WO2020200002A1

WO2020200002A1 - Communication method and terminal device

Info

Publication number: WO2020200002A1
Application number: PCT/CN2020/081064
Authority: WO
Inventors: 黎超; 袁璞; 张兴炜; 黄海宁
Original assignee: 华为技术有限公司
Priority date: 2019-03-29
Filing date: 2020-03-25
Publication date: 2020-10-08
Also published as: CN111757458A; CN111757458B

Abstract

The present application sets forth a communication method and a terminal device, the method comprising: a first terminal device determining, in accordance with synchronization information of said first terminal device, a first reference signal sequence, and/or, the first terminal device determining, in accordance with synchronization information of said first terminal device, resources used for sending a first reference signal; the first terminal device sending the first reference signal to a second terminal device; wherein, the synchronization information comprising at least one of the following information items: a type of synchronization source of the first terminal device; a hop count from the first terminal device to a satellite or to a network device; whether the first terminal device directly synchronizes to the satellite or to the network device; whether the first terminal device is within the coverage range of a network device. The communication method and terminal device of the present application may be applied in an Internet of Vehicles, for instance V2X, LTE-V, NR-V, V2V, etc., and enhance terminal device synchronization efficiency.

Description

Communication method and terminal device

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201910252643.8, and the application name is "Communication Method and Terminal Device" on March 29, 2019, the entire content of which is incorporated into this application by reference.

Technical field

This application relates to the field of communication technology, and in particular to a communication method and terminal device.

Background technique

Device-to-device (D2D) communication, vehicle-to-vehicle (V2V) communication, vehicle-to-pedestrian (V2P) communication, or vehicle-to-infrastructure/network (V2I/ N) Communication is a technology for direct communication between terminal devices, vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (vehicle to pedestrian, V2P) are collectively referred to as V2X (vehicle to everything, V2X), that is, the vehicle communicates with everything.

D2D and V2X communication needs to achieve synchronization between communicating terminal devices. When the communicating UE can directly detect the network or GNSS, the best strategy for the UE is to synchronize to these devices. When the UE cannot detect the network or GNSS, the UE can synchronize to the synchronization source UE that sends the synchronization signal. However, in order to control the system overhead, the transmission period of the synchronization signal is usually relatively long. For example, the period of the LTE-V2X synchronization signal is 160 ms. In this case, if the UE misses the detection or misses the synchronization signal, it will increase the time for the device to obtain the timing and lock the frequency, thereby affecting the communication performance. Therefore, how to improve the signal synchronization efficiency of the terminal device has become an important issue to be solved urgently.

Summary of the invention

The present application provides a communication method and terminal device, which can improve the efficiency of signal synchronization of the terminal device.

In a first aspect, a communication method is provided, including: a first terminal device determines a sequence of a first reference signal according to synchronization information of the first terminal device, and/or, the first terminal device determines a sequence of a first reference signal according to the first terminal device The synchronization information of the device determines the resource used to send the first reference signal; the first terminal device sends the first reference signal to the second terminal device; wherein the synchronization information includes at least one of the following information: The type of synchronization source of the first terminal device, the number of hops between the first terminal device and the satellite or network equipment, whether the first terminal device is directly synchronized to the satellite or network equipment, whether the first terminal device In the coverage of network equipment.

In the embodiment of the present application, the first terminal device may use the parameters of the sequence of generating the first reference signal to indicate or carry synchronization information. Optionally, the first terminal device may only be a device that transmits a sidelink synchronization signal SLSS (sidelink synchronization signal), or the first terminal device may only be a device that does not transmit an SLSS.

For example, the first terminal device may use the parameters of the sequence generating the reference signal (RS) to indicate the synchronization information, the first terminal device may be a device that sends a synchronization signal, or the first terminal device may not send a synchronization signal Device.

The first terminal device uses the parameters of the corresponding synchronization sequence to generate the corresponding RS according to the corresponding synchronization information, and then sends the corresponding RS to the second terminal device.

For example, when the synchronization information indicated by the sequence of the reference signal sent by the first terminal device is 1 bit, the sequence of the reference signal includes RS1 and RS2, and the first terminal device sends RS1 or RS2 to the second terminal device according to the synchronization information to be transmitted. .

For example, when the indicated synchronization information is 2 bits, the sequence of the reference signal includes RS1, RS2, RS3, RS4, and the first terminal device sends RS1, RS2, RS3, or RS4 to the second terminal device according to the synchronization information to be transmitted.

With reference to the first aspect, in some implementations of the first aspect, the synchronization information of the first terminal device is used by the second terminal device to determine the synchronization source of the second terminal device.

With reference to the first aspect, in some implementation manners of the first aspect, the first terminal device determining the sequence of the first reference signal according to the synchronization information of the first terminal device includes: The synchronization information determines a parameter of the sequence of the first reference signal, and the parameter includes at least one of the following parameters: the initial value of the sequence of the first reference signal, the root sequence number, the cyclic shift value of the sequence, Orthogonal cover code (OCC) and sequence length of the sequence.

With reference to the first aspect, in some implementation manners of the first aspect, the first terminal device determining the resource for sending the first reference signal according to the synchronization information of the first terminal device includes: the first terminal device according to The synchronization information determines the subcarrier of the first reference signal in the physical resource block.

With reference to the first aspect, in some implementation manners of the first aspect, the first terminal device determining the sequence of the first reference signal according to the synchronization information of the first terminal device includes: the first terminal device according to the synchronization information Information and the synchronization signal identifier used by the first device to determine at least one of the following parameters of the sequence of the first reference signal: the initial value of the sequence of the first reference signal, the root sequence number, and the cyclic shift of the sequence Bit value, sequence orthogonal cover code OCC, sequence length.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: the first terminal device determines the first reference signal according to the number of symbols in the time slot in which the first reference signal is carried And/or, the first terminal device determines the sequence length of the first reference signal according to the bandwidth of the first reference signal.

With reference to the first aspect, in some implementation manners of the first aspect, the first terminal device determines the resource for sending the first reference signal according to the synchronization information of the first terminal device, including: the first terminal The apparatus determines the resource for sending the first reference signal according to the resource mapping mode of the synchronization information and the first reference signal; wherein the resource mapping mode of the synchronization information and the first reference signal includes: The synchronization information is mapped on two adjacent symbols of the time slot where the first reference signal is located; the time slot where the first reference signal is located includes at least two symbols.

With reference to the first aspect, in some implementations of the first aspect, the type of the synchronization source includes at least one of the following: Global Navigation Satellite System GNSS, terminal devices synchronized to the GNSS, NR network equipment, synchronization Terminal devices to the NR base station equipment, LTE base station equipment, and equipment synchronized to the LTE base station equipment.

With reference to the first aspect, in some implementations of the first aspect, the first reference signal includes any one of the following reference signals: a demodulation reference signal (demodulation reference signal, DMRS) used for control channels, Demodulation reference signal DMRS for data channel, demodulation reference signal DMRS for broadcast channel, reference signal for feedback channel, channel state information reference signal (channel state information-reference signal, CSI-RS), phase tracking reference Signal (phase tracking reference signal, PT-RS).

For example, for different types of reference signals, the reference signal RS#1 may be the DMRS used when UE#1 transmits data, and/or the DMRS used for control information when UE#1 transmits scheduling data.

With reference to the first aspect, in some implementations of the first aspect, before the first terminal device sends the first reference signal to the second terminal device, the method further includes: the first terminal device determines The sequence length of the first reference signal is greater than a first preset value; or the first terminal device determines that the bandwidth of the first reference signal is greater than a second preset value.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: the first terminal device sends first control information to the second terminal device, where the first control information is used to indicate Part or all of the synchronization information of the first terminal device; or, the cyclic redundancy check code of the first control information is used to indicate part or all of the synchronization information of the first terminal device.

With reference to the first aspect, in some implementations of the first aspect, the method further includes: the first terminal device sends first data to the second terminal device, and the cyclic redundancy correction of the first data The verification code is used to indicate part or all of the synchronization information of the first terminal device.

With reference to the first aspect, in some implementations of the first aspect, before the first terminal device sends the first reference signal to the second terminal device, the method further includes: the first terminal device determines The first terminal device supports synchronization based on the first reference signal.

With reference to the first aspect, in some implementations of the first aspect, the first reference signal, the first control information, and/or the first data are located in the same time slot; or, the first reference The signal, the first control information and/or the first data are located in multiple consecutive time slots in the time domain.

In a second aspect, a communication method is provided, including: a second terminal device receives a first reference signal from a first terminal device; the second terminal device determines the first reference signal according to a sequence of the first reference signal The synchronization information of the terminal device, and/or the second terminal device determines the synchronization information of the first terminal device according to the resource of the first reference signal; the second terminal device determines the synchronization information of the first terminal device according to the The synchronization information determines the synchronization source of the second terminal device; wherein the synchronization information includes at least one of the following information: the type of the synchronization source of the first terminal device, the synchronization source of the first terminal device and The number of synchronization hops between satellites, whether the first terminal device is directly synchronized to the satellite or network equipment, and whether the first terminal device is within the coverage of the network equipment.

In the embodiment of the present application, the second terminal device may detect different reference signals (RS) corresponding to the synchronization information, and the second terminal device obtains the synchronization information of the first terminal device according to the received different RSs.

For example, the second terminal device acquires the synchronization information of the first terminal device according to the sequence of the reference signal RS#1 transmitted by the first terminal device.

When the synchronization information indicated by the sequence of the reference signal sent by the first terminal device is 1 bit, the second terminal device detects the sequence actually used by the first terminal device from the two candidate synchronization sequences (RS1, RS2) to obtain Up to this 1-bit synchronization information.

When the synchronization information indicated by the sequence of the reference signal sent by the first terminal device is 2 bits, the second terminal device detects from the 4 candidate synchronization sequences (RS1, RS2, RS3, RS4), the actual use of the first terminal device Sequence to obtain the 2-bit synchronization information actually transmitted.

With reference to the second aspect, in some implementation manners of the second aspect, the second terminal device determining synchronization information of the first terminal device according to the resource of the first reference signal includes: the second terminal device The synchronization information of the first terminal device is determined according to the subcarriers of the first reference signal in the physical resource block.

With reference to the second aspect, in some implementations of the second aspect, the synchronization information is used by the second terminal device to determine the synchronization source of the second terminal device.

With reference to the second aspect, in some implementations of the second aspect, the second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device, including: the second terminal The device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device and the priority information of the synchronization source.

With reference to the second aspect, in some implementations of the second aspect, the method further includes: the second terminal device detects the signal quality of the first reference signal; when the signal quality of the first reference signal is greater than At the first threshold, the second terminal device uses the first terminal device as a candidate synchronization source; the second device determines the synchronization source of the second device according to the candidate synchronization source.

With reference to the second aspect, in some implementations of the second aspect, the method further includes: the second terminal device receives the first data and/or first control information from the first terminal device; When the first terminal device satisfies a preset condition, the second terminal device uses the first terminal device as a candidate synchronization source; the second device determines the synchronization source of the second device according to the candidate synchronization source; Wherein, the preset condition includes at least one of the following conditions: the cyclic redundancy check code of the first data is checked correctly; or the cyclic redundancy check code of the first control information is checked correctly Or, the bandwidth of the first reference signal is greater than a first preset value.

With reference to the second aspect, in some implementation manners of the second aspect, the method further includes: the second terminal device receiving first data and/or first control information from the first terminal device; The second terminal device determines the synchronization information of the first terminal device according to the DMRS of the first data and the DMRS of the first control information; or the second terminal device determines the synchronization information of the first terminal device according to the cyclic redundancy calibration of the first data. The verification code and/or the cyclic redundancy check code of the first control information determines the synchronization information of the first terminal device.

With reference to the second aspect, in some implementations of the second aspect, the method further includes: the second terminal device detects the side link synchronization signal sent by the third device, and the second terminal device detects A priority information determines the synchronization source of the second terminal device, and the first priority information includes any one of the following: the number of hops that the third device synchronizes to a satellite or a base station and the first terminal device The number of hops synchronized to the satellite or base station is the same, and the priority of the first terminal device and the third device are the same; the number of hops synchronized to the satellite or the base station by the third device is the same as that of the first terminal device to the satellite Or the number of hops of the base station is the same, the first terminal device has a higher priority relative to the third device; the third device is synchronized to the satellite or the number of hops of the base station is synchronized to the satellite Or the number of hops of the base station is the same, the first terminal device has a lower priority relative to the third device; the third device is synchronized to the satellite or the number of hops of the base station is synchronized to the satellite Or the number of hops of the base station is the same, and the first terminal device determines the priorities of the first terminal device and the third device according to pre-configuration information.

With reference to the second aspect, in some implementations of the second aspect, before the second terminal device receives the first reference signal from the first terminal device, the method further includes: the second terminal device determines the second The terminal device supports synchronization based on the first reference signal.

With reference to the second aspect, in some implementations of the second aspect, the type of the synchronization source includes at least one of the following: Global Navigation Satellite System GNSS, equipment synchronized to the GNSS, NR base station equipment, synchronized to The equipment of the NR base station equipment, the LTE base station equipment, and the equipment synchronized to the LTE base station equipment.

With reference to the second aspect, in some implementations of the second aspect, the first reference signal includes any one of the following signals: a demodulation reference signal DMRS for a control channel, a demodulation reference signal DMRS for a data channel, and a broadcast Channel demodulation reference signal DMRS, feedback channel reference signal, channel state information reference signal CSI-RS, phase tracking reference signal PT-RS.

With reference to the second aspect, in some implementations of the second aspect, the first reference signal, the first control information, and/or the first data are located in the same time slot; or the first reference signal , The first control information and/or the first data are located in multiple consecutive time slots in the time domain.

With reference to the second aspect, in some implementations of the second aspect, the first terminal device is a device that sends a synchronization signal, or the first terminal device is a device that does not send a synchronization signal.

In a third aspect, a communication device is provided, and the terminal device is configured to execute the method in any one of the possible implementation manners of the first aspect or the second aspect.

Specifically, the terminal device may include a module for executing the method in any one of the possible implementation manners of the first aspect or the second aspect. The terminal device may be a network device, a terminal, a chip applied to a network device or a terminal, or other combination devices, components, etc. having the functions of the network device or terminal. When the terminal device is a network device or terminal, the receiving module may be a receiver, which may include an antenna and a radio frequency circuit, etc., the processing module may be a processor, for example, a central processing unit (CPU), and the sending module may be a transmitter. It may include antennas and radio frequency circuits, etc., where the receiver and transmitter may be integrated transceivers. When the terminal device is a component with the aforementioned network equipment or terminal function, the receiving module may be a radio frequency unit, the processing module may be a processor, and the sending module may be a radio frequency unit. When the terminal device is a chip system, the receiving module may be an input port of the chip system, the processing module may be a processor of the chip system, and the sending module may be an output port of the chip system.

In a fourth aspect, a communication device is provided. The terminal device includes a memory and a processor, the memory is used to store instructions, and the processor is used to execute instructions stored in the memory, and perform operations on the instructions stored in the memory. Executing causes the processor to execute the method in any one of the possible implementation manners of the first aspect or the second aspect.

In one design, the device is a communication chip, and the communication chip may include an input circuit or interface for sending information or data, and an output circuit or interface for receiving information or data.

In another design, the apparatus is a communication device, and the communication device may include a device for sending information or data and a device for receiving information or data.

In a fifth aspect, a computer-readable medium is provided, and the computer-readable medium stores a computer program (also called code, or instruction) when it runs on a computer, causing the computer to execute the first aspect to the first aspect. The method in any one of the two possible implementation modes.

Description of the drawings

Fig. 1 shows a schematic scene diagram of the communication method provided by the present application.

Fig. 2 shows a schematic scene diagram of the communication method provided by the present application.

Fig. 3 shows a schematic interaction diagram of a communication method of the present application.

Fig. 4 shows a schematic flowchart of a communication method of the present application.

Fig. 5 shows a schematic flowchart of another communication method of the present application.

Fig. 6 shows a schematic interaction diagram of another communication method of the present application.

Fig. 7 shows a schematic flowchart of yet another communication method of the present application.

Fig. 8 shows a schematic flowchart of yet another communication method of the present application.

Fig. 9 shows a schematic flowchart of yet another communication method of the present application.

Fig. 10 shows a schematic flowchart of yet another communication method of the present application.

FIG. 11 shows a schematic structural diagram of the reference signal sequence of the present application.

FIG. 12 shows a schematic structural diagram of the reference signal sequence of the present application.

FIG. 13 shows a schematic structural diagram of the sequence of the reference signal of the present application.

FIG. 14 shows a schematic structural diagram of reference signal resources of the present application.

FIG. 15 shows a schematic structural diagram of a terminal device provided by this application.

FIG. 16 shows a schematic structural diagram of a terminal device provided by this application.

detailed description

The technical solution in this application will be described below in conjunction with the drawings.

The technical solutions of the embodiments of this application can be applied to various communication systems, such as: Global System of Mobile Communication (GSM) system, Code Division Multiple Access (CDMA) system, and Wideband Code Division Multiple Access (Wideband Code Division Multiple Access, WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, the future 5th Generation (5th Generation, 5G) system or New Radio (NR), etc.

The terminal equipment in the embodiments of the present application may refer to user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile equipment, user terminal, terminal, wireless Communication equipment, user agent or user device. The terminal device can also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (Wireless Local Loop, WLL) station, a personal digital processing (Personal Digital Assistant, PDA), with wireless communication Functional handheld devices, computing devices, or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in the future 5G network, or future evolution of the public land mobile network (Public Land Mobile Network, PLMN) Terminal equipment, etc., this embodiment of the present application does not limit this.

The network device in the embodiment of the application may be a device used to communicate with a terminal device. The network device may be a Global System of Mobile Communication (GSM) system or Code Division Multiple Access (CDMA) The base station (Base Transceiver Station, BTS) in the LTE system can also be the base station (NodeB, NB) in the Wideband Code Division Multiple Access (WCDMA) system, or the evolutionary base station (Evolutional Base Station) in the LTE system. NodeB, eNB, or eNodeB), it can also be a wireless controller in Cloud Radio Access Network (CRAN) scenarios, or the network device can be a relay station, access point, vehicle-mounted device, wearable device, and future The network equipment in the 5G network or the network equipment in the future evolved PLMN network, etc., are not limited in the embodiment of the present application.

The terminal device in the embodiments of the present application may be a network device, a terminal, a chip applied to a network device or terminal, or other combination devices or components with the above-mentioned network device or terminal function.

The communication method of this application can be applied to device to device (D2D) communication, vehicle to vehicle (V2V) communication, vehicle to pedestrian (Vehicle to Pedestrian, V2P) communication, or vehicle to infrastructure/network ( Vehicle to Infrastructure/Network, V2I/N) communication.

D2D and V2X communication needs to achieve synchronization between communicating terminal devices. When the communicating terminal device can directly detect the network or GNSS, the best strategy for the terminal device is to synchronize to these devices. When the terminal device cannot detect the network or GNSS, the terminal device can synchronize to the synchronization source terminal device that sends the synchronization signal. However, in order to control the system overhead, the transmission period of the synchronization signal is usually relatively long. For example, the period of the LTE-V2X synchronization signal is 160 ms. In this case, if the terminal device misses the detection or misses the synchronization signal, it will increase the time for the device to obtain the timing and lock the frequency, thereby affecting the communication performance.

Hereinafter, a brief introduction to the relevant terms involved in this application is given.

1. CAZAC sequence

CAZAC (Const Amplitude Zero Auto-Corelation), namely constant envelope zero auto-correlation sequence, CAZAC sequence characteristics include the following characteristics: 1. Constant envelope characteristics: CAZAC sequence of any length has a constant amplitude. 2. Ideal periodic autocorrelation characteristics: After any CAZAC sequence is shifted by n bits, and n is not an integral multiple of the period of the CAZAC sequence, the shifted sequence is not related to the original sequence. 3. Good cross-correlation characteristics: the cross-correlation and partial correlation values are close to 0. 4. Low peak-to-average ratio: The signal composed of any CAZAC sequence has a very low ratio of its peak value to its average value. 5. CAZAC sequence after Fourier transform: any CAZAC sequence is still CAZAC sequence after Fourier positive and negative changes.

CAZAC sequences are now widely used in the field of pulse radar compression, spread spectrum communication systems (synchronous CDMA and MC-CDMA), and OFDM systems (LTE and WiMAX). CAZAC sequence mainly includes Zadoff-off sequence (ie ZC sequence), Frank sequence, Golomb polyphase sequence and Chirp sequence. CAZAC sequence is often used in synchronization algorithms of communication systems. Among them, the ZC sequence has good auto-correlation and cross-correlation characteristics, so it is selected as the pilot sequence in the wireless communication system, and is specifically applied to the primary synchronization signal (Primary Synchronization Signal, PSS) and uplink in the downlink. Reference Signal (RS) and Preamble (Preamble) sequence in the uplink physical random access channel (Physical Random Access Channel, PRACH).

2. Reference signal

RS (Reference Signal) reference signal is the "pilot" signal. Among them, the downlink reference signal has two functions: 1. Downlink channel quality measurement; 2. Downlink channel estimation, used for coherent detection and demodulation on the terminal equipment side. For the OFDM system, the downlink reference signal is based on REs, that is, one reference signal occupies one RE (resource element).

In this application, for the convenience of description, the reference signal sent by the first terminal device is abbreviated as RS#1, which is the first reference signal mentioned in this application.

For example, the reference signal can be divided into two columns: reference signal #1 and reference signal #2, where reference signal #1 is located in the first OFDM symbol of slot 0, and reference signal #2 is located in the third OFDM symbol from the bottom of the slot. symbol. The reference signal #1 located in the first OFDM symbol helps the downlink control signal to be demodulated as soon as possible. In the frequency domain, a reference signal is inserted every 6 subcarriers. This value is the result of balancing channel estimation performance and RS overhead. It can not only achieve good channel estimation performance in typical frequency selective fading channels, but also Control RS at a low level. The time domain density of RS is that two rows of RS are inserted in each slot.

Figure 1 shows a schematic diagram of an application scenario of the communication method of the present application. It should be noted that the following uses UE as an example. For the convenience of description, as a shorthand description, UE#1, UE#2, UE#3, UE#4, UE#5, UE#6, UE Any one or more of #7 can be considered as a specific example of the first terminal device and the third terminal device when it is a transmitter; it can be considered as a specific example of the second terminal device when it is a receiver . The foregoing description of the present invention does not constitute a limitation on the scope of the first terminal device, the second terminal device, and the third terminal device.

As shown in Figure 1, the communication method of the present application can be applied to the Internet of Vehicles. In the signal synchronization system of the Internet of Vehicles, it includes: multiple vehicle-mounted devices (UE#1, UE#2, UE#3), between vehicle-mounted devices Can communicate with each other; one or more roadside units (RSU) can communicate with various vehicle-mounted equipment and/or eNB; one or more LTE base station equipment (eNB) can communicate with each vehicle-mounted equipment and/or RSU; One or more NR base station equipment (gNB), which can communicate with various vehicle-mounted equipment and/or RSU; one or more global navigation satellite systems (GNSS: global navigation satellite system), which can provide positioning and positioning for multiple vehicle-mounted equipment Timing information. Among them, the function of the RSU unit can be either a function of a vehicle-mounted device, a function of an eNB or gNB device, or a function of a vehicle-mounted device + an eNB device.

The vehicle-mounted equipment moves at a high speed with the vehicle, and the relative movement between UE#1 and UE#2 has the maximum relative moving speed. The above-mentioned various devices can communicate with each other, and the spectrum of the cellular link can be used for communication, and the spectrum of intelligent traffic can also be used, for example, the spectrum near 5.9 GHz. The technology for each device to communicate with each other can be enhanced based on the LTE protocol, can also be enhanced based on the D2D technology, or it can be a newly defined side link system in NR. Among them, eNB and/or gNB are optional. If there is eNB and/or gNB, it is a scenario with network coverage; if there is no eNB or gNB, it is a scenario without network coverage.

Hereinafter, in order to facilitate the understanding of the communication method of the present application, the first terminal device and the second terminal device are referred to as UE#1 and UE#2, respectively.

Figure 2 shows a schematic diagram of a network structure of multiple types of synchronization sources.

As shown in Figure 2, UE#2 can detect synchronization signals and/or reference signals sent from UE#1, UE#3, and UE#7. Therefore, when UE#1, UE#3, and UE#7 meet the preset requirements Under conditions, UE#1, UE#3, and UE#7 can be used as candidate synchronization sources for UE#2.

For example, UE#2 can receive data #D1 and/or scheduling assignment (SA) information sent from UE#1 (or UE#3, UE#7); when UE#1, UE#3, UE# 7 When the preset conditions are met, UE#1, UE#3, and UE#7 can be used as candidate synchronization sources of UE#2 or directly determined as synchronization sources. Optionally, SA is usually used to indicate the transmission parameters of data #D1 so that the receiver can be used to demodulate and decode the data. For example, these sending parameters include indication information of time and frequency resources for transmitting data, indication information of modulation and coding mode, indication information of retransmission, etc.

For example, the above-mentioned preset condition may include at least one of the following conditions: the cyclic redundancy check of data #D1 is correct or successful; the cyclic redundancy check of the scheduled allocation SA information is correct or successful; reference The resource bandwidth occupied by the symbols of the signal RS#1 is greater than the first preset value; the sequence length of the reference signal RS#1 is greater than the second preset value.

In the embodiment of this application, when UE#1 sends a reference signal to UE#2, it can indicate to UE#2 that the candidate synchronization source type of UE#1 is GNSS, and that UE#2's hop count is The first hop, here, assume that the number of hops from GNSS to UE#1 is the 0th hop.

Since UE#2 can receive the reference signals sent by UE#1 and UE#3, when UE#1 and UE#3 have the same synchronization source, UE#2 can synchronize to the synchronization source according to UE#1 and UE#3. The number of hops selects the synchronization source; or, UE#2 can select the synchronization source according to the signal quality of the reference signals sent by UE#1 and UE#3. Among them, the synchronization source of UE#1 and UE#3 may be GNSS or eNB/gNB.

UE#2 simultaneously detects the synchronization signal SLSS sent by UE#3 and the reference signal RS sent by UE#1. Wherein, the synchronization source of UE#1 is GNSS, and UE#1 may carry synchronization information in the reference signal RS sent to it before the time when the synchronization signal is sent. UE#3 may be a UE that sends a synchronization signal, and UE#3 is synchronized to the GNSS or eNB, so that UE#2 can receive synchronization information sent by UE#1 and UE#3 at the same time.

In the embodiment of the present application, when UE#2 detects the synchronization signal SLSS sent by UE#3 and the reference signal RS sent by UE#1 at the same time, when the RS detected by UE#2 from UE#1 meets the preset condition, UE#2 can use UE#1 as the synchronization source of UE#2.

The following is a brief introduction to the synchronization information in this application.

In the embodiment of the present application, the synchronization information may be used to indicate at least one of the following information: the type of synchronization source of UE#1, the number of hops between UE#1 and the synchronization source GNSS or synchronization source gNB/eNB, UE Whether #1 is directly synchronized to a satellite or network equipment, and whether UE#1 is within the coverage of the network equipment.

For example, the type of synchronization source includes any one of GNSS, eNB, gNB, and UE. The UE may be: a UE that is synchronized to GNSS, a UE that is synchronized to an eNB, a UE that is synchronized to a gNB, or a UE that is not synchronized to other devices.

For example, the synchronization information may indicate that UE#1 is synchronized to GNSS, or gNB/eNB. The synchronization information may indicate the number of synchronization hops between UE#1 and GNSS or gNB/eNB.

It should be understood that the number of synchronization hops between UE#1 synchronized to GNSS or gNB/eNB can be understood as the number of timing transfers for UE#1 to synchronize to GNSS or gNB/eNB. For example, when the synchronization source of UE1# is GNSS, the number of synchronization hops between UE#1 and GNSS is 1. UE4 synchronizes to UE1, and UE1 directly synchronizes to GNSS, the number of hops from UE4 to GNSS is 2.

For another example, when there is less synchronization information, fewer bits can be used to indicate whether UE#1 is directly synchronized to a satellite or network device. For example, using 1 bit and a value of 1 indicates direct synchronization to a satellite or network device. A value of 0 means that it is not directly synchronized to a satellite or network device.

Another example: Or use fewer bits to indicate whether UE#1 is within the coverage of the network device. For example, 1 bit is used to indicate whether UE#1 is within the coverage of the network device. Being within the coverage of the network device here means that the UE can receive system messages sent from the network device, or can establish a connection state with the network device. Optionally, the network device may be a GNSS or gNB/eNB that sends a synchronization signal, and it may also be a UE that sends a synchronization signal.

Optionally, the synchronization information may only include the type of synchronization source of the first terminal device, the number of synchronization hops between the first terminal device and the GNSS or network equipment synchronization source, whether the first terminal device is directly synchronized to the satellite or network equipment, Whether the first terminal device is in any one of the multiple types of information within the coverage of the network device may also be any two, any three, or all four.

For example, optionally, the synchronization information may be the type of synchronization source and whether it is directly synchronized to GNSS or network equipment. For example, 1 bit can be used to indicate whether the synchronization source is a network device or a satellite; 1 bit can be used to indicate whether to directly synchronize to a GNSS or network device. The synchronization information is 2 bits in total.

For example, optionally, the synchronization information may include: the type of the synchronization source of the first terminal device, and the number of synchronization hops between the first terminal device and the synchronization source of the GNSS or network equipment. At this time, 1 bit can be used to indicate that the type of synchronization source is GNSS or network equipment, and 2 bits can be used to indicate the number of synchronization hops between the first terminal device and the synchronization source of the GNSS or network equipment.

For example, optionally, if the transmitter of the first reference signal of the present application can only be a UE synchronized to GNSS, the synchronization information is whether to directly synchronize to GNSS. Use 1 bit to indicate synchronization information.

Optionally, the synchronization information may include the type of synchronization source of the first terminal device, the number of synchronization hops between the first terminal device and the synchronization source of the GNSS or network equipment, and whether the first terminal device is within the coverage of the network equipment. Kind of information. A total of 4 bits can be used to indicate. At this time, 1 bit can be used to indicate that the type of synchronization source is GNSS or network equipment, 2 bits are used to indicate the number of synchronization hops between the first terminal device and the synchronization source of GNSS or network equipment, and 1 bit is used to indicate whether it is in the coverage of the network equipment. Inside.

Optionally, the synchronization information may include the type of the synchronization source of the first terminal device, the number of synchronization hops between the first terminal device and the GNSS or network equipment synchronization source, whether the first terminal device is directly synchronized to the satellite or network equipment, and the All four types of information are whether a terminal device is within the coverage of network equipment. A total of 5 bits can be used to indicate.

Optionally, in this embodiment of the present application, the priority of a UE that is directly synchronized to a satellite or network device is higher than that of a UE that is indirectly synchronized to a satellite or network device. Optionally, the priority of the UE synchronized to the GNSS is higher than that of the UE synchronized to the gNB/eNB, or the priority of the UE synchronized to the GNSS is lower than the priority of the UE synchronized to the gNB/eNB.

In the embodiment of the present application, the type of synchronization source of UE#1 may be Global Navigation Satellite System GNSS, terminal devices synchronized to the GNSS, NR network equipment, terminal devices synchronized to the NR base station equipment, LTE base station equipment , A device synchronized to the LTE base station device.

For example, the type of synchronization source of UE#1 in FIG. 2 may be Global Navigation Satellite System GNSS, UE#3 synchronized to GNSS, gNB/eNB, and UE#5 synchronized to gNB/eNB.

Fig. 3 shows a schematic interaction diagram of a communication method provided by the present application.

In S301, the first terminal device determines the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the first terminal device determines to send the first reference signal according to the synchronization information of the first terminal device. Signal resources.

Specifically, UE#1 determines the sequence of the reference signal RS#1 according to the synchronization information of UE#1; and/or UE#1 determines the resource for transmitting the reference signal RS#1 according to the synchronization information of UE#1.

Manner A#1: UE#1 determines the sequence of the reference signal RS#1 according to the synchronization information of UE#1.

In the embodiment of the present application, the sequence of the reference signal RS#1 may be a ZC sequence or a random sequence. The sequence parameters of the reference signal RS#1 include at least one of the following: the initial value of the sequence of the reference signal RS#1, the root sequence number, the cyclic shift value of the sequence, the orthogonal cover code OCC of the sequence, and the sequence length.

In the embodiment of the present application, UE#1 may use the parameters of the sequence generating the reference signal RS#1 to indicate or carry synchronization information. Optionally, UE#1 may only be a device that transmits a side link synchronization signal SLSS (Sidelink Synchronization Signal), or UE#1 may only be a device that does not transmit SLSS.

UE#1 uses the parameters of the corresponding synchronization sequence to generate the corresponding RS according to the corresponding synchronization information, and then sends the corresponding RS to UE#2.

For example, when the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 1 bit, the sequence of the reference signal includes RS1 and RS2, and UE#1 sends RS1 or RS2 to UE#2 according to the synchronization information to be transmitted.

For example, when the indicated synchronization information is 2 bits, the sequence of the reference signal includes RS1, RS2, RS3, and RS4, and UE#1 sends RS1, RS2, RS3, or RS4 to UE#2 according to the synchronization information to be transmitted.

Manner A#2: UE#1 determines the resource for transmitting the reference signal RS#1 according to the synchronization information of UE#1.

Optionally, the resources here may be any one or more of frequency domain resources and time domain resources.

For example, specifically, UE#1 determines the subcarrier of the reference signal RS#1 in the physical resource block according to the synchronization information.

For example, determine which REs in a physical resource block (PRB). For example, if a PRB occupies 12 REs, when there are 2 REs in each PRB, the position of RS#1 in the PRB can be n, n+6, where n=0,1,2,...,5 . For another example, if a PRB occupies 12 REs, when there are 3 REs in each PRB, the position of RS#1 in the PRB can be n, n+4, n+8, where n=0,1, 2, 3. For another example, if a PRB occupies 12 REs, when there are 4 REs in each PRB, the position of RS#1 in the PRB can be n, n+3, n+6, n+8, where n= 0,1,2. When n takes different values, the position of RS#1 in the PRB can be used to indicate different states or values of synchronization information.

Optionally, when UE#1 determines the subcarrier of reference signal RS#1 in the physical resource block according to the synchronization information, the transmit power on RS#1 is higher than the power of the subcarrier occupied by data or control information by a preset value. value. This preset value may be indicated by signaling, or pre-configured or predefined. For example, this preset value is 1, 2 or 3dB.

For example, UE#1 determines the symbol position of the reference signal RS#1 in the time slot according to the synchronization information.

In S302, the first terminal device sends the first reference signal to the second terminal device.

Specifically, UE#1 sends the reference signal RS#1 to UE#2.

Further optionally, RS#1 may be multiple reference signals RS of the same type in the same time slot, or multiple reference signals of different types in the same time slot.

For example, for different types of reference signals, the reference signal RS#1 may be a DMRS used when UE#1 transmits data, and/or a DMRS used for control information when UE#1 transmits scheduling data.

For another example, the reference signal RS#1 may be a reference signal RS that is sent together when UE#1 sends scheduling data, including PT-RS, CSI-RS, or RS used in the feedback channel PSFCH.

For another example, the reference signal RS#1 may be the RS separately transmitted when the UE#1 has no data transmission, including: PT-RS, CSI-RS or RS used in the feedback channel PSFCH. It can also be PT-RS, CSI-RS or RS used in the feedback channel PSFCH carried in the data transmission slot.

Optionally, before UE#1 sends reference signal RS#1 to UE#2, UE#1 determines that the sequence length of reference signal RS#1 is greater than a first preset value, or UE#1 determines that the reference signal RS#1 The bandwidth is greater than the second preset value.

In S303, the second terminal device receives the first reference signal from the first terminal device.

In S304, the second terminal device determines the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or the second terminal device determines the first terminal according to the resource of the first reference signal The synchronization information of the device.

Specifically, UE#2 obtains the synchronization information of UE#1 according to the sequence of the reference signal RS#1; and/or UE#2 obtains the synchronization information of UE#1 according to the resource of the reference signal RS#1.

For example, UE#2 detects the RS carrying synchronization information, and UE#2 obtains the synchronization information of UE#1 based on detecting the RS sent by UE#1.

For example, when the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 1 bit, UE#2 detects the sequence actually used by UE#1 from the two candidate synchronization sequences (RS1, RS2), and obtains This 1-bit synchronization information.

For another example, when the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 2 bits, UE#2 detects from the 4 candidate synchronization sequences (RS1, RS2, RS3, RS4) that UE#1 actually uses Sequence to obtain the 2-bit synchronization information actually transmitted.

In S305, the second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device.

Specifically, UE#2 determines the synchronization source of UE#2 according to the synchronization information of UE#1.

For example, when UE#2 includes a candidate synchronization source (UE#1), UE#2 can determine the synchronization source of UE#2 according to the synchronization information of UE#1.

For example, when UE#2 includes multiple candidate synchronization sources, UE#2 may determine the synchronization source of UE#2 according to the synchronization information of UE#1 and the priority information of the synchronization source.

Below, the priority information of this application is briefly introduced.

Table 1 shows priority information #P1 based on GNSS synchronization.

Table 1

P0P0	GNSSGNSS
P1P1	直接同步到GNSS的UEUE directly synchronized to GNSS
P2P2	间接同步到GNSS的UEIndirectly synchronized to GNSS UE
P3P3	其它的UEOther UE

When used as a synchronization source, the priorities of P0 to P3 in Table 1 above are sequentially decreased.

Table 2 shows priority information #P2 based on gNB/eNB synchronization.

Table 2

P0P0	gNB/eNBgNB/eNB
P1P1	直接同步到gNB/eNB的UEUE directly synchronized to gNB/eNB
P2P2	间接同步到gNB/eNB的UEUE indirectly synchronized to gNB/eNB
P3P3	GNSSGNSS
P4P4	直接同步到GNSS的UEUE directly synchronized to GNSS
P5P5	间接同步到GNSS的UEIndirectly synchronized to GNSS UE
P6P6	其它的UEOther UE

When used as a synchronization source, the priorities of P0 to P6 in Table 2 above decrease sequentially.

Optionally, whether the rule of Table 1 or the rule of Table 2 is specifically used is configured or pre-configured by base station signaling.

In the foregoing priority information based on GNSS synchronization, UEs directly synchronized to GNSS have the same priority, and UEs that indirectly synchronized to GNSS have the same priority; or in the foregoing priority information based on gNB/eNB synchronization, directly UEs synchronized to GNSS have the same priority, and UEs synchronized to GNSS indirectly have the same priority.

Further optionally, under the condition of the same priority, if the receiver still detects multiple candidate synchronization sources, it selects signal quality (such as Reference Signal Received Power) and/or the received signal The strength indicator RSSI (Received Signal Strength Indicator) and/or Reference Signal Receiving Quality (RSRQ) is the best as the synchronization reference source.

FIG. 4 shows a schematic flowchart of another communication method provided by the present application, and the method may be executed by the first terminal device.

In S401, the first terminal device determines the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the first terminal device determines to send the first reference signal according to the synchronization information of the first terminal device. Signal resources.

For example, the reference signal RS#1 may be a DMRS used when UE#1 transmits data, and a DMRS used for control information when UE#1 transmits scheduling data.

For another example, the reference signal RS#1 may be the RS separately transmitted when the UE#1 has no data transmission, including: PT-RS, CSI-RS or RS used in the feedback channel PSFCH.

In the embodiment of the present application, UE#1 may determine the parameters of the sequence of the reference signal RS#1 according to at least one item in the synchronization information, and UE#1 may determine that the reference signal RS#1 is physically located according to at least one item in the synchronization information. The subcarriers in the resource block. UE#1 may determine the subcarrier of reference signal RS#1 in the physical resource block according to the value of the synchronization information.

In S402, the first terminal device sends the first reference signal to the second terminal device.

Specifically, UE#1 sends the reference signal RS#1 to UE#2.

Optionally, before UE#1 sends the reference signal RS#1 to UE#2, UE#1 determines that UE#1 supports synchronization based on the reference signal.

It should be understood that whether to support synchronization based on reference signals may be a capability of the UE. If the UE's capability does not support synchronization based on reference signals, UE#1 does not transmit the RS carrying synchronization information. If the UE's capability supports synchronization based on reference signals, UE#1 can send RSs carrying synchronization information.

Optionally, the UE sends to the network device whether it supports the UE capability based on the reference signal.

Optionally, before UE#1 sends reference signal RS#1 to UE#2, UE#1 determines that the sequence length of reference signal RS#1 is greater than a first preset value, or UE#1 determines that the reference signal RS#1 The bandwidth is greater than the second preset value. Optionally, the first preset value and the second preset value may be indicated by the network device through signaling, or may be pre-configured. Optionally, the signaling indicated by the network device may be a system message or a radio resource control RRC message.

In this embodiment of the application, UE#1 sends scheduling allocation SA information to UE#2, and the scheduling allocation SA information is used to indicate part or all of the synchronization information of UE#1; or, the scheduling allocation SA information The cyclic redundancy check code is used to indicate part or all of the synchronization information of UE#1.

Optionally, the cyclic redundancy check code may be RNTI (Radio Network Tempory Identity: Radio Network Temporary Identity) or a mask used on CRC. The so-called mask refers to the use of a predefined code string of length L and CRC modulo 2 addition on the CRC check bit of length L. When there are 2 codeword strings of length L, it can indicate 1-bit information, and when there are 4 codeword strings of length L, it can indicate 2-bit information. Optionally, L is an integer, such as 8, 16, 24, 32, etc., which is not limited in this application.

Optionally, the receiver can detect the CRC mask by trying different CRC masks to obtain the corresponding synchronization information.

In the embodiment of the present application, UE#1 sends data #D1 to UE#2, and the cyclic redundancy check code of the data #D1 is used to indicate synchronization information of UE#1.

In the embodiment of the present application, the reference signal RS#1, the scheduling allocation SA information and/or data #D1 are located in the same time slot; or, the reference signal RS#1, the scheduling allocation SA information and/or data# D1 is located in multiple consecutive time slots in the time domain.

In the embodiment of the present application, UE#1 may use the parameters of the sequence generating the reference signal RS#1 to indicate synchronization information, UE#1 may be a device that sends synchronization signals, or UE#1 may be a device that does not send synchronization signals .

Optionally, UE#1 can only send a reference signal carrying synchronization information in an asynchronous time slot. Optionally, when UE#1 is a device for sending a synchronization signal, UE#1 sends a reference signal carrying synchronization information in an asynchronous time slot, and sends an SLSS in a synchronization time slot.

Fig. 5 shows a schematic flowchart of another communication method provided by the present application.

In S501, the second terminal device receives the first reference signal from the first terminal device.

Specifically, UE#2 receives the reference signal RS#1 from UE#1.

Optionally, before UE#2 receives the reference signal RS#1 from UE#1, UE#2 determines that UE#2 supports synchronization based on the reference signal.

It should be understood that whether to support synchronization based on reference signals may be a capability of the UE. If the UE's capability does not support synchronization based on reference signals, UE#2 does not receive the RS carrying synchronization information. If the UE's capability supports synchronization based on reference signals, UE#2 can receive the RS carrying synchronization information.

In S502, the second terminal device determines the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or, the second terminal device determines the first terminal device according to the resource of the first reference signal Synchronization information of a terminal device.

In the embodiment of the present application, UE#2 can detect different RSs corresponding to the synchronization information, and UE#2 obtains the synchronization information of UE#1 according to the received different RSs.

For example, UE#2 obtains the synchronization information of UE#1 according to the sequence of the reference signal RS#1 sent by UE#1.

When the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 1 bit, UE#2 detects the sequence actually used by UE#1 from the two candidate synchronization sequences (RS1, RS2), and obtains this 1 Bits of synchronization information.

When the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 2 bits, UE#2 detects the sequence actually used by UE#1 from the 4 candidate synchronization sequences (RS1, RS2, RS3, RS4), thereby Get the actually transmitted 2-bit synchronization information.

In S503, the second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device.

Specifically, UE#2 determines the synchronization source of UE#2 according to the synchronization information and priority information of UE#1.

For example, when the candidate synchronization source of UE#2 includes one synchronization source, UE#2 may determine the synchronization source of UE#2 according to the synchronization information of UE#1.

For example, when the candidate synchronization source of UE#2 includes multiple synchronization sources, UE#2 may determine the synchronization source of UE#2 according to the synchronization information of UE#1 and the priority information of the synchronization source.

In the embodiment of the present application, when UE#2 detects the synchronization signal SLSS sent by UE#3 and the reference signal RS sent by UE#1 at the same time, UE#2 can select the synchronization source according to priority information #P3.

Specifically, when the second terminal device simultaneously detects the SLSS sent by the third terminal device and the first reference signal sent by the first terminal device, any of the following methods can be used to determine the priority between the SLSS and the first reference signal relationship:

When the number of hops synchronized by the third terminal device to the satellite or base station is the same as the number of hops synchronized by the first terminal device to the satellite or base station, the priorities of the first terminal device and the third terminal device are the same;

When the number of hops synchronized by the third terminal device to the satellite or base station is the same as the number of hops synchronized by the first terminal device to the satellite or base station, the first terminal device has a higher priority than the third terminal device;

When the number of hops synchronized by the third terminal device to the satellite or base station is the same as the number of hops synchronized by the first terminal device to the satellite or base station, the first terminal device has a lower priority than the third terminal device;

When the number of hops synchronized by the third terminal device to the satellite or base station is the same as the number of hops synchronized by the first terminal device to the satellite or base station, the first terminal device determines the priorities of the first terminal device and the third terminal device according to the pre-configuration information .

Optionally, the pre-configuration information may be indicated by the network device or pre-configured. The pre-configuration information is used to indicate which priority is higher for the first terminal device and the third terminal device with the same number of hops.

In the embodiment of the present application, Table 3 shows priority information #P3 based on reference signal synchronization.

Table 3A

When used as a synchronization source, the priorities of P1 to P5 in Table 3A above decrease in order.

Optionally, when the number of hops for UE#3 to synchronize to the satellite or base station is the same as the number of hops for UE#1 to synchronize to the satellite or base station, UE#1 has a lower priority than UE#3. As in the example in Table 3B.

Table 3B

When used as a synchronization source, the priorities of P1 to P5 in Table 3B above are sequentially decreased.

In Table 3B, when the number of hops for UE#3 to synchronize to the satellite or base station is the same as the number of hops for UE#1 to synchronize to the satellite or base station, UE#1 has a higher priority than UE#3.

Table 3C

In Table 3C, when the number of hops for UE#3 to synchronize to the satellite or base station is the same as the number of hops for UE#1 to synchronize to the satellite or base station, UE#1 and UE#3 have the same priority.

Fig. 6 shows a schematic interaction diagram of another communication method provided by the present application.

In S601, the first terminal device determines the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the first terminal device determines to send the first reference signal according to the synchronization information of the first terminal device. Signal resources.

Referring to step S301, UE#1 determines the sequence of the reference signal RS#1 according to the synchronization information of UE#1; and/or UE#1 determines the resource for transmitting the reference signal RS#1 according to the synchronization information of UE#1.

In S602, the first terminal device sends the first reference signal, the first data and/or the first control information to the second terminal device.

Specifically, UE#1 sends reference signal RS#1, data #D1 and/or scheduling allocation SA information to UE#2.

In the embodiment of the present application, UE#1 may use transmission sequences on multiple DMRS symbols of data #D1 to indicate synchronization information.

Optionally, long sequences corresponding to sequences on multiple DMRS symbols may be used to indicate synchronization information. For example, data #D1 has M columns of DMRS, where the DMRS length is L, and the sequence length of the reference signal RS#1 carrying synchronization information is kL, where k≤M.

Optionally, it is equivalent to using a sequence of length kL to indicate synchronization information, and the sequence of length kL is truncated into k sequences of length L to generate k DMRS symbols. For example: M=4, k=2, L=12, a sequence of length 24 is used to indicate synchronization information, and the sequence of length 24 is truncated into two sequences of length 12 to generate 2 DMRS symbols.

Optionally, a sequence on k adjacent DMRS symbols in the time domain carrying multiple DMRS symbols on the time slot may be used to indicate synchronization information. For example: when there are 3 (or 4) DMRSs carried on the data #D1, the two closest DMRSs in the time domain can be used to indicate synchronization information.

Optionally, multiple DMRSs in the time slot can be divided into different subgroups, respectively indicating the same part or different parts of the synchronization information. Optionally, the part here may be the same certain type or types of specific synchronization information in the synchronization information, and may also be the same bits in the same type of synchronization information. For example, when there are multiple DMRS symbols S1, S2, S3, S4 in data #D1, {S1, S2} and {S3, S4} can be used to indicate the same or different synchronization information respectively.

In S603, the second terminal device receives the first reference signal, the first data and/or the first control information from the first terminal device.

In S604, the second terminal device determines the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or the second terminal device determines the first terminal device according to the resource of the first reference signal The synchronization information of the device.

Referring to step S304, UE#2 obtains the synchronization information of UE#1 according to the sequence of the reference signal RS#1; and/or UE#2 obtains the synchronization information of UE#1 according to the resource of the reference signal RS#1.

In S605, the second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device.

Fig. 7 shows a schematic flowchart of another communication method provided by the present application.

In S701, the first terminal device determines the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the first terminal device determines to send the first reference signal according to the synchronization information of the first terminal device. Signal resources.

In S702, the first terminal device sends the first reference signal, the first data and/or the first control information to the second terminal device.

Fig. 8 shows a schematic flowchart of another communication method provided by the present application.

In the embodiment of the present application, the terminal device may use the same type of reference signal or different types of reference signals to indicate synchronization information. For example, the generation sequence of the DMRS on the data and the DMRS on the control information SA can be used at the same time to indicate the synchronization information. Optionally, the indicated synchronization information may be the same or different.

In S801, the second terminal device receives the first reference signal, the first data and/or the first control information from the first terminal device.

Specifically, UE#2 receives reference signal RS#1, data #D1 and/or scheduling allocation SA information, and/or CSI-RS, and or PT-RS from UE#1.

In the embodiment of the present application, UE#1 may be a device that sends synchronization signals, or UE#1 may be a device that does not send synchronization signals.

In S802, the second terminal device determines the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or, the second terminal device determines the first terminal device according to the resource of the first reference signal Synchronization information of a terminal device.

Specifically, UE#2 obtains synchronization information, and/or CSI-RS, and or PT-RS of UE#1 according to the DMRS of data #D1 and the DMRS of the scheduling allocation SA information.

Optionally, UE#2 obtains the synchronization information of UE#1 according to the cyclic redundancy check code of data #D1 and/or the cyclic redundancy check code of the scheduling allocation SA information.

In the embodiment of this application, UE#2 receives data #D1 and/or scheduling allocation SA information from UE#1; UE#2 obtains UE#1's data according to the DMRS of data #D1 and the DMRS of the scheduling allocation SA information. Synchronization information; or UE#2 obtains the synchronization information of UE#1 according to the cyclic redundancy check code of data #D1 and/or the cyclic redundancy check code of the SA information of the scheduling allocation.

Optionally, the synchronization information obtained above may be the same part of the same part of the same information, or may be a different part of the same synchronization information.

S803: The second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device.

As shown in Figure 2, UE#2 can detect the reference signals sent from UE#1, UE#3, and UE#7. Therefore, when UE#1, UE#3, and UE#7 meet the preset conditions, UE# 1. UE#3 and UE#7 can be used as candidate synchronization sources for UE#2.

For example, UE#2 can receive data #D1 and/or scheduling allocation SA information sent from UE#1 (or UE#3, UE#7); when UE#1, UE#3, UE#7 meet preset conditions At this time, UE#1, UE#3, and UE#7 can be used as candidate synchronization sources for UE#2.

Wherein, the above-mentioned preset condition includes at least one of the following conditions: the cyclic redundancy check code of data #D1 is checked correctly; the cyclic redundancy check code of the scheduling allocation SA information is checked correctly; reference signal RS# The resource bandwidth occupied by the symbol of 1 is greater than the first preset value; the sequence length of the reference signal RS#1 is greater than the second preset value.

In the embodiment of the present application, when the terminal device detected by UE#2 serves as the synchronization source, at least one of the following conditions needs to be met: the cyclic redundancy check code of the data is verified correctly; the cycle of the control information SA The redundancy check is correct; the bandwidth occupied by the symbols of the reference signal is greater than the first preset value; the length of the first reference signal sequence is greater than the second preset value.

When the terminal device detected by UE#2 satisfies the aforementioned conditions, UE#2 determines the candidate synchronization source of UE#2 according to the aforementioned conditions, or UE#2 determines whether the detected RS is valid according to the aforementioned conditions. For example, when the SA detection of UE#2 is correct, the data #D1 bears the corresponding RS#1 availability, that is, the data #D1 detected by UE#2 meets the reliability requirement.

Fig. 9 shows a schematic flowchart of another communication method provided by the present application.

In S901, the second terminal device detects the signal quality of the first reference signal sent from the first terminal device.

Specifically, UE#2 detects the signal quality of the reference signal RS#1.

In S902, when the signal quality of the first reference signal is greater than the first threshold, the second terminal device determines that the first terminal device is a candidate synchronization source.

Specifically, when the signal quality of the reference signal RS#1 is greater than the first threshold, UE#2 uses UE#1 as the candidate synchronization source.

For example, if the signal quality on the RS detected by UE#2 is greater than the first signal quality threshold, UE#2 uses UE#1 as the candidate synchronization source.

Optionally, this preset threshold may be indicated by signaling, or may be pre-configured or predefined.

For example, if the signal quality on the RS detected by UE#2 is greater than the second signal quality threshold, it can be directly used as a candidate synchronization source.

In this embodiment of the application, if multiple RSs greater than the first preset threshold are detected, UE#2 selects the one with the best signal quality that meets the above three conditions as the candidate synchronization source.

Optionally, the signal quality includes at least one of the following: for example, Reference Signal Received Power (RSRP), Received Signal Strength Indicator (RSSI), and Reference Signal Received Quality (RSRQ). ).

In S903, the second terminal device determines the synchronization source of the second terminal device according to the synchronization information and the priority information of the candidate synchronization source.

Specifically, UE#2 determines the synchronization source of UE#2 according to the synchronization information of UE#1 and the priority information of candidate synchronization sources.

In the embodiment of this application, UE#2 detects the signal quality of the reference signal RS#1; when the signal quality of the reference signal RS#1 is greater than the first threshold, UE#2 uses UE#1 as the candidate synchronization source; UE#2 Determine the synchronization source of UE#2 according to the candidate synchronization source.

In the embodiment of the present application, UE#2 of the UE has no synchronization signal reception capability, and the UE only determines the synchronization source in the detected RS.

FIG. 10 shows a schematic flowchart of another communication method provided by the present application.

In S1001, the second terminal device receives the first reference signal, the first data and/or the first control information from the first terminal device.

Specifically, UE#2 receives reference signal RS#1, data #D1 and/or scheduling allocation SA information from UE#1.

For example, UE#2 detects the reference signal RS#1, data #D1 and/or scheduling allocation SA information sent by UE#1, where the scheduling allocation SA information is that when UE#1 sends data #D1, it is used to indicate data #D1. Control information.

In S1002, when the first reference signal, the first data, and/or the first control information of the first terminal device meet a preset condition, the second terminal device determines that the first terminal device is a candidate synchronization source.

In S1003, the second terminal device determines the synchronization source of the second terminal device according to the synchronization information and the priority information of the candidate synchronization source.

Referring to Figure 11, data #D1 carries 2 DMRSs (RS1, RS2) of length L1, and there are n DMRSs of length L2 on SA, then the length of the DMRS indicating synchronization information is: (2*L1+n *L2).

Or, use 2L1 to indicate synchronization information #1; use nL2 to indicate synchronization information #2.

Data #D1 carries 4 DMRS symbols: RS1, RS2, RS3, RS4, these DMRS can be divided into 2 parts {RS1, RS2}, {RS3, RS4}, of which {RS1, RS2}, {RS3, RS4} The indicated synchronization information can be the same or different.

For example, {RS1, RS2} may indicate synchronization information #1, {RS3, RS4} may indicate synchronization information #2.

When multiple DMRSs are carried on data #D1, the two closest DMRSs in the time domain can be used to indicate synchronization information. For example, data #D1 bears 3 DMRS symbols: RS1, RS2, RS3, and synchronization information can be mapped on two adjacent symbols {RS1, RS2}.

Fig. 14 shows the resource mapping manner of the reference signal of the present application on the PRS.

Referring to FIG. 14, in the embodiment of the present application, the frequency domain position set in each RB where the RS is located may be used to indicate synchronization information, where different mapping modes of the RS in the frequency domain indicate different synchronization information. The mapping mode #1 represents 0, and the mapping mode #2 represents 1, to indicate 2-bit synchronization information. Mapping mode #1 and mapping mode #2 respectively include two columns of RS.

If the interval of the RS in the frequency domain is 4, there can be a total of 4 mapping methods, which are represented as 0, 1, 2, and 3 respectively. These 4 values can indicate 2-bit synchronization information.

Optionally, when there are 4 columns of RSs, they can be divided into 2 groups, and each group respectively indicates 1 or 2 bits of synchronization information in the above manner. The indicated synchronization information can be the same or different.

In the embodiment of this application, UE#1 determines the resource for transmitting the reference signal RS#1 according to the synchronization information of UE#1, and UE#1 can indicate the synchronization information of UE#1 in the following manner:

Way #A1

In the embodiment of the present application, UE#1 may use the sequence on multiple DMRS symbols of data #D1 to indicate synchronization information.

For example, data #D1 has M columns of DMRS, where the DMRS length is L, and the sequence length of the reference signal RS#1 carrying synchronization information is kL, where k≤M. When there are 3 (or 4) DMRSs carried on the data #D1, the two closest DMRSs in the time domain can be used to indicate synchronization information.

For example, when there are multiple DMRS symbols RS1, RS2, RS3, RS4 in data #D1, {RS1, RS2} and {RS3, RS4} can be used to indicate different synchronization information respectively.

Way #A2

The DMRS of the data #D1 and the DMRS of the scheduling allocation SA information of the scheduling data #D1 are used to indicate jointly.

For example, if data #D1 carries k DMRSs of length L1, and SA has n DMRSs of length L2, the length of the DMRS indicating synchronization information is: (k*L1+n*L2).

Or, use kL1 to indicate synchronization information #1; use nL2 to indicate synchronization information #2.

Way #A3

When the data #D1 carries DMRS, PTRS or CSI-RS, the DMRS, PTRS or CSI-RS together indicate synchronization information.

For example, if data #D1 carries k DMRSs of length L1, and there are n DMRSs of length L3 on the RS, the length of the DMRS indicating synchronization information is: (k*L1+n*L3).

Or, optionally, use kL1 to indicate synchronization information #1; use nL3 to indicate synchronization information #2.

Way #A4

When multiple DMRS symbols are carried on the data #D1, these DMRS can be divided into two parts, and the RS in the first part is the same or different from the RS in the second part to indicate 1-bit synchronization information.

For example, data #D1 carries 2 DMRS, RS1 and RS2 are the same or different, indicating 1-bit synchronization information.

For example, if data #D1 carries 4 DMRSs, {RS1, RS2} and {RS3, RS4} are the same or different to indicate 1-bit synchronization information.

For example, if data #D1 carries 4 DMRS, RS1 and RS2 are the same or different to indicate 1-bit synchronization information #1; RS3 and RS4 are the same or different to indicate the same 1-bit synchronization information# 1.

Way #A5

Referring to FIG. 13, in the embodiment of the present application, the frequency domain position set in each RB where the RS is located may be used to indicate synchronization information, where different mapping modes of the RS in the frequency domain represent different information.

For example, mapping mode #1 represents 0, and mapping mode #1 represents 1. Among them, these 2 values can represent 2-bit synchronization information.

Way #A6

Use scheduling allocation SA information and/or CRC code of data #D1 to indicate synchronization information.

Optionally, it may be implemented in a manner of scrambling the cyclic redundancy check (cyclic redundancy check, CRC) of the PSCCH carrying the SA and the PSSCH carrying the data #D1.

The scrambling sequence string or bit string or scrambling mask used for different scrambling corresponds to a state of synchronization information. When the indicated synchronization information has n bits, there are a total of 2 ⁿ CRC scrambling methods.

Way #A7

Directly use the display signaling in the scheduling allocation SA information to indicate the synchronization information.

The above is a detailed solution of the communication method of the present application, and the process of determining the sequence of the reference signal RS#1 according to the synchronization information of the UE#1 of the present application will be introduced below.

In the embodiment of the present application, UE#1 determines the sequence of the reference signal RS#1 according to the synchronization information of UE#1, including:

(1) Generate the initial value of the sequence, for example:

Among them, r(m) is the sequence of the reference signal on a certain RE, and c() is the random sequence.

Example 1: Cinit is to generate a random sequence, which can be generated from synchronization information.

E.g:

or

among them,

Is the number of time slots μ under the corresponding subcarrier interval in the radio frame, i _x is synchronization information, a, b, c, d are integers

It is the identification of the synchronization signal.

Example 2: Cinit is to generate a random sequence, which can be generated from synchronization information and synchronization signal identification and/or cell identification.

E.g:

or

among them,

Is the number of timeslots μ in the corresponding subcarrier interval in the radio frame, i _x is synchronization information, a, b, c, d are integers, and N _PCID is the cell identifier.

Example 3: Cinit is to generate a random sequence, which can be generated by synchronization information and synchronization information identification, and/or generated by a preset synchronization identification, and/or generated by the source or destination identification indicated in the control information, for example:

or

Among them, a, b, c, d are integers. among them

The identifier carried in the SA can be any of the following: the identifier of UE#1, the identifier of UE#2, the source identifier, the destination identifier, and the combined identifier of the source identifier and the destination identifier. further,

It can be the identifier of UE#1, the identifier of UE#2, the source identifier, the destination identifier, all the identifiers or the identifiers corresponding to some fields in the combined identifier of the source identifier and the destination identifier.

Cinit is the initial value of the random sequence, ix is all or part of the synchronization information to be transmitted,

Represents the identification of the synchronization signal, mod represents the remainder operation.

(2) The cyclic shift and root sequence number of the sequence are used when generating the sequence.

Optionally, the cyclic shift and root sequence number of the sequence may be generated from synchronization information and synchronization information identification, and/or generated from a certain preset synchronization identification, and/or source or destination identification indicated in the control information.

For example, this embodiment can be used for RS generated by ZC sequence.

u=f(x)mod M or u=(a+f(x))mod M or u=(a+b+f(x))mod M

Among them, M represents the maximum number of root sequences supported, such as 30 or the length of the sequence L; u is the root sequence number of the ZC sequence. f(x) is a function of synchronization information x.

For example, f(x)=x, and the value of x can be 0, 1, 2, 3, etc. Another example is f(x)=a*x, a is a non-zero integer.

For example, to generate the parameters of the sequence cyclic shift α:

Among them, N represents the length of the sequence to be transmitted, h(x) is a function based on the above parameters, and h(x) can be defined in a manner similar to the function f(x).

For example: h(x)=a*x, a is a non-zero integer. Another example: h(x)=a+bx, a and b are non-zero integers.

(3) The orthogonal cover code OCC used when generating the sequence, the length of the OCC is determined by the symbol of the RS in the time domain.

Optionally, the orthogonal cover code OCC used in the sequence may be generated from synchronization information and synchronization information identification, and/or generated from a certain preset synchronization identification, and/or source or destination identification indicated in the control information.

E.g:

[+1 +1 +1 +1]if i _x =0

[+1 -1 +1 -1]if i _x =1

Indicates that there are at least 4 RS symbols in the time domain. or,

[+1 +1 +1]if i _x =0

[+1 -1 +1]if i _x =1

Indicates that there are at least 3 RS symbols in the time domain. or

[+1 +1]if i _x =0

[+1 -1]if i _x =1

Indicates that there are at least 2 RS symbols in the time domain.

Based on the above communication method, the terminal device and chip system of the present application will be described in detail below.

According to the foregoing method, FIG. 15 is a schematic diagram of a communication device 10 provided by an embodiment of the application. As shown in FIG. 15, the device 10 may be a terminal device, or a chip or circuit, such as a chip or circuit that can be set in a terminal device. . The device 10 may include a processing unit 11 and a storage unit 12. The storage unit 12 is used to store instructions, and the processing unit 11 is used to execute the instructions stored in the storage unit 12, so that the device 10 implements the steps performed by the terminal device in the above-mentioned method.

Further, the device 10 may also include an input port 13 and an output port 14. Further, the processing unit 11, the storage unit 12, the input port 13 and the output port 14 can communicate with each other through internal connection paths to transfer control and/or data signals. The storage unit 12 is used to store a computer program, and the processing unit 11 can be used to call and run the calculation program from the storage unit 12 to control the input port 13 to receive signals and the output port 14 to send signals to complete the above method Steps for terminal equipment. The storage unit 12 can be integrated in the processing unit 11 or can be provided separately from the processing unit 11.

If the device 10 is a terminal device, the input port 13 is a receiver, and the output port 14 is a transmitter. The receiver and transmitter may be the same or different physical entities. When they are the same physical entity, they can be collectively called a transceiver. If the device 10 is a chip or a circuit, the input port 13 is an input interface, and the output port 14 is an output interface.

In an implementation manner, the device 10 may be used as a device for sending reference signals, or a device for sending reference signals, control information, and/or data. The method steps performed by the device 10 as a sending device are described in detail below.

In S401, the processing unit 11 of the device 10 determines the sequence of the first reference signal according to the synchronization information of the device 10, and/or the processing unit 11 determines the resource for sending the first reference signal according to the synchronization information of the device 10.

Specifically, the processing unit 11 of the device 10 determines the sequence of the reference signal RS#1 according to the synchronization information of the device 10; and/or the processing unit 11 determines the resource for transmitting the reference signal RS#1 according to the synchronization information of the device 10.

Manner A#1: The processing unit 11 of the device 10 determines the sequence of the reference signal RS#1 according to the synchronization information of the device 10.

In the embodiment of the present application, the processing unit 11 of the device 10 may use the parameters of the sequence generating the reference signal RS#1 to indicate synchronization information, the device 10 may be a device that sends a synchronization signal, or the device 10 may not send a synchronization signal. Device.

The processing unit 11 of the device 10 uses the parameters of the corresponding synchronization sequence to generate the corresponding RS according to the corresponding synchronization information, and then sends the corresponding RS to UE#2.

In the embodiment of the present application, the processing unit 11 of the device 10 may use the parameters of the sequence generating the reference signal RS#1 to indicate or carry synchronization information. Optionally, the device 10 may only be a device that transmits a sidelink synchronization signal SLSS (Sidelink Synchronization Signal), or the device 10 may only be a device that does not transmit an SLSS.

For example, when the synchronization information indicated by the sequence of the reference signal sent by the device 10 is 1 bit, the sequence of the reference signal includes RS1 and RS2, and the device 10 sends RS1 or RS2 to UE#2 according to the synchronization information to be transmitted.

For example, when the indicated synchronization information is 2 bits, the sequence of the reference signal includes RS1, RS2, RS3, and RS4, and the device 10 sends RS1, RS2, RS3, or RS4 to UE#2 according to the synchronization information to be transmitted.

Manner A#2: The processing unit 11 of the device 10 determines the resource for transmitting the reference signal RS#1 according to the synchronization information of the device 10.

For example, specifically, the processing unit 11 determines the subcarrier of the reference signal RS#1 in the physical resource block according to the synchronization information.

For example, the processing unit 11 determines the symbol position of the reference signal RS#1 in the time slot according to the synchronization information.

In S402, the device 10 transmits the first reference signal to the second terminal device (for example, the aforementioned UE#2).

Specifically, the device 10 (for example, the aforementioned UE#1) sends the reference signal RS#1 to the UE#2.

For example, for different types of reference signals, the reference signal RS#1 may be a DMRS used when the device 10 transmits data, and/or a DMRS used for control information when the device 10 transmits scheduling data.

For another example, the reference signal RS#1 may be a reference signal RS that is sent together when the device 10 sends scheduling data, including PT-RS, CSI-RS, or RS used in the feedback channel PSFCH.

For another example, the reference signal RS#1 may be an RS separately transmitted by the device 10 when no data is transmitted, including: PT-RS, CSI-RS or RS used in the feedback channel PSFCH. It can also be PT-RS, CSI-RS or RS used in the feedback channel PSFCH carried in the data transmission slot.

Optionally, before the device 10 sends the reference signal RS#1 to the UE#2, the device 10 determines that the sequence length of the reference signal RS#1 is greater than the first preset value, or the device 10 determines that the bandwidth of the reference signal RS#1 is greater than the first preset value. Two preset values.

In an implementation form, the processing unit 11 of the device 10 may determine the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the processing unit 11 may determine the sequence of the first reference signal according to the synchronization information of the first terminal device. The resource of the first reference signal; the output port 14 is used to send the first reference signal to the second terminal device; wherein the synchronization information includes at least one of the following information: the type of the synchronization source of the first terminal device, the first terminal The number of synchronization hops between the synchronization source of the device and the satellite, whether the first terminal device is directly synchronized to the satellite or network equipment, and whether the first terminal device is within the coverage of the network equipment.

For example, the processing unit 11 of the device 10 may determine the sequence of the first reference signal according to the synchronization information of the first terminal device, including: the processing unit 11 determines the parameters of the sequence of the first reference signal according to the synchronization information, and the parameters include at least one of the following parameters One item: the initial value of the sequence of the first reference signal, the root sequence number, the cyclic shift value of the sequence, the orthogonal cover code OCC of the sequence, and the sequence length.

For example, the processing unit 11 of the device 10 may determine the resource for sending the first reference signal according to the synchronization information of the first terminal device, including: the processing unit 11 determines the subcarrier of the first reference signal in the physical resource block according to the synchronization information.

For example, the processing unit 11 of the device 10 may determine the sequence of the first reference signal according to the synchronization information of the first terminal device, including: the processing unit 11 determines the sequence of the first reference signal according to the synchronization information and the synchronization signal identifier used by the first device At least one of the following parameters: the initial value of the sequence of the first reference signal, the root sequence number, the cyclic shift value of the sequence, the orthogonal cover code OCC of the sequence, and the sequence length.

For example, the processing unit 11 of the apparatus 10 may determine the sequence length of the first reference signal according to the number of symbols in the time slot in which the first reference signal is carried; and/or the processing unit 11 is specifically configured to determine the first reference signal according to the bandwidth of the first reference signal. The sequence length of the reference signal.

For example, the processing unit 11 of the device 10 may determine the resource for sending the first reference signal according to the synchronization information of the first terminal device, including: the processing unit 11 determines to send the first reference signal according to the resource mapping mode of the synchronization information and the first reference signal. The resource of the signal; wherein the resource mapping mode of the synchronization information and the first reference signal includes: the synchronization information is mapped on two adjacent symbols of the time slot where the first reference signal is located; the time slot where the first reference signal is located includes at least two symbol.

For example, before the output port 14 of the device 10 sends the first reference signal to the second terminal device, the processing unit 11 determines that the sequence length of the first reference signal is greater than the first preset value; or the processing unit 11 determines that the bandwidth of the first reference signal is greater than The second preset value.

For example, the output port 14 of the device 10 is also used to send first control information to the second terminal device, the first control information is used to indicate part or all of the synchronization information of the first terminal device; or, the cycle of the first control information The redundancy check code is used to indicate part or all of the synchronization information of the first terminal device.

For example, the output port 14 of the device 10 is also used to send the first data to the second terminal device, and the cyclic redundancy check code of the first data is used to indicate part or all of the synchronization information of the first terminal device.

For example, before the output port 14 of the device 10 sends the first reference signal to the second terminal device, the processing unit 11 determines that the first terminal device supports synchronization based on the first reference signal.

In an implementation manner, the device 10 may be used as a device for receiving reference signals, or a device for receiving reference signals, control information and/or data. The method steps performed by the device 10 as a receiving device are described in detail below.

In S501, the input port 13 of the device 10 (for example, the aforementioned UE#2) receives the first reference signal from the first terminal device.

Specifically, the input port 13 of the device 10 receives the reference signal RS#1 from the first terminal device (for example, the aforementioned UE#1).

Optionally, before the device 10 receives the reference signal RS#1 from the UE#1, the processing unit 11 determines that the device 10 supports synchronization based on the reference signal.

It should be understood that whether to support synchronization based on reference signals may be a capability of the UE. If the UE's capabilities do not support synchronization based on reference signals, the device 10 does not receive RSs carrying synchronization information. If the UE's capability supports synchronization based on the reference signal, the device 10 can receive the RS carrying synchronization information.

Optionally, the apparatus 10 sends to the network device whether it supports the UE capability based on the reference signal.

Specifically, the device 10 obtains the synchronization information of the UE#1 according to the sequence of the reference signal RS#1; and/or the device 10 obtains the synchronization information of the UE#1 according to the resource of the reference signal RS#1.

In the embodiment of the present application, the device 10 can detect different RSs corresponding to the synchronization information, and the device 10 obtains the synchronization information of UE#1 according to the received different RSs.

For example, the device 10 obtains the synchronization information of the UE#1 according to the sequence of the reference signal RS#1 sent by the UE#1.

When the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 1 bit, the device 10 detects the sequence actually used by UE#1 from the two candidate synchronization sequences (RS1, RS2), and obtains the 1 bit. Synchronization information.

When the synchronization information indicated by the sequence of the reference signal sent by UE#1 is 2 bits, the device 10 detects the sequence actually used by UE#1 from the four candidate synchronization sequences (RS1, RS2, RS3, RS4), and obtains To the 2-bit synchronization information actually transmitted.

In S503, the processing unit 11 of the device 10 determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device.

Specifically, the processing unit 11 of the device 10 determines the synchronization source of the device 10 according to the synchronization information and priority information of the UE#1.

For example, when the candidate synchronization source of the device 10 includes one synchronization source, the device 10 may determine the synchronization source of the device 10 according to the synchronization information of UE#1.

For example, when the candidate synchronization source of the device 10 includes multiple synchronization sources, the device 10 may determine the synchronization source of the device 10 according to the synchronization information of UE#1 and the priority information of the synchronization source.

In the embodiment of the present application, when the device 10 detects the synchronization signal SLSS sent by UE#3 and the reference signal RS sent by UE#1 at the same time, the device 10 can select the synchronization source according to the priority information #P3 in Table 3A.

Table 3A

Table 3B

Table 3C

For example, before the input port 13 of the device 10 receives the first reference signal from the first terminal device, the processing unit 11 determines that the second terminal device supports synchronization based on the first reference signal.

In an implementation form, the input port 13 of the device 10 receives the first reference signal from the first terminal device; the processing unit 11 determines the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or the processing unit 11 Determine the synchronization information of the first terminal device according to the resource of the first reference signal; the processing unit 11 determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device; wherein the synchronization information includes at least one of the following information: The type of synchronization source of the first terminal device, the number of hops of the path from which the first terminal device is synchronized to the synchronization source, whether the first terminal device is directly synchronized to a satellite or network device, and whether the first terminal device is within the coverage of the network device.

For example, the processing unit 11 of the device 10 determines the synchronization information of the first terminal device according to the resources of the first reference signal, including: the processing unit 11 determines the synchronization information of the first terminal device according to the subcarriers of the first reference signal in the physical resource block .

For example, the processing unit 11 of the device 10 determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device, including: the processing unit 11 determines the second terminal device according to the synchronization information of the first terminal device and the priority information of the synchronization source Synchronization source.

For example, the input port 13 of the device 10 is also used to detect the signal quality of the first reference signal; when the signal quality of the first reference signal is greater than the first threshold, the processing unit 11 uses the first terminal device as a candidate synchronization source.

For example, the input port 13 of the device 10 receives first data and/or first control information from a first terminal device; when the first terminal device meets a preset condition, the processing unit 11 uses the first terminal device as a candidate synchronization source; Wherein, the preset condition includes at least one of the following conditions: the cyclic redundancy check code of the first data is checked correctly; or, the cyclic redundancy check code of the first control information is checked correctly; or, the first reference The bandwidth of the signal is greater than the first preset value.

For example, the input port 13 of the device 10 is also used to receive first data and/or first control information from the first terminal device; the processing unit 11 determines the first terminal device according to the DMRS of the first data and the DMRS of the first control information Or the processing unit 11 determines the synchronization information of the first terminal device according to the cyclic redundancy check code of the first data and/or the cyclic redundancy check code of the first control information.

For example, the input port 13 of the device 10 detects the side link synchronization signal sent by the third device, and the processing unit 11 determines the synchronization source of the second terminal device according to the first priority information (Table 3).

As an implementation manner, the functions of the input port 13 and the output port 14 may be implemented by a transceiver circuit or a dedicated chip for transceiver. The processing unit 11 may be implemented by a dedicated processing chip, a processing circuit, a processing unit, or a general-purpose chip.

As another implementation manner, a general-purpose computer may be considered to implement the terminal device provided in the embodiment of the present application. The program codes that realize the functions of the processing unit 11, the input port 13 and the output port 14 are stored in the storage unit 12. The general processing unit implements the functions of the processing unit 11, the input port 13 and the output port 14 by executing the code in the storage unit 12 .

FIG. 16 is a schematic structural diagram of a terminal device 20 provided by this application. The foregoing apparatus 20 may be configured in the terminal device 20, or the apparatus 20 itself may be the terminal device 20. In other words, the terminal device 20 can execute the actions performed by the terminal device in the foregoing method.

For ease of description, FIG. 16 only shows the main components of the terminal device. As shown in FIG. 16, the terminal device 20 includes a processor, a memory, a control circuit, an antenna, and an input and output device.

The processor is mainly used to process the communication protocol and communication data, and to control the entire terminal device, execute the software program, and process the data of the software program, for example, to support the terminal device to execute the above-mentioned transmission precoding matrix instruction method embodiment The described action. The memory is mainly used to store software programs and data, for example, to store the codebook described in the above embodiments. The control circuit is mainly used for the conversion of baseband signals and radio frequency signals and the processing of radio frequency signals. The control circuit and the antenna together can also be called a transceiver, which is mainly used to send and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, and keyboards, are mainly used to receive data input by users and output data to users.

When the terminal device is turned on, the processor can read the software program in the storage unit, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor performs baseband processing on the data to be sent and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then sends the radio frequency signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor, and the processor converts the baseband signal into data and processes the data.

Those skilled in the art can understand that, for ease of description, FIG. 16 only shows a memory and a processor. In actual terminal devices, there may be multiple processors and memories. The memory may also be referred to as a storage medium or a storage device, etc., which is not limited in the embodiment of the present application.

For example, the processor may include a baseband processor and a central processing unit. The baseband processor is mainly used to process communication protocols and communication data. The central processing unit is mainly used to control the entire terminal device, execute software programs, and process software programs. data. The processor in FIG. 16 integrates the functions of the baseband processor and the central processing unit. Those skilled in the art can understand that the baseband processor and the central processing unit may also be independent processors and are interconnected by technologies such as buses. Those skilled in the art can understand that the terminal device may include multiple baseband processors to adapt to different network standards, the terminal device may include multiple central processors to enhance its processing capabilities, and various components of the terminal device may be connected through various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processing unit can also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and communication data can be built in the processor, or can be stored in the storage unit in the form of a software program, and the processor executes the software program to realize the baseband processing function.

Exemplarily, in the embodiment of the present application, the antenna and control circuit with the transceiver function may be regarded as the transceiver unit 201 of the terminal device 20, and the processor with the processing function may be regarded as the processing unit 202 of the terminal device 20. As shown in FIG. 16, the terminal device 20 includes a transceiver unit 201 and a processing unit 202. The transceiver unit may also be referred to as a transceiver, a transceiver, a transceiver, and so on. Optionally, the device for implementing the receiving function in the transceiver unit 201 can be regarded as the receiving unit, and the device for implementing the sending function in the transceiver unit 201 can be regarded as the sending unit, that is, the transceiver unit 201 includes a receiving unit and a sending unit. Exemplarily, the receiving unit may also be called a receiver, a receiver, a receiving circuit, etc., and the sending unit may be called a transmitter, a transmitter, or a transmitting circuit, etc.

A person of ordinary skill in the art may be aware that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the above-described system, device, and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

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

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of this application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code .

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A method of communication, characterized in that it comprises:

The first terminal device determines the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the first terminal device determines the resource for sending the first reference signal according to the synchronization information of the first terminal device ；

Sending the first reference signal to the second terminal device by the first terminal device;

Wherein, the synchronization information includes at least one of the following information: the type of synchronization source of the first terminal device, the number of hops between the first terminal device and satellite or network equipment, and the first terminal device Whether it is directly synchronized to a satellite or a network device, and whether the first terminal device is within the coverage of the network device.
The method according to claim 1, wherein the first terminal device determining the sequence of the first reference signal according to the synchronization information of the first terminal device comprises:

The first terminal device determines a parameter of the sequence of the first reference signal according to the synchronization information, and the parameter includes at least one of the following parameters: an initial value of the sequence of the first reference signal, a root sequence number , The cyclic shift value of the sequence, the orthogonal cover code OCC of the sequence, and the sequence length.
The method according to claim 1 or 2, wherein the first terminal device determining the resource for sending the first reference signal according to the synchronization information of the first terminal device comprises:

The first terminal device determines the subcarrier of the first reference signal in the physical resource block according to the synchronization information.
The method according to any one of claims 1-3, wherein the method further comprises:

The first terminal device determines the sequence length of the first reference signal according to the number of symbols in the time slot in which the first reference signal is carried; and/or, the first terminal device determines the sequence length of the first reference signal according to the The bandwidth determines the sequence length of the first reference signal.
The method according to any one of claims 1 to 4, wherein the first terminal device determining the resource for sending the first reference signal according to the synchronization information of the first terminal device comprises:

The first terminal device determines the resource for transmitting the first reference signal according to the resource mapping mode of the synchronization information and the first reference signal; the resource mapping mode of the synchronization information and the first reference signal includes : The synchronization information is mapped on two adjacent symbols of the time slot where the first reference signal is located; the time slot where the first reference signal is located includes at least two symbols.
The method according to any one of claims 1-5, wherein the first reference signal is any one of the following reference signals:

Demodulation reference signal DMRS for control channel, demodulation reference signal DMRS for data channel, demodulation reference signal DMRS for broadcast channel, reference signal for feedback channel, channel state information reference signal CSI-RS, Phase tracking reference signal PT-RS.
The method according to any one of claims 1-6, wherein before the first terminal device sends the first reference signal to the second terminal device, the method further comprises:

The first terminal device determines that the sequence length of the first reference signal is greater than a first preset value; or

The first terminal device determines that the bandwidth of the first reference signal is greater than a second preset value.
The method according to any one of claims 1-7, wherein the method further comprises:

The first terminal device sends first control information to the second terminal device, where the first control information is used to indicate part or all of the synchronization information of the first terminal device; or, the first control The cyclic redundancy check code of the information is used to indicate part or all of the synchronization information of the first terminal device.
The method according to any one of claims 1-8, wherein the method further comprises:

The first terminal device sends first data to the second terminal device, and the cyclic redundancy check code of the first data is used to indicate part or all of the synchronization information of the first terminal device.
The method according to any one of claims 1-9, wherein before the first terminal device sends the first reference signal to the second terminal device, the method further comprises:

The first terminal device determines that the first terminal device supports synchronization based on the first reference signal.
A method of communication, characterized in that it comprises:

The second terminal device receives the first reference signal from the first terminal device;

The second terminal device determines the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or the second terminal device determines the synchronization information according to the resource used to receive the first reference signal Said synchronization information of the first terminal device;

The second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device;

Wherein, the synchronization information includes at least one of the following information: the type of synchronization source of the first terminal device, the number of hops between the first terminal device and satellite or network equipment, and the first terminal device Whether it is directly synchronized to a satellite or a network device, and whether the first terminal device is within the coverage of the network device.
The method according to claim 11, wherein the second terminal device determining the synchronization information of the first terminal device according to the resource used to receive the first reference signal comprises:

The second terminal device determines the synchronization information of the first terminal device according to the subcarriers in the physical resource block of the first reference signal.
The method according to any one of claims 11 or 12, wherein the second terminal device determining the synchronization source of the second terminal device according to the synchronization information of the first terminal device comprises:

The second terminal device determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device and the priority information of the synchronization source.
The method according to any one of claims 11-13, wherein the method further comprises:

Detecting the signal quality of the first reference signal by the second terminal device;

When the signal quality of the first reference signal is greater than a first threshold, the second terminal device uses the first terminal device as a candidate synchronization source;

The second device determines the synchronization source of the second device according to the candidate synchronization source.
The method according to any one of claims 11-14, wherein the method further comprises:

The second terminal device receives the first data and/or first control information from the first terminal device;

When the first terminal device meets a preset condition, the second terminal device uses the first terminal device as a candidate synchronization source;

Determining, by the second device, the synchronization source of the second device according to the candidate synchronization source;

Wherein, the preset condition includes at least one of the following conditions: the cyclic redundancy check code of the first data is checked correctly; or the cyclic redundancy check code of the first control information is checked correctly Or, the bandwidth of the first reference signal is greater than a first preset value.
The method according to any one of claims 11-15, wherein the method further comprises:

The second terminal device receives the first data and/or first control information from the first terminal device;

The second terminal device determines the synchronization information of the first terminal device according to the DMRS of the first data and the DMRS of the first control information; or

The second terminal device determines the synchronization information of the first terminal device according to the cyclic redundancy check code of the first data and/or the cyclic redundancy check code of the first control information.
The method according to any one of claims 11-16, wherein the method further comprises:

The second terminal device detects the side link synchronization signal sent by the third device, the second terminal device determines the synchronization source of the second terminal device according to the first priority information, and the first priority information Including any of the following:

The number of hops synchronized by the third device to the satellite or base station is the same as the number of hops synchronized by the first terminal device to the satellite or base station, and the priorities of the first terminal device and the third device are the same;

The number of hops that the third device synchronizes to the satellite or base station is the same as the number of hops that the first terminal device synchronizes to the satellite or the base station, and the first terminal device has a higher priority relative to the third device;

The number of hops that the third device synchronizes to the satellite or base station is the same as the number of hops that the first terminal device synchronizes to the satellite or the base station, and the first terminal device has a lower priority relative to the third device;

The number of hops that the third device synchronizes to the satellite or base station is the same as the number of hops that the first terminal device synchronizes to the satellite or the base station, and the first terminal device determines the first terminal device and the first terminal device according to pre-configuration information. The priority of the third device.
The method according to any one of claims 11-17, wherein before the second terminal device receives the first reference signal from the first terminal device, the method further comprises:

The second terminal device determines that the second terminal device supports synchronization based on the first reference signal.
The method according to any one of claims 11-18, wherein the first reference signal comprises any one of the following signals:

Control channel demodulation reference signal DMRS, data channel demodulation reference signal DMRS, broadcast channel demodulation reference signal DMRS, feedback channel reference signal, channel state information reference signal CSI-RS, phase tracking reference signal PT-RS.
The method according to any one of claims 11-19, wherein the first terminal device is a device that sends a synchronization signal, or the first terminal device is a device that does not send a synchronization signal.
A communication device, characterized in that it comprises:

The processing unit is configured to determine the sequence of the first reference signal according to the synchronization information of the first terminal device, and/or the processing unit is configured to determine the resource for sending the first reference signal according to the synchronization information of the first terminal device;

A sending unit, configured to send the first reference signal to a second terminal device;

Wherein, the synchronization information includes at least one of the following information: the type of synchronization source of the first terminal device, the number of hops between the first terminal device and satellite or network equipment, and the first terminal device Whether it is directly synchronized to a satellite or a network device, and whether the first terminal device is within the coverage of the network device.
The device according to claim 21, wherein the processing unit determines the sequence of the first reference signal according to the synchronization information of the first terminal device, comprising:

The processing unit determines the parameters of the sequence of the first reference signal according to the synchronization information, where the parameters include at least one of the following parameters: the initial value of the sequence of the first reference signal, the root sequence number, and the sequence The cyclic shift value of the sequence, the orthogonal cover code OCC of the sequence, and the sequence length.
The device according to claim 21 or 22, wherein the processing unit determines the resource for sending the first reference signal according to the synchronization information of the first terminal device, comprising:

The processing unit is configured to determine the subcarrier of the first reference signal in the physical resource block according to the synchronization information.
The apparatus according to any one of claims 21-23, wherein the processing unit is further configured to determine the sequence of the first reference signal according to the number of symbols in the time slot in which the first reference signal is carried Length; and/or, the processing unit is configured to determine the sequence length of the first reference signal according to the bandwidth of the first reference signal.
The device according to any one of claims 21-24, wherein the processing unit is further configured to determine a resource for sending the first reference signal according to synchronization information of the first terminal device, comprising:

The processing unit is configured to determine the resource for sending the first reference signal according to the resource mapping mode of the synchronization information and the first reference signal; the resource mapping mode of the synchronization information and the first reference signal includes : The synchronization information is mapped on two adjacent symbols of the time slot where the first reference signal is located; the time slot where the first reference signal is located includes at least two symbols.
The apparatus according to any one of claims 21-25, wherein the first reference signal comprises any one of the following reference signals:

Demodulation reference signal DMRS for control channel, demodulation reference signal DMRS for data channel, demodulation reference signal DMRS for broadcast channel, reference signal for feedback channel, channel state information reference signal CSI-RS, Phase tracking reference signal PT-RS.
The device according to any one of claims 21-26, wherein before the sending unit sends the first reference signal to the second terminal device, the first terminal device determines the first reference signal The sequence length of the signal is greater than the first preset value; or the first terminal device determines that the bandwidth of the first reference signal is greater than the second preset value.
The device according to any one of claims 21-27, wherein the sending unit is further configured to send first control information to the second terminal device, and the first control information is used to indicate the Part or all of the synchronization information of the first terminal device; or, the cyclic redundancy check code of the first control information is used to indicate part or all of the synchronization information of the first terminal device.
The device according to any one of claims 21-28, wherein the sending unit is further configured to send first data to the second terminal device, a cyclic redundancy check code of the first data Used to indicate part or all of the synchronization information of the first terminal device.
The device according to any one of claims 21-29, wherein before the sending unit sends the first reference signal to the second terminal device, the first terminal device determines that the first terminal device Support synchronization based on the first reference signal.
A communication device, characterized in that it comprises:

A receiving unit, configured to receive a first reference signal from a first terminal device;

The processing unit is configured to determine the synchronization information of the first terminal device according to the sequence of the first reference signal, and/or the processing unit is configured to determine the first terminal according to the resource of the first reference signal Synchronization information of the device;

The processing unit determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device;

Wherein, the synchronization information includes at least one of the following information: the type of synchronization source of the first terminal device, the number of hops between the first terminal device and the synchronization source, and whether the first terminal device directly It is synchronized to a satellite or network equipment, and whether the first terminal device is within the coverage of the network equipment.
The device according to claim 31, wherein the processing unit determines the synchronization information of the first terminal device according to the resource of the first reference signal, comprising:

The processing unit determines the synchronization information of the first terminal device according to the subcarriers of the first reference signal in the physical resource block.
The device according to any one of claims 31 or 32, wherein the processing unit determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device, comprising:

The processing unit determines the synchronization source of the second terminal device according to the synchronization information of the first terminal device and the priority information of the synchronization source.
The apparatus according to any one of claims 31-33, wherein the receiving unit is further configured to detect the signal quality of the first reference signal;

When the signal quality of the first reference signal is greater than a first threshold, the second terminal device uses the first terminal device as a candidate synchronization source;

The second device determines the synchronization source of the second device according to the candidate synchronization source.
The device according to any one of claims 31-34, wherein the second terminal device receives first data and/or first control information from the first terminal device;

When the first terminal device meets a preset condition, the second terminal device uses the first terminal device as a candidate synchronization source;

Determining, by the second device, the synchronization source of the second device according to the candidate synchronization source;

Wherein, the preset condition includes at least one of the following conditions: the cyclic redundancy check code of the first data is checked correctly; or the cyclic redundancy check code of the first control information is checked correctly Or, the bandwidth of the first reference signal is greater than a first preset value.
The device according to any one of claims 31-35, wherein the receiving unit is further configured to receive first data and/or first control information from the first terminal device;

The processing unit determines the synchronization information of the first terminal device according to the DMRS of the first data and the DMRS of the first control information; or

The processing unit determines the synchronization information of the first terminal device according to the cyclic redundancy check code of the first data and/or the cyclic redundancy check code of the first control information.
The apparatus according to any one of claims 31-36, wherein the receiving unit detects the side link synchronization signal sent by the third device, and the processing unit is configured to determine according to the first priority information For the synchronization source of the second terminal device, the first priority information includes any one of the following:

The number of hops synchronized by the third device to the satellite or base station is the same as the number of hops synchronized by the first terminal device to the satellite or base station, and the priorities of the first terminal device and the third device are the same;

The number of hops that the third device synchronizes to the satellite or base station is the same as the number of hops that the first terminal device synchronizes to the satellite or the base station, and the first terminal device has a higher priority relative to the third device;

The number of hops that the third device synchronizes to the satellite or base station is the same as the number of hops that the first terminal device synchronizes to the satellite or the base station, and the first terminal device has a lower priority relative to the third device;

The number of hops that the third device synchronizes to the satellite or base station is the same as the number of hops that the first terminal device synchronizes to the satellite or the base station, and the processing unit is configured to determine the first terminal device and the first terminal device and the base station according to pre-configuration information. The priority of the third device.
The device according to any one of claims 31-37, wherein before the second terminal device receives the first reference signal from the first terminal device, the second terminal device determines that the second terminal device supports Synchronization based on the first reference signal.
The device according to any one of claims 31-38, wherein the first reference signal comprises any one of the following signals:

Control channel demodulation reference signal DMRS, data channel demodulation reference signal DMRS, broadcast channel demodulation reference signal DMRS, feedback channel reference signal, channel state information reference signal CSI-RS, phase tracking reference signal PT-RS.
The device according to any one of claims 31-39, wherein the first terminal device is a device that sends a synchronization signal, or the first terminal device is a device that does not send a synchronization signal.