshold includes first threshold #1 and first threshold #2. The first condition is the comparison result of the measured value with the first threshold #1 and first threshold #2. The terminal with a measured value less than the first threshold #1 selects time-frequency resource unit #1; the terminal with a measured value greater than or equal to the first threshold #1 and less than or equal to the first threshold #2 selects time-frequency resource unit #2; and the terminal with a measured value greater than the first threshold #2 selects time-frequency resource unit #3. No further examples will be given here.

[0316] From the above, it can be seen that in this embodiment, the terminal device compares the measurement value with the first threshold, and sends a preamble code in different time domain resources of the first time-frequency resource according to the comparison result to achieve random access, that is, the terminal device with a measurement value greater than or equal to the first threshold and the terminal device with a measurement value less than the first threshold uses the first time-frequency resource in a time-division manner; or, the terminal device sends a preamble code in different time domain resources of the first time-frequency resource according to the state of the terminal device to achieve random access, that is, the terminal device in an idle or inactive state and the terminal device in a connected state use the first time-frequency resource in a time-division manner; or, the terminal device sends a preamble code in different time domain resources of the first time-frequency resource according to the type of the terminal device to achieve random access, that is, the first type or the second type of terminal device uses the first time-frequency resource in a time-division manner, which can provide prior information for the network device to estimate and control interference, so that the network device can perform scheduling based on the prior information to reduce interference between terminal devices.

[0317] Exemplarily, the network device schedules users and controls downlink transmission on downlink (DL) resources corresponding to the first time-frequency resource unit and the second time-frequency resource unit.

[0318] For example, for a PDSCH user in the time period when a user with high interference (such as a user using the first time-frequency resource unit) uses PRACH, the network device can allocate higher PDSCH transmit power to the PDSCH user, allocate DL resources away from PRACH, schedule users using beams with large isolation from the current SSB beam, schedule users far away from the current user, lower the MCS, enable repeated transmission, etc. to reduce interference. Among them, the user with high interference can be any of the following users:

[0319] When the first condition is that the measured value is greater than or equal to the first threshold, and the first threshold is the received power of the reference signal, the interference-heavy user may be a user determined not to meet the first condition; or,

[0320] When the first condition is that the measured value is greater than or equal to a first threshold, and the first threshold is the transmit power of the reference signal, the path loss, or the distance between the terminal device and the network device, the interference-heavy user may be a user determined to meet the first condition; or,

[0321] When the first condition is that the terminal is in an idle state or an inactive state, the high-interference user may be a user that is determined to meet the first condition; or,

[0322] When the first condition is that the terminal is in a connected state, the interference-heavy user may be a user that is determined not to meet the first condition; or

[0323] When the first condition is that the terminal type is the first type, the high-interference user may be a user determined not to meet the first condition; or, when the first condition is that the terminal type is the second type, the high-interference user may be a user determined to meet the first condition.

[0324] Exemplarily, the first time-frequency resource includes a first time-frequency resource unit and a second time-frequency resource unit. The time domain occupied by the first time domain resource is the first time period, the time domain occupied by the first time-frequency resource unit is the first sub-time period, and the time domain occupied by the second time-frequency resource unit is the second sub-time period.

[0325] If the network device receives a preamble code from the terminal device on the first time-frequency resource unit, the network device can send first scheduling information to a third device that performs physical downlink shared channel PDSCH transmission in the first sub-time period, and the first scheduling information includes at least one of the following information: the PDSCH transmission power, the downlink resources for transmitting the PDSCH, the beam for sending the PDSCH, a repeated transmission indication, a modulation and coding strategy MCS or a precoding strategy, wherein the PDSCH transmission power is greater than or equal to the second threshold, the distance between the downlink resources for transmitting the PDSCH and the first time-frequency resource unit is greater than or equal to the third threshold, and the repeated transmission indication is used to indicate that the PDSCH can be repeatedly transmitted and the MCS is less than or equal to the fourth threshold.

[0326] If the network device receives a preamble code from the terminal device on the second time-frequency resource unit, the network device can send second scheduling information to the fourth device that performs physical downlink shared channel PDSCH transmission in the second sub-time period, and the second scheduling information includes at least one of the following information: the PDSCH transmission power, the downlink resources for transmitting the PDSCH, the beam for transmitting the PDSCH, a repeated transmission indication, or a modulation and coding strategy MCS, wherein the PDSCH transmission power is less than the second threshold, the distance between the downlink resources for transmitting the PDSCH and the first time-frequency resource unit is less than the third threshold, and the repeated transmission indication is used to indicate that the PDSCH cannot be repeatedly transmitted and the MCS is greater than or equal to the fourth threshold.

[0327] The second threshold, the third threshold, or the fourth threshold may be predefined or determined through negotiation between the network device and the terminal device, and this embodiment does not impose any limitation thereto.

[0328] Furthermore, the network device allocates resources in the SBFD uplink subband that are farther away from the downlink subband to important channels such as PRACH and PUCCH, and allocates resources in the SBFD uplink subband that are closer to the downlink subband to less important channels such as PUSCH. For example, the frequency division multiplexing RO occupying the lowest frequency position in the frequency division multiplexing RO of the SBFD-PRACH starts from the lowest RE or lowest RB of the SBFD uplink subband, or the frequency division multiplexing RO occupying the highest frequency position in the frequency division multiplexing RO of the SBFD-PRACH ends at the highest RE or highest RB of the uplink subband, or the center frequency position of the PRACH is aligned with the center frequency position of the uplink subband (the deviation does not exceed a given threshold, the specific number of which can be predefined), or the PRACH does not occupy one or more RBs or REs closest to the downlink subband (the specific number of which can be predefined).

[0329] As shown in Figure 19, the network device configures the SBFD-PRACH resource in the middle of the UL (the farthest from the downlink subband). The terminal device that sends the preamble code in the second time-frequency resource unit can be a cell edge terminal device with a large transmission power. The network device schedules the RAR of the terminal device to be at the bottom of the lower DL or the top of the upper DL, Msg5 and Msg3 to be in the middle of the UL subband, and Msg4 to be at the bottom of the lower DL or the top of the upper DL; in other words, the terminal device that sends the preamble code in the second time-frequency resource unit can be a cell edge terminal device with a large transmission power. The network device schedules the RAR of the terminal device to be farther away from the SBFD-PRACH resource than the RAR of the terminal device that sends the preamble code in the first time-frequency resource unit (for example, a device located in the center of the cell). The network device schedules the Msg5 and Msg3 of the terminal device to be closer to the middle of the UL subband than the Msg5 and Msg3 of the terminal device that sends the preamble code in the first time-frequency resource unit (for example, a device located in the center of the cell).

[0330] As shown in Figure 20, the network device configures the SBFD-PRACH resource in the middle of the UL (the farthest from the downlink subband). The terminal device that sends the preamble code in the second time-frequency resource unit can be a cell edge terminal device with a large transmission power. The network device schedules the RAR of the terminal device to be at the bottom of the lower DL, Msg5 and Msg3 to be in the middle of the UL subband, and Msg4 to be at the bottom of the lower DL; in other words, the terminal device that sends the preamble code in the second time-frequency resource unit can be a cell edge terminal device with a large transmission power. The network device schedules the RAR of the terminal device to be farther away from the SBFD-PRACH resource than the RAR of the terminal device that sends the preamble code in the first time-frequency resource unit (for example, a device located in the center of the cell). The network device schedules the Msg5 and Msg3 of the terminal device to be closer to the middle of the UL subband than the Msg5 and Msg3 of the terminal device that sends the preamble code in the first time-frequency resource unit (for example, a device located in the center of the cell).

[0331] In the communication method shown in Figure 13, the base station adds signaling to indicate the usage of SBFD-PRACH, that is, the conditions under which SBFD-PRACH is used for random access, for example, which ROs can be used by which UEs, and controls the average UE-UE interference level caused by random access within the cell, thereby achieving a compromise between UE access capability enhancement and interference control.

[0332] This application also provides another communication method, which reduces UE-UE interference by configuring a longer preamble format and lower transmit power for SBFD-PRACH resources. For ease of understanding, the communication method is described in detail below with reference to FIG21.

[0333] FIG21 is a schematic flow chart of another communication method provided in an embodiment of the present application, comprising the following steps:

[0334] S2110, the network device sends fourth information to the terminal device, and correspondingly, the terminal device receives the fourth information from the network device.

[0335] Specifically, the fourth information is used to configure a first parameter corresponding to the first time-frequency resource, where the first parameter includes at least one of the following parameters:

[0336] The format of the first preamble, the first receiving power, or the first transmitting power. For the introduction of the first time-frequency resource, please refer to the description of the first time-frequency resource in the communication method shown in FIG13 above, which will not be repeated here.

[0337] S2120, the network device sends the fifth information to the terminal device, and correspondingly, the terminal device receives the fifth information from the network device.

[0338] Specifically, the fifth information is used to configure a second parameter corresponding to the second time-frequency resource, where the second parameter includes at least one of the following parameters:

[0339] The format of the second preamble, the second receiving power, or the second transmitting power. For the introduction of the second time-frequency resource, please refer to the description of the second time-frequency resource in the communication method shown in FIG13 above, which will not be repeated here.

[0340] In this embodiment, the fourth information and the fifth information are configured independently. For example, the fourth information and the fifth information can be carried by different signaling respectively. For another example, the fourth information and the fifth information are carried (or indicated) by different fields.

[0341] Exemplarily, in this embodiment, the fourth information and the fifth information may be the following information:

[0342] For example, the fourth signal includes a first prach-ConfigurationIndex field configuring the format of the first preamble corresponding to the first time-frequency resource; the fifth signal includes a second prach-ConfigurationIndex field configuring the format of the second preamble corresponding to the second time-frequency resource;

[0343] The first prach-ConfigurationIndex field and the second prach-ConfigurationIndex field may be located in the same information element, such as both located in RACH-ConfigGeneric, or the first prach-ConfigurationIndex field and the second prach-ConfigurationIndex field may be located in different information elements.

[0344] Optionally, the fourth signal further includes a first preambleReceivedTargetPower field configuring a first received power corresponding to the first time-frequency resource; the fifth signal further includes a second preambleReceivedTargetPower field configuring a second received power corresponding to the second time-frequency resource;

[0345] The first preambleReceivedTargetPower field and the second preambleReceivedTargetPower field may be located in the same information element, such as both located in RACH-ConfigGeneric, or the first preambleReceivedTargetPower field and the second preambleReceivedTargetPower field may be located in different information elements.

[0346] For ease of understanding, the resource configuration of the network device for the terminal device through the fourth information and the fifth information in this embodiment is briefly introduced in conjunction with Figure 22.

[0347] As can be seen from Figure 22, the length of the preamble format configured by the base station for SBFD-PRACH is greater than the preamble format configured for UL-PRACH, and the target received power P0 configured for SBFD-PRACH is less than the target received power configured for UL-PRACH.

[0348] In the communication method shown in Figure 21, the UE's transmit power on the SBFD-PRACH is low, resulting in low UE-UE interference. At the same time, the long preamble occupies a longer time, which can also complete more power accumulation. This achieves the purpose of reducing interference while ensuring that the RACH access performance remains unchanged.

[0349] It should be understood that the size of the serial numbers of the above processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0350] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0351] It should also be understood that in some of the above embodiments, the devices in the existing network architecture are mainly used as examples for illustrative description (such as network devices, terminal devices, etc.), and it should be understood that the embodiments of the present application are not limited to the specific form of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

[0352] It is understandable that in the above-mentioned various method embodiments, the methods and operations implemented by devices (such as network devices, terminal devices) can also be implemented by components of the devices (such as chips or circuits).

[0353] The communication method provided in the embodiments of the present application is described in detail above with reference to Figures 13 and 21. The communication method is primarily described from the perspective of interaction between a terminal device and a network device. It is understood that, in order to implement the aforementioned functions, the terminal device and the network device include hardware structures and / or software modules corresponding to the respective functions.

[0354] Those skilled in the art should be aware that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0355] The communication device provided in this application is described in detail below with reference to Figures 23 to 25. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment. Therefore, for matters not described in detail, please refer to the method embodiment above. For the sake of brevity, some contents will not be repeated.

[0356] In the embodiment of the present application, the functional modules of the transmitting device or the receiving device can be divided according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation. The following is an example of dividing each functional module according to each function.

[0357] Figure 23 is a schematic block diagram of a communication device 10 provided in an embodiment of the present application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can implement corresponding communication functions, and the processing module 12 is used to process data. In other words, the transceiver module 11 is used to perform operations related to receiving and sending, and the processing module 12 is used to perform other operations besides receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0358] Optionally, the device 10 may further include a storage module 13, which may be used to store instructions and / or data. The processing module 12 may read the instructions and / or data in the storage module so that the device implements the actions of the devices in the aforementioned method embodiments.

[0359] In one design, the apparatus 10 may correspond to the terminal device in the above method embodiment, or a component (such as a chip) of the terminal device.

[0360] The device 10 can implement the steps or processes executed by the terminal device in the above method embodiment, wherein the transceiver module 11 can be used to execute the transceiver-related operations of the terminal device in the above method embodiment, and the processing module 12 can be used to execute the processing-related operations of the terminal device in the above method embodiment.

[0361] In one possible implementation, a transceiver module 11 is configured to receive first information, where the first information indicates a first time-frequency resource, the first time-frequency resource is used for random access, the first time-frequency resource includes two or more time-frequency resource units, any two of the two or more time-frequency resource units do not overlap in the time domain, the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, the first time domain resource is located in the first time domain unit, the first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission, and the first frequency domain resource is located in the first subband. A processing module 12 is configured to select one of the two or more time-frequency resource units as the time-frequency resource for random access based on a first condition.

[0362] In another possible implementation, the transceiver module 11 is used to receive fourth information, where the fourth information indicates a first parameter corresponding to a first time-frequency resource, where the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, where the first time domain resource is located in a first time domain unit, where the first frequency domain unit corresponding to the first time domain unit includes a frequency domain resource for uplink transmission and a frequency domain resource for downlink transmission, where the first frequency domain resource is located in the first frequency domain unit, and where the first parameter includes at least one of the following parameters: a format of a first preamble code, a first receiving power, or a first transmitting power. The transceiver module 11 is also used to receive fifth information, wherein the fifth information indicates a second parameter corresponding to a second time-frequency resource, the second time-frequency resource corresponds to a second time domain resource and a second frequency domain resource, the second time domain resource is located in a second time domain unit, the frequency domain resource included in the second frequency domain unit corresponding to the second time domain unit is used for uplink transmission, the second frequency domain resource is located in the second frequency domain unit, and the second parameter includes at least one of the following parameters: the format of the second preamble code, the second receiving power, or the second transmitting power; the length of the format of the first preamble code is greater than the length of the format of the second preamble code, the first receiving power is less than the second receiving power, and the first transmitting power is greater than the second transmitting power.

[0363] When the device 10 is used to execute the method in Figure 13, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S1310, S1321, S1322 and S1323; the processing module 12 can be used to execute the processing steps in the method, such as step S1320.

[0364] When the device 10 is used to execute the method in Figure 21, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S2110 and S2120; the processing module 12 can be used to execute the processing steps in the method.

[0365] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment, and for the sake of brevity, it will not be repeated here.

[0366] In another design, the apparatus 10 may correspond to the network device in the above method embodiment, or a component (such as a chip) of the network device.

[0367] The device 10 can implement the steps or processes executed by the network device in the above method embodiment, wherein the transceiver module 11 can be used to perform the transceiver-related operations of the network device in the above method embodiment, and the processing module 12 can be used to perform the processing-related operations of the network device in the above method embodiment.

[0368] In one possible implementation, processing module 12 is configured to determine first information, where the first information indicates a first time-frequency resource, the first time-frequency resource is used for random access, the first time-frequency resource includes two or more time-frequency resource units, any two of the two or more time-frequency resource units do not overlap in the time domain, the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, the first time domain resource is located in the first time domain unit, the first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission, and the first frequency domain resource is located in the first subband. Transceiver module 11 is configured to send the first information to the first device.

[0369] In another possible implementation, the transceiver module 11 is used to send fourth information, where the fourth information indicates a first parameter corresponding to a first time-frequency resource, where the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, where the first time domain resource is located in a first time domain unit, where the first frequency domain unit corresponding to the first time domain unit includes a frequency domain resource for uplink transmission and a frequency domain resource for downlink transmission, where the first frequency domain resource is located in the first frequency domain unit, and where the first parameter includes at least one of the following parameters: a format of a first preamble code, a first receiving power, or a first transmitting power. The transceiver module 11 is also used to send fifth information, wherein the fifth information indicates a second parameter corresponding to the second time-frequency resource, the second time-frequency resource corresponds to a second time domain resource and a second frequency domain resource, the second time domain resource is located in a second time domain unit, the frequency domain resource included in the second frequency domain unit corresponding to the second time domain unit is used for uplink transmission, the second frequency domain resource is located in the second frequency domain unit, and the second parameter includes at least one of the following parameters: the format of the second preamble code, the second receiving power, or the second transmitting power; the length of the format of the first preamble code is greater than the length of the format of the second preamble code, the first receiving power is less than the second receiving power, and the first transmitting power is greater than the second transmitting power.

[0370] When the device 10 is used to execute the method in Figure 13, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S1310, S1321, S1322 and S1323; the processing module 12 can be used to execute the processing steps in the method.

[0371] When the device 10 is used to execute the method in Figure 21, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps S2110 and S2120; the processing module 12 can be used to execute the processing steps in the method.

[0372] It should be understood that the specific process of each unit executing the above corresponding steps has been described in detail in the above method embodiment and will not be repeated here.

[0373] It should also be understood that the device 10 here is embodied in the form of a functional module. The term "module" here may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a dedicated processor or a group processor, etc.) and memory for executing one or more software or firmware programs, a combined logic circuit and / or other suitable components that support the described functions. In an optional example, those skilled in the art will understand that the device 10 may be specifically the mobile management network element in the above-mentioned embodiment, and may be used to execute the various processes and / or steps corresponding to the mobile management network element in the above-mentioned method embodiments; or, the device 10 may be specifically the terminal device in the above-mentioned embodiment, and may be used to execute the various processes and / or steps corresponding to the terminal device in the above-mentioned method embodiments. To avoid repetition, it will not be described here.

[0374] The apparatus 10 of each of the above-described solutions has the function of implementing the corresponding steps performed by the devices (such as terminal devices and network devices) in the above-described methods. This function can be implemented by hardware, or by hardware executing corresponding software implementations. The hardware or software includes one or more modules corresponding to the above-described functions; for example, the transceiver module can be replaced by a transceiver (for example, the transmitting unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as the processing module, can be replaced by a processor to respectively perform the transceiver operations and related processing operations in each method embodiment.

[0375] In addition, the transceiver module 11 may also be a transceiver circuit (for example, may include a receiving circuit and a sending circuit), and the processing module may be a processing circuit.

[0376] Figure 24 is a schematic diagram of another communication device 20 provided in an embodiment of the present application. Device 20 includes a processor 21, which is configured to execute computer programs or instructions stored in memory 22, or read data / signaling stored in memory 22, to perform the methods described in the above method embodiments. Optionally, there may be one or more processors 21.

[0377] Optionally, as shown in FIG24 , the device 20 further includes a memory 22 for storing computer programs or instructions and / or data. The memory 22 may be integrated with the processor 21 or may be separately provided. Optionally, there may be one or more memories 22 .

[0378] Optionally, as shown in Figure 24, the device 20 further includes a transceiver 23, which is used to receive and / or send signals. For example, the processor 21 is used to control the transceiver 23 to receive and / or send signals.

[0379] As a solution, the apparatus 20 is used to implement the operations performed by the terminal device in each of the above method embodiments.

[0380] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0381] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory and / or a non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0382] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) can be integrated into the processor.

[0383] It should also be noted that the memory described herein is intended to comprise, but not be limited to, these and any other suitable types of memory.

[0384] 25 is a schematic diagram of a chip system 30 provided in an embodiment of the present application. The chip system 30 (or also referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0385] The logic circuit 31 may be a processing circuit in the chip system 30. The logic circuit 31 may be coupled to a storage unit and call instructions in the storage unit so that the chip system 30 can implement the methods and functions of the various embodiments of the present application. The input / output interface 32 may be an input / output circuit in the chip system 30, outputting information processed by the chip system 30 or inputting data or signaling information to be processed into the chip system 30 for processing.

[0386] As a solution, the chip system 30 is used to implement the operations performed by the terminal device in the above various method embodiments.

[0387] For example, the logic circuit 31 is used to implement the processing-related operations performed by the terminal device in the above method embodiment; the input / output interface 32 is used to implement the sending and / or receiving-related operations performed by the terminal device in the above method embodiment.

[0388] An embodiment of the present application further provides a computer-readable storage medium on which computer instructions for implementing the methods executed by the device in the above-mentioned method embodiments are stored.

[0389] For example, when the computer program is executed by a computer, the computer can implement the methods executed by the terminal device or the network device in each embodiment of the above method.

[0390] An embodiment of the present application also provides a computer program product, comprising instructions, which, when executed by a computer, implement the methods performed by a terminal device or a network device in the above-mentioned method embodiments.

[0391] An embodiment of the present application also provides a communication system, including the aforementioned terminal device and network device.

[0392] The explanation of the relevant contents and beneficial effects of any of the above-mentioned devices can be referred to the corresponding method embodiments provided above, which will not be repeated here.

[0393] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0394] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0395] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0396] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0397] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0398] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0399] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, characterized in that: include: A first device receives first information from a second device, where the first information indicates a first time-frequency resource, the first time-frequency resource is used for random access, the first time-frequency resource includes two or more time-frequency resource units, any two of the two or more time-frequency resource units do not overlap in the time domain, the two or more time-frequency resource units include a first time-frequency resource unit and a second time-frequency resource unit, the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, the first time domain resource is located in the first time domain unit, the first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission, and the first frequency domain resource is located in the first subband; If the first condition is met, the first device selects the first time-frequency resource unit as the time-frequency resource for random access; or, If the first condition is not met, the first device selects the second time-frequency resource unit as the time-frequency resource for random access.

2. The method according to claim 1, characterized in that The first condition is that a measurement value is greater than or equal to a first threshold, and the measurement value is measured by the first device.

3. The method according to claim 2, characterized in that The method further comprises: The first device receives second information from the second device, where the second information indicates the first threshold.

4. The method according to claim 2 or 3, characterized in that The first threshold is a reference signal received power threshold, and the measured value is the received power of the reference signal; or The first threshold is a reference signal transmission power threshold, and the measured value is the transmission power of the reference signal; or The first threshold is a reference signal path loss threshold, and the measured value is the reference signal path loss; or The first threshold is a distance threshold between the first device and the second device, and the measurement value is the distance between the first device and the second device.

5. The method according to claim 1, wherein The first condition is that the state of the first device is idle or inactive; or, The first condition is that the state of the first device is a connected state.

6. The method according to claim 5, characterized in that The method further comprises: The first device obtains a first association relationship, where the first association relationship is an association relationship between a state of the first device and the two or more time-frequency resource units.

7. The method according to claim 1, characterized in that The time domain occupied by the first time domain resource is the first time period, the time domain occupied by the first time-frequency resource unit is the first sub-time period, and the time domain occupied by the second time-frequency resource unit is the second sub-time period, wherein the starting point of the first sub-time period is the starting point of the first time period, the end point of the first sub-time period is the starting point of the second sub-time period, and the end point of the second sub-time period is the end point of the first time period.

8. The method according to claim 1 or 7, characterized in that The method further comprises: The first device receives a system message from the second device, where the system message indicates a synchronization signal block SSB index, where the SSB index is associated with a first random access opportunity set and a second random access opportunity set, where the first random access opportunity set belongs to the first time-frequency resource unit, and the second random access opportunity set belongs to the second time-frequency resource unit.

9. The method according to claim 8, characterized in that The first random access opportunity set is indicated by a first mask index, and the second random access opportunity set is indicated by a second mask index; or, The first random access opportunity set is located in odd time slots, and the second random access opportunity set is located in even time slots; or, The starting time of the first random access opportunity in the first random access opportunity set is an odd-numbered orthogonal frequency division multiplexing symbol, and the starting time of the second random access opportunity in the second random access opportunity set is an even-numbered orthogonal frequency division multiplexing symbol; or, The index of each random access opportunity in the first random access opportunity set is an odd number, and the index of each random access opportunity in the second random access opportunity set is an even number.

10. The method according to any one of claims 1 to 9, characterized in that The first time-frequency resource is a physical random access channel PRACH resource.

11. A communication method, characterized in that: include: The second device determines first information, where the first information indicates a first time-frequency resource, the first time-frequency resource is used for random access, and the first time-frequency resource includes two or more time-frequency resource units, and any two of the two or more time-frequency resource units do not overlap in the time domain. The overlapping part, the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, the first time domain resource is located in a first time domain unit, the first frequency domain unit corresponding to the first time domain unit includes a first subband for uplink transmission and a second subband for downlink transmission, and the first frequency domain resource is located in the first subband; The second device sends the first information to the first device.

12. The method according to claim 11, characterized in that The method further comprises: The second device sends second information to the first device, where the second information indicates a first threshold. The first threshold and a measurement value are used by the first device to select one of the two or more time-frequency resource units as a time-frequency resource for random access, and the measurement value is obtained by measurement by the first device.

13. The method according to claim 12, characterized in that The first threshold is a reference signal received power threshold, and the measured value is the received power of the reference signal; or The first threshold is a reference signal transmission power threshold, and the measured value is the transmission power of the reference signal; or The first threshold is a reference signal path loss threshold, and the measured value is the reference signal path loss; or The first threshold is a distance threshold between the first device and the second device, and the measurement value is the distance between the first device and the second device.

14. The method according to claim 11, characterized in that The method further comprises: The second device sends third information to the first device, where the third information indicates a first association relationship, where the first association relationship is an association relationship between a state of the first device and the two or more time-frequency resource units.

15. The method according to any one of claims 11 to 14, characterized in that The two or more time-frequency resource units include a first time-frequency resource unit and a second time-frequency resource unit. The time domain occupied by the first time domain resource is a first time period, the time domain occupied by the first time-frequency resource unit is a first sub-time period, and the time domain occupied by the second time-frequency resource unit is a second sub-time period.

16. The method according to claim 15, characterized in that The method further comprises: The second device receives a preamble from the first device on the first time-frequency resource unit; The second device sends first scheduling information to a third device that performs physical downlink shared channel (PDSCH) transmission in the first sub-time period, where the first scheduling information includes at least one of the following information: The PDSCH transmission power, the downlink resource for transmitting the PDSCH, the beam for transmitting the PDSCH, the repetition transmission indication, the modulation and coding strategy MCS or the precoding strategy, Among them, the PDSCH transmission power is greater than or equal to the second threshold, the distance between the downlink resource for transmitting the PDSCH and the first time-frequency resource unit is greater than or equal to the third threshold, and the repeated transmission indication is used to indicate that the PDSCH can be repeatedly transmitted and the MCS is less than or equal to the fourth threshold.

17. The method according to claim 15, characterized in that The method further comprises: The second device receives a preamble from the first device on the second time-frequency resource unit; The second device sends second scheduling information to a fourth device that performs physical downlink shared channel PDSCH transmission in the second sub-time period, where the second scheduling information includes at least one of the following information: The PDSCH transmission power, the downlink resource for transmitting the PDSCH, the beam for transmitting the PDSCH, the repetition transmission indication, or the modulation and coding strategy MCS, Among them, the PDSCH transmission power is less than the second threshold, the distance between the downlink resource for transmitting the PDSCH and the first time-frequency resource unit is less than the third threshold, and the repeated transmission indication is used to indicate that the PDSCH cannot be repeatedly transmitted and the MCS is greater than or equal to the fourth threshold.

18. The method according to any one of claims 15 to 17, characterized in that The method further comprises: The second device sends a system message to the first device, where the system message indicates a synchronization signal block SSB index, where the SSB index is associated with a first random access opportunity set and a second random access opportunity set, where the first random access opportunity set belongs to the first time-frequency resource unit, and the second random access opportunity set belongs to the second time-frequency resource unit.

19. The method according to claim 18, characterized in that The first random access opportunity set is indicated by a first mask index, and the second random access opportunity set is indicated by a second mask index; or, The first random access opportunity set is located in odd time slots, and the second random access opportunity set is located in even time slots; or, The starting time of the first random access opportunity in the first random access opportunity set is an odd-numbered orthogonal frequency division multiplexing symbol, and the starting time of the second random access opportunity in the second random access opportunity set is an even-numbered orthogonal frequency division multiplexing symbol; or, The index of each random access opportunity in the first random access opportunity set is an odd number, and the index of each random access opportunity in the second random access opportunity set is an even number.

20. A communication method, characterized in that: include: Receive fourth information, where the fourth information indicates a first parameter corresponding to a first time-frequency resource, where the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, where the first time domain resource is located in a first time domain unit, and where a first frequency domain unit corresponding to the first time domain unit includes a frequency domain resource for uplink transmission and a frequency domain resource for downlink transmission, where the first frequency domain resource is located in the first frequency domain unit, and where the first parameter includes at least one of the following parameters: a format of the first preamble, a first receiving power, or a first transmitting power; Receive fifth information, where the fifth information indicates a second parameter corresponding to the second time-frequency resource, where the second time-frequency resource corresponds to a second time domain resource and a second frequency domain resource, where the second time domain resource is located in a second time domain unit, and where the frequency domain resource included in the second frequency domain unit corresponding to the second time domain unit is used for uplink transmission, where the second frequency domain resource is located in the second frequency domain unit, and where the second parameter includes at least one of the following parameters: a format of a second preamble, a second receiving power, or a second transmitting power; The fourth information and the fifth information are carried through different signaling, or the fourth information and the fifth information are carried through different fields.

21. A communication method, characterized in that: include: Send fourth information, where the fourth information indicates a first parameter corresponding to the first time-frequency resource, where the first time-frequency resource corresponds to a first time domain resource and a first frequency domain resource, where the first time domain resource is located in a first time domain unit, and the first frequency domain unit corresponding to the first time domain unit includes a frequency domain resource for uplink transmission and a frequency domain resource for downlink transmission, where the first frequency domain resource is located in the first frequency domain unit, and the first parameter includes at least one of the following parameters: a format of the first preamble, a first receiving power, or a first transmitting power; Send fifth information, where the fifth information indicates a second parameter corresponding to the second time-frequency resource, where the second time-frequency resource corresponds to a second time domain resource and a second frequency domain resource, where the second time domain resource is located in a second time domain unit, and the frequency domain resource included in the second frequency domain unit corresponding to the second time domain unit is used for uplink transmission, and the second frequency domain resource is located in the second frequency domain unit, and the second parameter includes at least one of the following parameters: a format of a second preamble, a second receiving power, or a second transmitting power; The fourth information and the fifth information are carried through different signaling, or the fourth information and the fifth information are carried through different fields.

22. The method according to claim 20 or 21, characterized in that A length of a format of the first preamble code is greater than a length of a format of the second preamble code, the first receiving power is less than the second receiving power, and the first transmitting power is greater than the second transmitting power.

23. A communication device, characterized in that: Used to implement the method according to any one of claims 1 to 10, 20 and 22.

24. The communication device according to claim 23, wherein: The communication device includes a terminal device or a chip.

25. A communication device, characterized in that: Used to implement the method according to any one of claims 11 to 19, 21 and 22.

26. The communication device according to claim 25, characterized in that The communication device includes a network device or a chip.

27. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and when the computer instructions are executed, the method according to any one of claims 1 to 22 is implemented.

28. A computer program product, characterized in that When the computer program product is executed, the method according to any one of claims 1 to 22 is implemented.

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