Sidelink synchronization method, apparatus and device

Abstract

The present application provides a sidelink synchronization method, apparatus and device. The method is applied to a first device, and comprises: sending a first synchronization channel to a second device, wherein the first synchronization channel carries first synchronization information, and the first synchronization channel comprises 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).

Description

A method, device and equipment for synchronizing a direct link

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311861547.6 filed in China on December 29, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a synchronization method, apparatus, and device for a direct link. Background Art

[0004] At present, the synchronization scheme of 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 primary synchronization signal (PSS) / secondary synchronization signal (SSS) carried by the S-SS / PSBCH. After the receiving UE is synchronized, it decodes the corresponding PSBCH to obtain the corresponding synchronization information, and finally completes the synchronization process.

[0005] However, in actual NR SL deployments, given that most scenarios are covered by the Global Navigation Satellite System (GNSS), it is likely that the S-SS / PSBCH blocks specifically used for synchronization will no longer be introduced. Therefore, further research is needed to implement direct link synchronization in the absence of GNSS coverage. Summary of the Invention

[0006] The present application provides a direct link synchronization method, apparatus and device, which solves the problem of how to implement the direct link synchronization process in the absence of GNSS coverage.

[0007] In a first aspect, an embodiment of the present application provides a synchronization method for a through link, applied to a first device, including:

[0008] A first synchronization channel is sent 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 (Physical Sidelink Control Channel, PSCCH), a first physical sidelink shared channel (Physical Sidelink Shared Channel, PSSCH), a first direct link positioning reference signal (Sidelink Positioning Reference Signal, SL-PRS) and a first physical sidelink feedback channel (Physical Sidelink Feedback Channel, PSFCH).

[0009] Optionally, sending the first synchronization channel to the second device includes:

[0010] Send the first synchronization channel on a target resource in a first resource set, wherein the target resource is one of the following:

[0011] The resources corresponding to any time slot number;

[0012] The resources corresponding to a specific time slot number;

[0013] The resource corresponding to any time slot number in a specific time slot number set.

[0014] Optionally, the synchronization method of the through link further includes:

[0015] In a case where the first synchronization channel includes a first PSCCH and a first PSSCH, a preset time slot number is used to generate a demodulation reference signal (DMRS) of the first PSCCH and / or a DMRS of the first PSSCH, and the first PSCCH or the first PSSCH carries a time slot number corresponding to a target resource, and the target resource is a transmission resource of the first synchronization channel; or

[0016] In a case where the first synchronization channel includes the first PSCCH and the first SL-PRS, a preset time slot number is used to generate the DMRS and the first SL-PRS of the first PSCCH, and the first PSCCH carries the time slot number corresponding to the target resource; or

[0017] In a case where the first synchronization channel includes the first PSCCH and the first SL-PRS, a DMRS of the first PSCCH is generated by using a preset time slot number, and the first PSCCH carries the time slot number corresponding to the target resource; or

[0018] In a case where the first synchronization channel includes the first PSCCH, the first PSSCH, and the first PSFCH, indicating the timeslot number corresponding to the target resource through the first PSFCH; or

[0019] In a case where the first synchronization channel includes a first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH.

[0020] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing (TDM).

[0021] Optionally, when the first synchronization channel includes the first PSFCH, sending the first synchronization channel to the second device includes:

[0022] Sending the first PSFCH on a first resource subset;

[0023] Sending a second PSFCH on a second resource subset; wherein the second PSFCH is generated using a preconfigured sequence;

[0024] The first PSFCH and the second PSFCH include one or more PSFCHs;

[0025] 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.

[0026] Optionally, 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 a synchronization process.

[0027] Optionally, after sending the first synchronization channel to the second device, the method further includes:

[0028] receiving a second synchronization channel sent by the second device;

[0029] performing timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0030] A third synchronization channel is sent 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.

[0031] In a second aspect, an embodiment of the present application provides a synchronization method for a through link, which is applied to a second device, including:

[0032] 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;

[0033] Acquire first synchronization information carried in the first synchronization channel;

[0034] A first synchronization process is performed according to the first synchronization information.

[0035] Optionally, the acquiring the first synchronization information carried in the first synchronization channel includes:

[0036] Obtaining a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel;

[0037] The first synchronization channel is decoded according to the time slot number corresponding to the target resource to obtain the first synchronization information.

[0038] Optionally, before obtaining the time slot number corresponding to the target resource, the method further includes:

[0039] determining a rising edge and / or a falling edge of energy change according to the energy measurement result;

[0040] The starting boundary and / or ending boundary of the time slot is determined according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0041] Optionally, the acquiring of the time slot number corresponding to the target resource includes one of the following:

[0042] Traversing all time slot numbers, performing blind detection on the DMRS of the first synchronization channel, and determining the time slot number corresponding to the target resource; or

[0043] Determine the specific time slot number as the time slot number corresponding to the target resource; or

[0044] Traversing the time slot numbers in the specific time slot number set, performing blind detection on the DMRS of the first synchronization channel, and determining the time slot number corresponding to the target resource;

[0045] Decoding the first synchronization channel using a preset time slot number to obtain a time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH;

[0046] In the case where the first synchronization channel includes at least a first PSFCH, the first PSFCH is detected according to the energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0047] 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 timeslot according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the timeslot includes:

[0048] According to the rising edge and / or falling edge of the energy change, the starting symbol position and symbol number configuration of the first PSCCH in the time slot, as well as the configuration information of the SL-PRS resources in the time slot, determine the starting boundary and / or ending boundary of the time slot.

[0049] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0050] Optionally, when the first synchronization channel includes at least a first PSFCH, determining the starting boundary of the timeslot according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the timeslot includes:

[0051] The starting boundary and / or ending boundary of the time slot is determined according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

[0052] Optionally, when the first synchronization channel includes the first PSFCH, the receiving the first synchronization channel sent by the first device includes:

[0053] Receiving the first PSFCH sent by the first device on a first resource subset;

[0054] 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;

[0055] The method further comprises:

[0056] A search is performed according to the second PSFCH to perform frequency synchronization.

[0057] Optionally, the first synchronization channel carries a synchronization flag bit, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for a synchronization process.

[0058] Optionally, after receiving the first synchronization channel sent by the first device, the method further includes:

[0059] sending a second synchronization channel to the first device;

[0060] 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;

[0061] A second synchronization process is performed according to the second synchronization signal.

[0062] In a third aspect, an embodiment of the present application provides a first device, comprising: a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the direct link synchronization method as described in the first aspect are implemented.

[0063] In a fourth aspect, an embodiment of the present application provides a second device, comprising: a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the direct link synchronization method as described in the second aspect are implemented.

[0064] In a fifth aspect, an embodiment of the present application provides a synchronization apparatus for a direct link, applied to a first device, including:

[0065] The first sending module is used 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 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.

[0066] In a sixth aspect, an embodiment of the present application provides a method for applying to a second device, including:

[0067] A second receiving module is 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;

[0068] A first acquisition module, configured to acquire first synchronization information carried in the first synchronization channel;

[0069] The first synchronization processing module is configured to execute a first synchronization process according to the first synchronization information.

[0070] In a seventh aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the direct link synchronization method as described in the first aspect or the second aspect.

[0071] The beneficial effects of the above technical solution of this application are:

[0072] In the above solution, the first device sends 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 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). In the solution of the present application, the second device can achieve direct link synchronization in the absence of GNSS coverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] FIG1 shows a flow chart of a synchronization method for a direct link according to an embodiment of the present application;

[0074] FIG2 shows one schematic diagram of target resources according to an embodiment of the present application;

[0075] FIG3 shows a second schematic diagram of target resources according to an embodiment of the present application;

[0076] FIG4 is a schematic diagram showing a PSFCH indicating a time slot number according to an embodiment of the present application;

[0077] FIG5 shows a second flow chart of the synchronization method of the direct link according to an embodiment of the present application;

[0078] FIG6 shows one of the energy change waveform diagrams according to an embodiment of the present application;

[0079] FIG7 shows a second schematic diagram of energy change waveforms according to an embodiment of the present application;

[0080] FIG8 shows a third schematic diagram of energy change waveforms according to an embodiment of the present application;

[0081] FIG9 shows a third flowchart of the synchronization method of the direct link according to an embodiment of the present application;

[0082] FIG10 shows one structural block diagram of a synchronization device for a direct link according to an embodiment of the present application;

[0083] FIG11 shows a second structural block diagram of the synchronization device for a direct link according to an embodiment of the present application;

[0084] FIG12 is a schematic diagram showing the hardware structure of a first device according to an embodiment of the present application;

[0085] FIG13 is a schematic diagram showing the hardware structure of the second device according to an embodiment of the present application. DETAILED DESCRIPTION

[0086] In order to make the technical problems, technical solutions and advantages to be solved by the present application clearer, the following will be described 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 fully understand the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, for clarity and brevity, the description of known functions and structures has been omitted.

[0087] It should be understood that references throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present application. Therefore, the appearances of "in one embodiment" or "in an embodiment" throughout this specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0088] In the various embodiments of the present application, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0089] Additionally, the terms "system" and "network" are often used interchangeably herein.

[0090] In the embodiments provided herein, it should be understood that "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should also be understood that determining B based on A does not mean determining B based solely on A; B can also be determined based on A and / or other information.

[0091] First embodiment

[0092] As shown in FIG1 , an embodiment of the present application provides a synchronization method for a through link, which is applied to a first device and specifically includes the following steps:

[0093] 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.

[0094] Among them, the first device is a device that has completed synchronization, and its synchronization process can be performed by receiving the synchronization channel sent by other synchronized devices, or it can be a synchronization process based on GNSS or base station; the second device is a device that is not synchronized or is in poor synchronization status or needs to be synchronized.

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

[0096] In an exemplary implementation, the first synchronization channel includes a first PSCCH and a first SL-PRS.

[0097] In an exemplary implementation, the first synchronization channel includes a first PSCCH, a first PSSCH, and a first PSFCH.

[0098] In one exemplary implementation, the first synchronization channel includes a first PSFCH.

[0099] Optionally, the first synchronization information is carried by at least one of the following: a first stage SCI (1st stage SCI), a second stage SCI (2nd stage SCI), a media access control (MAC) control element (CE), data (Data), and a first PSFCH.

[0100] The first synchronization information includes at least one of the following:

[0101] Time Division Duplex (TDD) configuration information;

[0102] Determination information of whether the first device is within network coverage;

[0103] Frame number information of the first synchronization channel;

[0104] Time slot index information where the first synchronization channel is located;

[0105] Reserved bits;

[0106] a synchronization level of the first device;

[0107] ID information of the first device;

[0108] coordinate information of the first device;

[0109] Universal Time UTC information;

[0110] a timing adjustment amount for the first device;

[0111] an estimated deviation between the local timing of the first device and UTC;

[0112] a frequency deviation adjustment amount of the first device;

[0113] An estimate of the deviation between the local frequency of the first device and a reference frequency.

[0114] Optionally, the frame number information includes: a system frame number (SFN) or a direct frame number (DFN).

[0115] Exemplarily, the synchronization level of the first device includes [0, 255]; wherein 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 service.

[0116] In the above embodiment, the second device can implement the synchronization process of the direct link in the absence of GNSS coverage. Moreover, the synchronization process does not require the allocation of dedicated synchronization resources for the first synchronization channel, thereby improving resource utilization.

[0117] In some embodiments, in step 101, sending the first synchronization channel to the second device includes:

[0118] Send the first synchronization channel on a target resource in a first resource set, wherein the target resource is one of the following:

[0119] The resources corresponding to any time slot number;

[0120] The resources corresponding to a specific time slot number;

[0121] The resource corresponding to any time slot number in a specific time slot number set.

[0122] It should be noted that the first resource set may be a configured or pre-configured synchronization dedicated resource pool, or the first resource set may be a resource pool consisting of reserved time slots, or the first resource set may also belong to a normal communication resource pool.

[0123] It should be noted that the time slot number refers to the time slot number in each frame. For NR direct link devices, the actually available resources need to exclude some specific resources. For example, the logical resources in Figure 2 are the first resource set that are truly available. 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, such as the first device can only send the first synchronization channel in the time slot with a specific time slot number = i, where i is a preset value.

[0124] For example, as shown in Figure 3, when the first synchronization channel includes the first PSFCH, taking the first PSFCH period as four time slots in the resource pool as an example, the first device can only transmit the first PSFCH in a time slot numbered i in which a PSFCH resource appears. The second device, based on detection of the first PSFCH, determines the time slot number corresponding to the transmission resource of the first PFSCH; further, based on the time slot number, receives the first PSCCH.

[0125] It should be noted that if the first device is restricted to transmitting the first synchronization channel only on specific time slot numbers, there may be a situation where the number of actually available resources is small or completely nonexistent. Therefore, the first device can transmit the first synchronization channel on the resources corresponding to any time slot number in the specific time slot number set, thereby increasing the number of actually available resources.

[0126] Accordingly, since the second device does not know which time slot number in the specific time slot number set corresponds to the resource on which the first synchronization channel is transmitted by the first device, 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 to generate a local PSCCH DMRS sequence using different time slot numbers, and then perform correlation detection with the received PSCCH DMRS to obtain the time slot number corresponding to the target resource.

[0127] In some other embodiments, the synchronization method of the through link further includes one of the following:

[0128] Option 1

[0129] In a case where the first synchronization channel includes a first PSCCH and a first PSSCH, a demodulation reference signal DMRS of the first PSCCH and / or a DMRS of the first PSSCH is generated using a preset time slot number, and the first PSCCH or the first PSSCH carries a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel;

[0130] Optionally, the time slot number corresponding to the target resource is carried by the MAC CE carried by the first PSSCH or by data, or by the reserved bit of the SCI in the first PSCCH.

[0131] It should be pointed out that the DMRS sequence generation process is related to the time slot number corresponding to the actual transmission time slot, that is, if the second device is not in a synchronized state, it is impossible to know the time slot number information of the first synchronization channel. Therefore, even if the time slot boundaries are aligned, the subsequent PSCCH and PSSCH channel estimation and decoding processes cannot be completed. Based on this, in order to solve this problem, this embodiment makes the DMRS of the first PSCCH and / or the DMRS of the first PSSCH use a pre-configured time slot number instead of the actual time slot number during the sequence initialization process. The actual time slot number (i.e., the time slot number corresponding to the target resource) is carried in the first PSSCH or the first PSCCH.

[0132] Correspondingly, after completing waveform synchronization, the second device performs channel estimation and decoding of PSCCH / PSSCH according to the preset time slot number, and finally obtains the real time slot number.

[0133] Example 1: If a preset time slot number is used to generate the DMRS of the first PSSCH, the first PSCCH carries a synchronization flag bit, and the DMRS of the PSCCH is generated by the actual time slot number; the first PSSCH or the first PSCCH carries the first synchronization information.

[0134] Example 2: If a preset time slot number is used to generate the DMRS of the first PSCCH, the first PSCCH carries a synchronization flag bit, and the DMRS of the PSSCH is generated by the actual time slot number; the first PSSCH or the first PSCCH carries the first synchronization information.

[0135] Example 3: If a preset time slot number is used to generate the DMRS of the first PSCCH and the DMRS of the PSSCH, the first PSCCH carries a synchronization flag bit, and the first PSSCH or the first PSCCH carries the first synchronization information.

[0136] Option 2

[0137] In a case where the first synchronization channel includes the first PSCCH and the first SL-PRS, a preset time slot number is used to generate the DMRS and the first SL-PRS of the first PSCCH, and the first PSCCH carries the time slot number corresponding to the target resource;

[0138] Optionally, the timeslot number corresponding to the target resource is carried by a reserved bit in sidelink control information (Sidelink Control Information, SCI) format 1-b carried by the first PSCCH.

[0139] It should be noted that, when the first synchronization channel includes the first SL-PRS, each time slot is required to include an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0140] Optionally, to facilitate energy detection, the SL-PRS resource may be placed adjacent to its associated PSCCH in the time domain.

[0141] It should be pointed out that the difference between Scheme 2 and Scheme 1 is that Scheme 2 replaces the first PSSCH with the first SL-PRS. The advantage of Scheme 2 is that the subsequent timing measurement using the first SL-PRS is more accurate, but since there is no PSSCH, the corresponding synchronization information can only be carried by the first PSCCH.

[0142] Option 3

[0143] In a case where the first synchronization channel includes the first PSCCH and the first SL-PRS, a DMRS of the first PSCCH is generated using a preset timeslot number, and the first PSCCH carries the timeslot number corresponding to the target resource;

[0144] It should be noted that, when the first synchronization channel includes the first SL-PRS, each time slot is required to include an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0145] Optionally, to facilitate energy detection, the SL-PRS resource may be placed adjacent to its associated PSCCH in the time domain.

[0146] It should be noted that in this scheme three, the sequence initialization process of the first SL-PRS uses the real time slot number (that is, 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.

[0147] Option 4

[0148] In a case where the first synchronization channel includes the first PSCCH, the first PSSCH, and the first PSFCH, indicating the timeslot number corresponding to the target resource through the first PSFCH;

[0149] Plan 5

[0150] In a case where the first synchronization channel includes a first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH.

[0151] Optionally, when the first synchronization channel only includes the first PSFCH, the first synchronization information is carried by the first PSFCH.

[0152] Optionally, when the first synchronization channel only includes the first PSFCH, the first device or the third device may also send PSCCH or PSSCH to the second device to carry part or all of the content of the first synchronization information. The PSCCH and PSSCH may be located in the same time slot or different time slots as the PSFCH.

[0153] For the above-mentioned solutions 4 and 5, when the first device indicates the timeslot number corresponding to the target resource via the first PSFCH, the first PSFCH may include one or more PSFCHs. That is, the first device may transmit one PSFCH or multiple PSFCHs simultaneously on the preconfigured frequency domain resources. Accordingly, the second device detects the PSFCH on the preconfigured frequency domain resources. Since the generation of the PSFCH sequence is independent of the timeslot number, direct detection is possible.

[0154] In specific implementation, the first PSFCH may use cyclic shift and part or all of the information in the resource block (RB) index to indicate the time slot number of the target resource.

[0155] For example, referring to FIG4 , taking the use of the first PSFCH to indicate a 7-bit timeslot number as an example, the first device needs to send 7 PSFCHs on the preconfigured 7 RBs, and the PSFCH sequence on each RB can use different cyclic shift values ​​to distinguish between state "0" or state "1".

[0156] It should be noted that the PSFCH time domain resources are determined by high-level parameter configuration or a pre-configured PSFCH period, and the PSFCH frequency domain resources are RBs at fixed frequency domain index positions configured by high-level parameter configuration or a pre-configured one. In other words, all devices share the same frequency domain resources when indicating synchronization information such as timeslot numbers via the PSFCH.

[0157] For example, N RBs are configured in the frequency domain for transmitting the first PSFCH, where N is the number of time slots contained in each frame. 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 in the N RBs for transmitting the first PSFCH based on the time slot number of the currently occupied resource. The second device determines the time slot number in which the first synchronization channel is received based on the RB index of the detected first PSFCH.

[0158] For example, N×M RBs are configured in the frequency domain for transmitting the first PSFCH, where N is the number of time slots contained in each frame. N total Indicates the number of PSFCH resources contained in the resource pool or the number of PSFCH resources configured or pre-configured in the resource pool. total The PSFCH resources are divided into M sets, each set contains N RBs; wherein, the RB with RB index i corresponds to the time slot with time slot number i.

[0159] It should be noted that when the first device sends the first PSFCH, it first determines an RB resource set for sending the first PSFCH from among the M sets based on identity information (e.g., including at least one of the following: source ID, destination ID) and at least one of synchronization priority information. It then determines, within the RB resource set, the RB specifically used to send the first PSFCH based on the timeslot number of the target resource. Accordingly, the second device determines the timeslot number corresponding to the target resource based on the RB index of the first PSFCH detected in a PSFCH resource set.

[0160] In some embodiments, when the first synchronization channel includes the first PSFCH, in step 101, sending the first synchronization channel to the second device includes:

[0161] Sending the first PSFCH on a first resource subset;

[0162] Sending a second PSFCH on a second resource subset; wherein the second PSFCH is generated using a preconfigured sequence; the preconfigured sequence indicates that sequence generation is a preconfigured sequence initialization value used;

[0163] The first PSFCH and the second PSFCH include one or more PSFCHs;

[0164] 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.

[0165] In this embodiment, by using the preconfigured sequence to generate the second PSFCH, the second device can use the preconfigured sequence to perform sequence correlation search in the possible frequency domain rate range of the second PSFCH to complete frequency synchronization.

[0166] In some embodiments, 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 a synchronization process.

[0167] 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.

[0168] In some embodiments, after sending the first synchronization channel to the second device, the method further includes:

[0169] receiving a second synchronization channel sent by the second device;

[0170] performing timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0171] A third synchronization channel is sent 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.

[0172] Optionally, the timing measurement result includes at least a propagation delay of the signal.

[0173] The second synchronization information includes at least one of the following:

[0174] Time Division Duplex (TDD) configuration information;

[0175] Determination information of whether the first device is within network coverage;

[0176] Frame number information of the first synchronization channel;

[0177] Time slot index information where the first synchronization channel is located;

[0178] Timing measurement results;

[0179] Reserved bits;

[0180] a synchronization level of the first device;

[0181] ID information of the first device;

[0182] coordinate information of the first device;

[0183] Universal Time UTC information;

[0184] a timing adjustment amount for the first device;

[0185] an estimated deviation between the local timing of the first device and UTC;

[0186] a frequency deviation adjustment amount of the first device;

[0187] An estimate of the deviation between the local frequency of the first device and a reference frequency.

[0188] In the above embodiment, 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.

[0189] Second embodiment

[0190] As shown in FIG5 , an embodiment of the present application provides a synchronization method for a through link, which is applied to a second device and specifically includes the following steps:

[0191] 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.

[0192] Among them, the first device is a device that has completed synchronization, and its synchronization process can be performed by receiving the synchronization channel sent by other synchronized devices, or it can be a synchronization process based on GNSS or base station; the second device is a device that is not synchronized or is in poor synchronization status or needs to be synchronized.

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

[0194] In an exemplary implementation, the first synchronization channel includes a first PSCCH and a first SL-PRS.

[0195] In an exemplary implementation, the first synchronization channel includes a first PSCCH, a first PSSCH, and a first PSFCH.

[0196] In one exemplary implementation, the first synchronization channel includes a first PSFCH.

[0197] Step 202: Acquire first synchronization information carried in the first synchronization channel.

[0198] In this step, when the time slot boundaries are aligned, the first synchronization information carried in the first synchronization channel is obtained.

[0199] Specifically, obtaining the first synchronization information carried in the first synchronization channel includes: obtaining the time slot number corresponding to the 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.

[0200] The first synchronization information includes at least one of the following:

[0201] Time Division Duplex (TDD) configuration information;

[0202] Determination information of whether the first device is within network coverage;

[0203] Frame number information of the first synchronization channel;

[0204] Time slot index information where the first synchronization channel is located;

[0205] Reserved bits;

[0206] a synchronization level of the first device;

[0207] ID information of the first device;

[0208] coordinate information of the first device;

[0209] Universal Time Coordinated (UTC) information;

[0210] a timing adjustment amount for the first device;

[0211] an estimated deviation between the local timing of the first device and UTC;

[0212] a frequency deviation adjustment amount of the first device;

[0213] An estimate of the deviation between the local frequency of the first device and a reference frequency.

[0214] Step 204: Execute a first synchronization process according to the first synchronization information.

[0215] It should be noted that the first synchronization process is a preliminary synchronization process between the second device and the first device, and at this time there is still a synchronization error caused by signal propagation delay and timing measurement error.

[0216] In the above embodiment, the second device can implement the synchronization process of the direct link based on the first synchronization channel sent by the first device when there is no GNSS coverage.

[0217] In some embodiments, obtaining the time slot number corresponding to the target resource includes one of the following:

[0218] Method 1: 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.

[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 a resource corresponding to any time slot number, the second device performs blind detection using the DMRS of the received first PSCCH according to the possible values ​​of the time slot number, determines the time slot number corresponding to the target resource, and generates a local PSCCH DMRS and / or PSSCH DMRS sequence using the time slot number corresponding to the target resource; based on the generated local PSCCH DMRS and / or PSSCH DMRS sequence, performs channel estimation and decoding of PSCCH and / or PSSCH to obtain first synchronization information; and completes the first synchronization process according to the first synchronization information.

[0220] Method 2: Determine the specific time slot number as the time 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 a resource corresponding to a specific time slot number, the second device can determine, based on the detected signal, that the time slot number corresponding to the target resource is a preset specific time slot number, and use the time slot code to generate a local PSCCH DMRS and / or PSSCH DMRS sequence; based on the generated local PSCCH DMRS and / or PSSCH DMRS sequence, perform channel estimation and decoding of PSCCH and / or PSSCH to obtain first synchronization information; and complete the first synchronization process based on the first synchronization information.

[0222] Method three: traverse the time slot numbers in the specific time slot number set, perform blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource.

[0223] 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 a resource corresponding to any time slot number in a specific time slot number set, the second device uses the received DMRS of the first PSCCH to perform blind detection based on the detected signal and the possible value of the time slot number, determines the time slot number corresponding to the target resource, and generates a local PSCCH DMRS and / or PSSCH DMRS sequence using the time slot number corresponding to the target resource; performs channel estimation and decoding of the PSCCH and / or PSSCH based on the generated local PSCCH DMRS and / or PSSCH DMRS sequence to obtain the first synchronization information; and completes the first synchronization process based on the first synchronization information.

[0224] Method 4: Use a preset time slot number to decode the first synchronization channel and obtain the time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH.

[0225] In specific implementation, when the first device uses a preset time slot number to generate the demodulation reference signal DMRS of the first PSCCH and / or the DMRS of the first PSSCH, and the first PSSCH or the first PSCCH carries the time slot number corresponding to the target resource, the second device uses the preset time slot number to generate a local PSCCH DMRS and / or PSSCH DMRS sequence; based on the generated local PSCCH DMRS and / or PSSCH DMRS sequence, channel estimation and decoding of the PSCCH and / or PSSCH are performed to obtain first synchronization information; and based on the first synchronization information, the first synchronization process is completed.

[0226] In specific implementation, when the first device uses a preset time slot number to generate the DMRS and the first SL-PRS of the first PSCCH, and the first PSCCH carries the time slot number corresponding to the target resource, the second device uses the preset time slot number to generate a local PSCCH DMRS; based on the generated local PSCCH DMRS, channel estimation and decoding of the first PSCCH are performed to obtain the first synchronization information; and based on the first synchronization information, the first synchronization process is completed.

[0227] In specific implementation, when the first device uses a preset time slot number to generate the DMRS of the first PSCCH, and the first PSCCH carries the time slot number corresponding to the target resource, the second device uses the preset time slot number to generate a local PSCCH DMRS; based on the generated local PSCCH DMRS, channel estimation and decoding of the first PSCCH are performed to obtain the first synchronization information; and based on the first synchronization information, the first synchronization process is completed.

[0228] Method 5: When the first synchronization channel includes at least a first PSFCH, the first PSFCH is detected according to an energy waveform to obtain a time slot number corresponding to the target resource indicated by the first PSFCH.

[0229] In specific implementation, when the first synchronization channel includes the first PSCCH, the first PSSCH and the first PSFCH, or when the first synchronization channel includes the 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.

[0230] In some embodiments, before obtaining the time slot number corresponding to the target resource, the method further includes:

[0231] determining a rising edge and / or a falling edge of energy change according to the energy measurement result;

[0232] The starting boundary and / or ending boundary of the time slot is determined according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0233] For example, referring to Figure 6, when the first synchronization channel includes the first PSCCH and the first PSSCH, an energy change waveform is shown in Figure 6, and the concave parts in time slot 1 (slot1), slot3, slot4 and slot5 indicate that the power drops to 0 due to the gap (Gap) symbol, and the concave part in slot2 includes: the power drops to 0 due to the gap (Gap) symbol and the failure to send the first PSCCH and the first PSSCH.

[0234] In this embodiment, the starting boundary and / or ending boundary of the time slot are determined based on the rising edge and / or falling edge of the energy change, as well as the starting symbol position and symbol number configuration of the first synchronization channel in the time slot, which can improve the accuracy of the time slot boundary alignment.

[0235] In some embodiments, when the first synchronization channel includes the first PSCCH and the first SL-PRS, determining the start boundary and / or end boundary of the timeslot according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the timeslot includes:

[0236] According to the rising edge and / or falling edge of the energy change, the starting symbol position and symbol number configuration of the first PSCCH in the time slot, as well as the configuration information of the SL-PRS resources in the time slot, determine the starting boundary and / or ending boundary of the time slot.

[0237] It should be noted that, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0238] For example, referring to Figure 7, when the first synchronization channel includes the first PSCCH and the first SL-PRS, the energy change waveform is as described in Figure 7. The time domain position of the PSCCH in Figure 7 in the slot is fixed, but there may be one or more SL-PRS in the slot, so there may be more waveform changes, but 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.

[0239] In some embodiments, when the first synchronization channel includes at least a first PSFCH, determining the starting boundary of the timeslot according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the timeslot includes:

[0240] The starting boundary and / or ending boundary of the time slot is determined according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

[0241] It should be pointed out that the falling edge can be considered simultaneously with the rising edge, which helps to improve the accuracy of energy waveform detection.

[0242] In an exemplary embodiment, the starting boundary and / or ending boundary of the time slot is determined based on the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information, including: determining the interval between two adjacent rising edges of energy change in the time domain; if the interval is greater than or equal to a preset value, determining the starting boundary of the time slot based on the first rising edge of the two energy change rising edges and the starting symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0243] In an exemplary embodiment, the starting boundary and / or ending boundary of the time slot is determined based on the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information, including: determining the rising edge and falling edge of two adjacent energy changes in the time domain, or the interval between the falling edge and rising edge of two adjacent energy changes in the time domain, and determining the boundary of the time slot in combination with the time domain structure configuration information of the time slot.

[0244] Optionally, the preset value is the length of the interval between the start position of the timeslot and the start position of the PSFCH resource.

[0245] For example, when the first synchronization channel includes the first PSFCH, or when the first synchronization channel includes the first PSCCH, the first PSSCH and the 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 the PSFCH on the corresponding PSFCH resource. Referring to Figure 8, it shows the change in signal energy waveform when 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). In Figure 8, the concave part indicates that the power drops to 0 due to the gap symbol or the failure to send PSFCH.

[0246] In some embodiments, when the first synchronization channel includes the first PSFCH, the receiving the first synchronization channel sent by the first device includes:

[0247] Receiving the first PSFCH sent by the first device on a first resource subset;

[0248] 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;

[0249] The method further comprises:

[0250] A search is performed according to the second PSFCH to perform frequency synchronization.

[0251] In this embodiment, the second PSFCH is generated by using a preconfigured sequence, so that the second device can perform sequence correlation search using the preconfigured sequence within a possible frequency domain rate range of the second PSFCH to complete frequency synchronization.

[0252] In some embodiments, the first synchronization channel carries a synchronization flag bit, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for a synchronization process.

[0253] 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.

[0254] In some embodiments, after receiving the first synchronization channel sent by the first device, the method further includes:

[0255] sending a second synchronization channel to the first device;

[0256] 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;

[0257] A second synchronization process is performed according to the second synchronization signal.

[0258] 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.

[0259] Optionally, the second device uses resources in the second resource set to send a second synchronization channel; the first device uses resources in the third resource set to send a third synchronization channel; wherein, 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 may be the same as the first resource set.

[0260] The second synchronization information includes at least one of the following:

[0261] Time Division Duplex (TDD) configuration information;

[0262] Determination information of whether the first device is within network coverage;

[0263] Frame number information of the first synchronization channel;

[0264] Time slot index information where the first synchronization channel is located;

[0265] Timing measurement results;

[0266] Reserved bits;

[0267] a synchronization level of the first device;

[0268] ID information of the first device;

[0269] coordinate information of the first device;

[0270] Universal Time UTC information;

[0271] a timing adjustment amount for the first device;

[0272] an estimated deviation between the local timing of the first device and UTC;

[0273] a frequency deviation adjustment amount of the first device;

[0274] An estimate of the deviation between the local frequency of the first device and a reference frequency.

[0275] In the above embodiment, 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. The second synchronization process can reduce synchronization errors and improve synchronization accuracy.

[0276] The synchronization process of the through link in the embodiment of the present application is described below with reference to FIG9 .

[0277] As shown in Figure 9, the synchronization process for a direct link includes the following steps:

[0278] 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 PSCCH, a first PSSCH, a first SL-PRS and a first PSFCH.

[0279] Step 2: The second device performs waveform detection and performs time slot boundary alignment; the second device obtains the first synchronization information carried in the first synchronization channel; and completes the first synchronization process according to the first synchronization information.

[0280] Step 3. The second device sends a second synchronization channel to the first device; 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.

[0281] Step 4: The first device performs a first timing measurement according to the second synchronization channel to obtain a timing measurement result.

[0282] 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.

[0283] Step 6: The second device performs a second timing measurement according to the third synchronization channel; and completes a second synchronization process according to the second synchronization information carried in the third synchronization channel.

[0284] Third embodiment

[0285] As shown in FIG10 , the third embodiment of the present application provides a synchronization apparatus 1000 for a direct link, which is applied to a first device and includes:

[0286] The first sending module 1001 is used 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 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.

[0287] Optionally, the first sending module 1001 includes:

[0288] A first sending submodule is 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:

[0289] The resources corresponding to any time slot number;

[0290] The resources corresponding to a specific time slot number;

[0291] The resource corresponding to any time slot number in a specific time slot number set.

[0292] Optionally, the apparatus 1000 further includes:

[0293] a first processing module, configured to generate, when the first synchronization channel includes a first PSCCH and a first PSSCH, 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 a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel; or

[0294] a second processing module, configured to generate the DMRS and the first SL-PRS of the first PSCCH by using a preset time slot number when the first synchronization channel includes the first PSCCH and the first SL-PRS, and the first PSCCH carries the time slot number corresponding to the target resource; or

[0295] a third processing module, configured to generate a DMRS for the first PSCCH using a preset time slot number when the first synchronization channel includes the first PSCCH and a first SL-PRS, and the first PSCCH carries the time slot number corresponding to the target resource; or

[0296] a fourth processing module, configured to indicate, when the first synchronization channel includes the first PSCCH, the first PSSCH, and the first PSFCH, a timeslot number corresponding to the target resource through the first PSFCH; or

[0297] The fifth processing module is configured to indicate the time slot number corresponding to the target resource through the first PSFCH when the first synchronization channel includes the first PSFCH.

[0298] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0299] Optionally, when the first synchronization channel includes the first PSFCH, the first sending module 1001 includes:

[0300] Sending the first PSFCH on a first resource subset;

[0301] Sending a second PSFCH on a second resource subset; wherein the second PSFCH is generated using a preconfigured sequence;

[0302] The first PSFCH and the second PSFCH include one or more PSFCHs;

[0303] 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.

[0304] Optionally, 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 a synchronization process.

[0305] Optionally, the apparatus 1000 further includes:

[0306] A first receiving module, configured to receive a second synchronization channel sent by the second device;

[0307] an acquisition module, configured to perform timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0308] The second sending module is used 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.

[0309] Fourth embodiment

[0310] As shown in FIG11 , an embodiment of the present application provides a synchronization apparatus 1100 for a direct link, which is applied to a second device and includes:

[0311] The second receiving module 1101 is 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;

[0312] A first acquisition module 1102 is configured to acquire first synchronization information carried in the first synchronization channel;

[0313] The first synchronization processing module 1103 is configured to execute a first synchronization process according to the first synchronization information.

[0314] Optionally, the first acquisition module 1102 includes:

[0315] A first acquisition submodule, 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;

[0316] The second acquisition submodule is configured to decode the first synchronization channel according to the time slot number corresponding to the target resource, and acquire the first synchronization information.

[0317] Optionally, the apparatus 1100 further includes:

[0318] A first determining module is used to determine a rising edge and / or a falling edge of an energy change according to an energy measurement result;

[0319] The second determination module is used to determine the starting boundary and / or ending boundary of the time slot according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0320] Optionally, the first acquisition submodule includes one of the following:

[0321] A first acquiring unit is 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

[0322] A second acquiring unit is configured to determine a specific time slot number as a time slot number corresponding to the target resource; or

[0323] a third acquiring unit, configured to traverse the time slot numbers in the specific time slot number set, perform blind detection on the DMRS of the first synchronization channel, and determine the time slot number corresponding to the target resource;

[0324] a fourth acquiring unit, configured to decode the first synchronization channel by using a preset time slot number, and acquire a time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH;

[0325] The fifth acquisition unit is used to detect the first PSFCH according to the energy waveform when the first synchronization channel includes at least the first PSFCH, and obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0326] Optionally, when the first synchronization channel includes the first PSCCH and the first SL-PRS, the second determining module includes:

[0327] The first determination unit is used to determine the starting boundary and / or ending boundary of the time slot based on the rising edge and / or falling edge of the energy change, the starting 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.

[0328] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0329] Optionally, when the first synchronization channel includes at least a first PSFCH, the second determining module includes:

[0330] The second determining unit is configured to 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.

[0331] Optionally, when the first synchronization channel includes the first PSFCH, the second receiving module 1101 includes:

[0332] A first receiving submodule, configured to receive the first PSFCH sent by the first device on a first resource subset;

[0333] a second receiving submodule, configured to receive 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;

[0334] The apparatus 1100 further includes:

[0335] A frequency synchronization module is used to search according to the second PSFCH and perform frequency synchronization.

[0336] Optionally, the first synchronization channel carries a synchronization flag bit, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for a synchronization process.

[0337] The apparatus 1100 further includes:

[0338] A third sending module, configured to send a second synchronization channel to the first device;

[0339] 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;

[0340] The second synchronization processing module is used to perform a second synchronization process according to the second synchronization signal.

[0341] The second embodiment of the present application corresponds to the method of the first embodiment above. All implementation means in the first embodiment above are applicable to the embodiment of the synchronization device of the direct link and can achieve the same technical effect.

[0342] Fifth embodiment

[0343] To better achieve the above objectives, as shown in FIG12 , the fifth embodiment of the present application further provides a first device, including:

[0344] A processor 1200; and a memory 1220 connected to the processor 1200 via a bus interface, wherein 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.

[0345] The transceiver 1210 is connected to the bus interface and is used to receive and send data under the control of the processor 1200. The processor 1200 is used to read the program in the memory 1220 to implement the following steps:

[0346] A first synchronization channel is sent 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 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.

[0347] In FIG12 , the bus architecture may include any number of interconnected buses and bridges, specifically linking various circuits of one or more processors represented by processor 1200 and memory represented by memory 1220. The bus architecture may also link various other circuits, such as peripherals, voltage regulators, and power management circuits, all of which are well known in the art and, therefore, will not be further described herein. The bus interface provides an interface. The transceiver 1210 may be a plurality of components, including a transmitter and a transceiver, providing a unit for communicating with various other devices over a transmission medium. For different devices, the user interface 1230 may also be an interface capable of connecting external or internal devices as required, including but not limited to keypads, displays, speakers, microphones, joysticks, and the like. The processor 1200 is responsible for managing the bus architecture and general processing, while the memory 1220 may store data used by the processor 1200 when performing operations.

[0348] Optionally, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0349] Send the first synchronization channel on a target resource in a first resource set, wherein the target resource is one of the following:

[0350] The resources corresponding to any time slot number;

[0351] The resources corresponding to a specific time slot number;

[0352] The resource corresponding to any time slot number in a specific time slot number set.

[0353] Optionally, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0354] In a case where the first synchronization channel includes a first PSCCH and a first PSSCH, a preset time slot number is used to generate a demodulation reference signal DMRS of the first PSCCH and / or a DMRS of the first PSSCH, and the first PSCCH or the first PSSCH carries a time slot number corresponding to a target resource, and the target resource is a transmission resource of the first synchronization channel; or

[0355] In a case where the first synchronization channel includes the first PSCCH and the first SL-PRS, a preset time slot number is used to generate the DMRS and the first SL-PRS of the first PSCCH, and the first PSCCH carries the time slot number corresponding to the target resource; or

[0356] In a case where the first synchronization channel includes the first PSCCH and the first SL-PRS, a DMRS of the first PSCCH is generated by using a preset time slot number, and the first PSCCH carries the time slot number corresponding to the target resource; or

[0357] In a case where the first synchronization channel includes the first PSCCH, the first PSSCH, and the first PSFCH, indicating the timeslot number corresponding to the target resource through the first PSFCH; or

[0358] In a case where the first synchronization channel includes a first PSFCH, the time slot number corresponding to the target resource is indicated by the first PSFCH.

[0359] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0360] 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:

[0361] Sending the first PSFCH on a first resource subset;

[0362] Sending a second PSFCH on a second resource subset; wherein the second PSFCH is generated using a preconfigured sequence;

[0363] The first PSFCH and the second PSFCH include one or more PSFCHs;

[0364] 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 but overlap in the time domain.

[0365] Optionally, 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 a synchronization process.

[0366] Optionally, the processor 1200 is configured to read a program in the memory 1220 to implement the following steps:

[0367] receiving a second synchronization channel sent by the second device;

[0368] performing timing measurement according to the second synchronization channel to obtain a timing measurement result;

[0369] A third synchronization channel is sent 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.

[0370] The first device provided in the present application 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 PSCCH, a first PSSCH, a first SL-PRS and a first PSFCH, which can enable the second device to realize the synchronization process of the direct link in the absence of GNSS coverage.

[0371] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing relevant hardware through a computer program, wherein the computer program includes instructions for executing part or all of the steps of the above method; and the computer program may be stored in a readable storage medium, which may be any form of storage medium.

[0372] Sixth embodiment

[0373] In order to better achieve the above objectives, as shown in FIG13 , the fourth embodiment of the present application further provides a second device, including:

[0374] A processor 1300; and a memory 1320 connected to the processor 1300 via a bus interface, wherein the memory 1320 is used to store programs and data used by the processor 1300 when performing operations, and the processor 1300 calls and executes the programs and data stored in the memory 1320.

[0375] The 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:

[0376] 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;

[0377] Acquire first synchronization information carried in the first synchronization channel;

[0378] A first synchronization process is performed according to the first synchronization information.

[0379] In FIG13 , the bus architecture may include any number of interconnected buses and bridges, specifically linking various circuits such as one or more processors represented by processor 1300 and memory represented by memory 1320. The bus architecture may also link various other circuits such as peripherals, voltage regulators, and power management circuits, all of which are well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 1310 may be a plurality of components, including a transmitter and a transceiver, providing a unit for communicating with various other devices over a transmission medium. For different devices, the user interface 1330 may also be an interface capable of connecting external or internal devices as needed, including but not limited to keypads, displays, speakers, microphones, joysticks, and the like. The processor 1300 is responsible for managing the bus architecture and general processing, while the memory 1320 may store data used by the processor 1300 when performing operations.

[0380] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0381] Obtaining a time slot number corresponding to a target resource, where the target resource is a transmission resource of the first synchronization channel;

[0382] The first synchronization channel is decoded according to the time slot number corresponding to the target resource to obtain the first synchronization information.

[0383] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0384] determining a rising edge and / or a falling edge of energy change according to the energy measurement result;

[0385] The starting boundary and / or ending boundary of the time slot is determined according to the rising edge and / or falling edge, and the starting symbol position and symbol number configuration of the first synchronization channel in the time slot.

[0386] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement one of the following steps:

[0387] Traversing all time slot numbers, performing blind detection on the DMRS of the first synchronization channel, and determining the time slot number corresponding to the target resource; or

[0388] Determine the specific time slot number as the time slot number corresponding to the target resource; or

[0389] Traversing the time slot numbers in the specific time slot number set, performing blind detection on the DMRS of the first synchronization channel, and determining the time slot number corresponding to the target resource;

[0390] Decoding the first synchronization channel using a preset time slot number to obtain a time slot number corresponding to the target resource carried in the first PSSCH or the first PSCCH;

[0391] In the case where the first synchronization channel includes at least a first PSFCH, the first PSFCH is detected according to the energy waveform to obtain the time slot number corresponding to the target resource indicated by the first PSFCH.

[0392] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0393] According to the rising edge and / or falling edge of the energy change, the starting symbol position and symbol number configuration of the first PSCCH in the time slot, as well as the configuration information of the SL-PRS resources in the time slot, determine the starting boundary and / or ending boundary of the time slot.

[0394] Optionally, when the first synchronization channel includes the first SL-PRS, each time slot includes an SL-PRS resource, or the time slot where the first synchronization channel is located does not support multi-user time division multiplexing TDM.

[0395] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0396] The starting boundary and / or ending boundary of the time slot is determined according to the rising edge and / or falling edge of the energy change and the PSFCH resource configuration information.

[0397] 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:

[0398] Receiving the first PSFCH sent by the first device on a first resource subset;

[0399] 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;

[0400] A search is performed according to the second PSFCH to perform frequency synchronization.

[0401] Optionally, the first synchronization channel carries a synchronization flag bit, and the synchronization flag bit is used to indicate that the first synchronization channel can be used for a synchronization process.

[0402] Optionally, the processor 1300 is configured to read a program in the memory 1320 to implement the following steps:

[0403] sending a second synchronization channel to the first device;

[0404] 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;

[0405] A second synchronization process is performed according to the second synchronization signal.

[0406] The second device provided in the present application receives a first synchronization channel transmitted by the first device, the first synchronization channel including at least one of the following: a first PSCCH, a first PSSCH, a first SL-PRS, and a first PSFCH; obtains first synchronization information carried in the first synchronization channel; and performs a first synchronization process based on the first synchronization information. In this way, a synchronization process for a direct link can be implemented in the absence of GNSS coverage.

[0407] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing relevant hardware through a computer program, wherein the computer program includes instructions for executing part or all of the steps of the above method; and the computer program may be stored in a readable storage medium, which may be any form of storage medium.

[0408] In addition, a specific embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When executed by a processor, the program implements the steps of the method described in the first or second embodiment. The program can achieve the same technical effects and, to avoid repetition, is not further described here.

[0409] In addition, it should be noted that, in the apparatus and method of the present application, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present application. Moreover, the steps of performing the above-mentioned series of processes can naturally be performed in chronological order according to the order of description, but do not necessarily need to be performed in chronological order, and some steps can be performed in parallel or independently of each other. For those of ordinary skill in the art, it will be understood that all or any steps or components of the method and apparatus of the present application can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices with 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 application.

[0410] Therefore, the purpose of the present application can also be achieved by running a program or a group of programs on any computing device. The computing device can be a well-known general-purpose device. Therefore, the purpose of the present application can also be achieved simply by providing a program product containing program code that implements the method or device. That is to say, such a program product also constitutes the present application, and the storage medium storing such a program product also constitutes the present application. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be pointed out that in the device and method of the present application, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present application. In addition, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but do not necessarily need to be performed in chronological order. Certain steps can be performed in parallel or independently of each other.

[0411] The above is an optional implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A synchronization method for a direct link, applied to a first device, the synchronization method for the direct link comprising: Sending a first synchronization channel to a second device, the first synchronization channel carrying 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).

2. The synchronization method for the direct link according to claim 1, wherein, 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 the direct link according to claim 1, the method further comprising: In the case where 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, the target resource being the transmission resource of the first synchronization channel; or In the case where 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 In the case where 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 In the case where 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 In the case where 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, wherein, 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).

5. The synchronization method for a direct link according to claim 1, wherein, In the case where 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 but overlap in the time domain.

6. The synchronization method of the direct link according to claim 1, wherein, 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 for a 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 sidelink synchronization method applied to a second device, the sidelink synchronization method includes: Receiving a first synchronization channel sent by a first device, the first synchronization channel including 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 for a direct link according to claim 8, wherein, The obtaining of 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 for 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 an 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 a start symbol position and symbol number configuration of the first synchronization channel in the time slot.

11. The synchronization method of the direct link according to claim 9, wherein, The obtaining of 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 time slot number set, blindly detecting the DMRS of the first synchronization channel to determine the time slot number corresponding to the target resource; Decoding 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; 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 for a 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 of 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: 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, the configuration of the starting symbol position and the number of symbols of the first PSCCH in the time slot, and the configuration information of the SL-PRS resources in the time slot.

13. The synchronization method for the direct link according to claim 12, wherein, 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, wherein, When the first synchronization channel includes at least the first PSFCH, the determination of the start boundary of the time slot according to the rising edge and / or falling edge, and the configuration of the starting symbol position and the number of symbols of the first synchronization channel in the time slot includes: 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.

15. The synchronization method of the direct link according to claim 8, wherein, When the first synchronization channel includes the first PSFCH, the receiving of 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: Perform frequency synchronization by searching according to the second PSFCH.

16. The synchronization method for a direct link according to claim 8, wherein, 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 for a direct link according to claim 8, wherein, 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 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; Perform 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, the steps of the direct link synchronization method according to any one of claims 1 to 7 are implemented.

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, the steps of the direct link synchronization method according to any one of claims 8 to 17 are implemented.

20. A direct link synchronization device applied to a first device, the direct link synchronization device includes: A first transmission module, configured to transmit 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).

21. A sidelink synchronization device, applied to a second device, the sidelink synchronization device includes: A second receiving module, configured to receive the first synchronization channel sent by a first device, the first synchronization channel including 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 the 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, on which a computer program is stored, and when the computer program is executed by a processor, it 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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