Direct link synchronization method, device and equipment

Abstract

The invention provides a direct link synchronization method, device and equipment. The method is applied to a first device, and comprises: sending a first synchronization channel to a second device, the first synchronization channel carrying first synchronization information; wherein the first synchronization channel comprises at least one of the following items: a first physical straight-through link control channel (PSCCH), a first physical straight-through link shared channel (PSSCH), a first straight-through link positioning reference signal (SL-PRS) and a first physical straight-through link feedback channel (PSFCH). According to the scheme of the invention, the second device can realize the synchronization process of the straight-through link without GNSS coverage.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular, to a method, apparatus, and device for synchronizing a direct link. Background Art

[0002] Currently, the synchronization scheme for the New Radio (NR) Sidelink (SL) mainly uses the sidelink Synchronization Signal (S-SS) / Physical sidelink broadcast channel (PSBCH) block. The synchronized UE sends the S-SS / PSBCH, and the receiving UE performs synchronization measurement on the PSS / SSS carried by the S-SS / PSBCH. After the receiving UE is synchronized and aligned, it decodes the corresponding PSBCH to obtain the corresponding synchronization information, and finally completes the synchronization process.

[0003] However, in the actual NR SL deployment, considering that most scenarios are covered by the Global Navigation Satellite System (GNSS), it is very likely that the S-SS / PSBCH block dedicated to synchronization will no longer be introduced. Therefore, in the case of no GNSS coverage, how to implement the direct link synchronization process needs to be further designed. Summary of the Invention

[0004] The present invention provides a method, apparatus, and device for synchronizing a direct link, which solves the problem of how to implement the direct link synchronization process in the case of no GNSS coverage.

[0005] In a first aspect, an embodiment of the present invention provides a method for synchronizing a direct link, which is applied to a first device and includes:

[0006] Sending a first synchronization channel to a second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first Physical Sidelink Control Channel (PSCCH), a first Physical Sidelink Shared Channel (PSSCH), a first Sidelink Positioning Reference Signal (SL-PRS), and a first Physical Sidelink Feedback Channel (PSFCH).

[0007] Optionally, sending the first synchronization channel to the second device includes:

[0008] Sending the first synchronization channel on a target resource in a first resource set; wherein the target resource is one of the following:

[0009] Resources corresponding to any time slot number;

[0010] Resources corresponding to a specific time slot number;

[0011] Resources corresponding to any time slot number belonging to a set of specific time slot numbers.

[0012] Optionally, the above direct link synchronization method further includes:

[0013] When the first synchronization channel includes a first PSCCH and a first PSSCH, generating a demodulation reference signal DMRS of the first PSCCH and / or the DMRS of the first PSSCH using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH or the first PSSCH, where the target resource is the transmission resource of the first synchronization channel; or

[0014] When the first synchronization channel includes the first PSCCH and a first SL-PRS, generating the DMRS of the first PSCCH and the first SL-PRS using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH; or

[0015] When the first synchronization channel includes the first PSCCH and a first SL-PRS, generating the DMRS of the first PSCCH using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH; or

[0016] When the first synchronization channel includes the first PSCCH, the first PSSCH, and a first PSFCH, indicating the time slot number corresponding to the target resource through the first PSFCH; or

[0017] When the first synchronization channel includes a first PSFCH, indicating the time slot number corresponding to the target resource through the first PSFCH.

[0018] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0019] Optionally, when the first synchronization channel includes the first PSFCH, sending the first synchronization channel to the second device includes:

[0020] Sending the first PSFCH on a first resource subset;

[0021] Sending a second PSFCH on a second resource subset; wherein, the second PSFCH is generated using a preconfigured sequence;

[0022] wherein, the first PSFCH and the second PSFCH include one or more PSFCHs;

[0023] The first resource subset and the second resource subset belong to a first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain.

[0024] Optionally, a synchronization flag is carried in the first synchronization channel, and the synchronization flag is used to indicate that the first synchronization channel is used for the synchronization process.

[0025] Optionally, after sending the first synchronization channel to the second device, the method further includes:

[0026] Receiving a second synchronization channel sent by the second device;

[0027] Performing timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0028] Sending a third synchronization channel to the second device, where second synchronization information is carried in the third synchronization channel; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH.

[0029] In a second aspect, an embodiment of the present invention provides a direct link synchronization method applied to a second device, including:

[0030] Receiving a first synchronization channel sent by a first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH;

[0031] Obtaining first synchronization information carried in the first synchronization channel;

[0032] Performing a first synchronization process according to the first synchronization information.

[0033] Optionally, obtaining the first synchronization information carried in the first synchronization channel includes:

[0034] Obtain the time slot number corresponding to the target resource, where the target resource is the transmission resource of the first synchronization channel;

[0035] Decode the first synchronization channel according to the time slot number corresponding to the target resource to obtain the first synchronization information.

[0036] Optionally, before obtaining the time slot number corresponding to the target resource, the method further includes:

[0037] Determine the rising edge and / or falling edge of the energy change according to the energy measurement result;

[0038] Determine the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0039] Optionally, obtaining the time slot number corresponding to the target resource includes one of the following:

[0040] Traverse all time slot numbers, perform blind detection on the DMRS of the first synchronization channel to determine the time slot number corresponding to the target resource; or

[0041] Determine a specific time slot number as the time slot number corresponding to the target resource; or

[0042] Traverse the time slot numbers in a specific set of time slot numbers, perform blind detection on the DMRS of the first synchronization channel to determine the time slot number corresponding to the target resource;

[0043] Decode the first synchronization channel using a preset time slot number to obtain the time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH;

[0044] When the first synchronization channel includes at least the first PSFCH, detect the first PSFCH according to the energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0045] Optionally, when the first synchronization channel includes the first PSCCH and the first SL-PRS, determining the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot includes:

[0046] Determine the start boundary and / or end boundary of the time slot where it is located according to the rising edge and / or falling edge of the energy change, the start symbol position and symbol number configuration of the first PSCCH in the time slot, and the configuration information of the SL-PRS resource in the time slot.

[0047] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0048] Optionally, when the first synchronization channel includes at least the first PSFCH, determining the start boundary of the time slot according to the rising edge and / or falling edge, and the start symbol position and number of symbols of the first synchronization channel in the time slot, includes:

[0049] Determine the start boundary and / or end boundary of the time slot where it is located according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

[0050] Optionally, when the first synchronization channel includes the first PSFCH, receiving the first synchronization channel sent by the first device includes:

[0051] Receiving the first PSFCH sent by the first device on a first resource subset;

[0052] Receiving a second PSFCH sent by the first device on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence; wherein, the first resource subset and the second resource subset belong to the first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain; the first PSFCH and the second PSFCH include one or more PSFCHs;

[0053] The method further includes:

[0054] Perform frequency synchronization according to the second PSFCH.

[0055] Optionally, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for the synchronization process.

[0056] Optionally, after receiving the first synchronization channel sent by the first device, the method further includes:

[0057] Sending a second synchronization channel to the first device;

[0058] Receiving a third synchronization channel sent by the first device, where the second synchronization information is carried in the third synchronization channel; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, a third PSFCH;

[0059] Perform a second synchronization process according to the second synchronization signal.

[0060] In a third aspect, an embodiment of the present invention provides a first device, including: a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the direct link synchronization method described in the first aspect are implemented.

[0061] In a fourth aspect, an embodiment of the present invention provides a second device, including: a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the direct link synchronization method described in the second aspect are implemented.

[0062] In a fifth aspect, an embodiment of the present invention provides a direct link synchronization device applied to a first device, including:

[0063] A first sending module, configured to send a first synchronization channel to a second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first physical sidelink control channel (PSCCH), a first physical sidelink shared channel (PSSCH), a first sidelink positioning reference signal (SL-PRS), and a first physical sidelink feedback channel (PSFCH).

[0064] In a sixth aspect, an embodiment of the present invention provides an application for a second device, including:

[0065] A second receiving module, configured to receive the first synchronization channel sent by the first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH;

[0066] A first obtaining module, configured to obtain the first synchronization information carried in the first synchronization channel;

[0067] A first synchronization processing module, configured to perform a first synchronization process according to the first synchronization information.

[0068] In a seventh aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the direct link synchronization method described in the first aspect or the second aspect are implemented.

[0069] The beneficial effects of the above technical solutions of the present invention are:

[0070] In the above solution, the first device sends a first synchronization channel to the second device, and the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first physical sidelink control channel (PSCCH), a first physical sidelink shared channel (PSSCH), a first sidelink positioning reference signal (SL-PRS), and a first physical sidelink feedback channel (PSFCH). In the solution of the present invention, the second device can achieve the synchronization process of the sidelink in the case of no GNSS coverage. Description of the Drawings

[0071] Figure 1 Fig. 1 shows one of the flowcharts of the sidelink synchronization method according to an embodiment of the present invention;

[0072] Figure 2 Fig. 2 shows one of the schematic diagrams of the target resource according to an embodiment of the present invention;

[0073] Figure 3 Fig. 3 shows another schematic diagram of the target resource according to an embodiment of the present invention;

[0074] Figure 4 Fig. 4 shows the schematic diagram of the PSFCH indicating the time slot number according to an embodiment of the present invention;

[0075] Figure 5 Fig. 5 shows another flowchart of the sidelink synchronization method according to an embodiment of the present invention;

[0076] Figure 6 Fig. 6 shows one of the schematic diagrams of the energy change waveform according to an embodiment of the present invention;

[0077] Figure 7 Fig. 7 shows another schematic diagram of the energy change waveform according to an embodiment of the present invention;

[0078] Figure 8 Fig. 8 shows another schematic diagram of the energy change waveform according to an embodiment of the present invention;

[0079] Figure 9 Fig. 9 shows another flowchart of the sidelink synchronization method according to an embodiment of the present invention;

[0080] Figure 10 Fig. 10 shows one of the block diagrams of the structure of the sidelink synchronization device according to an embodiment of the present invention;

[0081] Figure 11 Fig. 11 shows another block diagram of the structure of the sidelink synchronization device according to an embodiment of the present invention;

[0082] Figure 12 Fig. 12 shows the schematic diagram of the hardware structure of the first device according to an embodiment of the present invention;

[0083] Figure 13 Fig. 13 shows the schematic diagram of the hardware structure of the second device according to an embodiment of the present invention. Detailed implementation manners

[0084] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should clearly understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, descriptions of known functions and configurations are omitted for clarity and conciseness.

[0085] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present invention. Therefore, the "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0086] In various embodiments of the present invention, it should be understood that the magnitudes of the serial numbers of the following processes do not mean the order of execution is prior or subsequent, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0087] In addition, the terms "system" and "network" are often used interchangeably herein.

[0088] In the embodiments provided in the present application, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0089] First embodiment

[0090] As Figure 1 shown, the embodiment of the present invention provides a method for synchronizing a direct link, which is applied to a first device, and specifically includes the following steps:

[0091] Step 101: Send a first synchronization channel to a second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first physical direct link control channel PSCCH, a first physical direct link shared channel PSSCH, a first direct link positioning reference signal SL-PRS, and a first physical direct link feedback channel PSFCH.

[0092] Among them, the first device is a device that has completed synchronization. Its synchronization process can be synchronization performed by receiving a synchronization channel sent by other synchronized devices, or a synchronization process completed based on GNSS or a base station; the second device is a device without synchronization, with poor synchronization status, or in need of synchronization.

[0093] In an exemplary implementation, the first synchronization channel includes a first PSCCH and a first PSSCH.

[0094] In an exemplary implementation, the first synchronization channel includes a first PSCCH and a first SL-PRS.

[0095] In an exemplary implementation, the first synchronization channel includes a first PSCCH, a first PSSCH, and a first PSFCH.

[0096] In an exemplary implementation, the first synchronization channel includes a first PSFCH.

[0097] Optionally, the first synchronization information is carried by at least one of the following: the first-stage SCI (1st stage SCI), the second-stage SCI (2nd stage SCI), the Media Access Control (MAC) control element (CE), data, and the first PSFCH.

[0098] Among them, the first synchronization information includes at least one of the following:

[0099] Configuration information of time-division duplexing (TDD);

[0100] Judgment information on whether the first device is within the network coverage area;

[0101] Frame number information where the first synchronization channel is located;

[0102] Slot index information where the first synchronization channel is located;

[0103] Reserved bits;

[0104] Synchronization level of the first device;

[0105] ID information of the first device;

[0106] Coordinate information of the first device;

[0107] Coordinated Universal Time (UTC) information;

[0108] Timing adjustment amount of the first device;

[0109] The deviation estimation between the local timing of the first device and UTC;

[0110] The frequency deviation adjustment of the first device;

[0111] The deviation estimation between the local frequency of the first device and the reference frequency.

[0112] Optionally, the frame number information includes: system frame number (SFN) or direct frame number (DFN)

[0113] Exemplarily, the synchronization level of the first device includes [0, 255]; where 0 is the highest synchronization level, indicating synchronization based on GNSS, 1 is the second highest, and so on, 254 is the lowest; 255 indicates that the first device cannot provide synchronization services.

[0114] In the above embodiments, the second device can achieve the synchronization process of the direct link without GNSS coverage. Moreover, the synchronization process does not require dedicated synchronization resources to be allocated for the first synchronization channel, improving resource utilization.

[0115] In some embodiments, in step 101 above, sending the first synchronization channel to the second device includes:

[0116] Sending the first synchronization channel on the target resource in the first resource set; where the target resource is one of the following:

[0117] Resources corresponding to any slot number;

[0118] Resources corresponding to a specific slot number;

[0119] Resources corresponding to any slot number belonging to a specific set of slot numbers.

[0120] It should be noted that the first resource set can be a configured or pre-configured dedicated synchronization resource pool, or the first resource set is a resource pool composed of reserved time slots, or the first resource set can also belong to a normal communication resource pool.

[0121] It should be noted that the slot number refers to the slot number in each frame. For NR direct link devices, some specific resources need to be excluded from the actually available resources. Exemplarily, such as Figure 2The logical resources therein are the truly available first resource set. Since the second device receives the first synchronization channel, it is necessary to first determine the time slot number where the first synchronization channel is located. Therefore, in order to ensure that the second device can obtain relevant information about the time slot number when receiving the first synchronization channel, relevant mapping rules can be preset. For example, the first device can only send the first synchronization channel in a time slot with a specific time slot number = i, where i is a preset value.

[0122] Exemplarily, such as Figure 3 In, when the first synchronization channel includes the first PSFCH, taking 4 time slots in the resource pool with the first PSFCH period as an example, the first device can only send the first PSFCH in a time slot with a time slot number of i and where there is a PSFCH resource. The second device determines the time slot number corresponding to the transmission resource of the first PFSCH based on the detection of the first PSFCH; further, according to the time slot number, the first PSCCH is received.

[0123] It should be noted that if it is limited that the first device can only send the first synchronization channel in a specific time slot number, there may be a situation where the number of actually available resources is small or there are no resources at all. Therefore, the first device can send the first synchronization channel on the resources corresponding to any time slot number in a specific time slot number set, which can increase the number of actually available resources.

[0124] Correspondingly, since the second device does not know on which resource corresponding to which time slot number in the specific time slot number set the first device sends the first synchronization channel, it is necessary to perform blind detection on each possible time slot number value in the specific time slot number set. The specific blind detection method is: generating a local PSCCH DMRS sequence using different time slot numbers, and then performing correlation detection with the received PSCCH DMRS to obtain the time slot number corresponding to the target resource.

[0125] In some other embodiments, the above direct link synchronization method further includes one of the following:

[0126] Solution 1

[0127] In the case where the first synchronization channel includes the first PSCCH and the first PSSCH, the demodulation reference signal DMRS of the first PSCCH and / or the DMRS of the first PSSCH is generated using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH or the first PSSCH, where the target resource is the transmission resource of the first synchronization channel;

[0128] Optionally, the time slot number corresponding to the target resource is carried by the MAC CE carried by the first PSSCH or by the data, or by the reserved bits of the SCI in the first PSCCH.

[0129] It should be noted that the DMRS sequence generation process is related to the slot number corresponding to the actual transmission time slot. That is, if the second device does not have a synchronization state, it cannot know the slot number information of the first synchronization channel. Therefore, even if the slot boundaries are aligned, the subsequent channel estimation and decoding processes of the PSCCH and PSSCH cannot be completed. Based on this, in order to solve this problem in this embodiment, the DMRS of the first PSCCH and / or the DMRS of the first PSSCH adopt pre-configured slot numbers instead of actual slot numbers during the sequence initialization process, and the actual slot number (i.e., the slot number corresponding to the target resource) is carried in the first PSSCH or the first PSCCH.

[0130] Correspondingly, after the second device completes waveform synchronization, it performs channel estimation and decoding processes for the PSCCH / PSSCH according to the preset slot number, and finally obtains the real slot number.

[0131] Example 1: If the DMRS of the first PSSCH is generated using the preset slot number, a synchronization flag bit is carried in the first PSCCH, and the DMRS of the PSCCH is generated by the actual slot number; the first PSSCH or the first PSCCH carries the first synchronization information.

[0132] Example 2: If the DMRS of the first PSCCH is generated using the preset slot number, a synchronization flag bit is carried in the first PSCCH, and the DMRS of the PSSCH is generated by the actual slot number; the first PSSCH or the first PSCCH carries the first synchronization information.

[0133] Example 3: If the DMRS of the first PSCCH and the DMRS of the PSSCH are generated using the preset slot number, a synchronization flag bit is carried in the first PSCCH, and the first PSSCH or the first PSCCH carries the first synchronization information.

[0134] Solution 2

[0135] In the case where the first synchronization channel includes the first PSCCH and the first SL-PRS, the DMRS of the first PSCCH and the first SL-PRS are generated using the preset slot number, and the slot number corresponding to the target resource is carried in the first PSCCH;

[0136] Optionally, the slot number corresponding to the target resource is carried by the reserved bits in the Sidelink Control Information (SCI) format1-b carried by the first PSCCH.

[0137] It should be noted that when the first synchronization channel includes the first SL-PRS, it is required that each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0138] Optionally, to facilitate energy detection, the SL-PRS resource can be made adjacent in the time domain to the associated PSCCH.

[0139] It should be noted that the difference between Solution 2 and Solution 1 is that Solution 2 replaces the first PSSCH with the first SL-PRS. The advantage of Solution 2 is that the accuracy of subsequent timing measurements using the first SL-PRS is higher. However, since there is no PSSCH, the corresponding synchronization information can only be carried by the first PSCCH.

[0140] Solution 3

[0141] When the first synchronization channel includes the first PSCCH and the first SL-PRS, the DMRS of the first PSCCH is generated using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH.

[0142] It should be noted that when the first synchronization channel includes the first SL-PRS, it is required that each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0143] Optionally, to facilitate energy detection, the SL-PRS resource can be made adjacent in the time domain to the associated PSCCH.

[0144] It should be noted that in this Solution 3, the sequence initialization process of the first SL-PRS uses the actual time slot number (i.e., the time slot number corresponding to the target resource). The second device needs to first complete the decoding of the first PSCCH based on the preset time slot number before it can correctly receive the first SL-PRS.

[0145] Solution 4

[0146] When the first synchronization channel includes the first PSCCH, the first PSSCH, and the first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH.

[0147] Solution 5

[0148] When the first synchronization channel includes the first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH.

[0149] Optionally, when the first synchronization channel only includes the first PSFCH, the first synchronization information is carried by the first PSFCH.

[0150] Optionally, when the first synchronization channel only includes the first PSFCH, the first device or the third device may also send a PSCCH or a PSSCH to the second device for carrying part or all of the content in the first synchronization information. The PSCCH and the PSSCH may be located in the same time slot or different time slots from the PSFCH.

[0151] For the above solutions 4 and 5, when the first device indicates the time slot number corresponding to the target resource through the first PSFCH, the first PSFCH may include one or more PSFCHs. That is, the first device may send one PSFCH or multiple PSFCHs simultaneously on the preconfigured frequency domain resources. Correspondingly, the second device performs PSFCH detection on the preconfigured frequency domain resources; among them, since the generation of the PSFCH sequence is independent of the time slot number, it can be directly detected.

[0152] In specific implementation, the first PSFCH may use some or all of the information in the cyclic shift and RB index to indicate the time slot number of the target resource.

[0153] For example, referring to Figure 4 , taking the case where the first PSFCH is used to indicate a 7-bit time slot number as an example, the first device needs to send 7 PSFCHs on 7 preconfigured RBs. The PSFCH sequences on each RB can use different cyclic shift values to distinguish the state "0" or state "1".

[0154] It should be noted that the time domain resource of the PSFCH is determined by high-layer parameters or the preconfigured PSFCH period, and the PSFCH frequency domain resource is an RB at a fixed frequency domain index position configured by high-layer parameters. That is to say, when all devices indicate synchronization information such as the time slot number through the PSFCH, they share the same frequency domain resources.

[0155] For example, if N RBs are configured in the frequency domain for the transmission of the first PSFCH, and N is the number of time slots included in each frame, then the RB with RB index i in the N RBs corresponds to the time slot with time slot number i. The first device selects the corresponding RB from the N RBs for sending the first PSFCH according to the time slot number of the currently occupied resource. The second device then determines the time slot number where the first synchronization channel is received according to the RB index where the first PSFCH is detected.

[0156] For example, if N×M RBs are configured in the frequency domain for the transmission of the first PSFCH, N is the number of time slots included in each frame, N totalIndicates the number of PSFCH resources included in the resource pool or the number of configured or pre-configured PSFCH resources in the resource pool. That is, N total PSFCH resources are divided into M sets, and each set contains N RBs; among them, the RB with RB index i corresponds to the time slot with time slot number i.

[0157] It should be noted that when the first device sends the first PSFCH, it first determines the RB resource set for sending the first PSFCH in the M sets based on at least one of the identity information (such as including at least one of the following: source ID, destination ID) and the synchronization priority information; in this RB resource set, the specific RB for sending the first PSFCH is determined based on the time slot number of the target resource. Correspondingly, the second device determines the time slot number corresponding to the target resource based on the RB index of the first PSFCH detected in a PSFCH resource set.

[0158] In some embodiments, when the first synchronization channel includes the first PSFCH, in step 101 above, sending the first synchronization channel to the second device includes:

[0159] Sending the first PSFCH on a first resource subset;

[0160] Sending a second PSFCH on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence; the pre-configured sequence represents the initial value of the pre-configured sequence used for sequence generation;

[0161] Wherein, the first PSFCH and the second PSFCH include one or more PSFCHs;

[0162] The first resource subset and the second resource subset belong to a first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain.

[0163] In this embodiment, by generating the second PSFCH using a pre-configured sequence, the second device can perform sequence correlation search using the pre-configured sequence within the possible frequency range of the second PSFCH to complete frequency synchronization.

[0164] In some embodiments, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel is used for the synchronization process.

[0165] In this embodiment, the synchronization flag bit carried in the first synchronization channel can notify the second device that the first synchronization channel can be used for the synchronization process through the synchronization flag bit.

[0166] In some embodiments, after sending a first synchronization channel to a second device, the method further includes:

[0167] Receiving a second synchronization channel sent by the second device;

[0168] Performing a timing measurement based on the second synchronization channel to obtain a timing measurement result;

[0169] Sending a third synchronization channel to the second device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, a third PSFCH.

[0170] Optionally, the timing measurement result includes at least the propagation delay of the signal.

[0171] Wherein, the second synchronization information includes at least one of the following:

[0172] Configuration information of time division duplexing (TDD);

[0173] Judgment information on whether the first device is within the network coverage area;

[0174] Frame number information of the first synchronization channel;

[0175] Slot index information of the first synchronization channel;

[0176] The timing measurement result;

[0177] Reserved bits;

[0178] Synchronization level of the first device;

[0179] ID information of the first device;

[0180] Coordinate information of the first device;

[0181] Coordinated Universal Time (UTC) information;

[0182] Timing adjustment amount of the first device;

[0183] Estimated deviation amount between the local timing of the first device and UTC;

[0184] Frequency deviation adjustment amount of the first device;

[0185] Estimated deviation amount between the local frequency of the first device and the reference frequency.

[0186] In the above embodiments, by sending a third synchronization channel to the second device, the second device can perform a second synchronization process according to the second synchronization information carried in the third synchronization channel.

[0187] Second Embodiment

[0188] As Figure 5 shown, an embodiment of the present invention provides a method for synchronizing a direct link, which is applied to a second device and specifically includes the following steps:

[0189] Step 201: Receive a first synchronization channel sent by a first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH.

[0190] Among them, the first device is a device that has completed synchronization. Its synchronization process can be synchronization performed by receiving a synchronization channel sent by other synchronized devices, or a synchronization process completed based on GNSS or a base station; the second device is a device without synchronization, with a poor synchronization state, or in need of synchronization.

[0191] In an exemplary implementation, the first synchronization channel includes a first PSCCH and a first PSSCH.

[0192] In an exemplary implementation, the first synchronization channel includes a first PSCCH and a first SL-PRS.

[0193] In an exemplary implementation, the first synchronization channel includes a first PSCCH, a first PSSCH, and a first PSFCH.

[0194] In an exemplary implementation, the first synchronization channel includes a first PSFCH.

[0195] Step 202: Obtain first synchronization information carried in the first synchronization channel.

[0196] In this step, when the time slot boundaries are aligned, obtain the first synchronization information carried in the first synchronization channel.

[0197] Specifically, the obtaining of the first synchronization information carried in the first synchronization channel includes: obtaining the time slot number corresponding to a target resource, where the target resource is the transmission resource of the first synchronization channel; decoding the first synchronization channel according to the time slot number corresponding to the target resource to obtain the first synchronization information.

[0198] Among them, the first synchronization information includes at least one of the following:

[0199] Configuration information of time division duplexing TDD;

[0200] Judgment information on whether the first device is within the network coverage area;

[0201] Frame number information where the first synchronization channel is located;

[0202] The time slot index information where the first synchronization channel is located;

[0203] Reserved bits;

[0204] The synchronization level of the first device;

[0205] The ID information of the first device;

[0206] The coordinate information of the first device;

[0207] Coordinated Universal Time (UTC) information;

[0208] The timing adjustment amount of the first device;

[0209] The deviation estimation amount between the local timing of the first device and UTC;

[0210] The frequency deviation adjustment amount of the first device;

[0211] The deviation estimation amount between the local frequency of the first device and the reference frequency.

[0212] Step 203: Perform a first synchronization process according to the first synchronization information.

[0213] It should be noted that the first synchronization process is a preliminary synchronization process between the second device and the first device. At this time, there are still synchronization errors caused by signal propagation delay and timing measurement errors.

[0214] In the above embodiment, the second device can achieve the synchronization process of the direct link based on the first synchronization channel sent by the first device in the case of no GNSS coverage.

[0215] In some embodiments, obtaining the time slot number corresponding to the target resource includes one of the following:

[0216] Method 1: Traverse all time slot numbers, perform a blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource.

[0217] In specific implementation, when the first device sends the first synchronization channel on the target resource in the first resource set, if the target resource is the resource corresponding to any slot number, the second device blindly detects according to the possible values of the slot number by using the DMRS of the received first PSCCH to determine the slot number corresponding to the target resource, and generates a local PSCCH DMRS and / or PSSCH DMRS sequence by using the slot number corresponding to the target resource; according to the generated local PSCCH DMRS and / or PSSCH DMRS sequence, channel estimation and decoding of the PSCCH and / or PSSCH are performed to obtain the first synchronization information; according to the first synchronization information, the first synchronization process is completed.

[0218] Method 2: Determine the slot number corresponding to the target resource as a specific slot number.

[0219] In specific implementation, when the first device sends the first synchronization channel on the target resource in the first resource set, if the target resource is the resource corresponding to a specific slot number, the second device can determine that the slot number corresponding to the target resource is a preset specific slot number according to the detected signal, and generates a local PSCCH DMRS and / or PSSCH DMRS sequence by using the slot number; according to the generated local PSCCH DMRS and / or PSSCH DMRS sequence, channel estimation and decoding of the PSCCH and / or PSSCH are performed to obtain the first synchronization information; according to the first synchronization information, the first synchronization process is completed.

[0220] Method 3: Traverse the slot numbers in a specific slot number set, blindly detect the DMRS of the first synchronization channel, and determine the slot number corresponding to the target resource.

[0221] In specific implementation, when the first device sends the first synchronization channel on the target resource in the first resource set, if the target resource is the resource corresponding to any slot number in a specific slot number set, the second device blindly detects according to the detected signal and the possible values of the slot number by using the DMRS of the received first PSCCH to determine the slot number corresponding to the target resource, and generates a local PSCCH DMRS and / or PSSCH DMRS sequence by using the slot number corresponding to the target resource; according to the generated local PSCCH DMRS and / or PSSCH DMRS sequence, channel estimation and decoding of the PSCCH and / or PSSCH are performed to obtain the first synchronization information; according to the first synchronization information, the first synchronization process is completed.

[0222] Method 4: Use a preset slot number to decode the first synchronization channel to obtain the slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH.

[0223] In specific implementation, when the first device generates the demodulation reference signal DMRS of the first PSCCH and / or the DMRS of the first PSSCH using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSSCH or the first PSCCH, the second device generates a local PSCCH DMRS and / or a PSSCH DMRS sequence using the preset time slot number; performs channel estimation and decoding of the PSCCH and / or the PSSCH according to the generated local PSCCH DMRS and / or PSSCH DMRS sequence to obtain first synchronization information; and completes the first synchronization process according to the first synchronization information.

[0224] In specific implementation, when the first device generates the DMRS of the first PSCCH and the first SL-PRS using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH, the second device generates a local PSCCH DMRS using the preset time slot number; performs channel estimation and decoding of the first PSCCH according to the generated local PSCCH DMRS to obtain first synchronization information; and completes the first synchronization process according to the first synchronization information.

[0225] In specific implementation, when the first device generates the DMRS of the first PSCCH using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH, the second device generates a local PSCCH DMRS using the preset time slot number; performs channel estimation and decoding of the first PSCCH according to the generated local PSCCH DMRS to obtain first synchronization information; and completes the first synchronization process according to the first synchronization information.

[0226] Mode Five: When the first synchronization channel includes at least a first PSFCH, detect the first PSFCH according to the energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0227] In specific implementation, when the first synchronization channel includes a first PSCCH, a first PSSCH, and a first PSFCH, or when the first synchronization channel includes a first PSFCH, the second device detects the first PSFCH according to the energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0228] In some embodiments, before obtaining the time slot number corresponding to the target resource, the method further includes:

[0229] Determine the rising edge and / or falling edge of the energy change according to the energy measurement result;

[0230] Determine the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0231] Exemplarily, refer to Figure 6 , in the case where the first synchronization channel includes a first PSCCH and a first PSSCH, an energy change waveform is as Figure 6 shown. The depressed parts in slot1, slot3, slot4, and slot5 indicate that the power drops to 0 due to the Gap symbol. The depression in slot2 includes: the power drops to 0 due to the Gap symbol and the non-transmission of the first PSCCH and the first PSSCH.

[0232] In this embodiment, determining the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge of the energy change, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot can improve the accuracy of time slot boundary alignment.

[0233] In some embodiments, in the case where the first synchronization channel includes the first PSCCH and the first SL-PRS, the determining the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot includes:

[0234] Determine the start boundary and / or end boundary of the time slot where it is located according to the rising edge and / or falling edge of the energy change, the start symbol position and symbol number configuration of the first PSCCH in the time slot, and the configuration information of the SL-PRS resource in the time slot.

[0235] It should be noted that in the case where the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0236] Exemplarily, refer to Figure 7 , in the case where the first synchronization channel includes a first PSCCH and a first SL-PRS, the energy change waveform is as Figure 7 described, Figure 7 The time domain position of the PSCCH in the slot is fixed, but there may be one or more SL-PRSs in the slot, so there may be more waveform changes. However, the position of the SL-PRS resource in the time domain is fixed, so the rising edge and falling edge of these waveforms are also at specific positions in the slot. Therefore, the rising edge and / or falling edge of the waveform, as well as the configuration of the SL-PRS resource, can still be used to determine the boundary of the time slot.

[0237] In some embodiments, when the first synchronization channel at least includes a first PSFCH, determining the start boundary of a time slot according to the rising edge and / or falling edge, and the start symbol position and number of symbols of the first synchronization channel in the time slot includes:

[0238] Determine the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

[0239] It should be noted that while considering the rising edge, the falling edge can also be synchronously considered, which helps to improve the accuracy of energy waveform detection.

[0240] In an exemplary embodiment, determining the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information includes: determining the interval between two adjacent rising edges of the energy change in the time domain; if the interval is greater than or equal to a preset value, then determine the start boundary of the time slot according to the first rising edge among the two rising edges of the energy change, and the start symbol position and number of symbols of the first synchronization channel in the time slot.

[0241] In an exemplary embodiment, determining the start boundary and / or end boundary of the time slot according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information includes: determining the interval between two adjacent rising and falling edges of the energy change in the time domain, or the interval between two adjacent falling and rising edges of the energy change in the time domain, and combining the time domain structure configuration information of the time slot to determine the boundary of the time slot.

[0242] Optionally, the above preset value is the interval length between the start position of the time slot and the start position of the PSFCH resource.

[0243] For example, when the first synchronization channel includes a first PSFCH, or when the first synchronization channel includes a first PSCCH, a first PSSCH, and a first PSFCH, assuming that the period of the first PSFCH is 2 time slots in the resource pool, in the actual process, the first device may send the first PSFCH on the PSFCH resource, or may not need to send a PSFCH on the corresponding PSFCH resource. Refer to Figure 8 , which shows the signal energy waveform change when the PSFCH appears (such as the time slot where the slot with PSFCH is located in Figure 8 ) or does not appear (such as the time slot where the slot w / o PSFCH is located in Figure 8 ). Figure 8 In , the depressed part indicates that the power drops to 0 due to the Gap symbol or when no PSFCH is sent.

[0244] In some embodiments, when the first synchronization channel includes the first PSFCH, receiving the first synchronization channel sent by the first device includes:

[0245] Receiving the first PSFCH sent by the first device on a first resource subset;

[0246] Receiving a second PSFCH sent by the first device on a second resource subset; wherein, the second PSFCH is generated using a preconfigured sequence; wherein, the first resource subset and the second resource subset belong to the first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain; the first PSFCH and the second PSFCH include one or more PSFCHs;

[0247] The method further includes:

[0248] Performing frequency synchronization according to the second PSFCH.

[0249] In this embodiment, generating the second PSFCH using a preconfigured sequence enables the second device to perform sequence correlation search using the preconfigured sequence within the possible frequency range of the second PSFCH to complete frequency synchronization.

[0250] In some embodiments, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for the synchronization process.

[0251] In this embodiment, the synchronization flag bit carried in the first synchronization channel can notify the second device that the first synchronization channel can be used for the synchronization process through the synchronization flag bit.

[0252] In some embodiments, after receiving the first synchronization channel sent by the first device, the method further includes:

[0253] Sending a second synchronization channel to the first device;

[0254] Receiving a third synchronization channel sent by the first device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, a third PSFCH;

[0255] Performing a second synchronization process according to the second synchronization signal.

[0256] Among them, the second synchronization channel is S-SS / PSBCH, or the second synchronization channel includes at least one of the following: a third PSCCH, a third PSSCH, a third PSFCH, and a third SL-PRS.

[0257] Optionally, the second device uses the resources in the second resource set to send the second synchronization channel; the first device uses the resources in the third resource set to send the third synchronization channel; among them, the second resource set may belong to or be equal to the first resource set, or may have no intersection with the first resource set; the third resource set may be the same as the second resource set or the same as the first resource set.

[0258] Among them, the second synchronization information includes at least one of the following:

[0259] Configuration information of time-division duplexing TDD;

[0260] Judgment information on whether the first device is within the network coverage area;

[0261] Frame number information where the first synchronization channel is located;

[0262] Slot index information where the first synchronization channel is located;

[0263] Timing measurement results;

[0264] Reserved bits;

[0265] Synchronization level of the first device;

[0266] ID information of the first device;

[0267] Coordinate information of the first device;

[0268] Coordinated Universal Time UTC information;

[0269] Timing adjustment amount of the first device;

[0270] Deviation estimation amount between the local timing of the first device and UTC;

[0271] Frequency deviation adjustment amount of the first device;

[0272] Deviation estimation amount between the local frequency of the first device and the reference frequency.

[0273] In the above embodiments, by sending the third synchronization channel to the second device, the second device can perform the second synchronization process according to the second synchronization information carried in the third synchronization channel. Through the second synchronization process, the synchronization error can be reduced and the synchronization accuracy can be improved.

[0274] The following combines with the appendix Figure 9The synchronization process of the direct link in the embodiments of the present application is introduced.

[0275] As Figure 9 shown, the synchronization process of the direct link includes the following steps:

[0276] Step 1: The first device sends a first synchronization channel to the second device; the first synchronization channel includes at least one of the following: a first Physical Sidelink Control Channel (PSCCH), a first Physical Sidelink Shared Channel (PSSCH), a first Sidelink Positioning Reference Signal (SL-PRS), and a first Physical Sidelink Feedback Channel (PSFCH).

[0277] Step 2: The second device performs waveform detection for slot boundary alignment; the second device obtains the first synchronization information carried in the first synchronization channel; and based on the first synchronization information, completes the first synchronization process.

[0278] Step 3: The second device sends a second synchronization channel to the first device; the second synchronization channel is an S-SS / PSBCH, or the second synchronization channel includes at least one of the following: a third PSCCH, a third PSSCH, a third PSFCH, and a third SL-PRS.

[0279] Step 4: The first device performs a first timing measurement based on the second synchronization channel to obtain a timing measurement result.

[0280] Step 5: The first device sends a third synchronization channel to the second device; the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH.

[0281] Step 6: The second device performs a second timing measurement based on the third synchronization channel; and based on the second synchronization information carried in the third synchronization channel, completes the second synchronization process.

[0282] The third embodiment

[0283] As Figure 10 shown, the third embodiment of the present invention provides a direct link synchronization device 1000 applied to the first device, including:

[0284] A first sending module 1001, configured to send a first synchronization channel to the second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first Physical Sidelink Control Channel (PSCCH), a first Physical Sidelink Shared Channel (PSSCH), a first Sidelink Positioning Reference Signal (SL-PRS), and a first Physical Sidelink Feedback Channel (PSFCH).

[0285] Optionally, the first sending module 1001 includes:

[0286] A first sending sub-module, configured to send the first synchronization channel on a target resource in a first resource set; wherein, the target resource is one of the following:

[0287] Resources corresponding to any time slot number;

[0288] Resources corresponding to a specific time slot number;

[0289] Resources corresponding to any time slot number belonging to a set of specific time slot numbers.

[0290] Optionally, the above device 1000 further includes:

[0291] A first processing module, configured to, when the first synchronization channel includes a first PSCCH and a first PSSCH, generate a demodulation reference signal DMRS of the first PSCCH and / or a DMRS of the first PSSCH by using a preset time slot number, and a time slot number corresponding to the target resource is carried in the first PSCCH or the first PSSCH, and the target resource is a transmission resource of the first synchronization channel; or

[0292] A second processing module, configured to, when the first synchronization channel includes the first PSCCH and a first SL-PRS, generate a DMRS of the first PSCCH and the first SL-PRS by using a preset time slot number, and a time slot number corresponding to the target resource is carried in the first PSCCH; or

[0293] A third processing module, configured to, when the first synchronization channel includes the first PSCCH and the first SL-PRS, generate a DMRS of the first PSCCH by using a preset time slot number, and a time slot number corresponding to the target resource is carried in the first PSCCH; or

[0294] A fourth processing module, configured to, when the first synchronization channel includes the first PSCCH, the first PSSCH, and a first PSFCH, indicate a time slot number corresponding to the target resource through the first PSFCH; or

[0295] A fifth processing module, configured to, when the first synchronization channel includes a first PSFCH, indicate a time slot number corresponding to the target resource through the first PSFCH.

[0296] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0297] Optionally, when the first synchronization channel includes the first PSFCH, the first transmission module 1001 includes:

[0298] Transmit the first PSFCH on a first resource subset;

[0299] Transmit a second PSFCH on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence;

[0300] Wherein, the first PSFCH and the second PSFCH include one or more PSFCHs;

[0301] The first resource subset and the second resource subset belong to a first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain.

[0302] Optionally, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel is used for the synchronization process.

[0303] Optionally, the above device 1000 further includes:

[0304] A first receiving module, configured to receive a second synchronization channel sent by the second device;

[0305] An acquisition module, configured to perform timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0306] A second transmission module, configured to send a third synchronization channel to the second device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH.

[0307] Fourth Embodiment

[0308] As Figure 11 shown, an in-direct link synchronization device 1100 provided by an embodiment of the present invention is applied to a second device and includes:

[0309] A second receiving module 1101, configured to receive a first synchronization channel sent by a first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH;

[0310] A first acquisition module 1102, configured to acquire first synchronization information carried in the first synchronization channel;

[0311] A first synchronization processing module 1103, configured to perform a first synchronization process according to the first synchronization information.

[0312] Optionally, the first acquisition module 1102 includes:

[0313] A first acquisition sub-module, configured to acquire a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel;

[0314] A second acquisition sub-module, configured to decode the first synchronization channel according to the time slot number corresponding to the target resource, and acquire the first synchronization information.

[0315] Optionally, the above-mentioned apparatus 1100 further includes:

[0316] A first determination module, configured to determine a rising edge and / or a falling edge of energy change according to an energy measurement result;

[0317] A second determination module, configured to determine a start boundary and / or an end boundary of a time slot according to the rising edge and / or the falling edge, and a start symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0318] Optionally, the first acquisition sub-module includes one of the following:

[0319] A first acquisition unit, configured to traverse all time slot numbers, perform blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource; or

[0320] A second acquisition unit, configured to determine a specific time slot number as the time slot number corresponding to the target resource; or

[0321] A third acquisition unit, configured to traverse the time slot numbers in a specific set of time slot numbers, perform blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource;

[0322] A fourth acquisition unit, configured to use a preset time slot number to decode the first synchronization channel, and acquire the time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH;

[0323] A fifth acquisition unit, configured to, when the first synchronization channel includes at least a first PSFCH, detect the first PSFCH according to an energy waveform, and acquire the time slot number corresponding to the target resource indicated by the first PSFCH.

[0324] Optionally, when the first synchronization channel includes the first PSCCH and the first SL-PRS, the second determination module includes:

[0325] A first determination unit, configured to determine a start boundary and / or an end boundary of a time slot according to an energy change rising edge and / or falling edge, a start symbol position and number of symbols configuration of the first PSCCH in the time slot, and configuration information of SL-PRS resources in the time slot.

[0326] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0327] Optionally, when the first synchronization channel includes at least a first PSFCH, a second determination module includes:

[0328] A second determination unit, configured to determine a start boundary and / or an end boundary of a time slot according to an energy change rising edge and / or falling edge and PSFCH resource configuration information.

[0329] Optionally, when the first synchronization channel includes the first PSFCH, a second receiving module 1101 includes:

[0330] A first receiving sub-module, configured to receive the first PSFCH sent by the first device on a first resource subset;

[0331] A second receiving sub-module, configured to receive a second PSFCH sent by the first device on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence; wherein, the first resource subset and the second resource subset belong to the first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain; the first PSFCH and the second PSFCH include one or more PSFCHs;

[0332] The above device 1100 further includes:

[0333] A frequency synchronization module, configured to perform frequency synchronization by searching according to the second PSFCH.

[0334] Optionally, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for the synchronization process.

[0335] The above device 1100 further includes:

[0336] A third sending module, configured to send a second synchronization channel to the first device.

[0337] A third receiving module, configured to receive a third synchronization channel sent by the first device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH;

[0338] A second synchronization processing module, configured to perform a second synchronization process according to the second synchronization signal.

[0339] The second embodiment of the present invention corresponds to the method of the first embodiment above. All the implementation means in the first embodiment are applicable to the embodiment of the direct link synchronization device and can achieve the same technical effects.

[0340] The fifth embodiment

[0341] To better achieve the above object, as Figure 12 shown, the fifth embodiment of the present invention further provides a first device, including:

[0342] A processor 1200; and a memory 1220 connected to the processor 1200 through a bus interface, where the memory 1220 is used to store programs and data used by the processor 1200 when performing operations, and the processor 1200 calls and executes the programs and data stored in the memory 1220.

[0343] Wherein, a transceiver 1210 is connected to the bus interface and is configured to receive and send data under the control of the processor 1200; the processor 1200 is configured to read the programs in the memory 1220 to implement the following steps:

[0344] Send a first synchronization channel to a second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first physical direct link control channel PSCCH, a first physical direct link shared channel PSSCH, a first direct link positioning reference signal SL-PRS, and a first physical direct link feedback channel PSFCH.

[0345] Wherein, in Figure 12Among them, the bus architecture may include any number of interconnected buses and bridges, specifically, various circuits of one or more processors represented by processor 1200 and memory represented by memory 1220 are linked together. The bus architecture can also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, and thus will not be further described herein. The bus interface provides an interface. The transceiver 1210 may be multiple components, that is, including a transmitter and a transceiver, and provides a unit for communicating with various other devices on the transmission medium. For different devices, the user interface 1230 may also be an interface capable of externally connecting or internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, etc. The processor 1200 is responsible for managing the bus architecture and general processing, and the memory 1220 can store data used by the processor 1200 when executing operations.

[0346] Optionally, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0347] Transmit the first synchronization channel on a target resource in the first resource set; wherein, the target resource is one of the following:

[0348] Resources corresponding to any time slot number;

[0349] Resources corresponding to a specific time slot number;

[0350] Resources corresponding to any time slot number belonging to a set of specific time slot numbers.

[0351] Optionally, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0352] When the first synchronization channel includes a first PSCCH and a first PSSCH, generate a demodulation reference signal DMRS of the first PSCCH and / or the DMRS of the first PSSCH using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH or the first PSSCH, and the target resource is the transmission resource of the first synchronization channel; or

[0353] When the first synchronization channel includes the first PSCCH and a first SL-PRS, generate the DMRS of the first PSCCH and the first SL-PRS using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH; or

[0354] When the first synchronization channel includes the first PSCCH and the first SL-PRS, the DMRS of the first PSCCH is generated using a preset time slot number, and the time slot number corresponding to the target resource is carried in the first PSCCH; or

[0355] When the first synchronization channel includes the first PSCCH, the first PSSCH, and the first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH; or

[0356] When the first synchronization channel includes the first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH.

[0357] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0358] Optionally, when the first synchronization channel includes the first PSFCH, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0359] Transmit the first PSFCH on a first resource subset;

[0360] Transmit a second PSFCH on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence;

[0361] Wherein, the first PSFCH and the second PSFCH include one or more PSFCHs;

[0362] The first resource subset and the second resource subset belong to a first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain.

[0363] Optionally, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel is used for the synchronization process.

[0364] Optionally, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0365] Receive a second synchronization channel sent by the second device;

[0366] Perform timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0367] Send a third synchronization channel to the second device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH.

[0368] The first device provided by the present invention can enable the second device to achieve the synchronization process of the direct link in the case of no GNSS coverage by sending a first synchronization channel to the second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH.

[0369] Those skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a computer program. The computer program includes instructions for executing part or all of the steps of the above method; and the computer program can be stored in a readable storage medium, and the storage medium can be any form of storage medium.

[0370] Sixth Embodiment

[0371] To better achieve the above object, as Figure 13 shown, the fourth embodiment of the present invention further provides a second device, including:

[0372] A processor 1300; and a memory 1320 connected to the processor 1300 through a bus interface, where the memory 1320 is used to store programs and data used by the processor 1300 when executing operations, and the processor 1300 calls and executes the programs and data stored in the memory 1320.

[0373] Wherein, a transceiver 1310 is connected to the bus interface and is used to receive and send data under the control of the processor 1300; the processor 1300 is used to read the program in the memory 1320 to implement the following steps:

[0374] Receive a first synchronization channel sent by the first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH;

[0375] Obtain the first synchronization information carried in the first synchronization channel;

[0376] Execute a first synchronization process according to the first synchronization information.

[0377] Wherein, in Figure 13Among them, the bus architecture may include any number of interconnected buses and bridges, specifically, various circuits represented by one or more processors represented by processor 1300 and memory represented by memory 1320 are linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, and thus will not be further described herein. The bus interface provides an interface. The transceiver 1310 may be multiple components, that is, including a transmitter and a transceiver, and provides a unit for communicating with various other devices on the transmission medium. For different devices, the user interface 1330 may also be an interface capable of externally connecting and internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, etc. The processor 1300 is responsible for managing the bus architecture and general processing, and the memory 1320 may store data used by the processor 1300 when performing operations.

[0378] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0379] Obtain a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel;

[0380] Decode the first synchronization channel according to the time slot number corresponding to the target resource to obtain the first synchronization information.

[0381] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0382] Determine a rising edge and / or a falling edge of an energy change according to an energy measurement result;

[0383] Determine a start boundary and / or an end boundary of a time slot according to the rising edge and / or the falling edge, and a start symbol position and a symbol number configuration of the first synchronization channel in the time slot.

[0384] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement one of the following steps:

[0385] Traverse all time slot numbers, perform a blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource; or

[0386] Determine a specific time slot number as the time slot number corresponding to the target resource; or

[0387] Traverse the time slot numbers in a specific set of time slot numbers, perform a blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource;

[0388] Decode the first synchronization channel by using a preset time slot number to obtain the time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH;

[0389] When the first synchronization channel at least includes a first PSFCH, detect the first PSFCH according to an energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0390] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0391] Determine the start boundary and / or end boundary of the time slot where it is located according to the rising edge and / or falling edge of the energy change, the start symbol position and the number of symbols configuration of the first PSCCH in the time slot, and the configuration information of the SL-PRS resource in the time slot.

[0392] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0393] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0394] Determine the start boundary and / or end boundary of the time slot where it is located according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

[0395] Optionally, when the first synchronization channel includes the first PSFCH, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0396] Receive the first PSFCH sent by the first device on a first resource subset;

[0397] Receive a second PSFCH sent by the first device on a second resource subset; wherein, the second PSFCH is generated by using a pre-configured sequence; wherein, the first resource subset and the second resource subset belong to the first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain; the first PSFCH and the second PSFCH include one or more PSFCHs;

[0398] Perform frequency synchronization according to the second PSFCH.

[0399] Optionally, a synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for the synchronization process.

[0400] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0401] Send a second synchronization channel to the first device;

[0402] Receive a third synchronization channel sent by the first device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH;

[0403] Perform a second synchronization process according to the second synchronization signal.

[0404] The second device provided by the present invention receives a first synchronization channel sent by a first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH; obtains the first synchronization information carried in the first synchronization channel; and performs a first synchronization process according to the first synchronization information. In this way, the synchronization process of the direct link can be achieved in the absence of GNSS coverage.

[0405] Those skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by hardware, or can be completed by instructing relevant hardware through a computer program. The computer program includes instructions for performing part or all of the steps of the above method; and the computer program can be stored in a readable storage medium, and the storage medium can be any form of storage medium.

[0406] In addition, a specific embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the steps of the method in the above first embodiment or second embodiment. And it can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0407] In addition, it should be noted that in the devices and methods of the present invention, obviously, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present invention. Moreover, the steps of performing the above series of processes can naturally be executed chronologically in the described order, but it is not necessary to execute them necessarily in chronological order. Some steps can be executed in parallel or independently of each other. For those of ordinary skill in the art, it is understandable that all or any steps or components of the methods and devices of the present invention can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices in the form of hardware, firmware, software, or a combination thereof, which can be achieved by those of ordinary skill in the art using their basic programming skills after reading the description of the present invention.

[0408] Therefore, the object of the present invention can also be achieved by running a program or a set of programs on any computing device. The computing device can be a well-known general-purpose device. Therefore, the object of the present invention can also be achieved only by providing a program product containing program code for implementing the method or device. That is to say, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be noted that in the devices and methods of the present invention, obviously, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present invention. Moreover, the steps of performing the above series of processes can naturally be executed chronologically in the described order, but it is not necessary to execute them necessarily in chronological order. Some steps can be executed in parallel or independently of each other.

[0409] The above are the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A synchronization method for a direct link, characterized in that, Applied to a first device, including: Sending a first synchronization channel to a second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first physical sidelink control channel (PSCCH), a first physical sidelink shared channel (PSSCH), a first sidelink positioning reference signal (SL-PRS), and a first physical sidelink feedback channel (PSFCH).

2. The synchronization method of the direct link according to claim 1, characterized in that The sending the first synchronization channel to the second device includes: Sending the first synchronization channel on a target resource in a first resource set; wherein, the target resource is one of the following: Resources corresponding to any time slot number; Resources corresponding to a specific time slot number; Resources corresponding to any time slot number belonging to a set of specific time slot numbers.

3. The synchronization method for a direct link according to claim 1, characterized in that The method further includes: When the first synchronization channel includes a first PSCCH and a first PSSCH, generating a demodulation reference signal (DMRS) of the first PSCCH and / or a DMRS of the first PSSCH using a preset time slot number, and the first PSCCH or the first PSSCH carries the time slot number corresponding to the target resource, where the target resource is the transmission resource of the first synchronization channel; or When the first synchronization channel includes the first PSCCH and a first SL-PRS, generating a DMRS of the first PSCCH and the first SL-PRS using a preset time slot number, and the first PSCCH carries the time slot number corresponding to the target resource; or When the first synchronization channel includes the first PSCCH and a first SL-PRS, generating a DMRS of the first PSCCH using a preset time slot number, and the first PSCCH carries the time slot number corresponding to the target resource; or When the first synchronization channel includes the first PSCCH, the first PSSCH, and a first PSFCH, indicating the time slot number corresponding to the target resource through the first PSFCH; or When the first synchronization channel includes a first PSFCH, indicating the time slot number corresponding to the target resource through the first PSFCH.

4. The synchronization method of the direct link according to claim 1, characterized in that, When the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

5. The synchronization method of the direct link according to claim 1, characterized in that, When the first synchronization channel includes the first PSFCH, the sending the first synchronization channel to the second device includes: Sending the first PSFCH on a first resource subset; Sending a second PSFCH on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence; Wherein, the first PSFCH and the second PSFCH include one or more PSFCHs; The first resource subset and the second resource subset belong to a first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain.

6. The synchronization method of the direct link according to claim 1, characterized in that The first synchronization channel carries a synchronization flag bit, and the synchronization flag bit is used to indicate that the first synchronization channel is used for the synchronization process.

7. The synchronization method of the direct link according to claim 1, wherein After sending the first synchronization channel to the second device, the method further includes: Receiving a second synchronization channel sent by the second device; Performing timing measurement according to the second synchronization channel to obtain a timing measurement result; Sending a third synchronization channel to the second device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, and a third PSFCH.

8. A synchronization method for a direct link, characterized in that Applied to a second device, it includes: Receiving a first synchronization channel sent by a first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH; Obtaining first synchronization information carried in the first synchronization channel; Performing a first synchronization process according to the first synchronization information.

9. The synchronization method of the direct link according to claim 8, characterized in that, The obtaining the first synchronization information carried in the first synchronization channel includes: Obtaining a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel; Decoding the first synchronization channel according to the time slot number corresponding to the target resource to obtain the first synchronization information.

10. The synchronization method of the direct link according to claim 9, wherein Before obtaining the time slot number corresponding to the target resource, the method further includes: Determining a rising edge and / or a falling edge of energy change according to an energy measurement result; Determining a start boundary and / or an end boundary of a time slot according to the rising edge and / or the falling edge, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot.

11. The synchronization method for the direct link according to claim 9, wherein The obtaining the time slot number corresponding to the target resource includes one of the following: Traversing all time slot numbers, blindly detecting the DMRS of the first synchronization channel to determine the time slot number corresponding to the target resource; or Determining a specific time slot number as the time slot number corresponding to the target resource; or Traversing the time slot numbers in a specific set of time slot numbers, blindly detecting the DMRS of the first synchronization channel to determine the time slot number corresponding to the target resource; Using a preset time slot number to decode the first synchronization channel to obtain the time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH; In the case where the first synchronization channel includes at least a first PSFCH, detecting the first PSFCH according to an energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

12. The synchronization method of the direct link according to claim 10, wherein In the case where the first synchronization channel includes the first PSCCH and the first SL-PRS, the determining the start boundary and / or the end boundary of the time slot according to the rising edge and / or the falling edge, and the start symbol position and symbol number configuration of the first synchronization channel in the time slot includes: Determining the start boundary and / or the end boundary of the time slot where it is located according to the rising edge and / or the falling edge of energy change, the start symbol position and symbol number configuration of the first PSCCH in the time slot, and the configuration information of the SL-PRS resource in the time slot.

13. The synchronization method of the direct link according to claim 12, characterized in that, When the first synchronization channel includes the first SL-PRS, each time slot includes one SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

14. The synchronization method of the direct link according to claim 10, characterized in that, When the first synchronization channel at least includes the first PSFCH, determining the start boundary of a time slot according to the rising edge and / or falling edge, and the start symbol position and number of symbols configuration of the first synchronization channel in the time slot includes: Determining the start boundary and / or end boundary of the time slot where it is located according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

15. The synchronization method of the direct link according to claim 8, characterized in that, When the first synchronization channel includes the first PSFCH, receiving the first synchronization channel sent by the first device includes: Receiving the first PSFCH sent by the first device on a first resource subset; Receiving a second PSFCH sent by the first device on a second resource subset; wherein, the second PSFCH is generated using a pre-configured sequence; wherein, the first resource subset and the second resource subset belong to the first resource set, and the first resource subset and the second resource subset do not overlap in the frequency domain and overlap in the time domain; the first PSFCH and the second PSFCH include one or more PSFCHs; The method further includes: Performing frequency synchronization by searching according to the second PSFCH.

16. The synchronization method of the direct link according to claim 8, characterized in that, A synchronization flag bit is carried in the first synchronization channel, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for the synchronization process.

17. The synchronization method of the direct link according to claim 8, characterized in that, After receiving the first synchronization channel sent by the first device, the method further includes: Sending a second synchronization channel to the first device; Receiving a third synchronization channel sent by the first device, where the third synchronization channel carries second synchronization information; wherein, the third synchronization channel includes at least one of the following: a second PSCCH, a second PSSCH, a second SL-PRS, a third PSFCH; Performing a second synchronization process according to the second synchronization signal.

18. A first device, comprising: A transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the computer program, it implements the steps of the direct link synchronization method according to any one of claims 1 to 7.

19. A second device, comprising: A transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the computer program, it implements the steps of the direct link synchronization method according to any one of claims 1 to 7.

20. A synchronization device for a direct link, characterized in that, Applied to a first device, it includes: A first sending module, configured to send a first synchronization channel to a second device, where the first synchronization channel carries first synchronization information; wherein, the first synchronization channel includes at least one of the following: a first physical direct link control channel (PSCCH), a first physical direct link shared channel (PSSCH), a first direct link positioning reference signal (SL-PRS), and a first physical direct link feedback channel (PSFCH).

21. A synchronization device for a direct link, characterized in that, Applied to a second device, it includes: A second receiving module, configured to receive a first synchronization channel sent by a first device, where the first synchronization channel includes at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH; A first obtaining module, configured to obtain first synchronization information carried in the first synchronization channel; A first synchronization processing module, configured to perform a first synchronization process according to the first synchronization information.

22. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the sidelink synchronization method according to any one of claims 1 to 7, or implements the steps of the sidelink synchronization method according to any one of claims 8 to 17.

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