Communication method and apparatus

Abstract

Disclosed in the present application are a communication method and apparatus, which can be applied to communication systems such as the Internet of Vehicles and the Internet of Things. The method comprises: a first terminal device sending a sidelink synchronization signal block; and a second terminal device receiving the sidelink synchronization signal block, and performing synchronization or beam training on the basis of the sidelink synchronization signal block, wherein the sidelink synchronization signal block comprises first indication information, which is used for determining that the sidelink synchronization signal block is used for synchronization or beam training, or resources of the sidelink synchronization signal block can be used for determining that the sidelink synchronization signal block is used for synchronization or beam training. By means of the method, a receiving-side device can be clear about the use of a received sidelink synchronization signal block, thereby avoiding the situation whereby the communication performance is affected due to it being impossible to normally perform synchronization or beam training as a result of the wrong use of the sidelink synchronization signal.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on August 10, 2023, with application number 202311010415.2 and application name “A Communication Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The embodiments of the present application relate to the field of sideline communication technology, and in particular, to a communication method and device. Background Art

[0004] 3rd Generation Partnership Project (3GPP) Release (Rel)-16 / 17 defines time synchronization between terminal devices based on the sidelink synchronization signal (physical broadcast channel, PBCH) block (S-SSB). The S-SSB carries information that can be used to distinguish synchronization sources.

[0005] Rel-18 proposes that terminal devices can perform beam training based on S-SSB and that the terminal identity can be indicated based on the information carried by the S-SSB. However, indicating the terminal identity based on the information carried by the S-SSB changes the meaning of the information carried by the traditional S-SSB, resulting in inconsistent understanding of the content carried by S-SSB by terminal devices of different versions. This can cause terminal devices to incorrectly use the sidelink synchronization signal, resulting in synchronization or beam training failures, and affecting communication performance.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a communication method and device that can reduce the inability to achieve synchronization or beam alignment due to incorrect use of side synchronization signal blocks.

[0008] To achieve the above objectives, the present invention adopts the following technical solutions:

[0009] In a first aspect, embodiments of the present application provide a communication method that can be performed by a first communication device. The first communication device can be a terminal device. Alternatively, the first communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the first aspect is described below using the first communication device as an example, wherein the first communication device is the first terminal device itself.

[0010] The communication method includes: a first terminal device determining a sideline synchronization signal block and transmitting the sideline synchronization signal block, wherein the sideline synchronization signal block includes first indication information, the first indication information being used to determine that the sideline synchronization signal block is used for synchronization or beam training; or, resources of the sideline synchronization signal block being used to determine that the sideline synchronization signal block is used for synchronization or beam training.

[0011] In a second aspect, embodiments of the present application provide a communication method that can be performed by a second communication device. The second communication device can be a terminal device. Alternatively, the second communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the second aspect is described below using the second communication device as an example, wherein the second communication device is the second terminal device itself.

[0012] The communication method includes: a second terminal device receiving a sideline synchronization signal block, and performing synchronization or beam training based on the sideline synchronization signal block. The sideline synchronization signal block includes first indication information, and the first indication information is used to determine whether the sideline synchronization signal block is used for synchronization; or resources of the sideline synchronization signal block can be used to determine whether the sideline synchronization signal block is used for synchronization or beam training.

[0013] In the methods of the first and second aspects, the sidelink synchronization signal block can be used for both synchronization and beam training. To ensure that the second terminal device and the first terminal device have a consistent understanding of the purpose of the sidelink synchronization signal block, the first terminal device can indicate the purpose of the sidelink synchronization signal block to the second terminal device. This solution facilitates the receiving terminal device to distinguish the purpose of the received sidelink synchronization signal block, thereby avoiding the incorrect use of the sidelink synchronization signal block, which could result in synchronization or beam training failures and affect communication performance.

[0014] In a possible implementation of the first aspect or the second aspect, the first indication information is used to determine whether the sidelink synchronization signal block is used for synchronization or beam training, and the first indication information is carried in a master indication block (MIB) included in the sidelink synchronization signal block.

[0015] In this solution, the MIB in the multiplexed side synchronization signal block carries the first indication information, which makes it easy for the receiving terminal device to directly decode the MIB and obtain the first indication information, thereby determining the purpose of the side synchronization signal block.

[0016] In a possible implementation of the first aspect or the second aspect, when the first indication information is used to determine whether the side synchronization signal block is used for beam training, the MIB also includes a first terminal identifier.

[0017] The first terminal identifier can be the identification information of the first terminal device or the identification information of the service of the first terminal device. The sidelink synchronization signal block carries the first terminal identifier, which allows the second terminal device to clearly understand that the beam alignment target is the first terminal device, facilitating the use of the aligned beam for subsequent sidelink transmission after beam alignment is completed.

[0018] In a possible implementation of the first aspect or the second aspect, the first terminal identifier is used for beam training.

[0019] In a possible implementation of the first or second aspect, the first indication information is used to indicate that a sidelink synchronization signal block is used for synchronization or beam training, and the first indication information is carried by a first synchronization signal identifier carried by the sidelink synchronization signal block. When the value of the first synchronization signal identifier is within a first range, the first indication information indicates that the sidelink synchronization signal block is used for synchronization; and when the value of the first synchronization signal identifier is within a second range, the first indication information indicates that the sidelink synchronization signal block is used for beam training.

[0020] The first synchronization signal identifier can be an SL SS ID. This solution uses the value range of the SL SS ID to distinguish the purpose of the sideline synchronization signal. In this way, the receiving terminal device can determine the purpose of the received sideline synchronization signal block through the SLSS ID, avoiding incorrect use of the sideline synchronization signal block and affecting the normal communication of the terminal device.

[0021] In a possible implementation of the first aspect or the second aspect, the first indication information is used to indicate that the side synchronization signal block is used for beam training, and the side synchronization signal block also includes a first terminal identifier, which is carried in the MIB included in the side synchronization signal block; or, the first indication information is also used to indicate the first terminal identifier.

[0022] The first terminal identifier can be the identification information of the first terminal device or the identification information of the service of the first terminal device. In order to ensure that the object of the beam alignment of the second terminal device is the first terminal device, the sideline synchronization signal block can also carry the first terminal identifier, so that after the beam alignment is completed, the aligned beam can be used for subsequent sideline transmission.

[0023] In a possible implementation of the first or second aspect, sending a sideline synchronization block includes: when the sideline synchronization signal block is used for synchronization, sending the sideline synchronization signal on a first resource; and when the sideline synchronization signal block is used for beam training, sending the sideline synchronization signal on a second resource. Accordingly, using the resource of the sideline synchronization signal block to determine whether the sideline synchronization signal block is used for synchronization or beam training includes: when the resource of the sideline synchronization signal block is the first resource, using the sideline synchronization signal block for synchronization; and when the resource of the sideline synchronization signal block is the second resource, using the sideline synchronization signal block for beam training.

[0024] This solution distinguishes the purpose of sidelink synchronization signal blocks by their resources, eliminating the need for additional signaling overhead. Furthermore, given that beam training requires beam scanning in different beam directions, which may require different resources than synchronization, this solution ensures that synchronization and beam training resources and transmissions do not interfere with each other.

[0025] In a possible implementation of the first or second aspect, the first resource belongs to a first resource set, and the second resource belongs to a second resource set. The resources in the first resource set are used to transmit sidelink synchronization signal blocks for synchronization, and the resources in the second resource set are used to transmit sidelink synchronization signal blocks for beam training.

[0026] In this solution, the first resource set and the second resource set are different resource sets, and the resources included in the two resource sets do not overlap in the time domain and / or frequency domain. The receiving terminal device distinguishes the use of the sidelink synchronization signal block based on the resource set containing the first resource or the resource containing the second resource, thereby minimizing the possibility of incorrect use of the sidelink synchronization signal block, which could affect normal communication of the terminal device.

[0027] Optionally, before the initial synchronization, the first terminal device may send a side synchronization signal block carrying first indication information. Accordingly, the second terminal device determines the purpose of the side synchronization signal block based on the first indication information during the initial synchronization process.

[0028] In a possible implementation of the first aspect or the second aspect, the structure of the sideline synchronization signal block used for beam training is different from the structure of the sideline synchronization signal block used for synchronization.

[0029] Because beam training does not require synchronization information, the structure of the sideline synchronization signal block used for beam training can be simpler than that used for synchronization. This structure can then indicate the purpose of the sideline synchronization signal block. Furthermore, more simplified sideline synchronization signal blocks can be accommodated within a given time domain resource, improving resource utilization. This also facilitates scanning in more beam directions, facilitating faster beam alignment.

[0030] In a possible implementation of the first or second aspect, the sidelink synchronization signal block includes a first terminal identifier; wherein the first terminal identifier is carried in the MIB of the sidelink synchronization signal block. Alternatively, the first terminal identifier is carried in a first synchronization signal identifier carried in the sidelink synchronization signal block, where the first synchronization signal identifier belongs to a synchronization signal identifier set, and the synchronization signal identifiers in the synchronization signal identifier set are used to indicate the type of the synchronization source.

[0031] This solution uses MIB or SL SS ID to carry the first terminal identification, so that the second terminal device can clearly know that the object of beam alignment is the first terminal device, which facilitates the use of the aligned beam for subsequent side transmission after the beam alignment is completed.

[0032] In a possible implementation of the first aspect or the second aspect, the side synchronization signal block also includes a beam index, which is carried by the MIB of the side synchronization signal block; or, the beam index is carried by the first synchronization signal identifier carried by the side synchronization signal block, and the first synchronization signal identifier belongs to a synchronization signal identifier set, and the synchronization signal identifier in the synchronization signal identifier set is used to indicate the type of the synchronization source.

[0033] When the side synchronization signal block is used for beam training, the side synchronization signal block can also carry a beam index so that the receiving terminal device knows the beam direction of the side synchronization signal block or the reference signal in the side synchronization signal block, which facilitates beam measurement and reports the index or related identifier of the best beam, thereby completing beam alignment.

[0034] Optionally, the beam index is the beam index of each sidelink primary synchronization signal (S-PSS) or sidelink secondary synchronization signal (S-SSS) included in the sidelink synchronization signal block, or the beam index is the beam index of the first S-PSS or the first S-SSS included in the sidelink synchronization signal block.

[0035] In a possible implementation of the first aspect or the second aspect, the first terminal device needs to establish a unicast link with at least one second terminal device, and the side synchronization signal block also includes an application layer identifier.

[0036] By carrying an application layer identifier, the second terminal device can clearly understand the first terminal device's need to establish a unicast link, and only then perform beam alignment with the first terminal device. This solution can reduce unnecessary beam alignment processes between terminal devices, thereby saving resources and reducing terminal device power consumption. It also facilitates the relationship between the beam training process and unicast link establishment, thereby determining the beam and resources required for unicast link establishment transmission.

[0037] In a possible implementation of the first aspect or the second aspect, the side synchronization signal block also includes a type identifier of the service of the first terminal device.

[0038] In this solution, the type identifier of the service of the first terminal device is used to indicate that the first terminal device needs to establish a unicast link. For example, the second terminal device is interested in the service indicated by the type identifier and can perform beam alignment with the first terminal device.

[0039] Optionally, the first terminal device does not need to establish a unicast link with any terminal device, and the side synchronization signal block includes a default application layer identifier and / or a default service type identifier, which is used to indicate that the side synchronization signal block is used for synchronization.

[0040] In a third aspect, embodiments of the present application provide a communication method that can be performed by a first communication device. The first communication device can be a terminal device. Alternatively, the first communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the third aspect is described below using the first communication device as an example, namely, the first terminal device itself. The first terminal device needs to establish a unicast link with at least one second terminal device.

[0041] The communication method includes: a first terminal device determines a sideline synchronization signal block and sends the sideline synchronization signal block, wherein the sideline synchronization signal block includes an application layer identifier.

[0042] In a fourth aspect, embodiments of the present application provide a communication method that can be performed by a second communication device. The second communication device can be a terminal device. Alternatively, the second communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the fourth aspect is described below using the second communication device as an example, wherein the second communication device is the second terminal device itself. The second terminal device can establish a unicast link with the first terminal device.

[0043] The communication method includes: the second terminal device receives a side synchronization signal block, which includes an application layer identifier; the second terminal device performs beam alignment with the first terminal device according to the application layer identifier and the side synchronization signal block.

[0044] In a possible implementation of the third aspect or the fourth aspect, the sideline synchronization signal block further includes beam information, where the beam information is used to indicate a beam index of the sideline synchronization signal block.

[0045] In a possible implementation of the third aspect or the fourth aspect, the sidelink synchronization signal block further includes a type identifier of the service of the first terminal device.

[0046] In a possible implementation of the third aspect or the fourth aspect, the sideline synchronization signal block also includes first indication information, and the first indication information is used to determine whether the sideline synchronization signal block is used for synchronization or beam training.

[0047] In a possible implementation of the third aspect or the fourth aspect, the first terminal device does not need to establish a unicast link with any terminal device, and the side synchronization signal block includes a default application layer identifier and / or a default service type identifier, and the default application layer identifier and / or the default service type identifier are used to indicate that the side synchronization signal block is used for synchronization.

[0048] The beneficial effects of the third to fourth aspects and their implementation methods mentioned above can be referred to the description of the beneficial effects of the first to second aspects and any possible implementation methods thereof, and will not be repeated here.

[0049] In a fifth aspect, embodiments of the present application provide a communication method that can be performed by a first communication device. The first communication device can be a terminal device. Alternatively, the first communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the fifth aspect is described below using the first communication device as the first terminal device itself as an example.

[0050] The communication method includes: a first terminal device obtains N consecutive time units, and sends a first transport block (TB) in the first time unit of the N time units. The first transport block includes at least one logical channel, and the at least one logical channel is determined from all logical channels to be sent in a first order according to priority and channel access priority class (CAPC).

[0051] In a sixth aspect, embodiments of the present application provide a communication method that can be performed by a second communication device. The second communication device can be a terminal device. Alternatively, the second communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the sixth aspect is described below using the second communication device as an example, wherein the second communication device is the second terminal device itself.

[0052] The communication method includes: the second terminal device determines N consecutive time units, receives a first transmission block in the first time unit of the N time units, and the first transmission block includes at least one logical channel. The at least one logical channel is determined from all logical channels to be sent in a first order according to priority and CAPC.

[0053] In the method of the fifth or sixth aspect, resource selection is performed according to the first transmission block, and at least one logical channel included in the first transmission block is determined based on the priorities and CAPC of all logical channels to be transmitted. This allows for both the importance of the logical channels and regulatory requirements for unlicensed spectrum to be considered. For example, when N transmission units are used for continuous transmission of multiple consecutive slot transmissions (MCSt), the CAPC value of subsequent transmissions is no greater than the CAPC value of the first transmission.

[0054] In a possible implementation of the fifth or sixth aspect, the first order of determining at least one logical channel is: the logical channel with the lowest priority value, the logical channel with the highest CAPC value for the same destination, and the logical channels with the same destination with priority values ​​from low to high.

[0055] In a possible implementation of the fifth or sixth aspect, the first order of determining the at least one logical channel is: the logical channel with the highest CAPC value, and the logical channels with the same destination and priority values ​​from low to high.

[0056] In a possible implementation of the fifth or sixth aspect, the logical channel with the highest CAPC value belongs to a logical channel whose priority value is less than or equal to the priority value of the resource selection.

[0057] In a possible implementation of the fifth aspect, the method also includes: the first terminal device discards the logical channel that makes the period of the transmission block different from the period in the resource selection parameter set, and / or discards the logical channel that makes the original remaining packet delay budget (remaining (packet delay budget, PDB)) of the transmission block less than the remaining PDB of the transmission block.

[0058] In a possible implementation of the fifth aspect, the method further includes: when the first condition is met, the first terminal device sends a repetition of the first transmission block within the second time unit of the N time units. In a possible implementation of the sixth aspect, the method further includes: when the first condition is met, the second terminal device receives a repetition of the first transmission block within the second time unit of the N time units. Wherein, the first condition includes one or more of the following: there are no other logical channels to be sent with the same destination as the transmission block of the first time unit, there are no logical channels to be sent, the priority value of at least one logical channel among the logical channels to be sent is higher than the priority value of the resource selection, the logical channel with the lowest priority value among the logical channels to be sent is different from the priority value of the resource selection, and the priority value of the logical channel with the lowest priority value among the logical channels to be sent is higher than the priority value of the resource selection.

[0059] In this scheme, a logical channel that failed to transmit a transport block in the first time unit due to insufficient resources can be transmitted using the MCSt's candidate resources. Alternatively, the MCSt's candidate resources can be used for transmissions to different destinations. In other words, multiple different transport blocks can be transmitted using the MCSt's candidate resources, thereby improving system performance and efficiency and increasing resource utilization.

[0060] In a possible implementation of the fifth aspect, the method further includes: if the first condition is not met, the first terminal device sends at least one logical channel among other logical channels to be sent within the second time unit. In a possible implementation of the sixth aspect, the method further includes: if the first condition is not met, the second terminal device receives at least one logical channel among other logical channels to be sent within the second time unit. The first order of sending the at least one logical channel is: the logical channel with the lowest priority value, the logical channel with the largest CPAC value for the same destination, and the logical channels with the same destination having a priority from low to high; or, the logical channel with the largest CPAC value, and the logical channel with the same destination having a priority from low to high.

[0061] In a possible implementation of the fifth or sixth aspect, the CAPC value of the other logical channels to be sent is not higher than the CAPC value of the first transport block.

[0062] In a possible implementation of the fifth aspect, the method further includes: the first terminal device sending sharing indication information, where the sharing indication information is used to indicate the shared time unit among the N time units. In a possible implementation of the sixth aspect, the method further includes: the second terminal device receiving sharing indication information, where the sharing indication information is used to indicate the shared time unit among the N time units.

[0063] In a seventh aspect, embodiments of the present application provide a communication method that can be performed by a first communication device. The first communication device can be a terminal device. Alternatively, the first communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the seventh aspect is described below using the first communication device as the first terminal device itself as an example.

[0064] The communication method includes: the first terminal device determines a first time domain resource, which is used to send and / or receive a side synchronization signal block; the first terminal device sends the side synchronization signal block with a first power on a first frequency domain resource within the time-frequency resource where the first time domain resource is located, and sends the side synchronization signal block with a second power on a second frequency domain resource within the time-frequency resource where the first time domain resource is located.

[0065] In an eighth aspect, embodiments of the present application provide a communication method that can be performed by a second communication device. The second communication device can be a terminal device. Alternatively, the second communication device can be a component used to implement the functions of the terminal device, for example, a unit / module, circuit, or chip within the terminal device. The method provided in the eighth aspect is described below using the second communication device as an example, wherein the second communication device is the second terminal device itself.

[0066] The communication method includes: the second terminal device determines a first time domain resource, where the first time domain resource is used to send and / or receive a side synchronization signal block; and the second terminal device receives the side synchronization signal block in the first time domain resource.

[0067] In a possible implementation of the seventh or eighth aspect, the first power is determined according to a first offset value, or the first power is (pre) configured; the second power is determined according to a second offset value, or the second power is (pre) configured, or the second power is determined according to the first power.

[0068] Optionally, the first power is the power of each S-SSB on the first frequency domain resource.

[0069] Optionally, the second power is the power of each S-SSB on the second frequency domain resource.

[0070] Optionally, the first frequency domain resource is an S-SSB resource determined according to the ARFCN, and the second frequency domain resource is an S-SSB resource used to send the S-SSB in addition to the first frequency domain resource; or, the first frequency domain resource is an S-SSB resource on an anchor RB set, and the second frequency domain resource is an S-SSB resource on an RB set used to send the S-SSB in addition to the first frequency domain resource. The anchor RB set is the RB set where the frequency indicated by the ARFCN is located.

[0071] In a possible implementation of the seventh or eighth aspect, the first power is determined based on the first offset value and / or the number of S-SSB frequency domain repetitions within the RB set; the second power is determined based on the second offset value and / or the number of S-SSB frequency domain repetitions within the RB set, or the second power is determined based on the first power.

[0072] Optionally, the first power is the total power of S-SSB on each RB set on the first frequency domain resource.

[0073] Optionally, the second power is the total power of S-SSB on each RB set on the second frequency domain resource.

[0074] Optionally, the first frequency domain resource is an S-SSB resource on an anchor RB set, and the second frequency domain resource is an S-SSB resource on an RB set used to send S-SSB except the first frequency domain resource. The anchor RB set is an RB set where the frequency indicated by the ARFCN is located.

[0075] In a possible implementation of the seventh or eighth aspect, the first offset value is (pre) configured, or the first offset value is determined according to 10log(M). M is the total number of RB sets in the resource pool or BWP, or M is (pre) configured, or M is the maximum number of S-SSBs that can be transmitted in the resource pool or BWP, or M is the number of RB sets actually used to send S-SSBs in the resource pool or BWP, or M is the number of S-SSB resources actually used to send S-SSBs in the resource pool or BWP.

[0076] In a possible implementation of the seventh or eighth aspect, the second offset value is (pre) configured, or determined according to 10log(N), or determined according to the first offset value. Wherein, N is the maximum number of S-SSBs that can be transmitted in the resource pool or BWP, or N is (pre) configured, or N is the total number of RB sets in the resource pool or BWP, or N is the number of RB sets actually used to send S-SSBs in the resource pool or BWP, or N is the number of S-SSB resources actually used to send S-SSBs in the resource pool or BWP.

[0077] In a possible implementation of the seventh or eighth aspect, the first offset value and the second offset value are the same.

[0078] In the ninth aspect, an embodiment of the present application provides a communication device, which has the function of implementing the behavior in the method example of any aspect of the first aspect to the eighth aspect. The beneficial effects can be found in the relevant description of the first aspect to the eighth aspect and will not be repeated here. For example, the communication device can be a terminal device in any aspect of the first aspect to the eighth aspect, or the communication device can be a device that can support the terminal device to implement the functions required by the method provided in the first aspect, for example, the communication device can be a chip or chip system in the terminal device.

[0079] In one possible design, the communication device includes a baseband device and a radio frequency device.

[0080] In one possible design, the communication device includes corresponding means (means) or modules for executing the method of any aspect from the first aspect to the eighth aspect. For example, the communication device includes a processing unit (sometimes also referred to as a processing module or processor) and / or a transceiver unit (sometimes also referred to as a transceiver module or transceiver). The transceiver unit can realize the sending function and the receiving function. When the transceiver unit realizes the sending function, it can be called a sending unit (sometimes also referred to as a sending module). When the transceiver unit realizes the receiving function, it can be called a receiving unit (sometimes also referred to as a receiving module). The sending unit and the receiving unit can be the same functional unit, which is called a transceiver unit, and the functional unit can realize the sending function and the receiving function; or, the sending unit and the receiving unit can be different functional units, and the transceiver unit is a general term for these functional units. These units (modules) can perform the corresponding functions in the method examples of any aspect from the first aspect to the eighth aspect above. Please refer to the detailed description in the method examples for details, which will not be repeated here.

[0081] In a tenth aspect, an embodiment of the present application provides a communication device, which may be the communication device in the ninth aspect of the above-mentioned embodiment, or a chip or chip system provided in the communication device in the ninth aspect. The communication device includes a communication interface and a processor, and optionally, further includes a memory. The memory is used to store computer programs or instructions or data, and the processor is coupled to the memory and the communication interface. When the processor reads the computer program or instructions or data, the communication device executes the method executed by the terminal device in the above-mentioned method embodiment. For example, the communication device may be a terminal device or a functional module in the terminal device, such as a baseband chip and a radio frequency chip.

[0082] In the eleventh aspect, an embodiment of the present application provides a chip system, which includes a processor and may also include a communication interface for implementing the method described in any of the first to eighth aspects. Optionally, the chip system also includes a memory. The memory is used to store computer programs (also referred to as codes, or instructions). The processor is used to call and run the computer program from the memory so that the device equipped with the chip system executes the method in any of the first to eighth aspects and any possible implementation thereof. The chip system can be composed of chips, and may also include chips and other discrete devices.

[0083] In a twelfth aspect, an embodiment of the present application provides a communication device, comprising an input / output interface and a logic circuit. The input / output interface is used to input and / or output information. The input / output interface can be an interface circuit, an output circuit, an input circuit, a pin, or related circuits. The logic circuit is used to execute the method described in any of aspects 1 to 8.

[0084] In a specific implementation, the communication device may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the logic circuit may be a transistor, a gate circuit, a trigger, or various logic circuits. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter. The input circuit and the output circuit may be the same circuit, which functions as an input circuit and an output circuit, respectively, at different times. This application does not limit the specific implementation of the input and output interfaces and logic circuits.

[0085] In one implementation, when the communication device is a wireless communication device, the wireless communication device may be a terminal device such as a mobile phone, the interface circuit may be a radio frequency processing chip in the wireless communication device, and the processing circuit may be a baseband processing chip in the wireless communication device.

[0086] In aspect 13, an embodiment of the present application provides a communication system, comprising a first terminal device and a second terminal device, wherein the first terminal device is used to implement the functions of the method described in aspect 1, and the second terminal device is used to implement the functions of the method described in aspect 2; or, the first terminal device is used to implement the functions of the method described in aspect 3, and the second terminal device is used to implement the functions of the method described in aspect 4; or, the first terminal device is used to implement the functions of the method described in aspect 5, and the second terminal device is used to implement the functions of the method described in aspect 6; or, the first terminal device is used to implement the functions of the method described in aspect 7, and the second terminal device is used to implement the functions of the method described in aspect 8.

[0087] In the fourteenth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store computer programs or instructions. When the computer-readable storage medium is executed, the method described in any aspect of the first to eighth aspects above and any possible implementation method thereof is implemented.

[0088] In the fifteenth aspect, an embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the method described in any of the above-mentioned aspects 1 to 8 and any possible implementation thereof to be implemented.

[0089] The beneficial effects of the above-mentioned ninth to fifteenth aspects and their implementation methods can refer to the description of the beneficial effects of the first to eighth aspects and any possible implementation methods thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] FIG1( a ) is a schematic diagram of the architecture of a communication system applicable to an embodiment of the present application (Example 1);

[0091] FIG1( b ) is a schematic diagram of the architecture of a communication system applicable to an embodiment of the present application (Example 2);

[0092] FIG1( c ) is a schematic diagram of the architecture of a communication system applicable to an embodiment of the present application (Example 3);

[0093] FIG1( d ) is a schematic diagram of the architecture of a communication system applicable to an embodiment of the present application (Example 4);

[0094] FIG2 is a schematic diagram of the structure of an S-SSB provided in an embodiment of the present application;

[0095] FIG3 is a flow chart of a communication method 300 provided in an embodiment of the present application;

[0096] FIG4 is a flow chart of a communication method 400 provided in an embodiment of the present application;

[0097] FIG5 is a schematic diagram of a time domain resource group within a period provided by an embodiment of the present application;

[0098] FIG6( a ) is a schematic diagram of a structure of an S-SSB provided in an embodiment of the present application;

[0099] FIG6( b ) is a schematic diagram of another structure of an S-SSB provided in an embodiment of the present application;

[0100] FIG6( c ) is a schematic diagram of another structure of an S-SSB provided in an embodiment of the present application;

[0101] FIG7( a ) is a schematic diagram of a resource of S-SSB provided in an embodiment of the present application;

[0102] FIG7( b ) is a schematic diagram of another resource of S-SSB provided in an embodiment of the present application;

[0103] FIG8 is a flow chart of a communication method 800 provided in an embodiment of the present application;

[0104] FIG9 is a flow chart of a communication method 900 provided in an embodiment of the present application;

[0105] FIG10 is a flow chart of a communication method 1000 provided in an embodiment of the present application;

[0106] FIG11 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0107] FIG12 is another schematic diagram of the structure of the communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0108] The method provided in the embodiment of the present application is applicable to sideline communication scenarios or sidelink (SL) communications. The sidelink may also be referred to as a side link, a sidelink, a direct link, a side link or an auxiliary link, etc. A sidelink refers to a link established between devices of the same type, and may also be referred to as a side link or a secondary link, etc. It is referred to as a sidelink in this article. The so-called devices of the same type may be a link between terminal devices or a link between relay nodes, etc., and the embodiment of the present application does not limit this.

[0109] For links between end devices, there are device-to-device (D2D) links defined in 3GPP Releases (Rel) 12 / 13, as well as V2X links and sidelink on unlicensed spectrum (SL-U) communication links defined by 3GPP for connected vehicles. V2X includes direct communications between vehicles (V2V), vehicles and roadside infrastructure (V2I), vehicles and pedestrians (V2P), as well as vehicle-to-network (V2N) or vehicle-to-any-entity V2X. For example, V2X links include those in Rel-14, Rel-15, Rel-16, and Rel-17, as well as future versions such as Rel-18. The V2X in the embodiments of the present application includes V2X based on long term evolution (LTE) (also known as LTE-V2X / LTE-V) and / or V2X based on new radio (NR) (also known as NR-V2X / NR-V).

[0110] In the embodiments of the present application, any device capable of performing data communication with a base station can be considered a terminal device. A terminal device is also referred to as a terminal, user equipment (UE), mobile station, or mobile terminal. Terminal devices can be widely used in various scenarios, such as D2D communication, V2X communication, machine-type communication (MTC), IoT, virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, or smart city. For example, a terminal device can be: a mobile phone, a computer, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a robotic arm, a camera, a robot, or a smart home device (such as a TV, air conditioner, vacuum cleaner, speaker, set-top box), a relay, a customer premise equipment (CPE), etc.

[0111] The various terminal devices introduced above, if located on a vehicle (for example, placed inside a vehicle or installed inside a vehicle), can all be considered as on-board terminal devices. The on-board terminal device can be an on-board module, on-board module, on-board component, on-board chip or on-board unit built into the vehicle as one or more components or units, and the vehicle can implement the method of the present application through the built-in on-board module, on-board module, on-board component, on-board chip or on-board unit. The on-board terminal device can be a complete vehicle device, an on-board module, a vehicle, an on-board unit (OBU), a roadside unit (RSU), a vehicle-mounted system (or a vehicle-mounted sending unit) (telematics box, T-box), a chip or a system on chip (SOC), etc. The above chip or SOC can be installed in a vehicle, OBU, RSU or T-box. The on-board terminal device may include an LTE-V2X communication module and / or an NR-V2X communication module.

[0112] The terminal device can be located within the coverage area of ​​the network device or outside the coverage area of ​​the network device. The terminal device within the coverage area can also communicate directly with the terminal device outside the coverage area. For example, Figures 1(a) to 1(d) show schematic diagrams of the architecture of various communication systems applicable to the embodiments of the present application.

[0113] Figure 1(a) shows the architecture of a communication system including cellular communication and direct communication between terminal devices. The communication system may include at least one network device and at least two terminal devices. Figure 1(a) shows only one network device and two terminal devices (terminal device 1 and terminal device 2 as shown in Figure 1(a)). The network device can send information to terminal device 1 via a downlink, and terminal device 1 can send information to the network device via an uplink. Terminal devices 1 and 2 can communicate directly via a sidelink.

[0114] In Figure 1(a), both terminal device 1 and terminal device 2 are shown within the coverage of the network device. Optionally, terminal device 1 may be within the coverage of the network device and terminal device 2 may be outside the coverage of the network device, without limitation.

[0115] Figure 1(b) shows the architecture of a communication system including cellular communication and vehicle network communication. The communication system may include at least one network device and at least two terminal devices. For example, Figure 1(b) shows one network device and three terminal devices. In Figure 1(b), the terminal devices are shown as vehicles, such as vehicle 1, vehicle 2, and vehicle 3 in Figure 1(b). The network device can send information to vehicle 1 via a downlink, and vehicle 1 can send information to the network device via an uplink. Vehicles 1 and 2 can communicate directly via a side link, and vehicles 1 and 3 can also communicate directly via a side link.

[0116] In Figure 1(b), vehicle 1 and vehicle 2 are within the coverage of the network device, and vehicle 3 is shown outside the coverage of the network device. Optionally, vehicle 1 may be within the coverage of the network device, and vehicle 2 and vehicle 3 may be outside the coverage of the network device, or vehicle 1 and vehicle 3 may be within the coverage of the network device, and vehicle 2 may be outside the coverage of the network device, without pre-restriction.

[0117] The above-mentioned cellular communication may include one or more of the following: LTE communication, 5G NR communication, or future mobile communication, etc., without limitation.

[0118] Figure 1(c) illustrates the architecture of a communication system for direct communication between terminal devices. This communication system can include two terminal devices. The two terminal devices can communicate with each other via a sidelink. Figure 1(c) illustrates an example in which one terminal device is an AR, VR, or MR device, and the other terminal device is a processing device or display device.

[0119] Figure 1(d) shows the architecture of a communication system that includes wireless fidelity (WiFi) communication and direct communication. The communication system may include at least one network device and at least two terminal devices. For example, Figure 1(d) shows a network device and three terminal devices (such as terminal device 1, terminal device 2, and terminal device 3 in Figure 1(d)). In Figure 1(d), the network device is shown as a router. The router can send information to terminal device 1 via a downlink, and terminal device 1 can send information to the router via an uplink. Terminal device 1 and terminal device 2 can communicate directly via a side link, and terminal device 1 and terminal device 3 can also communicate directly via a side link.

[0120] The network architecture and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field can know that with the evolution of network architecture and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0121] In a sidelink communication scenario, to ensure that the time between the two ends of the sidelink communication is synchronized, any terminal device in the network will send a synchronization signal to other terminal devices in the vicinity based on certain conditions. Other terminal devices will search for / listen for the synchronization signal and synchronize with the sender of the synchronization signal based on the synchronization signal. For example, to ensure time synchronization between vehicles, synchronization signals will be sent between vehicles. When vehicle 1 can send a synchronization signal to the surrounding area, vehicles 2 and 3 can search for the synchronization signal. When vehicle 2 or vehicle 3 searches for the synchronization signal, it can synchronize with vehicle 1 based on the synchronization signal.

[0122] In sideline communications, the synchronization signal may be carried on an S-SSB. The S-SSB is referred to as a sideline synchronization signal block in the embodiment of the present application.

[0123] Please refer to Figure 2, which shows the structure of S-SSB in the NR-V2X scenario. S-SSB includes S-PSS and S-SSS. S-SSB occupies 13 symbols or 11 symbols in the time domain, as shown in Figure 2. B in Figure 2 represents PSBCH, P represents S-PSS, and S represents S-SSS. In the frequency domain, PSBCH occupies 11 resource blocks (RBs) and S-PSS / S-SSS occupies 127 resource elements (REs). For example, the design of S-SSB in Rel-16 version is shown in Table 1.

[0124] Table 1

[0125] PSBCH can carry the master information block (MIB) of SL. MIB includes 5 fields, one of which is a reserved bit, and the remaining 4 fields indicate the contents including time division duplex (TDD) time slot structure configuration, coverage inside / outside identification, direct frame number (DFN) and time slot index. In other words, MIB includes TDD time slot structure configuration field, coverage inside / outside identification field, DFN field, time slot index field and reserved bit field. Among them, the TDD time slot structure configuration field occupies 12 bits, the coverage inside / outside identification field occupies 1 bit, the DFN field occupies 10 bits, the time slot index field occupies 7 bits, and the reserved bit field occupies 2 bits.

[0126] In the V2X link communication of Rel-16 and Rel-17 versions, there are three types of synchronization sources for terminal devices. These three types of synchronization sources are global navigation satellite system (GNSS), network equipment and reference terminal equipment. The network equipment involved in the embodiments of the present application is mainly access network equipment. Therefore, in the following text, unless otherwise specified, the "network equipment" refers to radio access network (RAN) equipment, which can be referred to as access network equipment for short. RAN can be a 3GPP-related cellular system, such as a 5G mobile communication system, or a future-oriented evolution system (such as a 6G mobile communication system). RAN can also be an open access network (open RAN, O-RAN or ORAN), a cloud radio access network (CRAN), or a virtualized radio access network (vRAN). RAN can also be a communication system that integrates two or more of the above systems. RAN equipment can also be called a RAN node, a RAN entity, or an access node. For example, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, or a base station in a future mobile communication system. A RAN node can be a macro base station, a micro base station, an indoor station, a relay node, a donor node / host node, or a wireless controller. A RAN node can also be a server, a wearable device, a vehicle, or an onboard device. For example, a RAN node can be a roadside unit (RSU).

[0127] The SLSS ID used to scramble the PSBCH and generate the S-PSS / S-SSS sequence can be used to distinguish synchronization sources. Alternatively, the type of synchronization source can be indicated by the SLSS ID. The value range of the SLSS ID is [0, 671], and the SLSS ID is divided into 6 groups, 6 groups, and 4 groups. Different groups of SLSS IDs are suitable for different scenarios, as shown in Tables 2 and 3. It can be understood that the SLSS IDs in the different scenarios described below have different priorities. Different SLSS ID groups can be referred to as different synchronization source types, synchronization source priorities, or synchronization source priority groups.

[0128] Table 2

[0129] Table 3

[0130] In V2X link communications in Rel-18 and subsequent versions, it is proposed that terminal devices can perform beam training based on S-SSB. Before completing unicast link establishment between terminal devices, beam training can be completed based on S-SSB to align the optimal beam, thereby receiving signals with the optimal beam. Beam training can be understood as the transmitter sending a set of S-SSBs in multiple beam directions, the receiver measuring the S-SSBs received in multiple beam directions, and determining which beam is the optimal beam based on the signal strength of the received S-SSBs. Beam alignment can also be called beam training or beam management.

[0131] In order for the receiving end to identify which transmitter the beam comes from, the transmitting end sends the identifier of the transmitting end while sending the S-SSB. Take the transmitting end as UE1 and the receiving end as UE2 as an example. When UE1 sends the S-SSB, it also sends the identifier of UE1. In a possible implementation method, it is proposed to map the UE identifier based on the SL SS ID. However, mapping the UE identifier based on the SL SS ID may change the meaning of the traditional SL SS ID, and considering the specific grouping of SL SS IDs in Tables 2 and 3, there may be a situation where UEs of Rel-16 and Rel-17 versions and UEs of Rel-18 and subsequent versions have inconsistent understandings of the same SL SS ID, resulting in different UEs using S-SSB incorrectly, unable to achieve synchronization or beam alignment, and affecting communication performance.

[0132] In order to solve the above technical problems, a solution of an embodiment of the present application is provided. In an embodiment of the present application, when the transmitting end sends the S-SSB, it also indicates the specific purpose of the S-SSB. For example, it indicates that the SSB is used for synchronization or beam training, or indicates that the S-SSB is used for both synchronization and beam training. Through this solution, terminal devices of various versions can clearly understand the purpose of the received S-SSB, and synchronization or beam alignment can be achieved based on the S-SSBs between them.

[0133] The technical solutions provided by the embodiments of the present application are described below in combination with the above content and the accompanying drawings.

[0134] In the embodiments of this application, the phrases "when," "if," and "if" all imply that the device will perform a corresponding action under certain objective circumstances. These phrases do not specify a timeframe, do not require the device to perform a judgment action, and do not imply any other limitations. "If" and "if" are interchangeable, and unless otherwise specified, "when" and "under the circumstances" are interchangeable. "Transmit" includes "sending and / or receiving."

[0135] (Pre) configuration, or pre-configuration, may refer to one or more of predefinition, radio resource control (RRC) configuration, downlink control information (DCI) indication, sidelink control information (SCI) indication, media access control (MAC) control element (CE) indication, and determination based on configuration or indication that if there is no configuration or indication, a default value is taken.

[0136] In the embodiments of this application, the concepts, terms, and explanations defined in a certain method are also applicable to other methods. The various aspects of the embodiments of this application can be implemented independently or in combination based on certain internal connections. Different aspects and different implementation methods of the embodiments of this application can be implemented in combination or independently.

[0137] For the number of nouns, unless otherwise specified, it means "singular or plural nouns", that is, "one or more". "Multiple" means two or more. In view of this, in the embodiments of the present application, "multiple" can also be understood as "at least two". "At least one" can be one or more, for example, at least one can be one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then the included ones can be A, B, C, A and B, A and C, B and C, or A and B and C. Similarly, the understanding of descriptions such as "at least one" is also similar. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character “ / ”, unless otherwise specified, generally indicates that the previous and next associated objects are in an “or” relationship.

[0138] Unless otherwise specified, ordinal numbers such as "first" and "second" in the embodiments of this application are used to distinguish multiple objects and are not used to limit the order, timing, priority, or importance of the multiple objects. The descriptions of "first" and "second" do not necessarily require that the objects be different. For example, the first synchronization signal identifier and the second synchronization signal identifier represent two synchronization signal identifiers, but do not limit the priority or importance of the two synchronization signal identifiers.

[0139] In an embodiment of the present application, the terminal identifier may be identification information of the terminal device, or identification information of the service of the terminal device. The terminal identifier may be: UE (identifier, ID), international mobile equipment identity (IMEI) code, source ID and / or destination ID of layer 1 (L1) or L2, application layer ID, or ID assigned by a higher layer, etc., which may be used to identify one or more of the identifiers of the terminal device. The beam direction may be equivalent to: beam, beam index, reference signal index, reference signal port, spatial domain filter, channel state information, channel state information index, etc. The offset may also be referred to as an offset interval / interval (interval or gap) or an offset value. The synchronization signal identifier involved in an embodiment of the present application may be an SL SS ID. For example, the first synchronization signal identifier herein is the first SL SS ID.

[0140] The embodiments of the present application provide a variety of communication methods (such as communication method 300, communication method 400, etc.) involving interactions between terminal devices. For ease of description, the communication methods involved below are described from the perspective of the interaction between a first terminal device and a second terminal device. It should be understood that the first terminal device can be a terminal device, for example, the first terminal device can be the terminal device in Figure 1 (a) to Figure 1 (d). The first terminal device can also be a component applied to the terminal device, such as a processor, a chip, or a chip system, etc., or a logic module or software that can implement all or part of the terminal device functions. For example, the first terminal device can be a chip (system) in the terminal device in Figure 1 (a) to Figure 1 (d). Similarly, the second terminal device can be a terminal device, or a component applied to the terminal device, such as a processor, a chip, or a chip system, etc., or a logic module or software that can implement all or part of the terminal device functions.

[0141] Please refer to Figure 3, which shows a flow chart of a communication method 300 provided in an embodiment of the present application. The flow of the communication method 300 includes the following steps.

[0142] S301. The first terminal device sends a side synchronization signal block.

[0143] The first terminal device may transmit a sideline synchronization signal block, and correspondingly, terminal devices around the first terminal device (eg, the second terminal device) may receive the sideline synchronization signal block.

[0144] S302. The second terminal device performs synchronization or beam training according to the sideline synchronization signal block.

[0145] The side synchronization signal block may be the aforementioned S-SSB. As mentioned above, time synchronization (referred to as synchronization for short) may be achieved between terminal devices based on S-SSB, and beam alignment may also be achieved based on S-SSB. The first terminal device may send S-SSB for synchronization or S-SSB for beam training according to actual needs. For example, if the first terminal device has a unicast link establishment requirement, the first terminal device sends S-SSB for beam training. For another example, the first terminal device may periodically send S-SSB for synchronization. The second terminal device may search for S-SSB, and the second terminal device searches / receives S-SSB, and synchronizes with the first terminal device or performs beam alignment according to the S-SSB.

[0146] To clarify the purpose of the S-SSB sent by the first terminal device to the second terminal device, the first terminal device may also indicate the purpose of the S-SSB when sending the S-SSB. For example, the S-SSB includes first indication information, which may indicate that the S-SSB is used for synchronization or beam training.

[0147] The first indication information is used to determine / indicate that S-SSB is used for synchronization or beam training, including but not limited to the following methods, which are introduced below.

[0148] Mode A: The first indication information is carried in the MIB in the S-SSB, indicating that the S-SSB is used for synchronization or beam training.

[0149] For example, the first indication information may be carried in the reserved bit of the MIB in the S-SSB. When the value of the reserved bit is the first value, it indicates that the S-SSB is used for synchronization; when the value of the reserved bit is the second value, it indicates that the S-SSB is used for beam training. For example, the value of the reserved bit is 0, indicating that the S-SSB is used for synchronization; when the value of the reserved bit is 1, indicating that the S-SSB is used for beam training. Alternatively, the value of the reserved bit is 1, indicating that the S-SSB is used for synchronization; when the value of the reserved bit is 0, indicating that the S-SSB is used for beam training.

[0150] The first indication information can also be used to indicate that the S-SSB is used for synchronization, for beam training, or for synchronization and beam training. For example, the first indication information is 2-bit information, and the different state values ​​of the 2 bits indicate different uses of the S-SSB. The different state values ​​of the 2 bits indicate different uses of different S-SSBs, and one state value indicates one use of the S-SSB. For example, the value of 2 bits is "00", indicating that the SSB is used for synchronization; the value of 2 bits is "01", indicating that the SSB is used for beam training; the value of 2 bits is "10", indicating that the SSB is used for synchronization and beam training. Optionally, the remaining state value (for example, "11") is a reserved state value.

[0151] In mode A, if the first indication information indicates that S-SSB is used for beam training, S-SSB may also indicate the identification information of the first terminal device (for example, the first terminal identification in this article), so that the receiving terminal device can know the identity or characteristics of the terminal device performing beam training, thereby facilitating the completion of the beam alignment process. The first terminal identification may be the UE1 ID, or the application layer identification of the UE1, or the source ID and / or destination ID of the UE1. The source ID and / or destination ID may be a layer 1 ID or a layer 2 ID.

[0152] As an example, the first terminal identifier can be carried in the MIB included in the S-SSB. For example, one or more fields included in the MIB can be reused to carry the first terminal identifier. For example, the first terminal identifier is carried in all or part of the bits of one of the TDD time slot structure configuration field, the covered inside / outside identification field, the DFN field, the time slot index field, or the reserved bit field in the MIB. Alternatively, the first terminal identifier is carried in all or part of the bits of a combination of multiple fields in the TDD time slot structure configuration field, the covered inside / outside identification field, the DFN field, the time slot index field, or the reserved bit field in the MIB. Since the S-SSB used for beam training may not carry some information used for synchronization, when the fields in the MIB are reused to carry the first terminal identifier, the meaning of the fields in the MIB can be redefined. For example, the meaning of the TDD time slot structure configuration field is modified to indicate the terminal, and the second terminal device parses the received S-SSB and determines that the content carried by the TDD time slot structure configuration field is the first terminal identifier, rather than the TDD time slot structure configuration.

[0153] As another example, the first terminal device can be carried by the SL SS ID included in the S-SSB. The first terminal identifier is the same as the SL SS ID, or the first terminal identifier and the SL SS ID have a mapping relationship. For example, the first terminal device can randomly select the SLSS ID from a certain range (e.g., [0,671]) as the first terminal identifier, or the first terminal device determines the SLSS ID based on the first terminal identifier and the mapping relationship between the first terminal identifier and the SLSS ID. Accordingly, the receiving terminal device determines the first terminal identifier based on the SLSS ID.

[0154] When the S-SSB carries the first terminal identifier, it can also be considered that the S-SSB is used for beam training, or the first terminal identifier can indicate that the S-SSB is used for beam training, or the first terminal identifier is used for beam training.

[0155] Optionally, the first indication information may also be carried by a cyclic shift or port of the DMRS of the PSBCH. For example, different cyclic shifts of the DMRS may be used to indicate that the S-SSB is used for synchronization and / or for beam training. For another example, different transmission ports of the DMRS may be used to indicate that the S-SSB is used for synchronization and / or for beam training.

[0156] In mode B, the first indication information is carried in the first synchronization signal identifier carried by the S-SSB, indicating that the S-SSB is used for synchronization or beam training. The first synchronization signal identifier is, for example, the first SL SS ID.

[0157] Method B can be understood as indicating that the S-SSB is used for beam training through the SL SS ID carried by the S-SSB. For example, when the value of the first SL SS ID is within the first range, the first indication information indicates that the S-SSB is used for synchronization; when the value of the first SL SS ID is within the second range, the first indication information indicates that the S-SSB is used for beam training. Exemplarily, the first range is [0, 671] and the second range is [672, 1343]. The embodiments of the present application do not limit the specific values ​​of the first range and the second range.

[0158] In mode B, the first indication information may also be the SL SS ID. When the value of the SL SS ID carried by the S-SSB is within the first range, the S-SSB is used for synchronization; when the value of the SL SS ID carried by the S-SSB is within the second range, the S-SSB is used for beam training.

[0159] If the first indication information indicates that the S-SSB is used for beam training, the first indication information also indicates the first terminal identifier. For example, the first terminal identifier may be carried in the SLSS ID; or the first terminal identifier may be carried in the MIB included in the S-SSB. For details, please refer to the description in the above-mentioned method A and will not be repeated here.

[0160] Method 300 allows the receiving end to clearly understand the purpose of the S-SSB sent by the transmitting end, thereby avoiding the incorrect use of the side synchronization signal block, which may cause synchronization or beam training to fail normally and affect communication performance. In addition, method 300 does not distinguish between terminal device versions and is compatible with terminal devices of later versions. For example, terminal devices of Rel-16 and Rel-17 versions can also achieve time synchronization or beam alignment with terminal devices of Rel-18 and later versions based on the S-SSB sent by terminal devices of Rel-18 and later versions.

[0161] In method 300, the resources used to transmit the sideline synchronization signal block for synchronization and the resources used to transmit the sideline synchronization signal block for beam training may be the same. Or the sideline synchronization signal block for synchronization and the sideline synchronization signal block for beam training share the same resource set. The resources of the resource set may be (pre) configured. For example, the resources within a period are determined by at least one of the following parameters: the starting position (i.e., the offset relative to the starting position of the period), the number of resources, and the interval between resources. For example, the period is 160ms, and the starting position of the period is the system frame number (SFN) mod 160ms = 0 or the time slot of the direct frame number (DFN) mod 160ms. The first terminal device sends the sideline synchronization signal block on the (pre) configured resources. mod represents modulo.

[0162] The embodiment of the present application further provides a communication method 400. In the communication method 400, the S-SSB resource can be used to distinguish whether the S-SSB is used for synchronization or beam training, without the need for additional signaling overhead, which can save signaling overhead and improve system resource utilization.

[0163] Please refer to Figure 4, which shows a flow chart of a communication method 400 provided in an embodiment of the present application. As shown in Figure 4, the flow of the communication method 400 includes the following steps.

[0164] S401. The first terminal device sends a side synchronization signal block.

[0165] Accordingly, the second terminal device receives the sideline synchronization signal block.

[0166] S402. The second terminal device performs synchronization or beam training according to the resources of the sideline synchronization signal block.

[0167] If the sideline synchronization signal block is used for synchronization, the first terminal device may send the sideline synchronization signal block on the first resource. If the sideline synchronization signal block is used for beam training, the first terminal device may send the sideline synchronization signal block on the second resource. The second terminal device receives the sideline synchronization signal block from the first terminal device and can determine, based on the resource carrying the sideline synchronization signal block, that the sideline synchronization signal block is used for synchronization or beam training. It is understandable that before the second terminal device completes the initial synchronization, it is impossible to accurately determine the resource where the sideline synchronization signal block is located. Therefore, before the initial synchronization, the second terminal device can determine, based on method 300, that the sideline synchronization signal block sent by the first terminal device is used for synchronization or beam alignment. After the initial synchronization, the second terminal device determines, based on the resource carrying the sideline synchronization signal block, that the sideline synchronization signal block is used for synchronization or beam training.

[0168] The first resource may be a resource within a first resource set, and the second resource may be a resource within a second resource set. The resources in the first resource set are used to transmit side synchronization signal blocks for synchronization, and the resources in the second resource set are used to transmit side synchronization signal blocks for beam training. Optionally, the first resource set includes one or more subsets. The first resource set and the second resource set are two different resource sets. For example, the resources within the first resource set and the resources within the second resource set are different in the time domain; or, the resources within the first resource set and the resources within the second resource set are different in the frequency domain; or, the resources within the first resource set and the resources within the second resource set are different in both the time domain and the frequency domain.

[0169] The time domain resources of the first resource set may be (pre) configured. For example, the time domain resource parameters of the first resource set may be (pre) configured. The time domain resources of the first resource set are determined according to at least one of the following time domain resource parameters: resource starting position, interval between resources, and number of resources. Optionally, the resource starting position is determined according to an offset relative to the start position of the period, or the parameter resource starting position may be an offset. For example, the length of the synchronization period may be 160 milliseconds (ms), and the starting position of the synchronization period may be a time slot of SFN mod160ms=0 or DFN mod160ms. For each synchronization period in the first resource set, parameters such as the resource starting position (the offset of the first time slot relative to the start position of the current period), the number of resources, and the interval between the side synchronization signal block time slots may be (pre) configured. Based on these parameters, the first terminal device may determine the time domain resources available for S-SSB within a period. In the frequency domain, the frequency domain position of the sidelink synchronization signal block can be determined according to the frequency configured by the absolute radio frequency channel number (ARFCN), and the ARFCN can be indicated by sl-AbsoluteFrequencySSB. For example, the frequency indicated by the ARFCN is the center frequency of the S-SSB, for example, the frequency position of the 66th subcarrier.

[0170] The resource period used for beam training and the resource period used for synchronization can be (pre) preconfigured. For example, candidate values ​​for the beam training period are {4, 5, 8, 10, 16, 20, 32, 40, 50, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} milliseconds or time slots. Alternatively, the resource period used for beam training can be the same as the synchronization period. Optionally, the starting position of the beam training period can be the same as the starting position of the synchronization period. Alternatively, the resource period used for beam training can be independently (pre)configured as the synchronization period. Independent (pre)configuration means that the resource period used for beam training and the resource period used for synchronization are not (pre)configured using the same parameters. For example, the starting position of the beam training period is the time slot with SFN mod period length = 0 or DFN mod period length = 0.

[0171] Similar to the first resource set, the second resource set can be (pre)configured. For example, the time domain resource parameters of the second resource set can be (pre)configured. The time domain resource parameters of the second resource set include at least one of the following: the starting position of the time domain resource, the time domain resource interval, the interval between each group of time domain resources, the interval of time domain resources within the time domain resource group, the number of time domain resources, the number of time domain resource groups, the number of time domain resources within each time domain resource group, and the time domain period. As shown in Figure 5, a time domain resource group within a period is shown. Figure 5 includes two time domain resource groups within a period, namely the first group and the second group in Figure 5. The time domain resource interval or the interval of time domain resources within the time domain resource group can be 0 or 1, in time slots. Optionally, the number of time domain resource groups or the number of time domain resources within each time domain resource group can be 1. The time domain resources of the second resource set can be determined based on at least one time domain resource parameter of the second resource set. For details, please refer to the method for determining the time domain resources of the aforementioned first resource set. The first resource set and the second resource set may be independently (pre-) configured; or, resource parameters within the first resource set and the second resource set may be independently (pre-) configured.

[0172] Optionally, the time domain resources of the second resource set can be determined by the time domain resources of the first resource set and a (pre) configured offset. If the time domain resource parameters of the first resource set are configured, and the time domain resources of the side synchronization signal block (pre) configured for beam training have an offset relative to the time domain resources of the side synchronization signal block used for synchronization, then the time domain resources of the side synchronization signal block used for beam training can be determined based on the time domain resources of the side synchronization signal block used for synchronization and the offset. For example, the resource starting position of the second resource set within a period is the sum of the resource starting position of the first resource set and an offset. Alternatively, the time domain position of the resources of the second resource set within a period is determined by the time domain position of the resources of the first resource set plus an offset. The offset can be (pre) configured.

[0173] Optionally, the time domain resources of the second resource set are the same as the time domain resources of the first resource set. For example, the time domain resources of the second resource set are determined according to the same parameters as the first resource set or according to the method for determining the first resource set.

[0174] It should be noted that the time domain resources of the first resource set refer to the time domain resources within the first resource set used to send the side synchronization signal block. The time domain resources of the second resource set refer to the time domain resources within the second resource set used to send the side synchronization signal block. The time domain resources of the first resource set and the time domain resources of the second resource set can be the same or different.

[0175] The frequency domain resources of the sideline synchronization signal block used for beam training are the same as the frequency domain resources of the sideline synchronization signal block used for synchronization. Alternatively, the frequency domain resources of the sideline synchronization signal block used for beam training are different from the frequency domain resources of the sideline synchronization signal block used for synchronization. For example, the frequency domain resources of the sideline synchronization signal block used for synchronization and the sideline synchronization signal block used for beam training can be determined based on the first ARFCN. The center frequency of the frequency domain resources of the sideline synchronization signal block used for beam training can be determined based on the second ARFCN, which is different from the first ARFCN; or, the center frequency of the frequency domain resources of the sideline synchronization signal block used for beam training can be determined based on the first ARFCN plus an offset. If the frequency domain resources of the sideline synchronization signal block (pre-)configured for beam training have an offset relative to the frequency domain resources of the sideline synchronization signal block used for synchronization, then the frequency domain resources of the sideline synchronization signal block used for beam training can be determined based on the frequency domain resources of the sideline synchronization signal block used for synchronization and the offset.

[0176] Optionally, the time domain resources of the first resource set and the time domain resources of the second resource set are the same, and the frequency domain resources of the first resource set and the frequency domain resources of the second resource set are different; the time domain resources of the first resource set and the time domain resources of the second resource set are different, and the frequency domain resources of the first resource set and the frequency domain resources of the second resource set are the same; or, when the time domain resources of the first resource set and the time domain resources of the second resource set are different, the frequency domain resources of the first resource set and the frequency domain resources of the second resource set are different.

[0177] Optionally, the sidelink synchronization signal blocks used for synchronization can be transmitted from multiple directions over multiple consecutive time slots on the first resource set, or omnidirectionally over one or more time slots. The sidelink synchronization signal blocks used for beam training can be transmitted from the same or different beam directions over multiple consecutive time slots on the second resource set.

[0178] Since the sideline synchronization signal block used for beam training does not carry information for synchronization, the structure of the sideline synchronization signal block used for beam training can be simpler than that of the sideline synchronization signal block used for synchronization. For example, the structure of the sideline synchronization signal block used for beam training can be different from that of the sideline synchronization signal block used for synchronization. In this case, the purpose of the sideline synchronization signal block can be indicated by the structure of the sideline synchronization signal block. For example, the structure of the sideline synchronization signal block used for synchronization is the structure shown in Figure 2, and the structure of the sideline synchronization signal block used for beam training can be a structure different from Figure 2. In an embodiment of the present application, the sideline synchronization signal block can include a combination of one or more of S-PSS, S-SSS, and PSBCH. For example, the sideline synchronization signal block used for synchronization can include S-PSS, S-SSS, and PSBCH. For example, the sideline synchronization signal block used for beam training can include S-PSS, S-SSS, and PSBCH, or can include S-PSS and S-SSS.

[0179] As an example, the S-SSB used for beam training may include only S-PSS and / or S-SSS, but not PSBCH, as shown in Figure 6(a). The S-SSB in Figure 6(a) includes S-PSS, S-PSS, S-SSS, and S-SSS, which is a structure of 4 symbols. Among them, the structure, frequency domain resources, and sequence design of S-PSS and S-SSS are the same as those of the S-SSB of Rel-16. Since the structure of the S-SSB used for beam training is simpler, more S-SSBs used for beam training can be accommodated within a certain time domain resource, which helps to improve resource utilization. In addition, it also helps to scan more beam directions, facilitating faster beam alignment. For example, the time domain resources occupied by the S-SSB in a time slot can be (pre-)configured. One S-PSS / S-SSS occupies one symbol. Taking the symbol numbering starting at 0 in a time slot as an example, two S-SSBs can be sent in a time slot. These two S-SSBs can occupy symbols 0 to 3 and symbols 7 to 10; alternatively, these two S-SSBs can occupy symbols 1 to 4 and symbols 8 to 11. For another example, three S-SSBs can be sent in a time slot. These three S-SSBs can occupy symbols 0 to 3 and symbols 7 to 10; alternatively, these two S-SSBs can occupy symbols 0 to 3, symbols 5 to 8, and symbols 10 to 13.

[0180] Optionally, a symbol for automatic gain control (AGC) may be added before one or more of the S-PSS, S-PSS, S-SSS, and S-SSS in FIG6(a). Alternatively, a symbol for AGC may be added before each of the reference signals (RS). A copy of the next symbol may be sent on the AGC symbol.

[0181] As another example, the S-SSB used for beam training may include S-PSS, S-SSS, and PSBCH. For example, the S-SSB includes PSBCH, S-PSS, S-PSS, S-SSS, S-SSS, and PSBCH, that is, the S-SSB has a structure of 6 symbols. Among them, the frequency domain resources and sequence design of S-PSS, S-SSS, and PSBCH are the same as those of the S-SSB of Rel-16. Optionally, a symbol for AGC can be added before one or more of the S-PSS, S-PSS, S-SSS, and S-SSS in the S-SSB, as shown in Figure 6(b). Figure 6(b) takes the example of sending 2 S-SSBs in one time slot, where one S-SSB is located at symbols 0-5 and the other S-SSB is located at symbols 7-13. For another example, the S-SSB includes an AGC symbol, S-PSS, S-PSS, S-SSS, S-SSS, and PSBCH, that is, the S-SSB has a structure of 6 symbols, as shown in Figure 6(c). Figure 6(c) takes the example of sending two S-SSBs in one time slot, where one S-SSB is located in symbols 0-5 and the other S-SSB is located in symbols 7-13. Among them, the frequency domain resources and sequence design of the S-PSS, S-SSS, and PSBCH are the same as those of the S-SSB in Rel-16. In Figures 6(b) and 6(c), P represents S-PSS, S represents S-SSS, and B represents PSBCH.

[0182] The S-SSB used for beam training may also include a first terminal identifier. If the structure of the S-SSB used for beam training is as shown in Figure 2, the first terminal identifier may be carried in the MIB or SL SS ID of the S-SSB, which will be described in detail below and will not be described here. The S-SSB used for beam training may also include a beam index, which is carried in the same manner as the first terminal identifier.

[0183] Optionally, the first beam index is the beam index of each S-PSS / S-SSS included in the S-SSB. “Each S-PSS / S-SSS included in the S-SSB” means all S-PSS / S-SSS of the S-SSB. Therefore, the first beam index is the beam index of all S-PSS / S-SSS of the S-SSB, or the first beam index is the beam index of the S-SSB.

[0184] Alternatively, the first beam index is the beam index of each S-PSS included in the S-SSB. It can also be understood that the first beam index is the beam index of all S-PSSs included in the S-SSB, that is, the first beam index is the beam index of the S-PSS of the S-SSB. Alternatively, the first beam index is the beam index of each S-SSS included in the S-SSB. It can also be understood that the first beam index is the beam index of all S-SSSs included in the S-SSB, that is, the first beam index is the beam index of the S-SSS of the S-SSB.

[0185] Alternatively, the first beam index is the beam index of the first S-PSS or the first S-SSS included in the S-SSB. For example, if the first beam index is the beam index of the first S-PSS included in the S-SSB, the beam indexes of the subsequent S-PSS, S-SSS, and S-SSS are the first beam index + 1, the first beam index + 2, and the first beam index + 3, respectively.

[0186] Alternatively, the first beam index is the beam index of the S-PSS included in the S-SSB. For example, the first beam index is the beam index of the S-PSS included in the S-SSB, then the beam index of the two S-PSSs is the first beam index, and the beam index of the two S-SSSs is the first beam index + 1.

[0187] Method 400 distinguishes between S-SSBs for synchronization and beam training by using S-SSB resources. This allows different versions of terminal devices to have a consistent understanding of the S-SSB's purpose, thereby avoiding incorrect use of sidelink synchronization signal blocks, which could result in synchronization or beam training failures and affect communication performance. Furthermore, considering that beam training requires beam scanning in different beam directions, which may differ from the number of resources required for synchronization, method 400 also ensures that the resources and transmissions for synchronization and beam training do not interfere with each other.

[0188] The embodiment of the present application further provides a communication method 500. The communication method 500 is applied in a sideline synchronization process, and indicates that the S-SSB is used for beam training by using a terminal identifier carried in the S-SSB.

[0189] When an S-SSB carries a terminal identifier, it can also be considered that the S-SSB is used for beam training, or the terminal identifier can indicate that the S-SSB is used for beam training. For example, when the S-SSB sent by the first terminal device carries the first terminal identifier, the S-SSB can be used for beam training. There are multiple ways to indicate that the S-SSB is used for beam training through the terminal identifier carried by the S-SSB, for example, Method C-1, Method C-2, or Method C-3.

[0190] Method C-1: the first terminal identifier can be carried in the MIB of the S-SSB.

[0191] For example, one or more fields included in the MIB can be reused to carry the first terminal identifier. Please refer to the aforementioned method A for details about the content of carrying the first terminal identifier through the MIB, which will not be repeated here. Of course, if the first terminal device sends a side synchronization signal for synchronization, then the content carried by the MIB in the S-SSB is the same as the content currently carried by the MIB. In other words, if the first terminal device sends a side synchronization signal for synchronization, there is no need to reinterpret the meaning of the fields contained in the MIB message in the S-SSB. For example, the meaning of the fields included in the MIB message in Rel-16 / Rel-17 can be used.

[0192] Mode C-2: The first terminal identifier is carried by the SL SS ID carried by the S-SSB.

[0193] For example, the SL SS ID carried by the S-SSB is the first SL SS ID, which carries the first terminal identifier. As shown in Tables 2 and 3 above, there are multiple SL SS IDs, which constitute a synchronization signal identifier set. The SL SS IDs in the set are all used to indicate the type of synchronization source. The embodiment of the present application does not limit the value range of the SL SS ID set. For example, the value range of the SL SS ID set can be [0, 671], which is compatible with the existing SL SS ID set.

[0194] In a possible implementation, a mapping relationship between a terminal identifier (UE ID) and a SL SS ID can be established, so that the second terminal device can determine the first terminal identifier based on the mapping relationship and the SL SS ID carried by the S-SSB. The mapping relationship between the terminal identifier and the SL SS ID can be protocol-defined or configured.

[0195] For example, similar to Table 2 and Table 3, SLSS IDs are divided into 6 groups, 6 groups, and 4 groups, and different groups of SLSS IDs are suitable for different scenarios. Different groups of SL SS IDs in Rel-16 have a mapping relationship with different SLSS ID groups in Rel-18, as shown in Table 4 and Table 5. For the convenience of description, the SL SS ID in Rel-16 is recorded as SL SS ID-R16; the SL SS ID in Rel-18 is recorded as SL SS ID-R18. Correspondingly, the SL SS ID group in Rel-16 is recorded as SL SS ID group-R16; the SL SS ID group in Rel-18 is recorded as SL SS ID group-R18. It should be noted that Table 4 and Table 5 are only examples, and the embodiment of the present application does not limit the value range of each group of SL SS ID-R16 and each group of SL SS ID-R18 in Table 4 and Table 5. It should be understood that SL SS ID-R18 is the definition of S-SSB for beam training.

[0196] Table 4

[0197] Table 5

[0198] The terminal device determines its SLSS ID group-R18 based on its SLSS ID-R16, and selects an SLSS ID-R18 from its SLSS ID group-R18 to send an S-SSB. The terminal device can randomly select an SLSS ID from its SLSS ID group-R18.

[0199] Alternatively, the relationship between SL SS ID-R18 and UE ID satisfies the following: SL SS ID-R18 = UE ID + starting SL SS ID of this group, or SL SS ID-R18 = UE ID + starting SL SS ID of this group - 1. The starting SL SS ID of this group refers to the starting SL SS ID of the corresponding SL SS ID group-R18. Taking Table 4 as an example, SL SS ID-R18 indicates that the UE ID is in the range [112-223], and the starting SL SS ID of this group is 112.

[0200] Alternatively, SL SS ID-R18 = (UE ID mod total number of SL SS IDs in this group) + starting SL SS ID of this group, or SL SS ID-R18 = (UE ID mod total number of SL SS IDs in this group) + starting SL SS ID of this group - 1. "Mod" indicates modulo operation. The total number of SL SS IDs in this group refers to the total number of SL SS IDs included in the corresponding SL SS ID group.

[0201] Mode C-3: The first terminal identifier is carried by the cyclic redundancy check (CRC) information of the MIB in the S-SSB.

[0202] In a possible scenario, S-SSB can be used for both synchronization and beam training. In this case, the terminal identifier carried by the dedicated channel / dedicated time-frequency resource can be used to indicate that the S-SSB is used for beam training and / or synchronization. Optionally, if the terminal identifier is carried on the dedicated time-frequency resource, the S-SSB is used for beam training. The dedicated time-frequency resource can be the time domain resource occupied by the S-SSB in the time domain, and can include at least one RB in the time domain resource where the S-SSB is located except for the frequency domain resource occupied by the S-SSB in the frequency domain. Alternatively, the time domain resource where the dedicated time-frequency resource is located has a mapping relationship with the time domain resource occupied by the S-SSB. Alternatively, the time domain resource where the dedicated time-frequency resource is located is different from the time domain resource occupied by the S-SSB, and the frequency domain resource of the dedicated time-frequency resource includes at least one resource block. For ease of understanding, the following is an explanation in conjunction with Figures 7(a) and 7(b). ID1, ID2, and ID3 in Figures 7(a) and 7(b) represent terminal identifiers.

[0203] Please refer to Figure 7(a), which is a schematic diagram of the time-frequency resources occupied by the S-SSB. Figure 7(a) takes the example of a dedicated time-frequency resource that can be the time domain resource occupied by the S-SSB in the time domain and can include at least one RB within the time domain resource where the S-SSB is located, excluding the frequency domain resource occupied by the S-SSB, in the frequency domain.

[0204] As shown in Figure 7(a), at each S-SSB opportunity, PRBs other than S-SSB can be used to carry terminal identification. For example, dedicated time-frequency resources are part of the resources in PRBs other than S-SSB, for example, dedicated time-frequency resources are PRBs other than PRBs used for S-SSB. Optionally, the dedicated time-frequency resources are separated from the S-SSB in the frequency domain by at least one RB, and the at least one RB can be used as a protection RB. In this way, the impact of power leakage on synchronization performance can be reduced. The dedicated time-frequency resources can be (pre) configured, for example, the frequency domain resources of the dedicated time-frequency resources are configured by bitmap. The number of at least one RB can also be (pre) configured.

[0205] Please refer to Figure 7(b), which is another schematic diagram of the time-frequency resources occupied by S-SSB. Figure 7(b) takes the example where the time domain resources where the dedicated time-frequency resources are located are different from the time domain resources occupied by S-SSB, and the frequency domain resources of the dedicated time-frequency resources include at least one resource block. For example, the time domain resources and frequency domain resources of the dedicated time-frequency resources can be (pre-)configured. For example, the time domain resources of the (pre-)configured dedicated time-frequency resources are separated by a first offset from the time domain resources occupied by the S-SSB, and the frequency domain resources of the (pre-)configured dedicated time-frequency resources may include at least one RB. Optionally, the frequency domain resources have a mapping relationship with the frequency domain resources where the S-SSB is located.

[0206] The frequency domain position of the dedicated time-frequency resource may have a mapping relationship with the terminal identifier or SLSS ID. In this case, when the terminal device sends the S-SSB, on the same time domain resource, it determines its own dedicated time-frequency resource based on the mapping relationship between the frequency domain position of the dedicated time-frequency resource and the terminal identifier or SLSS ID, as well as its own terminal identifier or SLSS ID. Subsequently, the dedicated time-frequency resource is transmitted in the same beam direction as the S-SSB and carries the terminal identifier. The receiving terminal device can determine the terminal identifier corresponding to the corresponding S-SSB by decoding the dedicated time-frequency resource. For example, determine the terminal identifier corresponding to the S-SSB with the corresponding SLSS ID. Among them, the beam direction on the dedicated time-frequency resource may be the same as the beam direction of the S-SSB corresponding to the dedicated time-frequency resource.

[0207] In a possible implementation, the S-SSB used for beam training may also include a beam index (beamindex). The carrying method of the beam index is similar to the carrying method of the first terminal identifier. For example, the S-SSB used for beam training includes a first beam index, and the first beam index is carried in the MIB in the PSBCH included in the S-SSB, such as the aforementioned method C-1 or method C-3. For another example, the first beam index is carried by the SL SS ID carried by the S-SSB by the first terminal identifier. For example, the first terminal identifier in methods C-1, C-2 and C-3 can be replaced by the first beam index. Optionally, the first beam index is carried by the demodulation reference signal (DMRS) of the PSBCH by the first terminal identifier.

[0208] The embodiment of the present application further provides a communication method 600. The communication method 600 is applied in a sideline synchronization process, and the SL SS ID can simultaneously indicate the identifier of the transmitting end and the type of the synchronization source.

[0209] For example, a first terminal device sends an S-SSB, where the S-SSB includes first indication information, where the first indication information indicates a first terminal identifier, and the first terminal identifier is carried by a first SL SS ID carried by the S-SSB. The first SL SS ID belongs to a SL SS ID group - R18. The SL SS IDs within the SL SS ID group - R18 can indicate the type of synchronization source. A second terminal device receives the S-SSB from the first terminal device, and can determine both the type of synchronization source and the first terminal identifier based on the first SL SS ID carried by the S-SSB. The first terminal identifier can be used for beam training.

[0210] In this case, the mapping relationship between SL SS ID Group-R16 and SL SS ID Group-R18 can be (pre-)configured, as shown in Tables 4 and 5 above. The terminal device determines the SLSS ID Group-R18 to which it belongs based on its own SLSS ID-R16, and selects the SLSS ID-R18 (for example, the first SL SS ID) to send the S-SSB from the SLSS ID Group-R18 to which it belongs. The terminal device can randomly select an SLSS ID from the SLSS ID Group-R18 to which it belongs. Alternatively, the relationship between SL SS ID-R18 and UE ID satisfies: SL SS ID-R18 = UE ID + starting SL SS ID of this group, or SL SS ID-R18 = UE ID + starting SL SS ID of this group-1. The starting SL SS ID of this group refers to the starting SL SS ID of the corresponding SL SS ID Group-R18. Taking Table 4 as an example, SL SS ID-R18 is a UE ID in the range [112-223], and the starting SL SS ID of this group is 112. Alternatively, SL SS ID-R18 = (UE ID mod total number of SL SS IDs in this group) + starting SL SS ID of this group, or SL SS ID-R18 = (UE ID mod total number of SL SS IDs in this group) + starting SL SS ID of this group - 1. "mod" represents a modulo operation. The total number of SL SS IDs in this group refers to the total number of SL SS IDs included in the corresponding SL SS ID group. For details, please refer to the relevant content in the aforementioned methods C-1, C-2, and C-3, which will not be repeated here.

[0211] The embodiment of the present application further provides a communication method 700. The communication method 700 is applied in a sideline synchronization process, wherein the method indicates a first terminal identifier through an SL SS ID and indicates a synchronization source type through other information.

[0212] For example, the first terminal device sends an S-SSB, which includes a first SL SS ID and a second indication information, the first SL SS ID is used to indicate the first terminal identifier, and the second indication information is used to indicate the type of synchronization source of the S-SSB. Alternatively, the first terminal identifier is carried on the first SL SS ID, and the second indication information is used to indicate the type of synchronization source of the S-SSB. The value range of the first SL SS ID can be [0,671]. The terminal device determines the SLSS ID group to which it belongs based on its SLSS ID-R16, and selects the first SL SS ID to send the S-SSB from the SLSS ID group to which it belongs. For details, please refer to the relevant content in the aforementioned method C-1, method C-2 and method C-3, which will not be repeated here.

[0213] The second indication information may be carried in a reserved bit of the MIB message included in the S-SSB, where different values ​​of the reserved bit indicate different synchronization source types. Alternatively, the second indication information may be carried in a DMRS included in the S-SSB.

[0214] When the first terminal device has the need to establish a unicast link, a direct communication request (DCR) message can be sent. The DCR message carries a source user identifier, which is the application layer identifier of the first terminal device. The DCR message can also carry a destination application layer identifier (application layer ID) (for example, the application layer identifier of the second terminal device). In addition, the DCR can also carry a service identifier. The destination terminal device or a device interested in the service (for example, the second terminal device) responds to the DCR message and sends a direct communication accept (DCA) message to the first terminal device. The DCA message can include the application layer identifier of the second terminal device. It can be understood that the service identifier can be a service type identifier.

[0215] If there is no prior information for link establishment, the beam alignment process needs to be completed between any two terminal devices. However, only a part of the terminal devices may have the need to establish a link, and the terminal devices without the need to establish a link still need to perform beam alignment, which will cause additional resource waste and increase the burden of power consumption. Moreover, after the beam alignment between the terminal devices, what they know is the mapping relationship between the UE ID and the best beam. In the subsequent link establishment process, what the terminal devices exchange is the application layer identifier (for example, the DCR message and the DCA message carry the application layer identifier), and the mapping relationship between the application layer identifier and the best beam is unknown, resulting in the terminal device not knowing which beam or beams to use to send the DCR message and the DCA message.

[0216] In order to solve the above technical problems, the embodiment of the present application proposes that if the first terminal device has a link establishment requirement, then the S-SSB carries information indicating the association with the link establishment and whether there is a link establishment requirement (such as an application layer identifier and / or a service identifier), so that other terminal devices can identify whether the first terminal device has a link establishment requirement, so that other terminal devices can only perform beam alignment with the terminal device with a link establishment requirement, thereby reducing resource waste and reducing power consumption. The terminal device can also determine the mapping relationship between the application layer identifier and the optimal beam through the S-SSB and the application layer identifier, so as to accurately use the corresponding beam to send the DCR message and DCA message.

[0217] For example, please refer to Figure 8, which shows a flow chart of a communication method 800 provided in an embodiment of the present application. As shown in Figure 8, the flow of the communication method 800 includes the following steps.

[0218] S801. The first terminal device sends a sideline synchronization signal block, where the sideline synchronization signal block includes an application layer identifier.

[0219] Accordingly, the second terminal device receives the sideline synchronization signal block.

[0220] S802: The second terminal device performs beam alignment with the first terminal device according to the sidelink synchronization signal block.

[0221] The first terminal device is a terminal device that has a link establishment requirement. For example, the first terminal device attempts to establish a unicast link with at least one second terminal device. In this case, the S-SSB sent by the first terminal device may include indication information of the link establishment requirement. The indication information may include an application layer identifier, which is the application layer identifier in the DCR message. Alternatively, the indication information may be a source ID (source ID) and / or a destination ID (destination ID). The second terminal device receives the S-SSB from the first terminal device and can determine the identifier of the first terminal device based on the S-SSB. For example, the indication information includes an application layer identifier, and the second terminal device can determine the identifier of the first terminal device based on the application layer identifier. For another example, the indication information is a source ID and / or a destination ID, and the second terminal device can determine the identifier of the first terminal device based on the source ID and / or the destination ID to facilitate subsequent beam alignment.

[0222] The S-SSB also includes a type identifier for the first terminal device's service. Based on the type identifier, the second terminal device determines whether it is interested in the first terminal device's service and, therefore, whether to perform beam alignment with the first terminal device. For example, if the second terminal device is interested in the first terminal device's service, the second terminal device may send a DCA to the first terminal device in response to the first terminal device's DCR.

[0223] If the second terminal device determines that there is a need to establish a link with the first terminal device, the second terminal device performs beam alignment with the first terminal device and reports the best beam to the first terminal device. For example, the second terminal device sends beam information to the first terminal device, and the beam information indicates the best beam. It should be noted that when the second terminal device reports the best beam, it also sends the application layer identifier of the second terminal device. That is, the beam information and the source application layer identifier of the second terminal device are sent together. If the second terminal device determines that there is no need to establish a link with the first terminal device, the second terminal device does not perform beam alignment with the first terminal device, that is, there is no need to report the best beam.

[0224] Optionally, the best beam may refer to the beam index with the highest measured RSRP or RSSI, and / or the corresponding RSRP or RSSI. Alternatively, the best beam may refer to the beam indexes and / or the corresponding RSRP or RSSI of multiple beams.

[0225] The S-SSB also includes beam information, which is used to indicate the beam index of the S-SSB (for example, the second beam index) so that the second terminal device knows the beam corresponding to the received S-SSB.

[0226] Optionally, the second beam index is the beam index of each S-PSS / S-SSS included in the S-SSB. “Each S-PSS / S-SSS included in the S-SSB” means all S-PSS / S-SSS of the S-SSB. Therefore, the second beam index is the beam index of all S-PSS / S-SSS of the S-SSB, or the second beam index is the beam index of the S-SSB.

[0227] Alternatively, the second beam index is the beam index of each S-PSS included in the S-SSB. It can also be understood that the second beam index is the beam index of all S-PSSs included in the S-SSB, that is, the second beam index is the beam index of the S-PSS of the S-SSB. Alternatively, the second beam index is the beam index of each S-SSS included in the S-SSB. It can also be understood that the first beam index is the beam index of all S-SSSs included in the S-SSB, that is, the second beam index is the beam index of the S-SSS of the S-SSB.

[0228] Alternatively, the second beam index is the beam index of the first S-PSS or the first S-SSS included in the S-SSB. For example, if the second beam index is the beam index of the first S-PSS included in the S-SSB, the beam indexes of the subsequent S-PSS, S-SSS, and S-SSS are the second beam index + 1, the second beam index + 2, and the second beam index + 3, respectively. Alternatively, the second beam index is the beam index of the S-PSS included in the S-SSB, for example, if the second beam index is the beam index of the S-PSS included in the S-SSB, then the beam indexes of the two S-PSSs are the second beam index, and the beam indexes of the two S-SSSs are the second beam index + 1.

[0229] It should be understood that the side synchronization signal block or S-SSB mentioned in the embodiments of the present application may refer to a signal or signal block having an R16 S-SSB structure, or may refer to a signal or signal block having a structure proposed in the embodiments of the present application.

[0230] After the first and second terminal devices have aligned their beams, the first terminal device transmits a DCR message based on the optimal beam and receives a DCA message from the second terminal device based on the optimal beam. The second terminal device receives the DCR message from the first terminal device based on the optimal beam and sends a DCA message to the first terminal device based on the optimal beam. The optimal beam includes a transmit beam and / or a receive beam. For example, the transmit beam and / or receive beam of the first terminal device and the transmit beam and / or receive beam of the second terminal device. Optionally, the optimal beam can also be an optimal beam pair.

[0231] Optionally, the time domain resource for reporting the best beam is determined based on (pre) configuration. For example, one or more of the following parameters are (pre) configured: the offset value between the best beam reporting information and the time domain resource of the "corresponding side synchronization signal block"; the offset value between the time domain resource for sending the DCR and the time domain resource for the "corresponding side synchronization signal block"; the offset value between the time domain resource for sending the DCR and the time domain resource for the best beam reporting information; the offset value between the time domain resource for sending the DCA and the time domain resource for the corresponding DCR. The "corresponding side synchronization signal block" refers to the side synchronization signal block transmitted using the best beam. The time domain resource for reporting the best beam is determined based on one or more of the above parameters and / or the index of the best beam.

[0232] In the communication method 800, the S-SSB also includes first indication information, which is used to indicate that the S-SSB is used for synchronization or beam training. For details, please refer to the aforementioned related content and will not be repeated here.

[0233] When the first terminal device does not need to establish a unicast link with any terminal device, the S-SSB sent by the first terminal device includes a default identifier for indicating that the S-SSB is used for synchronization. The default identifier can be a default application layer identifier (for example, a default destination ID) or a default service type identifier.

[0234] Optionally, the first terminal device may transmit the S-SSB without being constrained by a condition (e.g., a reference signal received power (RSRP) being less than a threshold value). Alternatively, the first terminal device may transmit the S-SSB when there is a link establishment requirement; and when the condition for transmitting the S-SSB for synchronization is met, the first terminal device may transmit the S-SSB.

[0235] In a possible scenario, beam alignment can be performed between the first terminal device and the second terminal device regardless of whether there is a link establishment requirement. The mapping relationship between the terminal identifier and the L2 ID or application layer ID can be maintained between the terminal devices. For example, the S-SSB sent by the first terminal device carries the identifier of the first terminal device. For example, UE1 ID and L2 ID can be the source ID and / or destination ID or application layer ID. When the second terminal device reports the best beam, it also reports the identifier of the second terminal device. In this way, the first terminal device and the second terminal device can know the best beam corresponding to the L2ID, so that the first terminal device sends a DCR message or receives a DCA message based on the best beam. Optionally, L2ID can be the source ID and / or destination ID. Optionally, L2 ID (layer 2ID) can also be L1 ID (layer 1ID).

[0236] Communication method 800 uses the S-SSB to carry information indicating whether a link establishment is required. This allows the receiving end to identify whether a transmitting end has a link establishment requirement. This allows the receiving end to perform beam alignment only with transmitting ends that have a link establishment requirement, reducing resource waste and power consumption. Furthermore, the mapping relationship between the application layer identifier and the optimal beam can be determined, allowing the corresponding beam to be used to accurately send DCR and DCA messages.

[0237] Optionally, communication method 800 can be combined with communication method 300. For example, the first terminal device sends an S-SSB for beam training, indicating the first indication information and / or the first terminal identifier using the method in communication method 300, which is not further described here. Optionally, the S-SSB is sent for beam training only when the first terminal device has a link establishment requirement.

[0238] Optionally, communication method 800 can be combined with communication method 400. For example, the first terminal device sends an S-SSB on the time-frequency resources (second resource set) used for beam training, and indicates the first terminal identifier through the method in communication method 400, which will not be repeated here. Optionally, the S-SSB for beam training is sent only when the first terminal device has a link establishment requirement. The information carried by the S-SSB is as described above and will not be repeated here.

[0239] Optionally, communication method 800 can be combined with communication method 500. For example, the first terminal device sends an S-SSB for beam training, and the method in communication method 500 is used to indicate that the S-SSB is used for beam training and the first terminal identifier is not further described here. Optionally, the S-SSB is sent for beam training only when the first terminal device has a link establishment requirement.

[0240] Communication method 800 can be combined with communication method 600. For example, the first terminal device sends an S-SSB for beam training, and the method in communication method 600 is used to indicate that the S-SSB is used for beam training and the first terminal identifier is not further described here. Optionally, the S-SSB is sent for beam training only when the first terminal device has a link establishment requirement.

[0241] Communication method 800 can be combined with communication method 700. For example, the first terminal device sends an S-SSB for beam training, and the method in communication method 700 is used to indicate that the S-SSB is used for beam training and the first terminal identifier is not further described here. Optionally, the S-SSB is sent for beam training only when the first terminal device has a link establishment requirement.

[0242] In the side-by-side scenario, when the MAC layer has a service transmission requirement, it triggers the PHY layer to select resources and provides a set of parameters (prio TX ,remaining PDB,L subCH and P rsvp_TX ), used by the PHY layer to determine the candidate resource set SA. TX Indicates the priority of resource selection, remaining PDB (packet delay budget) indicates the remaining packet delay budget (the selected resources cannot exceed the remaining PDB), L subCH The number of frequency domain subchannels for each candidate resource in the SA for resource selection, P rsvp_TX Indicates the resource selection cycle.

[0243] Based on the resource selection parameters provided by the MAC layer and specific resource selection rules, the PHY layer determines a candidate resource set (SA) and reports it to the MAC layer. The SA contains several available candidate resources. In Rel-16 / Rel-17 sidelink, the time domain granularity of each candidate resource is one time slot.

[0244] When the MAC layer transmits services, it selects candidate resources from the SA and performs logical channel prioritization (LCP). LCP involves two priorities, namely the priority of the logical channel and CAPC. These two priorities are introduced first. 1) Logical channel priority. Each logical channel has a service priority. The service priority of the final packaged TB is the highest priority among the logical channels contained in the TB. The highest priority corresponds to the lowest priority value. For example, the priority values ​​of the logical channel are 1-8, among which the logical channel with a priority value of 1 has the highest priority. 2) CAPC. Each logical channel has a CAPC. The CAPC of the final packaged TB is the lowest priority among the logical channels contained in the TB. The lowest priority corresponds to the highest priority value. For example, the CAPC values ​​of the logical channel are 1-4, among which the logical channel with a CAPC value of 1 has the highest CAPC.

[0245] The principle followed by LCP is: first select a destination (the destination is the destination corresponding to the logical channel with the highest priority among all the logical channels to be sent); then select one or more logical channels in descending order of priority from the logical channels to be sent corresponding to the destination; then allocate resources to the selected logical channels. When the resources are allocated, discard the other logical channels to be sent.

[0246] It should be noted that although there is only one destination when resource selection is triggered, there may be new business needs before the package is assembled, resulting in multiple destinations during LCP.

[0247] In Rel-18 SL-U, multiple consecutive slot transmission (MCSt) is supported to avoid frequent channel access.

[0248] In MCSt, the number of time slots provided by the MAC layer to the PHY layer for resource selection indicates the time domain length of each candidate resource. In fact, the MAC layer triggers PHY resource selection when it has a packet transmission requirement, and does not wait for multiple packets to arrive before triggering. Therefore, the resource selection of the PHY layer can only be performed for one TB (destination), that is, the PHY layer uses the resource selection parameters of the TB to be sent when triggering resource selection. In one implementation, the LCP of the first time slot of the candidate resource is executed according to Rel-16 / Rel-17, and the TB of the first time slot is repeatedly sent in other time slots. TB can also be called MAC PDU (protocol data unit).

[0249] In order to further improve system performance and efficiency, a method according to an embodiment of the present application is provided. This method can enable the candidate resources of MCSt to be used for the transmission of a logical channel that cannot be sent due to insufficient resources in the first time slot of a TB, as well as the transmission of multiple TBs with different destinations.

[0250] To this end, an embodiment of the present application provides a communication method 800. By enhancing the LCP, while selecting resources according to the resource selection parameters of a TB, communication method 800 enables MCSt candidate resources to be used for the transmission of logical channels that a TB failed to transmit due to insufficient resources in the first timeslot. MCSt candidate resources can also be used to transmit TBs with multiple different destinations, improving system performance and efficiency and increasing resource utilization.

[0251] Please refer to Figure 9, which shows a flow chart of a communication method 900 provided in an embodiment of the present application. Figure 9 introduces the method from the perspective of the first terminal device. Taking the MAC layer of the first terminal device triggering the PHY layer resource selection as an example, a resource selection parameter set 1 and N is provided, where N is the number of time slots for the PHY layer resource selection. The PHY layer performs resource selection and reports SA, where each candidate resource includes N consecutive time slots. As shown in Figure 9, the process of the communication method 900 includes the following steps.

[0252] S901. A first terminal device obtains N time units for continuous multi-slot transmission, where N is an integer greater than 1.

[0253] S902. The first terminal device sends a first transmission block in the first time unit of N time units. The first transmission block includes at least one logical channel. The at least one logical channel is determined from all logical channels to be sent in a first order according to priority and CAPC.

[0254] A time unit can be a time slot (this is used as an example below). The first transport block is TB1, which is sent in the first of N time slots. This TB1 includes at least one logical channel, which is determined from all logical channels to be sent. Specifically, the at least one logical channel can be determined from all logical channels to be sent in a first order based on priority and CAPC. The first order can be order A, order B, or order C.

[0255] Sequence A: The logical channel with the lowest priority value, the logical channel with the highest CAPC value for the same destination, and then logical channels with the same destination in ascending order of priority. "Same destination" means "the same destination as the logical channel with the lowest priority value." Sequence A can be understood as: first determine the logical channel with the lowest priority value and its corresponding destination; then determine the logical channel with the highest CAPC value for the same destination; and then determine logical channels with the same destination in ascending order of priority until all resources are allocated.

[0256] Sequence B: The logical channel with the highest CAPC value, followed by logical channels with the same destination, prioritized from lowest to highest. "Same destination" means "the same destination as the logical channel with the highest CAPC value." Sequence B can be understood as follows: first determine the logical channel with the highest CAPC value and its corresponding destination; then, prioritize logical channels with the same destination, from lowest to highest, until all resources are allocated.

[0257] Optionally, the logical channel with the highest CAPC value may be selected from logical channels whose priority values ​​are less than or equal to the priority value for resource selection. In other words, the logical channel with the highest CAPC value belongs to a logical channel whose priority value is less than or equal to the priority value for resource selection. The "priority value for resource selection" is the priority value in the resource selection parameter set. Optionally, the logical channels in the above-mentioned sequence A and sequence B should all satisfy the requirement that the priority value is less than or equal to the priority value for resource selection. It can be understood that logical channels with a priority value greater than the priority value for resource selection are excluded first, i.e., they do not participate in the logical channel selection and resource allocation process.

[0258] Sequence C: The logical channel with the lowest priority value among the logical channels corresponding to the destination selected for the transmission resource, the logical channel with the highest CAPC value for the same destination, and the logical channel with the lowest priority value for the same destination. Sequence C can be understood as: first, select the logical channel with the lowest priority value from the logical channels corresponding to the destination selected for the transmission resource; then determine the logical channel with the highest CAPC value for the same destination; and then determine the logical channels with the same destination in descending order of priority until all resources are allocated.

[0259] Determining at least one logical channel from all logical channels to be sent in the first order based on priority and CAPC can be understood as an enhancement to LCP. Under the premise of performing resource selection according to the resource selection parameters of a TB, the embodiment of the present application enhances LCP to ensure that the first time slot can send logical channels with small priority values ​​and large CAPC values ​​as much as possible, so that high-priority logical channels are transmitted first, while facilitating the use of subsequent time slots for the transmission of other logical channels, thereby meeting the requirement in the regulations that the CAPC value of subsequent transmissions is not greater than the CAPC value of the first transmission.

[0260] The first terminal device may drop logical channels on the first time slot that would make the period of TB1 different from the period in the resource selection parameter set. The first terminal device may also drop logical channels on the first time slot that would make the remaining PDB of TB1 less than the remaining PDB in the resource selection parameter set.

[0261] In the second time slot, if the first condition is met, TB2 can also be sent, and this TB2 can be a repetition of TB1. The first condition includes one or more of the following: there are no other logical channels to be sent with the same destination as TB1 in the first time slot; there are no logical channels to be sent; the priority value of at least one logical channel among the logical channels to be sent is higher than the priority value of the resource selection; the logical channel with the lowest priority value among the logical channels to be sent is different from the priority value of the resource selection; the priority value of the logical channel with the lowest priority value among the logical channels to be sent is higher than the priority value of the resource selection. It should be understood that when TB2 is a repetition of TB1, TB2 and TB1 can be considered to be the same TB.

[0262] Optionally, the logical channels to be transmitted must meet one or more of the following constraints: the CAPC value of the logical channel to be transmitted must not be higher than the CAPC value of TB1, the period of the logical channel to be transmitted must be the same as the period of the first timeslot, or the logical channels to be transmitted must not include logical channels with a priority value greater than a threshold. Optionally, the threshold is (pre)configured. Optionally, the set of candidate values ​​for the threshold is {1, 2, 3, 4, 5, 6, 7, 8}.

[0263] It is understood that the logical channels to be sent in the first condition must all meet one or more of the aforementioned constraints. For example, the CAPC value of the logical channel to be sent must not be higher than the CAPC value of TB1, the period of the logical channel to be sent must be the same as the period of the first timeslot, and the logical channels to be sent must not include logical channels with a priority value greater than a certain threshold. It is understood that only logical channels that meet one or more of the aforementioned constraints are considered logical channels to be sent for determination of the first condition.

[0264] If the first condition is not met, at least one of the other logical channels to be sent is sent in the second time slot. The first order of sending the at least one logical channel is: the logical channel with the lowest priority value, the logical channel with the highest CPAC value for the same destination, and then the logical channels with the same destination in descending order of priority. In other words, if the first condition is not met, among the other logical channels to be sent, if the CAPC value is not higher than that of the first time slot, the first logical channel with the lowest priority value is sent; then the first logical channel with the highest CAPC value for the same destination is sent; and then the logical channel with the same destination as the first logical channel and a lower priority value is sent.

[0265] Alternatively, when the first condition is not met, at least one of the other logical channels to be sent in the second time slot is sent in the following order: the logical channel with the largest CPAC value, followed by logical channels with the same destination from lowest priority to highest priority. That is, when the first condition is not met, among the other logical channels to be sent, the first logical channel with the largest CAPC value, whose CAPC value is not higher than that in the first time slot, is sent first; then logical channels with the same destination as the first logical channel and a lower priority value are sent.

[0266] Optionally, the other logical channels to be sent need to satisfy one or more of the following constraints: the CAPC value of the other logical channels to be sent is not higher than the CAPC value of TB1, the period of the other logical channels to be sent is the same as the period of the first time slot, the other logical channels to be sent do not include logical channels whose priority values ​​are greater than a certain threshold, the priority value of at least one logical channel sent in the second time slot is not higher than the priority value in the resource selection parameter set, or, optionally, if the second time slot has a logical channel with the same destination as the first time slot, then the logical channel with the same destination as the first time slot is preferentially sent in the second time slot.

[0267] When the constraints are met, TB3 can also be sent on the third time slot. The method for determining the logical channel on the third time slot can refer to the second time slot and will not be repeated here. Among them, the constraints corresponding to the third time slot can refer to the resource selection parameters, or the constraints of the first time slot, or the constraints corresponding to the second time slot. For example, the CAPC value of the logical channel to be sent is not higher than the CAPC value of the resource selection, or the CAPC value of the logical channel to be sent is not higher than the CAPC value of TB1, or the CAPC value of the logical channel to be sent is not higher than the CAPC value of TB2. The other constraint rules are similar and will not be repeated here.

[0268] In a possible implementation, the remaining time slots in the N time slots, except for the time slots used to send TB1 and / or TB2, can be shared with other responding terminal devices (responding UEs) for transmission. For example, the first terminal device can also send sharing indication information, which is used to indicate the shared time units in the N time units.

[0269] The sharing indication information may include one or more of the following information about the shared time unit: the offset of the shared starting time unit relative to the first time unit, the offset of the shared starting time unit relative to the time unit where the sharing indication information is located, the length of the shared time unit, the CPAC value of the shared time unit, etc.

[0270] For the selected MCSt resources, if the MAC layer does not use them to send MAC PDUs, the PHY layer can share them with the responding UE. When the responding UE performs LCP packetization, the CAPC value of the selected logical channel is greater than the CAPC value in the sharing indication information. When any one or more TBs in the MCSt do not receive feedback, for example, when the hybrid automatic repeat request (HARQ) feedback of any one or more TBs in the MCSt is a negative acknowledgment (NACK) or discontinuous reception (DTX), retransmit the TB with NACK or DTX, as well as the TBs on all time slots before the time slot where the TB is located, for example, the first time slot to the time slot before the time slot where the TB is located; or retransmit all TBs of the MCSt.

[0271] To meet occupied channel bandwidth (OCB) requirements, SL-U allows for repeated transmission of multiple S-SSBs within a single RB set during a single S-SSB occasion. This means that, in addition to the frequency resources specified by the ARFCN, S-SSBs can also be transmitted on different frequency resources within the RB set containing the ARFCN (called the anchor RB set). Furthermore, because data transmission may occupy multiple consecutive RB sets, if the S-SSB slot falls within the channel occupancy time (COT), the COT for RB sets where no S-SSBs are transmitted may be interrupted or lost. To ensure COT continuity, S-SSBs can be transmitted in multiple RB sets during a single S-SSB slot. This means that, in addition to transmitting S-SSBs within the anchor RB set, S-SSBs can also be transmitted on other RB sets where COT continuity is required. In summary, multiple S-SSBs can be transmitted within the same S-SSB slot, within one RB set or across multiple RB sets. The receiving end can receive all S-SSBs in the frequency domain and combine them according to the SLSS IDs carried by each of these S-SSBs to obtain a combined S-SSB. Optionally, other S-SSBs in the frequency domain can be repetitions of the ARFCN S-SSB.

[0272] When multiple S-SSBs are sent in one RB set or multiple RB sets in the same S-SSB time slot, the total power of multiple S-SSBs may exceed the maximum transmit power Pcmax of the terminal device by using the current method of calculating the power of each S-SSB. In addition, the number of RB sets used by the terminal device to send S-SSBs in each S-SSB time slot may be different, so the total power of multiple S-SSBs fluctuates, making the RSRP received by the receiver in different S-SSB time slots unstable, which may lead to frequent switching of the synchronization source and affect the synchronization performance. Furthermore, the receiver merges the SLSS IDs carried by all the received S-SSBs, which is more complex and requires higher processing capabilities of the receiver.

[0273] In order to solve the above problems, an embodiment of the present application proposes a communication method 900. The communication method 900 is applicable to scenarios where multiple S-SSBs are sent in one RB set or multiple RB sets in the same S-SSB time slot. Method 900 can ensure that the total power of multiple S-SSBs sent in parallel does not exceed the maximum transmit power of the transmitter. Method 900 can also make the transmit power of the transmitter in each S-SSB time slot more stable, reducing the number of times the receiver switches the synchronization source. Method 900 can also give priority to ensuring the power and coverage of the S-SSB indicated by the ARFCN or the S-SSB of the anchor RB set to meet the actual needs of synchronization.

[0274] Please refer to Figure 10, which shows a flow chart of a communication method 1000 provided in an embodiment of the present application. As shown in Figure 10, the flow of the communication method 1000 includes the following steps.

[0275] S1001: A first terminal device determines a first time domain resource.

[0276] The first time domain resource is used for sending and / or receiving S-SSB, or the first time domain resource is used for sending and / or receiving S-SSB.

[0277] The first time domain resource is (pre) configured. Optionally, the first time domain resource is a periodic S-SSB resource, or the first time domain resource is an additional S-SSB resource. Additional S-SSB resources refer to S-SSB resources that are additionally determined in addition to the periodic (pre) configured S-SSB resources of Rel-16. Optionally, each periodic S-SSB resource has a corresponding additional S-SSB resource. For example, the additional S-SSB resource is determined by at least one of the following (pre) configured parameters: an offset value or interval between the first additional S-SSB resource and the corresponding periodic S-SSB resource, and an interval between multiple additional S-SSB resources. Optionally, the aforementioned two parameters can be (pre) configured by the same parameter, for example, the interval of the additional S-SSB resource. Optionally, the additional S-SSB resource is also referred to as an additional S-SSB resource.

[0278] S1002, the first terminal device sends a first S-SSB with a first power on a first frequency domain resource within the time-frequency resource where the first time domain resource is located, and sends a second S-SSB with a second power on a second frequency domain resource within the time-frequency resource where the first time domain resource is located.

[0279] The first terminal device sends multiple S-SSBs in one RB set or multiple RB sets on the first time domain resource. Optionally, on the first time domain resource, the RB set used to send S-SSB includes an anchor RB set, and at least one of the following: the RB set included in the initial COT of the first terminal device, and the RB set included in the initial COT of other terminal devices. Here, "other terminal devices" refers to terminal devices other than the first terminal device. The first time domain resource may be located within the initial COT of the first terminal device and / or the initial COT of other terminal devices. Optionally, the first time domain resource is not the last time slot within the initial COT of the first terminal device and / or the initial COT of other terminal devices. Optionally, when at least two RB sets among the anchor RB set, the RB set included in the initial COT of the first terminal device, and the RB set included in the initial COT of other terminal devices are the same, the RB set used to send S-SSB is the union of the anchor RB set, the RB set included in the initial COT of the first terminal device, and the RB set included in the initial COT of other terminal devices.

[0280] The first terminal device may transmit a first S-SSB at a first power on a first frequency domain resource within the time-frequency resource where the first time domain resource is located, and transmit a second S-SSB at a second power on a second frequency domain resource within the time-frequency resource where the first time domain resource is located. Optionally, the second SSB is a repetition of the first SSB.

[0281] Optionally, the first terminal device sends the first S-SSB at the first power only on the first frequency domain resource within the time-frequency resource where the first time domain resource is located. Alternatively, the first terminal device sends the second S-SSB at the second power only on the second frequency domain resource within the time-frequency resource where the first time domain resource is located.

[0282] Among them, the first frequency domain resource may be an S-SSB resource determined according to ARFCN, and the second frequency domain resource is an S-SSB resource used to send S-SSB in addition to the S-SSB resource determined according to ARFCN. Alternatively, the first frequency domain resource is an S-SSB resource on an anchor RB set, and the second frequency domain resource is an S-SSB resource on an RB set used to send S-SSB in addition to the anchor RB set. Optionally, the RB set used to send S-SSB refers to: an RB set in the RB set used to send S-SSB in the time-frequency resource where the first time domain resource is located, in addition to the anchor RB set.

[0283] Before sending the first SSB and the second SSB, the first terminal device may determine the first power and the second power so that the total power of the first S-SSB and the second SSB sent in parallel by the first terminal device does not exceed the maximum transmit power of the first terminal device. The first power and / or the second power are non-negative values. When the first power is 0, the first terminal device does not send an S-SSB on the first frequency domain resource; when the second power is 0, the first terminal device does not send an S-SSB on the second frequency domain resource. Alternatively, when the first power is 0, the first terminal device sends the first S-SSB with a power of 0 on the first frequency domain resource; when the second power is 0, the first terminal device sends the second S-SSB with a power of 0 on the second frequency domain resource.

[0284] In the embodiment of the present application, the determination method of the first power and / or the second power includes but is not limited to the following method 1 and method 2, which are introduced in sequence below. The "offset value" involved below can also be called a scaling factor, an adjustment value, a proportional factor, etc., which is not limited in this application. In the formula involved below, P CMAX is the maximum transmit power supported by the first terminal device. Δ1 is the first offset value, and Δ2 is the second offset value. If the parameter d1-P0-PSBCH is provided, then P O,S-SSB The value is the value provided by dl-P0-PSBCH, otherwise P O,S-SSB (i) = P CMAX If the parameter dl-Alpha-PSBCH is provided, then α S-SSB The value provided by dl-Alpha-PSBCH, otherwise, α S-SSB= 1. PL represents the transmission loss estimated by the first terminal device based on the reference signal; represents the number of RBs allocated to one S-SSB transmission at transmission opportunity i; The number of RBs for each S-SSB. V is the number of S-SSB frequency domain repetitions within the RB set. And the "." and "*" in the formula represent multiplication, and " / " and "÷" represent division. In the formula, for Δ1 or Δ2 for + or -, Δ1 and / or Δ2 can be 0. For Δ1 or Δ2 for * or ÷, Δ1 and / or Δ2 can be 1. At this time, it can be understood that Δ1 and / or Δ2 exist in the formula, but the value is 0 or 1, or it can be understood that Δ1 and / or Δ2 do not exist in the formula. Optionally, the formulas in this application can be transformed through mathematical operations, such as logarithmic transformation, etc., and are still within the scope of protection of this application.

[0285] Method 1: The first power and the second power are calculated based on the power of each S-SSB. For example, the first power is the power of each S-SSB on the first frequency domain resource. The second power is the power of each S-SSB on the second frequency domain resource.

[0286] The first power can be determined based on the first offset value. For example, the third power and / or the fourth power can be determined based on the first offset value, and the first power can be determined based on the third power and / or the fourth power. For example, the first power is the minimum of the third power and the fourth power.

[0287] Among them, the first offset value can be (pre) configured. For example, the first offset value Δ1 is (pre) configured. Alternatively, the first offset value Δ1 is determined according to 10log(M). M is the total number of RB sets in the resource pool or bandwidth part (BWP), or M is (pre) configured, or M is the maximum total number of S-SSBs that can be transmitted in the resource pool or BWP, or M is the number of RB sets actually used to send S-SSBs in the resource pool or BWP, or M is the number of S-SSB resources actually used to send S-SSBs in the resource pool or BWP. It should be understood that the RB set actually used to send S-SSBs in the resource pool or BWP is the RB set included in the first frequency domain resources and the second frequency domain resources; the number of S-SSB resources actually used to send S-SSBs in the resource pool or BWP is the S-SSB resources for sending S-SSBs included in the first frequency domain resources and the second frequency domain resources.

[0288] For example, the third power is P CMAX -Δ1, the fourth power is Then the first power is Alternatively, the third power is P CMAX , the fourth power is The first power is

[0289] The "-" before Δ1 in the formula can also be replaced by a "+". The power unit in the above formula is dBm. When the PL cannot be estimated, the first power can be equal to the third power. Optionally, the candidate values ​​for Δ1 include one or more values ​​from a first set, expressed in dB. The first set is a set consisting of integers in the range [-29, 29]. It should be noted that the above first set is for example only, and the candidate values ​​for Δ1 may also include values ​​other than the first set.

[0290] The above formula can be converted into mW for calculation. At this time, the third power is: P CMAX (mW)×Δ1, or the third power is: P CMAX (mW) / Δ1. In this case, the candidate values ​​of Δ1 include one or more of the second set. The second set is: [1 / 15, 1 / 14, 1 / 13, 1 / 12, 1 / 11, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, 1 / 3, 1 / 2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15].

[0291] It should be noted that the above second set is only an example, and the candidate values ​​of Δ1 may also include values ​​other than the second set.

[0292] Similarly, the second power can be determined based on the second offset value. For example, the fifth power and / or the sixth power can be determined based on the second offset value, and the first power can be determined based on the fifth power and / or the sixth power. For example, the second power is the minimum value of the fifth power and the sixth power. The second offset value can be (pre) configured, or determined based on 10lg(N), or determined based on Δ1. N is the total number of S-SSBs that can be transmitted in the resource pool or BWP, or is (pre) configured, or N is the total number of RB sets in the resource pool or BWP, or N is the number of RB sets actually used to send S-SSBs in the resource pool or BWP, or N is the number of S-SSB resources actually used to send S-SSBs in the resource pool or BWP. It should be understood that the RB set actually used to send S-SSBs in the resource pool or BWP is the RB set included in the first frequency domain resources and the second frequency domain resources. The number of S-SSB resources actually used for sending S-SSBs in the resource pool or BWP is the S-SSB resources used for sending S-SSBs included in the first frequency domain resources and the second frequency domain resources.

[0293] For example, the fifth power is P CMAX -Δ2, the sixth power is The second power is Alternatively, the fifth power is P CMAX , the sixth power is Then the first power is

[0294] The explanation and usage of Δ2 refer to Δ1 and will not be repeated here.

[0295] The values ​​of Δ2 and Δ1 can be the same to ensure that the total concurrent power does not exceed P CMAX Optionally, the values ​​of Δ2 and Δ1 are (pre)configured separately and have the same value; or, Δ2 and Δ1 are (pre)configured for the same parameter (such as Δ). Optionally, M and N are (pre)configured for the same parameter. Alternatively, the relationship between Δ2 and Δ1 is: for + or - "Δ1 and Δ2", or, For * or ÷ offset values ​​"Δ1 and Δ2", Δ2 + Δ1 = 1, or A*Δ2 + B*Δ1 = 1. Where A is the number of S-SSBs on the second frequency domain resource, and B is the number of S-SSBs on the first frequency domain resource.

[0296] The second power can also be determined based on the first power. For example, the second power is P S-SSB (i) = P CMAX -∑P-101g A. ∑P is the total power of the S-SSBs on the first frequency domain resource, that is, ∑P = first power + 101gB, the first power is the power of each S-SSB on the first frequency domain resource, B is the number of S-SSBs on the first frequency domain resource, and A is the number of S-SSBs on the second frequency domain resource. A can be replaced by XB, and A can be (pre)configured. X is (pre)configured, or X is the total number of S-SSBs in the first frequency domain resource and the second frequency domain resource.

[0297] Method 1 ensures that the power of the S-SSB on the anchor RB set does not change due to changes in the number of RB sets used, thereby improving power stability and synchronization performance. When the S-SSB power on the non-anchor RB set is determined based on the second offset value or pre-configuration, the stability of the S-SSB power on the non-anchor RB set can be additionally guaranteed, so that terminal devices capable of receiving multiple S-SSBs in parallel can achieve better synchronization performance.

[0298] Method 2: The first power and the second power are calculated based on the total power of the S-SSBs on each RB set. For example, the first power is the total power of the S-SSBs on each RB set on the first frequency domain resource. The second power is the total power of the S-SSBs on each RB set on the second frequency domain resource. It can be understood that the total power of the S-SSBs on each RB set on the first frequency domain resource is the total power of the S-SSBs on the anchor RB set.

[0299] Optionally, the first power may be (pre) configured or determined based on a first offset value. For example, the third power and / or the fourth power may be determined based on the first offset value, and the first power may be determined based on the third power and / or the fourth power. For example, the first power is the minimum value of the third power and the fourth power. The first offset value may be (pre) configured. For example, the first offset value Δ1 is (pre) configured. Alternatively, the first offset value Δ1 is determined based on 10log(M), where M is the total number of RB sets in the resource pool or bandwidth part (BWP), or M is (pre) configured, or M is the maximum total number of S-SSBs that can be transmitted in the resource pool or BWP, or M is the number of RB sets actually used to transmit S-SSBs in the resource pool or BWP, or M is the number of S-SSB resources actually used to transmit S-SSBs in the resource pool or BWP. It should be understood that the RB set actually used to transmit S-SSBs in the resource pool or BWP is the RB set included in the first frequency domain resources and the second frequency domain resources. The number of S-SSB resources actually used for sending S-SSBs in the resource pool or BWP is the S-SSB resources used for sending S-SSBs included in the first frequency domain resources and the second frequency domain resources.

[0300] For example, the third power is P CMAX -Δ1, the fourth power is The first power is Alternatively, the third power is P CMAX -Δ1, the fourth power is The first power is Alternatively, the third power is P CMAX -Δ1, the fourth power is The first power is in, The total number of RBs in the S-SSB on the RB set.

[0301] For example, the third power is P CMAX , the fourth power is The first power is Alternatively, the third power is P CMAX , the fourth power is The first power is Alternatively, the third power is P CMAX , the fourth power is The first power is in, The total number of RBs in the S-SSB on the RB set.

[0302] The explanation and usage of Δ1 in Method 2 can refer to Δ1 in Method 1 and will not be repeated here.

[0303] Similarly, the second power can be determined according to the second offset value. For example, the fifth power and / or the sixth power can be determined according to the second offset value, and the first power can be determined according to the fifth power and / or the sixth power. For example, the second power is the minimum value of the fifth power and / or the sixth power. Among them, the second offset value can be (pre) configured, or determined according to 10lg(N), or determined according to Δ1. N is the total number of S-SSBs that can be transmitted in the resource pool or BWP, or is (pre) configured, or N is the total number of RB sets in the resource pool or BWP, or N is the number of RB sets actually used to send S-SSBs in the resource pool or BWP, or N is the number of S-SSB resources actually used to send S-SSBs in the resource pool or BWP. It should be understood that the RB set actually used to send S-SSBs in the resource pool or BWP is the RB set included in the first frequency domain resources and the second frequency domain resources. The number of S-SSB resources actually used for sending S-SSBs in the resource pool or BWP is the S-SSB resources used for sending S-SSBs included in the first frequency domain resources and the second frequency domain resources.

[0304] For example, the fifth power is P CMAX -Δ2, the sixth power is The second power is Alternatively, the fifth power is P CMAX -Δ2, the sixth power is The second power is Alternatively, the fifth power is P CMAX -Δ2, the sixth power is The second power is in, The total number of RBs in the S-SSB on the RB set.

[0305] For example, the fifth power is P CMAX , the sixth power is The second power is Alternatively, the fifth power is P CMAX , the sixth power is The first power is Alternatively, the fifth power is P CMAX , the sixth power is The first power is P S-SSB (i) = min(P CMAX ,P O,S-SSB + in, The total number of RBs in the S-SSB on the RB set.

[0306] The explanation and usage of Δ2 refer to Δ1 and will not be repeated here. Optionally, the relationship between Δ2 and Δ1 is: for + or - "Δ1 and Δ2", or, For * or ÷ "Δ1 and Δ2", Δ2 + Δ1 = 1, or, C * Δ2 + D * Δ1 = 1. Where C is the number of non-anchor RB sets for transmitting S-SSB on the second frequency domain resource, and D is the number of anchor RB sets for transmitting S-SSB on the first frequency domain resource. This ensures that the total concurrent power does not exceed P CMAX .

[0307] Alternatively, the second power can also be determined based on the first power. For example, the second power is P S-SSB (i) = P CMAX -∑P-10lg C. Wherein, ∑P is the total power of S-SSB on the first frequency domain resource, that is, ∑P=first power+10lgD. The first power is the total power of S-SSB on each RB set on the first frequency domain resource. D is the number of RB sets for sending S-SSB on the first frequency domain resource, and C is the number of RB sets for sending S-SSB on the second frequency domain resource. Optionally, C can be replaced by YD, which can be (pre) configured. Y is (pre) configured, or Y is the total number of RB sets for sending S-SSB on the first frequency domain resource and the second frequency domain resource.

[0308] Method 2 ensures that the power of the S-SSB on the anchor RB set does not change due to changes in the number of RB sets used, thereby ensuring power stability and improving synchronization performance. When the S-SSB power on the non-anchor RB set is determined based on the second offset value or pre-configuration, the stability of the S-SSB power on the non-anchor RB set can be additionally guaranteed, so that terminal devices capable of receiving multiple S-SSBs in parallel can achieve better synchronization performance.

[0309] In the embodiment of the present application, if the total power of multiple S-SSBs sent on the first time domain resource exceeds P CMAX , the transmission power of each S-SSB can be reallocated in descending order of priority so that the total power of multiple S-SSBs is no higher than P CMAX Reassigning transmit power in descending order can also be understood as rolling back transmit power. The power of S-SSBs ranked later in the priority order (lower priority) is rolled back or reduced first. When allocating, rolling back, or reducing transmit power, the power of S-SSBs of the same priority level is uniformly reduced simultaneously, or the manner of reduction depends on the implementation of the terminal device.

[0310] It can be understood that the transmit power is reallocated in descending order of priority, that is, the power is allocated to the first-ranked and higher-priority resource first; then the power is allocated to the second-ranked resource, and so on. Taking the S-SSB located in the first frequency domain resource and the S-SSB located in the second frequency domain resource as an example, the power requirement of the S-SSB located in the first frequency domain resource should be met first, and the power of the S-SSB located in the second frequency domain resource and / or other frequency domain resources should be reduced so that the total power does not exceed P CMAX Optionally, if the power of the S-SSB of the second frequency domain resource is reduced to 0, the total power is still higher than P CMAX , then reduce the power of the S-SSB located in the first frequency domain resource so that the total power does not exceed P CMAX In the embodiment of the present application, the order of descending priority is: S-SSB of the first frequency domain resource, S-SSB of the second frequency domain resource. In this way, the transmission power of the S-SSB of the anchor RB set can be prioritized.

[0311] It should be noted that the first terminal device determines the first power based on the first offset value, and it can also be considered that the first terminal device determines the first power based on the (pre) configuration. "Determination" includes direct determination / explicit determination, or indirect determination / implicit determination (that is, determination after certain calculations or processing). For example, the first terminal device determines the first power based on the (pre) configuration, which may mean that the first power is (pre) configured, or that the first power is obtained through calculation or processing based on the (pre) configured value. Other descriptions of "based on" in this application can be interpreted with reference to this paragraph.

[0312] Through method 1000, it is possible to ensure that the total power of multiple S-SSBs transmitted on the first time domain resource does not exceed the maximum transmit power of the first terminal device. It is also possible to stabilize the RSRP of the first terminal device in each S-SSB time slot, reduce the number of synchronization source switching times at the receiving end, and improve synchronization performance. In addition, when the receiving terminal device only receives S-SSBs of the ARFCN or anchor RB set, determining an appropriate offset value through method 900 can prioritize the power of the S-SSBs of the ARFCN or anchor RB set to ensure synchronization signal coverage and synchronization performance.

[0313] In the embodiments provided in this application, the methods provided in the embodiments of this application are introduced from the perspective of the interaction between the first terminal device and the second terminal device. The steps performed by the terminal device can be implemented by different functional entities that constitute the terminal device. In order to implement the various functions of the methods provided in the above embodiments of this application, the terminal device may include a hardware structure and / or a software module, and implement the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether one of the above functions is implemented in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0314] The following describes the communication device used to implement the above method in the embodiment of the present application with reference to the accompanying drawings. Therefore, the above contents can be used in subsequent embodiments, and repeated contents will not be repeated.

[0315] Figure 11 is a schematic block diagram of a communication device 1100 provided in an embodiment of the present application. The communication device 1100 may be a terminal device in the above-described embodiments. For example, the communication device 1100 may be the terminal device in Figure 1(a) or the vehicle in Figure 1(b); alternatively, the communication device 1100 may be a chip (system) in the terminal device, or a software module in the terminal device. The communication device 1100 may implement the functions or steps implemented by the terminal device in the above-described method embodiments. The communication device 1100 may include a processing module 1110 and a transceiver module 1120. Optionally, it may also include a storage module, which may be used to store instructions (code or program) and / or data. The storage module may be, for example, a memory. The processing module 1110 and the transceiver module 1120 may be coupled to the storage module. For example, the processing module 1110 may read the instructions (code or program) and / or data in the storage module to implement the corresponding method. When the communication device 1100 is a chip in the terminal device, the storage module may be a storage module within the chip, such as a register or cache. For example, the storage module may also be a storage module located outside the chip within the network device / terminal device, such as a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM), etc. The above-mentioned units may be independently provided or partially or fully integrated.

[0316] In one possible implementation, the processing module 1110 may be a processor or controller, such as a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like. The transceiver module 1120 is a transceiver, an interface circuit, a bus, a pin, or other possible communication interface for receiving signals from other devices. For example, when the device is implemented in the form of a chip, the transceiver module 1120 is an interface circuit for the chip to receive signals from other chips or devices, or an interface circuit for the chip to send signals to other chips or devices.

[0317] The communication device 1100 can implement the behaviors and functions of the terminal device in the above-mentioned method embodiments. The communication device 1100 can be a terminal device, or a component (such as a chip or circuit) used in a terminal device, or a chip or chipset in the terminal device, or a part of a chip used to perform the functions of the relevant method, or a software module capable of implementing the method performed by the terminal device in the above-mentioned method (such as any method in methods 300-900), without limitation.

[0318] In a possible implementation, the communication device 1100 implements the method performed by the first terminal device in the embodiment of the present application. Alternatively, the communication device 1100 implements the method performed by the second terminal device in the embodiment of the present application.

[0319] Exemplarily, the communication device 1100 implements the method performed by the first terminal device in the embodiment of FIG. 3 . The transceiver module 1120 can be used to perform S301 in the embodiment shown in FIG. 3 and / or other processes supporting the techniques described herein; the processing module 1110 can be used to perform other processes of the techniques described herein. For example, the processing module 1110 is used to determine a sideline synchronization signal block, where the sideline synchronization signal block includes first indication information, where the first indication information is used to determine whether the sideline synchronization signal block is used for synchronization or beam training. The transceiver module 1120 is used to transmit the sideline synchronization signal block. Alternatively, the communication device 1100 implements the method performed by the second terminal device in the embodiment of FIG. 3 . The transceiver module 1120 can be used to perform S301 in the embodiment shown in FIG. 3 and / or other processes supporting the techniques described herein; the processing module 1110 can be used to perform S302 in the embodiment shown in FIG. 3 and / or other processes performing the techniques described herein. For example, the transceiver module 1120 is configured to receive a sideline synchronization signal block, where the sideline synchronization signal block includes first indication information, where the first indication information is used to determine whether the sideline synchronization signal block is used for synchronization or beam training. The processing module 1110 is configured to perform synchronization or beam training / beam alignment based on the sideline synchronization signal block.

[0320] It should be understood that the communication device 1100 can be used to implement the steps performed by the first terminal device or the second terminal device in the communication method 300. The relevant features can be referred to the various embodiments above and will not be repeated here.

[0321] For example, communication device 1100 implements the method performed by the first terminal device in the embodiment of FIG. 4 . Transceiver module 1120 can be used to perform S401 in the embodiment shown in FIG. 4 and / or other processes supporting the techniques described herein; processing module 1110 can be used to perform other processes described herein. For example, processing module 1110 is used to determine a sideline synchronization signal block, and the resources of the sideline synchronization signal block can be used to determine whether the sideline synchronization signal block is used for synchronization or beam training. Transceiver module 1120 is used to transmit the sideline synchronization signal block. Alternatively, communication device 1100 implements the method performed by the second terminal device in the embodiment of FIG. 4 . Transceiver module 1120 can be used to perform S401 in the embodiment shown in FIG. 4 and / or other processes supporting the techniques described herein; processing module 1110 can be used to perform S402 in the embodiment shown in FIG. 4 and / or other processes performing the techniques described herein. For example, transceiver module 1120 is used to receive the sideline synchronization signal block, and the resources of the sideline synchronization signal block can be used to determine whether the sideline synchronization signal block is used for synchronization or beam training. The processing module 1110 is configured to perform synchronization or beam training according to resources of the sidelink synchronization signal block.

[0322] It should be understood that the communication device 1100 can be used to implement the steps performed by the first terminal device or the second terminal device in the communication method 400. The relevant features can be referred to the various embodiments above and will not be repeated here.

[0323] For example, communication device 1100 implements the method performed by the first terminal device in the embodiment of FIG. 8 . Transceiver module 1120 can be used to perform S801 in the embodiment shown in FIG. 8 and / or other processes supporting the techniques described herein; processing module 1110 can be used to perform other processes described herein. For example, processing module 1110 is used to determine a sidelink synchronization signal block, which includes an application layer identifier. Transceiver module 1120 is used to transmit the sidelink synchronization signal block. Alternatively, communication device 1100 implements the method performed by the second terminal device in the embodiment of FIG. 8 . Transceiver module 1120 can be used to perform S801 in the embodiment shown in FIG. 8 and / or other processes supporting the techniques described herein; processing module 1110 can be used to perform S802 in the embodiment shown in FIG. 8 and / or other processes performing the techniques described herein. For example, transceiver module 1120 is used to receive the sidelink synchronization signal block, which includes an application layer identifier. The processing module 1110 is configured to perform beam alignment with the first terminal device according to the application layer identifier and the sidelink synchronization signal block.

[0324] It should be understood that the communication device 1100 can be used to implement the steps performed by the first terminal device or the second terminal device in the communication method 800. The relevant features can be referred to the various embodiments above and will not be repeated here.

[0325] Exemplarily, the communication device 1100 implements the method executed by the first terminal device in the embodiment of Figure 9. The transceiver module 1120 can be used to execute S901 in the embodiment shown in Figure 9, and / or to support other processes of the technology described herein; the processing module 1110 can be used to execute other processes of the technology described herein. For example, the processing module 1110 is used to obtain N time units for MCSt, and to send a first transmission block within the first time unit of the N time units. The first transmission block includes at least one logical channel, and the at least one logical channel is determined from all logical channels to be sent in a first order according to priority and CAPC. The transceiver module 1120 is used to send the at least one logical channel.

[0326] It should be understood that the communication device 1100 can be used to implement the steps performed by the first terminal device or the second terminal device in the communication method 900. The relevant features can be referred to the various embodiments above and will not be repeated here.

[0327] It should be understood that the communication device 1100 can be used to implement the steps performed by the first terminal device or the second terminal device in one or more methods of the communication method 300 to the communication method 1000. The relevant features can be referred to the various embodiments above and will not be repeated here.

[0328] When the communication device 1100 is a chip-type device or circuit, the transceiver module may be an input / output circuit and / or a communication interface; the processing module may be an integrated processor or microprocessor or integrated circuit.

[0329] Figure 12 is a schematic block diagram of a communication device 1200 provided in an embodiment of the present application. The communication device 1200 can be the terminal device in the above embodiment. For example, the communication device 1200 can be the terminal device in Figure 1(a), the vehicle in Figure 1(b), etc.; or the communication device 1200 is a chip (system) in the terminal device. In the embodiment of the present application, the chip system can be composed of chips, or it can include chips and other discrete devices. For specific functions, please refer to the description in the above method embodiment.

[0330] The communication device 1200 includes one or more processors 1201, which are used to implement or support the communication device 1200 to implement the functions of the terminal device in the method provided in the embodiment of the present application. Please refer to the detailed description in the method example for details, which will not be repeated here. The processor 1201 can also be called a processing unit or a processing module, which can implement certain control functions. The processor 1201 can be a general-purpose processor or a dedicated processor. For example, it includes: a baseband processor, a central processing unit, an application processor, a modem processor, a graphics processor, an image signal processor, a digital signal processor, a video codec processor, a controller, a memory, and / or a neural network processor. The baseband processor can be used to process communication protocols and communication data. The central processing unit can be used to control the communication device 1200 (such as a terminal device), execute software programs and / or process data. Different processors can be independent devices or integrated into one or more processors, for example, integrated into one or more dedicated integrated circuits.

[0331] In one design, the processor 1201 may include a program 1203 (sometimes also referred to as code or instructions), which may be executed on the processor 1201 to cause the communication device 1200 to perform the methods described in the following embodiments. In another possible design, the communication device 1200 includes circuitry (not shown in FIG12 ) configured to implement the terminal device functions described in the above embodiments.

[0332] In one design, the communication device 1200 may include one or more memories 1202 on which a program 1204 (sometimes also referred to as code or instructions) is stored. The program 1204 can be run on the processor 1201, so that the communication device 1200 performs the method described in the above method embodiment, such as the process shown in Figures 3, 4, 8, 9 and one or more of Figures 10.

[0333] In one design, the processor 1201 and / or the memory 1202 may include an artificial intelligence (AI) module 1207 and an AI module 12010, each configured to implement AI-related functions. The AI ​​module may be implemented using software, hardware, or a combination of software and hardware. For example, the AI ​​module may include a RAN intelligent controller (RIC) module. For example, the AI ​​module may be a near-real-time RIC or a non-real-time RIC.

[0334] In a possible design, data may also be stored in the processor 1201 and / or the memory 1202. The processor and memory may be provided separately or integrated together.

[0335] In one possible design, the communication device 1200 may further include a transceiver 1205 and / or an antenna 1206. The processor 1201 may also be sometimes referred to as a processing unit, and controls the communication device 1200. The transceiver 1205 may also be sometimes referred to as a transceiver unit, a transceiver, a transceiver circuit, or a transceiver, and is configured to implement the transceiver function of the communication device through the antenna 1206.

[0336] In one possible design, the communication device 1200 may further include one or more of the following components: a wireless communication module, an audio module, an external memory interface, an internal memory, a universal serial bus (USB) interface, a power management module, an antenna, a speaker, a microphone, an input / output module, a sensor module, a motor, a camera, or a display screen, etc. It will be appreciated that in some embodiments, the communication device 1200 may include more or fewer components, or some components may be integrated or separated. These components may be implemented in hardware, software, or a combination of software and hardware.

[0337] The communication device in the above embodiments can be a terminal device, a circuit, a chip used in a terminal device, or other combined devices, components, etc. having the above terminal devices. When the communication device is a terminal device, the transceiver module can be a transceiver, which can include an antenna and a radio frequency circuit, etc., and the processing module can be a processor, such as a CPU. When the communication device is a component having the functions of the above terminal device, the transceiver module can be a radio frequency unit, and the processing module can be a processor. When the communication device is a chip system, the communication device can be an FPGA, a dedicated ASIC, a system on chip (SoC), a CPU, a network processor (NP), a DSP, a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated circuit. The processing module can be the processor of the chip system. The transceiver module or communication interface can be the input / output interface or interface circuit of the chip system. For example, the interface circuit can be a code / data read / write interface circuit. The interface circuit can be used to receive code instructions (the code instructions are stored in a memory and can be read directly from the memory or read from the memory via another device) and transmit them to the processor; the processor can be used to execute the code instructions to perform the method in the above method embodiment. For example, the interface circuit can also be a signal transmission interface circuit between a communication processor and a transceiver.

[0338] An embodiment of the present application also provides a communication system. Specifically, the communication system includes multiple terminal devices. Exemplarily, the communication system includes multiple terminal devices for implementing the functions related to Figure 3. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to Figure 4. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to Figure 8. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to Figure 9. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to Figure 10. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to communication method 500. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to communication method 600. Alternatively, the communication system includes multiple terminal devices for implementing the functions related to communication method 700. Please refer to the relevant description in the above method embodiment for details, which will not be repeated here.

[0339] In an embodiment of the present application, a computer-readable storage medium is also provided, comprising instructions, which, when executed on a computer, causes the computer to execute the method executed by the first terminal device or the second terminal device in Figure 3, Figure 4, Figure 8, Figure 9 or Figure 10; or, causes the computer to execute the method executed by the first terminal device or the second terminal device in one or more communication methods from communication method 300 to communication method 1000.

[0340] A computer program product is also provided in an embodiment of the present application, comprising instructions, which, when executed on a computer, causes the computer to execute the method executed by the first terminal device or the second terminal device in Figure 3, Figure 4, Figure 8, Figure 9 or Figure 10; or, causes the computer to execute the method executed by the first terminal device or the second terminal device in one or more communication methods from communication method 300 to communication method 1000.

[0341] The embodiment of the present application provides a chip system, which includes a processor and may also include a memory, for implementing the functions of the terminal device or network device in the above method. The chip system can be composed of a chip or include a chip and other discrete devices.

[0342] To implement the functions of the communication device shown in Figures 11 and 12 above, embodiments of the present application further provide a chip including a processor for supporting the communication device in implementing the functions of the terminal device in the above method embodiments. In one possible design, the chip is connected to or includes a memory, which is used to store computer programs, instructions, and data necessary for the communication device.

[0343] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned 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.

[0344] Those skilled in the art will appreciate that the various illustrative logical blocks and steps described in conjunction with the embodiments disclosed herein can be implemented using electronic hardware, computer software, 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. Professionals and technicians may 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.

[0345] 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.

[0346] 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.

[0347] 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.

[0348] 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 part that essentially contributes to the technical solution of the present application or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or 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 RAM, a magnetic disk or an optical disk.

[0349] Obviously, those skilled in the art may make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

Claims

1. A communication method, characterized in that: Applied to a first terminal device, the method includes: Determine a sideline synchronization signal block, where the sideline synchronization signal block includes first indication information, and the first indication information or a resource of the sideline synchronization signal block is used to determine that the sideline synchronization signal block is used for synchronization or beam training; Send the sideline synchronization signal block.

2. The method according to claim 1, characterized in that The first indication information is used to determine that the sideline synchronization signal block is used for synchronization or beam training, and the first indication information is carried in the master information block MIB included in the sideline synchronization signal block.

3. The method according to claim 2, characterized in that When the first indication information is used to determine that the side synchronization signal block is used for beam training, the MIB also includes a first terminal identifier.

4. The method according to claim 3, characterized in that The first terminal identifier is used for beam training.

5. The method according to claim 1, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for synchronization or beam training, and the first indication information is carried by the first synchronization signal identifier carried by the side synchronization signal block, wherein when the value of the first synchronization signal identifier is within a first range, the first indication information indicates that the side synchronization signal block is used for synchronization; when the value of the first synchronization signal identifier is within a second range, the first indication information indicates that the side synchronization signal block is used for beam training.

6. The method according to claim 5, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for beam training, and the side synchronization signal block also includes a first terminal identifier, and the first terminal identifier is carried in the MIB included in the side synchronization signal block; or, the first indication information is also used to indicate the first terminal identifier.

7. The method according to claim 1, characterized in that Sending the side synchronization block comprises: The sideline synchronization signal block is used for synchronization, and the sideline synchronization signal is sent on the first resource; or, The sideline synchronization signal block is used for beam training, and the sideline synchronization signal is sent on the second resource.

8. The method according to claim 7, characterized in that The first resource belongs to a first resource set, and the second resource belongs to a second resource set, wherein the resources in the first resource set are used to transmit side synchronization signal blocks for synchronization, and the resources in the second resource set are used to transmit side synchronization signal blocks for beam training.

9. The method according to claim 7 or 8, characterized in that The structure of the sideline synchronization signal block used for beam training is different from the structure of the sideline synchronization signal block used for synchronization.

10. The method according to claim 7, characterized in that The sideline synchronization signal block includes a first terminal identifier; The first terminal identifier is carried in the MIB of the sideline synchronization signal block; or The first terminal identifier carries a first synchronization signal identifier carried by the side synchronization signal block, the first synchronization signal identifier belongs to a synchronization signal identifier set, and the synchronization signal identifiers in the synchronization signal identifier set are used to indicate the type of synchronization source.

11. The method according to claim 10, characterized in that The sideline synchronization signal block includes a beam index, and the beam index is the beam index of each sideline primary synchronization signal S-PSS or sideline secondary synchronization signal S-SSS included in the sideline synchronization signal block, or the beam index is the beam index of the first S-PSS or the first S-SSS included in the sideline synchronization signal block.

12. The method according to any one of claims 1 to 11, characterized in that: The first terminal device needs to establish a unicast link with at least one second terminal device, and the sideline synchronization signal block also includes an application layer identifier.

13. The method according to claim 12, characterized in that The sideline synchronization signal block also includes beam information, and the beam information is used to indicate the beam index of the sideline synchronization signal block.

14. The method according to claim 12 or 13, characterized in that The sideline synchronization signal block further includes a type identifier of a service of the first terminal device.

15. The method according to any one of claims 1 to 14, characterized in that: The first terminal device does not need to establish a unicast link with any terminal device, and the side synchronization signal block includes a default application layer identifier and / or a default service type identifier, and the default application layer identifier and / or the default service type identifier are used to indicate that the side synchronization signal block is used for synchronization.

16. A communication method, characterized in that: Applied to a second terminal device, the method includes: receiving a sideline synchronization signal block, where the sideline synchronization signal block includes first indication information, and the first indication information or a resource of the sideline synchronization signal block is used to determine that the sideline synchronization signal block is used for synchronization or beam training; Synchronization or beam alignment is performed according to the sideline synchronization signal block.

17. The method according to claim 16, characterized in that The first indication information is used to determine that the sideline synchronization signal block is used for synchronization or beam training, and the first indication information is carried in the master information block MIB included in the sideline synchronization signal block.

18. The method according to claim 17, characterized in that When the first indication information is used to determine that the side synchronization signal block is used for beam training, the MIB also includes a first terminal identifier.

19. The method according to claim 16, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for synchronization or beam training, and the first indication information is carried by the first synchronization signal identifier carried by the side synchronization signal block, wherein when the value of the first synchronization signal identifier is within a first range, the first indication information indicates that the side synchronization signal block is used for synchronization; when the value of the first synchronization signal identifier is within a second range, the first indication information indicates that the side synchronization signal block is used for beam training.

20. The method of claim 19, wherein: The first indication information is used to indicate that the side synchronization signal block is used for beam training, and the side synchronization signal block also includes a first terminal identifier, and the first terminal identifier is carried in the MIB included in the side synchronization signal block; or, the first indication information is also used to indicate the first terminal identifier.

21. The method of claim 16, wherein: Sending the side synchronization block comprises: The sideline synchronization signal block is used for synchronization, and the sideline synchronization signal is sent on the first resource; or, The sideline synchronization signal block is used for beam training, and the sideline synchronization signal is sent on the second resource.

22. The method according to claim 21, characterized in that The first resource belongs to a first resource set, and the second resource belongs to a second resource set, wherein the resources in the first resource set are used to transmit side synchronization signal blocks for synchronization, and the resources in the second resource set are used to transmit side synchronization signal blocks for beam training.

23. The method according to claim 21 or 22, characterized in that The structure of the sideline synchronization signal block used for beam training is different from the structure of the sideline synchronization signal block used for synchronization.

24. The method according to any one of claims 16 to 23, characterized in that: The first terminal device needs to establish a unicast link with at least one second terminal device, and the sideline synchronization signal block also includes an application layer identifier.

25. The method of claim 24, wherein: The sideline synchronization signal block further includes a type identifier of a service of the first terminal device.

26. A communication device, characterized in that: include: a processing module, configured to determine a sideline synchronization signal block, wherein the sideline synchronization signal block includes first indication information, and the first indication information or a resource of the sideline synchronization signal block is used to determine that the sideline synchronization signal block is used for synchronization or beam training; The transceiver module is used to send the side synchronization signal block.

27. The device according to claim 26, characterized in that The first indication information is used to determine that the sideline synchronization signal block is used for synchronization or beam training, and the first indication information is carried in the master information block MIB included in the sideline synchronization signal block.

28. The device according to claim 27, characterized in that When the first indication information is used to determine that the side synchronization signal block is used for beam training, the MIB also includes a first terminal identifier.

29. The device according to claim 28, characterized in that The first terminal identifier is used for beam training.

30. The device according to claim 26, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for synchronization or beam training, and the first indication information is carried by the first synchronization signal identifier carried by the side synchronization signal block, wherein when the value of the first synchronization signal identifier is within a first range, the first indication information indicates that the side synchronization signal block is used for synchronization; when the value of the first synchronization signal identifier is within a second range, the first indication information indicates that the side synchronization signal block is used for beam training.

31. The device according to claim 30, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for beam training, and the side synchronization signal block also includes a first terminal identifier, and the first terminal identifier is carried in the MIB included in the side synchronization signal block; or, the first indication information is also used to indicate the first terminal identifier.

32. The device according to claim 26, characterized in that Sending the side synchronization block comprises: The sideline synchronization signal block is used for synchronization, and the sideline synchronization signal is sent on the first resource; or, The sideline synchronization signal block is used for beam training, and the sideline synchronization signal is sent on the second resource.

33. The device according to claim 32, characterized in that The first resource belongs to a first resource set, and the second resource belongs to a second resource set, wherein the resources in the first resource set are used to transmit side synchronization signal blocks for synchronization, and the resources in the second resource set are used to transmit side synchronization signal blocks for beam training.

34. The device according to claim 32 or 33, characterized in that The structure of the sideline synchronization signal block used for beam training is different from the structure of the sideline synchronization signal block used for synchronization.

35. The device according to claim 32, characterized in that The sideline synchronization signal block includes a first terminal identifier; The first terminal identifier is carried in the MIB of the sideline synchronization signal block; or The first terminal identifier is carried in the first synchronization signal identifier carried by the side synchronization signal block, and the first synchronization signal identifier belongs to In a synchronization signal identifier set, the synchronization signal identifier in the synchronization signal identifier set is used to indicate the type of synchronization source.

36. The device according to claim 35, characterized in that The sideline synchronization signal block includes a beam index, and the beam index is the beam index of each sideline primary synchronization signal S-PSS or sideline secondary synchronization signal S-SSS included in the sideline synchronization signal block, or the beam index is the beam index of the first S-PSS or the first S-SSS included in the sideline synchronization signal block.

37. The device according to any one of claims 26 to 36, characterized in that The communication device needs to establish a unicast link with at least one second terminal device, and the sideline synchronization signal block also includes an application layer identifier.

38. The device according to claim 37, characterized in that The sideline synchronization signal block also includes beam information, and the beam information is used to indicate the beam index of the sideline synchronization signal block.

39. The device according to claim 37 or 38, characterized in that The sideline synchronization signal block also includes a type identifier of the service of the communication device.

40. The device according to any one of claims 26 to 39, characterized in that The communication device does not need to establish a unicast link with any terminal device, and the side synchronization signal block includes a default application layer identifier and / or a default service type identifier, and the default application layer identifier and / or the default service type identifier are used to indicate that the side synchronization signal block is used for synchronization.

41. A communication device, characterized in that: The method comprises: A transceiver module, used for receiving a side synchronization signal block, where the side synchronization signal block includes first indication information, and the first indication information or a resource of the side synchronization signal block is used to determine whether the side synchronization signal block is used for synchronization or beam training; A processing module is used to perform synchronization or beam alignment according to the side synchronization signal block.

42. The device according to claim 41, characterized in that The first indication information is used to determine that the sideline synchronization signal block is used for synchronization or beam training, and the first indication information is carried in the master information block MIB included in the sideline synchronization signal block.

43. The device according to claim 42, characterized in that When the first indication information is used to determine that the side synchronization signal block is used for beam training, the MIB also includes a first terminal identifier.

44. The device according to claim 41, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for synchronization or beam training, and the first indication information is carried by the first synchronization signal identifier carried by the side synchronization signal block, wherein when the value of the first synchronization signal identifier is within a first range, the first indication information indicates that the side synchronization signal block is used for synchronization; when the value of the first synchronization signal identifier is within a second range, the first indication information indicates that the side synchronization signal block is used for beam training.

45. The device according to claim 44, characterized in that The first indication information is used to indicate that the side synchronization signal block is used for beam training, and the side synchronization signal block also includes a first terminal identifier, and the first terminal identifier is carried in the MIB included in the side synchronization signal block; or, the first indication information is also used to indicate the first terminal identifier.

46. ​​The device according to claim 41, characterized in that Sending the side synchronization block comprises: The sideline synchronization signal block is used for synchronization, and the sideline synchronization signal is sent on the first resource; or, The sideline synchronization signal block is used for beam training, and the sideline synchronization signal is sent on the second resource.

47. The device according to claim 46, characterized in that The first resource belongs to a first resource set, and the second resource belongs to a second resource set, wherein the resources in the first resource set are used to transmit side synchronization signal blocks for synchronization, and the resources in the second resource set are used to transmit side synchronization signal blocks for beam training.

48. The device according to claim 46 or 47, characterized in that The structure of the sideline synchronization signal block used for beam training is different from the structure of the sideline synchronization signal block used for synchronization.

49. The device according to any one of claims 41 to 48, characterized in that The first terminal device needs to establish a unicast link with at least one of the communication devices, and the sideline synchronization signal block also includes an application layer identifier.

50. The device according to claim 49, characterized in that The sideline synchronization signal block further includes a type identifier of a service of the first terminal device.

51. A communication device, characterized in that: The device comprises a processor configured to execute one or more computer programs or instructions so that the communication device performs the method according to any one of claims 1 to 15, or the communication device performs the method according to any one of claims 16 to 25.

52. A communication system, characterized in that: The method comprises a first communication device and a second communication device, wherein the first communication device is used to execute the method according to any one of claims 1 to 15, and the second communication device is used to execute the method according to any one of claims 16 to 25.

53. A computer-readable storage medium, characterized in that: A computer program or instruction is stored, wherein the computer program or instruction is used to implement the method according to any one of claims 1 to 15, or to implement the method according to any one of claims 16 to 25.

54. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is run on a computer, the computer is caused to perform the method according to any one of claims 1 to 15, or the computer is caused to perform the method according to any one of claims 16 to 25.

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