Sidelink monitoring method and device

Abstract

To provide a side link monitoring method and device that can effectively monitor the link quality of a side link.SOLUTION: A method includes detecting, by a first terminal device, side link data transmitted from a second terminal device during a first period, and determining, by the first terminal device, whether a side link between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to a detection result of the side link data. The side link data includes a reference signal and / or a side link control channel, or the side link data includes hybrid automatic repeat request (HARQ) feedback information.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to the field of communications technology, and more particularly, to a sidelink monitoring method and device. [Background technology]

[0002] Internet of Vehicles (Iov) (also known as Vehicle to Everything, V2X) communication adopts side link (SL) transmission technology based on device to device (D2D) communication. Unlike the conventional long term evolution (LTE) system that transmits and receives data via base stations, the Iov system adopts direct communication between terminals, resulting in higher spectral efficiency and lower transmission latency.

[0003] In the fifth generation (5G), i.e., V2X (NR-V2X) communication of a new radio (NR) system, a terminal device can measure a reference signal and judge the quality of a sidelink based on the measurement result. In NR-V2X, a reference signal may be transmitted aperiodically, and the terminal device needs to obtain resources for transmitting the reference signal through contention, so the transmission of the reference signal has uncertainty. At this time, how to monitor the quality of the sidelink has become a problem to be solved. Summary of the Invention

[0004] The present application provides a sidelink monitoring method and device that can effectively monitor the link quality of a sidelink.

[0005] In a first aspect, a sidelink monitoring method is provided, comprising: a first terminal device detecting sidelink data transmitted from a second terminal device during a first time period; and the first terminal device determining, depending on a result of the detection of the sidelink data, whether a sidelink between the first terminal device and the second terminal device is in a synchronous or asynchronous state. The sidelink data comprises a reference signal and / or a sidelink control channel, or the sidelink data comprises hybrid automatic repeat request (HARQ) feedback information.

[0006] In a second aspect, a sidelink monitoring method is provided, the method including: a second terminal device receiving first indication information transmitted from a first terminal device; and the second terminal device transmitting sidelink data to the first terminal device based on the first indication information. The first indication information is used to instruct the second terminal device to transmit the sidelink data to the first terminal device, and the sidelink data includes a reference signal and / or a sidelink control channel. The sidelink data is used by the first terminal device to determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous or asynchronous state.

[0007] In a third aspect, a terminal device is provided, the terminal device being adapted to perform the method of the first aspect or any alternative embodiment thereof. In particular, the terminal device may include a functional module adapted to perform the method of the first aspect or any alternative embodiment thereof.

[0008] In a fourth aspect, a terminal device is provided, the terminal device being adapted to perform the method of the second aspect or any of the alternative embodiments of the second aspect. In particular, the terminal device may include a functional module adapted to perform the method of the second aspect or any of the alternative embodiments of the second aspect.

[0009] In a fifth aspect, there is provided a terminal device comprising a processor and a memory, the memory adapted to store a computer program, and the processor adapted to perform the method of the first aspect or any alternative embodiment of the first aspect described above by calling and executing the computer program stored in the memory.

[0010] In a sixth aspect, there is provided a terminal device comprising a processor and a memory, the memory adapted to store a computer program, and the processor adapted to perform the method of the second aspect or any alternative embodiment of the second aspect described above by invoking and executing the computer program stored in the memory.

[0011] In a seventh aspect, there is provided a communications apparatus including a processor, the processor calling and executing a computer program from a memory to cause a device comprising the communications apparatus to perform the method of the first aspect or any alternative embodiment of the first aspect described above.

[0012] In an eighth aspect, there is provided a communications apparatus including a processor, the processor calling and executing a computer program from a memory to cause a device comprising the communications apparatus to perform the method of the second aspect or any alternative embodiment of the second aspect described above.

[0013] In a ninth aspect, there is provided a computer readable storage medium adapted to store a computer program, the computer program causing a computer to perform the method of the first aspect or any alternative embodiment of the first aspect described above.

[0014] In a tenth aspect, there is provided a computer readable storage medium adapted to store a computer program, the computer program causing a computer to perform the method of the second aspect or any alternative embodiment of the second aspect described above.

[0015] In an eleventh aspect, there is provided a computer program product comprising computer program instructions causing a computer to perform the method of the first aspect or any alternative embodiment of the first aspect described above.

[0016] In a twelfth aspect, there is provided a computer program product comprising computer program instructions causing a computer to perform the method of the second aspect or any alternative embodiment of the second aspect described above.

[0017] In a thirteenth aspect, a computer program is provided which, when executed by a computer, causes the computer to carry out a method of the first aspect or any alternative embodiment of the first aspect described above.

[0018] In a fourteenth aspect, a computer program is provided which, when executed by a computer, causes the computer to carry out the method of the second aspect or any alternative embodiment of the second aspect described above.

[0019] In a fifteenth aspect, a communication system is provided that includes a first terminal device and a second terminal device.

[0020] The second terminal device is used to receive the first instruction information sent from the first terminal device, and transmit sidelink data to the first terminal device based on the first instruction information, where the first instruction information is used to instruct the second terminal device to transmit sidelink data to the first terminal device, and the sidelink data includes a reference signal and / or a sidelink control channel.

[0021] The first terminal device is used to detect sidelink data transmitted from the second terminal device during a first period, and determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to a detection result of the sidelink data, where the sidelink data includes a reference signal and / or a sidelink control channel.

[0022] With the above technical solution, the first terminal device can detect sidelink data transmitted from the second terminal device in a first period of time, and determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to the detection result of the sidelink data, so as to effectively monitor the link quality of the sidelink. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is an architecture diagram illustrating an application scenario according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an architecture diagram illustrating an application scenario according to another embodiment of the present invention. [Diagram 3] FIG. 3 is a flowchart illustrating a sidelink monitoring method according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram illustrating transmitting a reference signal according to an embodiment of the present invention. [Diagram 5] FIG. 5 shows a possible embodiment based on the method shown in FIG. [Figure 6] FIG. 6 shows a possible embodiment based on the method shown in FIG. [Figure 7] FIG. 7 shows another possible embodiment based on the method shown in FIG. [Figure 8] FIG. 8 is a block diagram of a first terminal device according to an embodiment of the present invention. [Figure 9] FIG. 9 is a block diagram of a second terminal device according to an embodiment of the present invention. [Figure 10]FIG. 10 is a block diagram of a communication device according to an embodiment of the present invention. [Figure 11] FIG. 11 is a block diagram of a communication device according to an embodiment of the present invention. [Figure 12] FIG. 12 is a block diagram of a communication device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, technical solutions of the embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0025] The technical solutions according to the embodiments of the present application can be applied to various communication systems, such as a Global System of Mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a Long Term Evolution (LTE) system, a Frequency Division Duplex (LTE FDD) system, a Time Division Duplex (LTE TDD) system, an Advanced Long Term Evolution (LTE-A) system, a new radio (NR) system, an evolved system of an NR system, an LTE-based access to unlicensed spectrum (LTE-U) system, an NR-based access to unlicensed spectrum (NR-U) system, a universal mobile telecommunication system (UMTS), a wireless local area network (WLAN), a wireless fidelity (WiFi), a 5G system, or other communication systems.

[0026] The terminal device according to the embodiments of the present application may refer to a user equipment (UE), an access terminal, a user unit, a user station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device. The terminal device may be a cellular radio telephone, a cordless telephone, a Session Initiation Protocol (SIP) telephone, a Wireless Local Loop (WLL) station, a PDA, a handheld device with wireless communication capability, a computing device, or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device of a 5G network, or a terminal device in a future evolution PLMN, and the embodiments of the present application are not limited thereto.

[0027] The network device according to the embodiment of the present application can be a base station (Base Transceiver Station, BTS) in a GSM system or a CDMA system, a base station (Node B, NB) in a WCDMA system, an evolutional base station (Evolutional Node B, eNB or eNodeB) in an LTE system, or a radio controller in a Cloud Radio Access Network (Cloud Radio Access Network, CRAN). Alternatively, the network device can be a relay station, an access point, an in-vehicle device, a wearable device, a future network side device, or a network device in a future evolution PLMN, etc.

[0028] 1 and 2 are schematic diagrams illustrating application scenarios of the embodiments of the present application. FIG. 1 and FIG. 2 exemplarily show one network device and two terminal devices. Alternatively, the wireless communication system may include multiple network devices, and there may be other quantities of terminal devices within the coverage area of ​​each network device, and the embodiments of the present application are not limited thereto.

[0029] Furthermore, the wireless communication system may further include other network entities, such as a mobile management entity (MME), a serving gateway (S-GW) or a packet data network gateway (P-GW), although embodiments of the present invention are not limited thereto.

[0030] Specifically, the terminal device 20 and the terminal device 30 can communicate with each other through D2D communication. During D2D communication, the terminal device 20 and the terminal device 30 communicate directly through a sidelink. For example, as shown in FIG. 1 or FIG. 2, the terminal device 20 and the terminal device 30 communicate directly through a sidelink. As shown in FIG. 1, the terminal device 20 and the terminal device 30 communicate through a sidelink, and the transmission resources thereof are assigned by a network device. As shown in FIG. 2, the terminal device 20 and the terminal device 30 communicate through a sidelink, and the transmission resources thereof are not assigned by a network device but are selected by the terminal device 20 and the terminal device 30.

[0031] D2D includes Prose (Proximity based Service), V2X (Vehicle to Everything), and further research on LTE D2D (FeD2D). V2X includes vehicle to vehicle communication or V2X communication. In V2X communication, X can refer to any device with wireless transmission and reception capabilities, such as a wireless device moving at a low speed, an in-vehicle device moving at a high speed, or a network control node with wireless transmission and reception capabilities. It should be understood that the embodiments of the present application are mainly applied to V2X communication scenarios, but can also be applied to any other D2D communication scenarios, and are not limited thereto.

[0032] In a cellular system, when data is transmitted between a terminal device and a network device, it is necessary to maintain a connection between the terminal device and the network device. The network device periodically transmits a reference signal, and the terminal device judges the quality of the radio link by detecting the reference signal and judges whether the radio link is in a synchronous state or an asynchronous state. When the radio link is in a synchronous state, the terminal device can receive data transmitted from the network device. When the radio link is in an asynchronous state, the terminal device cannot receive data from the network device, and the terminal device needs to reconnect.

[0033] In NR-V2X, reference signals may be transmitted aperiodically, and resources for terminal devices to transmit reference signals need to be acquired through contention, so the transmission of reference signals has uncertainty, which affects the terminal devices' measurement of the reference signals, and the quality of the sidelink cannot be acquired accurately.

[0034] 3 is a flow chart illustrating a sidelink monitoring method according to an embodiment of the present invention. The method may be performed by a first terminal device and / or a second terminal device. The first terminal device may be the terminal device 20 shown in FIG. 1 or FIG. 2. The second terminal device may be the terminal device 30 shown in FIG. 1 or FIG. 2. As shown in FIG. 3, the method 300 includes some or all of the following contents:

[0035] In block 310, the first terminal device detects sidelink data transmitted from the second terminal device during a first time period.

[0036] The sidelink data may include reference signals and / or sidelink control channels, or may include hybrid automatic repeat request (HARQ) feedback information.

[0037] In block 320, the first terminal device determines whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to the detection result of the sidelink data.

[0038] Here, the "detection result" refers to a result indicating whether or not the detection of sidelink data in the first time period was successful, such as whether or not the sidelink data was successfully detected in the first time period, or the number or probability of the sidelink data being successfully detected in the first time period, or the number or probability of the sidelink data not being successfully detected in the first time period, etc.

[0039] In this embodiment, the first terminal device detects sidelink data transmitted from the second terminal device in a first period, and determines whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to the detection result of the sidelink data, so as to effectively monitor the sidelink. The technical solution of the present invention can be applied to various scenarios, such as periodic reference signals, aperiodic reference signals, or other scenarios supporting feedback transmission.

[0040] The embodiments of the present application do not particularly limit the reference signal. For example, the reference signal may be a channel state information-reference signal (CSI-RS) or a demodulation reference signal (DMRS), etc.

[0041] The sidelink control channel can be used to schedule the sidelink data channel and / or the reference signal, e.g., the sidelink control channel carries indication information indicating the time-frequency resources of the reference signal and / or whether the reference signal is transmitted simultaneously with the sidelink control channel or the sidelink data channel.

[0042] For example, the second terminal device instructs the first terminal device via sidelink control information (SCI) that the CSI-RS and the time-frequency resources of the CSI-RS are included in the physical sidelink shared channel (PSSCH).

[0043] If the reference signal is transmitted simultaneously with the sidelink data channel, the reference signal may occupy one symbol of the sidelink data channel. The time-frequency resource that the reference signal occupies may be indicated via the SCI, or may be pre-configured as agreed in the protocol, or may be configured for the terminal device by the network device and notified to the terminal device via configuration information. If the reference signal is not transmitted simultaneously with the sidelink data channel or the sidelink control channel, the reference signal may occupy a specific symbol in a timeslot, such as the penultimate symbol in the timeslot.

[0044] As shown in Figure 4, in time slot 0, CSI-RS is transmitted together with a physical sidelink shared channel (PSSCH). The physical sidelink control channel (PSCCH) can schedule the PSSCH and carry indication information indicating that the PSSCH includes the CSI-RS. Furthermore, the time domain resource occupied by the CSI-RS can be indicated via the PSCCH, and the frequency domain resource of the CSI-RS and the frequency domain resource of the PSSCH are the same.

[0045] CSI-RS is transmitted alone in timeslot 1. PSCCH is not transmitted in timeslot 1. If the terminal device needs to transmit CSI-RS in timeslot 1, the terminal device transmits CSI-RS in the penultimate symbol of timeslot 1.

[0046] Alternatively, the PSCCH may indicate that the CSI-RS is not transmitted together with the PSSCH. For example, in timeslot 1 shown in FIG. 4, the CSI-RS is transmitted alone and is not transmitted together with the PSSCH. At this time, the terminal device may also transmit the PSCCH in timeslot 1, and the PSCCH is used to indicate whether the CSI-RS exists in timeslot 1 and the time-frequency resource for transmitting the CSI-RS in timeslot 1.

[0047] In timeslot 3, no CSI-RS is transmitted and the PSCCH schedules only the transmission of the PSSCH.

[0048]

[0033] An embodiment of the present application can determine whether the sidelink is in synchronous or asynchronous state in the following three ways:

[0049] Method 1

[0050] As shown in FIG. 5, prior to the operation of block 310, the method may include some or all of the following operations.

[0051] In block 330, the first terminal device transmits the first instruction information to the second terminal device.

[0052] The first indication information may be carried, for example, in a sidelink control channel, a sidelink data channel, or SL Radio Resource Control (RRC) signaling.

[0053] In block 340, the second terminal device receives first instruction information transmitted from the first terminal device, the first instruction information being used to instruct the second terminal device to transmit sidelink data to the first terminal device.

[0054] In block 350, the second terminal device transmits sidelink data to the first terminal device based on the first indication information.

[0055] The sidelink data includes reference signals and / or sidelink control channels.

[0056] Optionally, the operation of block 320 includes the operation of block 321 and / or the operation of block 322.

[0057] In block 321, if no sidelink data is detected by the first terminal device during a first time period, it is determined that the sidelink is in an unsynchronized state.

[0058] In block 322, if sidelink data is detected by the first terminal device during a first time period, it is determined whether the sidelink is in a synchronous or asynchronous state based on measurements of the reference signal.

[0059] That is, after instructing the second terminal device to transmit sidelink data, the first terminal device detects sidelink data transmitted from the second terminal device in a first period, and if no sidelink data is detected, determines that the sidelink is in an asynchronous state, and if sidelink data is detected, determines whether the sidelink is in a synchronous state or an asynchronous state based on the measurement result of the reference signal.

[0060] If the first terminal device does not receive sidelink data transmitted from the second terminal device in the first period, there are two possibilities. One possibility is that due to the aperiodic transmission of sidelink data, the second terminal device did not transmit sidelink data to the first terminal device in the first period, so the first terminal device cannot detect the sidelink data transmitted from the second terminal device. However, this does not mean that the quality of the sidelink between the first terminal device and the second terminal device is bad. The other possibility is that the second terminal device transmitted sidelink data to the first terminal device, but the sidelink data was not detected by the first terminal device because the sidelink quality is bad. If the sidelink data is not detected, the first terminal device cannot determine which situation has occurred and cannot accurately determine the quality of the sidelink between the first terminal device and the second terminal device.

[0061] In this embodiment, the first terminal device sends first instruction information to the second terminal device to instruct the second terminal device to transmit sidelink data to the first terminal device. Since the first terminal device instructs the second terminal device to transmit sidelink data to the first terminal device, the second terminal device transmits sidelink data to the first terminal device upon receiving the first instruction information. At this time, if the quality of the sidelink between the first terminal device and the second terminal device is good, the first terminal device can successfully detect the sidelink data. If the sidelink data is not detected by the first terminal device, it is explained that the quality of the sidelink between the first terminal device and the second terminal device is poor. Therefore, the first terminal device can determine what situation has occurred and accurately determine the current quality of the sidelink between the first terminal device and the second terminal device.

[0062] In the above operations of blocks 321 and 322, the first terminal device may determine that the sidelink is in an asynchronous state based on one detection result for the sidelink data in the first time period. However, the present application is not limited thereto. The first terminal device may determine whether the sidelink is in an asynchronous state or in a synchronous state based on multiple detection results for the sidelink data. For example, if the first terminal device does not detect sidelink data N consecutive times in the first time period, it may determine that the sidelink between the first terminal device and the second terminal device is in an asynchronous state. In yet another example, if the first terminal device detects sidelink data M consecutive times in the first time period, it may determine that the sidelink between the first terminal device and the second terminal device is in a synchronous state.

[0063] In block 322, the first terminal device may determine whether the sidelink is in an asynchronous state or in a synchronous state based on a single measurement result of the reference signal during the first time period. However, the present application is not limited thereto. The first terminal device may determine whether the sidelink is in an asynchronous state or in a synchronous state based on multiple measurements of the reference signal. For example, if P consecutive measurements of the reference signal are less than a threshold during the first time period, the first terminal device may determine that the sidelink is in an asynchronous state. In yet another example, if Q consecutive measurements of the reference signal are greater than a threshold during the first time period, the first terminal device may determine that the sidelink is in a synchronous state.

[0064] M, N, P, and Q are positive integers and may be configurable by the network device or may be pre-configured.

[0065] The first instruction information may further indicate a first period of time, i.e., instruct the second terminal device to transmit sidelink data to the first terminal device during the first period of time.

[0066] Alternatively, the first period of time may also be configured for the terminal device by the network device or may be pre-configured as agreed upon in a protocol.

[0067] The first indication information may indicate time-frequency resources and / or transmission parameters of the sidelink data.

[0068] The first indication information may explicitly indicate the time-frequency resources of the sidelink data, i.e. directly indicate the time-frequency resources to be used for the transmission of the reference signal. The first indication information may also implicitly indicate the time-frequency resources of the sidelink data, e.g. indicate a time domain resource range within which the second terminal device selects resources for transmitting the sidelink data. The transmission parameters include parameters such as the transmission power of the reference signal.

[0069] Optionally, in block 322, the first terminal device may determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state based on at least one of a signal to interference plus noise ratio (SINR), a reference signal received power (RSRP), and a reference signal received quality (RSRQ) of the reference signal.

[0070] Taking SINR as an example, when a first terminal device detects an SCI transmitted from a second terminal device in a first period, and the SCI indicates that a CSI-RS is included in the PSSCH, the first terminal device measures the SINR of the CSI-RS based on the indication of the SCI.

[0071] The first terminal device compares the measured SINR with a threshold to determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state. For example, if the measured SINR is greater than the threshold, the first terminal device determines that the sidelink is in a synchronous state. If the measured SINR is equal to or less than the threshold, the first terminal device determines that the sidelink is in an asynchronous state.

[0072] The first terminal device can determine a PSCCH detection success probability or a PSCCH detection failure probability based on the measurement value of the SINR and by combining the correspondence between the SINR and the PSCCH detection probability. The first terminal device compares the PSCCH detection success probability or the PSCCH detection failure probability with a threshold to determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state. For example, the first terminal device determines that the sidelink is in an asynchronous state if the PSCCH detection failure probability is greater than a threshold, such as 10%. In yet another example, the first terminal device determines that the sidelink is in a synchronous state if the PSCCH detection failure probability is less than a threshold, such as 2%.

[0073] In the case of wireless links, the related process of measuring the reference signal is also called radio link monitoring (RLM) measurement.

[0074] Alternatively, as shown in FIG. 6, the operation of block 330 may include the operation of block 331 and the operation of block 332 .

[0075] In block 331, the first terminal device starts a timer when sidelink data is detected.

[0076] In block 332, if no sidelink data is detected before the timer expires, the first terminal device sends first indication information to the second terminal device.

[0077] The duration of the timer can be configured for the end device by the network device or can be pre-configured as agreed upon in the protocol.

[0078] The sending of the first indication information to the second terminal device is triggered by a timer. When the timer expires, the first terminal device sends the first indication information to the second terminal device. When the first terminal device detects sidelink data, such as a PSCCH or a reference signal, it starts or restarts the timer and continues to detect the sidelink data within the duration of the timer. If the sidelink data transmitted from the second terminal device by the first terminal device is not detected within the duration of the timer, i.e., the sidelink data transmitted from the second terminal device is not detected again before the timer expires, when the timer expires, the first terminal device sends the first indication information to the second terminal device to instruct the second terminal device to transmit sidelink data to the first terminal device.

[0079] If the first terminal device does not detect sidelink data transmitted from the second terminal device during a first period after transmitting the first indication information, the first terminal device determines that the sidelink between the first terminal device and the second terminal device is in an asynchronous state. If the first terminal device detects sidelink data transmitted from the second terminal device during the first period, the first terminal device measures a reference signal and restarts a timer, and determines whether the sidelink is in a synchronous state or an asynchronous state based on the measurement result of the reference signal.

[0080] Optionally, as shown in FIG. 7, the operation of block 330 includes the operation of block 333 and the operation of block 334.

[0081] In block 333, the first terminal device starts a counter when sidelink data is detected, and the counter is used to record the number of time units that have passed.

[0082] In block 334, if no sidelink data is detected before the value recorded in the counter reaches the set value, the first terminal device sends a first indication to the second terminal device.

[0083] The counter settings can be configured for the end device by the network device or can be pre-configured as agreed upon in the protocol.

[0084] The time unit may be a time slot or a subframe, etc.

[0085] The sending of the first indication information to the second terminal device is triggered by a counter. When the value recorded in the counter reaches a set value, the first terminal device sends the first indication information to the second terminal device. When the first terminal device detects sidelink data, such as a PSCCH or a reference signal, it starts or restarts the counter and continues to detect sidelink data transmitted from the second terminal device. The counter is used to record the number of elapsed time units. If the sidelink data transmitted from the second terminal device is not detected by the first terminal device during the counting period of the counter, i.e., the sidelink data transmitted from the second terminal device is not detected again before the value recorded in the counter reaches the set value, when the counter stops counting, the first terminal device sends the first indication information to the second terminal device to instruct the second terminal device to transmit sidelink data to the first terminal device.

[0086] If the first terminal device does not detect sidelink data transmitted from the second terminal device during a first period after transmitting the first indication information, the first terminal device determines that the sidelink between the first terminal device and the second terminal device is in an asynchronous state. If the first terminal device detects sidelink data transmitted from the second terminal device during the first period, the first terminal device measures a reference signal and restarts a counter, and determines whether the sidelink is in a synchronous state or an asynchronous state based on the measurement result of the reference signal.

[0087] Optionally, the time units are from a particular resource pool, or are from all resource pools configured by the network device.

[0088] For example, two resource pools, namely resource pool 1 and resource pool 2, are configured by a network device. Resource pool 1 includes time slots with even IDs, such as time slot 0, time slot 2, time slot 4, time slot 6, time slot 8, etc. Resource pool 2 includes time slots with odd IDs, such as time slot 1, time slot 3, time slot 5, time slot 7, time slot 9, etc. If the unicast transmission of the first terminal device and the second terminal device is performed in resource pool 1, the counter can count time slots such as time slot 0, time slot 2, time slot 4, time slot 6, time slot 8, etc. of resource pool 1. Of course, the counter can count time slots such as time slot 0, time slot 1, time slot 2, time slot 3, time slot 4, time slot 5, time slot 6, time slot 7, time slot 8, time slot 9, etc. of resource pool 1 and resource pool 2.

[0089] The counter can count each time unit along the timeline.

[0090] Alternatively, the first terminal device may determine whether the sidelink is in a synchronous state or an asynchronous state, and then transmit second indication information to the second terminal device, the second indication information being used to indicate whether the sidelink is in a synchronous state or an asynchronous state.

[0091] Optionally, the method further includes: if no sidelink data is detected by the first terminal device in the first time period, the first terminal device may increase a transmission power to transmit sidelink data to the second terminal device.

[0092] Similarly, when the first terminal device transmits second indication information to the second terminal device, and the second indication information indicates that the sidelink between the first terminal device and the second terminal device is in an asynchronous state, the second terminal device can increase its transmission power to transmit sidelink data to the first terminal device.

[0093] For example, the first or second terminal device may transmit the sidelink data by gradually increasing the transmission power until the transmission power reaches a maximum transmission power of the terminal device or until the transmission power reaches a maximum transmission power of the terminal device configured by the network device, or the first or second terminal device may stop increasing the transmission power if sidelink data is detected by the other party.

[0094] Method 2

[0095] For periodically transmitted sidelink data, optionally, in block 320, the first terminal device determines whether the sidelink is in a synchronous or asynchronous state based on the detection probability of the sidelink data during a first period of time.

[0096] The sidelink data includes reference signals and / or sidelink control channels.

[0097] The detection probability comprises a probability that sidelink data is detected in the first time period and / or a probability that sidelink data is not detected in the first time period. The probability of sidelink data detection in the first time period is equal to the ratio of the number of times that sidelink data is actually detected by the first terminal device in the first time period to the number of times that the first terminal device wishes to receive sidelink data in the first time period. The probability of sidelink data not being detected in the first time period is equal to the ratio of the number of times that sidelink data is not detected by the first terminal device in the first time period to the number of times that the first terminal device wishes to receive sidelink data in the first time period.

[0098] The first terminal device may determine whether the sidelink is in a synchronous or asynchronous state based on whether the detection probability reaches a first threshold, for example, if the probability of missed detection of the sidelink control channel is greater than a first threshold, the first terminal device may determine that the sidelink between the first terminal device and the second terminal device is in an asynchronous state.

[0099] The first threshold value may be configured for the end device by the network device or may be pre-configured as agreed upon in a protocol.

[0100] In this embodiment, the first terminal device can effectively monitor the link quality of the sidelink by determining whether the sidelink between the first terminal device and the second terminal device is in an asynchronous state or a synchronous state based on the detection probability of the sidelink data transmitted from the second terminal device in the first period.

[0101] Alternatively, the first terminal device may determine whether the sidelink is in a synchronous state or an asynchronous state and then send second indication information to the second terminal device, where the second indication information is used to indicate whether the sidelink is in a synchronous state or an asynchronous state.

[0102] Optionally, the method further includes: if the sidelink is in an unsynchronized state, the first terminal device may increase a transmission power to transmit sidelink data to the second terminal device.

[0103] Similarly, when the first terminal device transmits second indication information to the second terminal device, and the second indication information indicates that the sidelink between the first terminal device and the second terminal device is in an asynchronous state, the second terminal device can increase its transmission power to transmit sidelink data to the first terminal device.

[0104] For example, the first or second terminal device may transmit the sidelink data by gradually increasing the transmission power until the transmission power reaches a maximum transmission power of the terminal device or until the transmission power reaches a maximum transmission power of the terminal device configured by the network device, or the first or second terminal device may stop increasing the transmission power if sidelink data is detected by the other party.

[0105] Method 3

[0106] Optionally, in block 320, the first terminal device determines that the sidelink is in an unsynchronized state if the number of consecutive detections of a discontinuous transmission (DTX) state and / or the number of consecutive receptions of a HARQ negative acknowledgement (HARQ-NACK) after transmitting sidelink data reaches a second threshold.

[0107] The sidelink data includes, for example, HARQ feedback information.

[0108] The first terminal device expects to receive HARQ feedback information sent from the second terminal device after sending a sidelink control channel to the second terminal device, and the first terminal device can know the resource for the second terminal device to send HARQ feedback information. If the second terminal device successfully detects the sidelink control channel sent from the first terminal device, it sends HARQ-ACK or HARQ-NACK to the first terminal device according to the detection result of the sidelink control channel. If the second terminal device does not successfully detect the sidelink control channel, the second terminal device does not send HARQ feedback information to the first terminal device, and the first terminal device cannot detect the HARQ feedback information sent from the second terminal device, and this situation is called DTX state.

[0109] If the number of times that the DTX state is continuously detected by the first terminal device reaches a second threshold, or if the number of times that the HARQ-NACK feedback is continuously received reaches a second threshold, or if the number of times that the DTX state is continuously detected and the number of times that the HARQ-NACK feedback is continuously received reach a second threshold, the first terminal device determines that the sidelink between the first terminal device and the second terminal device is in an asynchronous state.

[0110] The second threshold may be configured for the end device by the network device or may be pre-configured as agreed upon in the protocol.

[0111] In this embodiment, the first terminal device can determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state based on the HARQ feedback transmitted from the second terminal device, and effectively monitor the link quality of the sidelink.

[0112] Alternatively, the first terminal device may determine whether the sidelink is in a synchronous state or an asynchronous state, and then transmit second indication information to the second terminal device, the second indication information being used to indicate whether the sidelink is in a synchronous state or an asynchronous state.

[0113] Optionally, the method further includes: when the sidelink is in an unsynchronized state, the first terminal device or the second terminal device may increase transmission power to transmit the sidelink data.

[0114] For example, the first terminal device may transmit sidelink data to the second terminal device by gradually increasing the transmission power until the transmission power reaches a maximum transmission power of the first terminal device or until the transmission power reaches a maximum transmission power of the first terminal device configured by the network device. If a HARQ-NACK transmitted from the second terminal device is detected by the first terminal device, the first terminal device may stop increasing the transmission power.

[0115] In the above three schemes, the first terminal device already knows that the second terminal device will transmit sidelink data in the first period. That is, the first terminal device expects to detect the sidelink data transmitted from the second terminal device at least once in the first period. For example, in scheme 1, the first terminal device transmits first instruction information to the second terminal device to instruct the second terminal device to transmit sidelink data such as a reference signal and / or a sidelink control channel to the first terminal device in the first period. In scheme 2, the second terminal device periodically transmits sidelink data such as a reference signal and / or a sidelink control channel to the first terminal device, so that the number of times the first terminal device can detect the sidelink data in the first period is constant. In scheme 3, after the first terminal device transmits sidelink data to the second terminal device, the second terminal device needs to transmit HARQ feedback information to the first terminal device in the first period.

[0116] In these circumstances, if the link quality of the sidelink between the first and second terminal devices is good, the first terminal device can detect the sidelink data expected in the first time period, if in fact no sidelink data expected by the first terminal device in the first time period is detected or if the quantity of detected sidelink data is not ideal, the first terminal device determines that the link quality of the sidelink is poor.

[0117] When the sidelink is in a synchronous state, it indicates that the link quality of the sidelink is good. When the sidelink is in an asynchronous state, it indicates that the link quality of the sidelink is poor. When the sidelink is in a synchronous state, a sidelink data transmission is performed between the first terminal device and the second terminal device. When the sidelink is in an asynchronous state, no sidelink data transmission is performed between the first terminal device and the second terminal device.

[0118] Furthermore, in an embodiment of the present application, if the number of consecutive determinations that the sidelink is in an unsynchronized state reaches a threshold, it can be considered that a Radio Link Failure (RLF) has occurred and the terminal device needs to reconnect.

[0119] Unless there is a conflict, each embodiment and / or the technical features of each embodiment of this application may be arbitrarily combined with each other, and the technical solution obtained by the combination shall also be included in the protection scope of this application.

[0120] In each embodiment of the present application, the sequence number of each process does not mean the execution order, and the execution order of each process should be determined by its function and / or internal logic, and should not limit the execution process of the embodiments of the present application.

[0121] The sidelink monitoring method has been described in detail above. Hereinafter, devices according to embodiments of the present application will be described with reference to Figures 8 to 12. The technical features described in the method embodiments are also applicable to the following device embodiments.

[0122] Fig. 8 is a block diagram of a terminal device 800 according to an embodiment of the present invention. As shown in Fig. 8, the terminal device 800 is a first terminal device, which includes a processing unit 810. The processing unit 810 is used to detect sidelink data transmitted from a second terminal device in a first period, and determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to a detection result of the sidelink data. The sidelink data includes a reference signal and / or a sidelink control channel, or the sidelink data includes hybrid automatic repeat request (HARQ) feedback information.

[0123] The first terminal device detects sidelink data transmitted from the second terminal device in a first period, and determines whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to the detection result of the sidelink data, so as to effectively monitor the link quality of the sidelink.

[0124] Optionally, the sidelink data includes a reference signal and / or a sidelink control channel, and the first terminal device further includes a transmitting unit 820. The transmitting unit 820 is used for transmitting first instruction information to the second terminal device. The first instruction information is used for instructing the second terminal device to transmit the sidelink data to the first terminal device.

[0125] The processing unit 810 is specifically used for determining that the sidelink is in an asynchronous state if no sidelink data is detected in the first period of time and / or for determining whether the sidelink is in a synchronous state or an asynchronous state based on a measurement result of a reference signal if sidelink data is detected in the first period of time.

[0126] The processing unit 810 is specifically used for determining whether the sidelink is in a synchronous state or an asynchronous state based on at least one of a signal-to-interference-plus-noise ratio (SINR), a reference signal received power (RSRP), and a reference signal received quality (RSRQ) of the reference signal.

[0127] Optionally, the first indication information is further used to indicate time-frequency resources and / or transmission parameters of the sidelink data.

[0128] Alternatively, the first indication information is carried on a sidelink control channel, a sidelink data channel or RRC signaling.

[0129] Optionally, the processing unit 810 is further adapted to start a timer when the sidelink data is detected, and the sending unit 820 is specifically adapted to send first indication information to the second terminal device if no sidelink data is detected before the timer expires.

[0130] Optionally, the processing unit 810 is further adapted for starting a counter when sidelink data is detected. The counter is adapted for recording a number of elapsed time units. The sending unit 820 is specifically adapted for sending a first indication information to the second terminal device if no sidelink data is detected before the value recorded in the counter reaches a set value.

[0131] Optionally, the time units are from a particular resource pool, or are from all resource pools configured by the network device.

[0132] Optionally, the time unit is a time slot or a subframe.

[0133] Alternatively, the sidelink data may include a reference signal and / or a sidelink control channel, and the processing unit 810 is specifically used for determining whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or in an asynchronous state based on a detection probability of the sidelink data in a first time period, the detection probability including a probability that the sidelink data is detected in the first time period and / or a probability that the sidelink data is not detected in the first time period.

[0134] Optionally, the processing unit 180 may be specifically used to determine whether the sidelink is in sync or async based on whether the detection probability reaches a first threshold.

[0135] Optionally, the sidelink data is transmitted periodically during the first period of time.

[0136] Optionally, the sidelink control channel carries indication information indicating the time-frequency resource of the reference signal.

[0137] Optionally, the sidelink control channel further indicates whether or not the reference signal is transmitted simultaneously with the sidelink data channel.

[0138] Optionally, the sending unit 820 is further used for sending second indication information to the second terminal device, the second indication information being used for indicating whether the sidelink is in a synchronous state or an asynchronous state.

[0139] Optionally, the sidelink data includes HARQ feedback information. The processing unit 810 is specifically used for determining that the sidelink is in an unsynchronized state when a number of consecutively detected discontinuous transmission (DTX) states and / or a number of consecutively received HARQ negative acknowledgements (HARQ-NACKs) after transmitting the sidelink data reaches a second threshold.

[0140] Optionally, the transmitting unit 820 is further used to perform sidelink transmission with increased transmit power when the sidelink is in an asynchronous state.

[0141] The terminal device 800 may perform the operations performed by the first terminal device in the method 300 according to the embodiment of the present application, which will not be repeated here for brevity.

[0142] 9 is a block diagram of a terminal device 900 according to an embodiment of the present invention. As shown in FIG. 9, the terminal device 900 is a second terminal device, which includes a receiving unit 910 and a sending unit 920.

[0143] The receiving unit 910 is used for receiving first instruction information sent from a first terminal device, the first instruction information being used for instructing a second terminal device to transmit sidelink data to the first terminal device, where the sidelink data includes a reference signal and / or a sidelink control channel.

[0144] The sending unit 920 is used for sending sidelink data to the first terminal device based on the first indication information, the sidelink data being used by the first terminal device to determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state.

[0145] When the first terminal device fails to detect sidelink data transmitted from the second terminal device within a certain period of time, the first terminal device instructs the second terminal device to transmit sidelink data to the first terminal device, so that the first terminal device detects the sidelink data transmitted from the second terminal device based on the first instruction information. According to the detection result of the sidelink data, the first terminal device can determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state, and thus can effectively monitor the link quality of the sidelink.

[0146] The first indication information is further used to indicate time-frequency resources and / or transmission parameters of the sidelink data.

[0147] Alternatively, the first indication information is carried on a sidelink control channel, a sidelink data channel or RRC signaling.

[0148] Optionally, the receiving unit 910 is further used for receiving second indication information sent from the first terminal device, the second indication information being used for indicating whether the sidelink is in an asynchronous state or a synchronous state.

[0149] The terminal device 900 may perform operations performed by the second terminal device in the method 300 according to an embodiment of the present application, which will not be repeated here for brevity.

[0150] Fig. 10 is a block diagram of a communication device 1000 according to an embodiment of the present invention. As shown in Fig. 10, the communication device 1000 includes a processor 1010. The processor 1010 can execute the method of the embodiment of the present application by calling and executing a computer program stored in a memory.

[0151] Optionally, as shown in Fig. 10, the communication device 1000 may further include a memory 1020. The processor 1010 may call and execute a computer program stored in the memory 1020 to perform the method of the embodiment of the present application.

[0152] The memory 1020 may be a separate device independent of the processor 1010 or may be integrated into the processor 1010 .

[0153] Optionally, as shown in Fig. 10, the communication device 1000 may further include a transceiver 1030. The processor 1010 may control the transceiver 1030 to communicate with other devices, in particular to transmit information or data to other devices or receive information or data transmitted from other devices.

[0154] The transceiver 1030 may include a transmitter and a receiver. The transceiver 1030 may further include an antenna. The number of antennas may be one or more.

[0155] Alternatively, the communication device 1000 may specifically be a first terminal device according to an embodiment of the present application, and the communication device 1000 may perform corresponding processes performed by the first terminal device in each method of the embodiment of the present application, which will not be repeated here for brevity.

[0156] Alternatively, the communication device 1000 may specifically be a second terminal device according to an embodiment of the present application, and the communication device 1000 may perform corresponding processes performed by the second terminal device in each method of the embodiment of the present application, which will not be repeated here for brevity.

[0157] Fig. 11 is a schematic diagram showing the structure of a communication device according to an embodiment of the present application. As shown in Fig. 11, the communication device 1100 includes a processor 1110. The processor 1110 can execute the method of the embodiment of the present application by calling and executing a computer program stored in a memory.

[0158] Optionally, as shown in Fig. 11, the communication device 1100 may further include a memory 1120. The processor 1110 may call and execute a computer program stored in the memory 1120 to execute the method of the embodiment of the present application.

[0159] The memory 1120 may be a separate device independent of the processor 1110 or may be integrated into the processor 1110 .

[0160] Optionally, the communication device 1100 may further include an input interface 1130. The processor 1110 may control the input interface 1130 to communicate with other devices or chips, and in particular, may receive information or data transmitted from other devices or chips.

[0161] Optionally, the communication device 1100 may further include an output interface 1140. The processor 1110 may control the output interface 1140 to communicate with other devices or chips, specifically, to output information or data to other devices or chips.

[0162] Alternatively, the communication device 1100 is applicable to a network device according to the embodiments of the present application, and the communication device can execute corresponding processes performed by the network device in each method of the embodiments of the present application, which will not be repeated here for the sake of brevity.

[0163] Alternatively, the communication device 1100 may be applied to a terminal device according to the embodiments of the present application, and the communication device may execute corresponding processes executed by the terminal device in each method of the embodiments of the present application, which will not be repeated here for brevity.

[0164] Alternatively, the communication device 1100 can be a chip.

[0165] The chips of this application may also be referred to as system level chips, system chips, chip systems, or system-on-chip (SOC).

[0166] The processor of the embodiment of the present application may be an integrated circuit chip having signal processing capabilities. In the implementation process, each step of the above-mentioned method embodiment may be completed by an integrated logic circuit in the form of hardware of the processor or an instruction in the form of software. The processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. The processor may realize or execute the method, steps and logic block diagrams disclosed in the embodiment of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application may be directly performed and completed by a hardware decoding processor, or may be performed and completed by a combination of hardware and software modules in the decoding processor. The software module can be in a storage medium mature in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is in the memory. The processor reads the information in the memory and completes the steps of the above-mentioned method together with the hardware of the processor.

[0167] The memory of the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memory. The non-volatile memory can be a Read-Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), or a Flash Memory. The volatile memory can be a Random Access Memory (RAM) that functions as an external high-speed cache. By way of illustrative, but non-limiting example, many types of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synch-link Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).

[0168] It should be understood that the above-mentioned memories are exemplary and not limiting. For example, the memory of the embodiments of the present application can be a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDRSDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM), and a direct Rambus random access memory (DRRAM), etc. That is, the memory of the embodiments of the present application can include, but is not limited to, these and any other suitable types of memory.

[0169] 12 is a block diagram of a communication system 1200 according to an embodiment of the present application. As shown in FIG. 12, the communication system 1200 includes a second terminal device 1210 and a first terminal device 1220.

[0170] The second terminal device 1210 is used to receive first instruction information sent from the first terminal device, and transmit sidelink data to the first terminal device based on the first instruction information, where the first instruction information is used to instruct the second terminal device to transmit sidelink data to the first terminal device, and the sidelink data includes a reference signal and / or a sidelink control channel.

[0171] The first terminal device 1220 is used to detect sidelink data transmitted from the second terminal device during a first period and determine whether the sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to the detection result of the sidelink data, the sidelink data including a reference signal and / or a sidelink control channel.

[0172] The second terminal device 1210 can perform the operations performed by the second terminal device in the method embodiments of the present application, and the second terminal device 1210 can be configured like the network device 900 shown in FIG. 9, which will not be repeated here for brevity.

[0173] The first terminal device 1220 may perform operations performed by the first terminal device in the method embodiments of the present application, and the first terminal device 1220 may be configured as the first terminal device 800 shown in FIG. 8, which will not be repeated here for brevity.

[0174] The embodiment of the present application further provides a computer-readable storage medium used to store a computer program. Optionally, the computer-readable storage medium can be applied to a first terminal device of the embodiment of the present application, and the computer program causes a computer to execute corresponding processes performed by the first terminal device in each method of the embodiment of the present application, which will not be repeated here for brevity. Optionally, the computer-readable storage medium can be applied to a second terminal device of the embodiment of the present application, and the computer program causes a computer to execute corresponding processes performed by the second terminal device in each method of the embodiment of the present application, which will not be repeated here for brevity.

[0175] The embodiment of the present application further provides a computer program product including computer program instructions. Optionally, the computer program product can be applied to a first terminal device of the embodiment of the present application, and the computer program instructions cause a computer to execute corresponding processes performed by the first terminal device in each method of the embodiment of the present application, which will not be repeated here for brevity. Optionally, the computer program product can be applied to a second terminal device of the embodiment of the present application, and the computer program instructions cause a computer to execute corresponding processes performed by the second terminal device in each method of the embodiment of the present application, which will not be repeated here for brevity.

[0176] The embodiment of the present application further provides a computer program. Optionally, the computer program can be applied to the first terminal device of the embodiment of the present application. When the computer program is executed on the computer, the computer executes the corresponding processes performed by the first terminal device in each method of the present embodiment, which are not repeated here for brevity. Optionally, the computer program can be applied to the second terminal device of the embodiment of the present application. When the computer program is executed on the computer, the computer executes the corresponding processes performed by the second terminal device in each method of the present embodiment, which are not repeated here for brevity.

[0177] The terms "system" and "network" in the embodiments of the present invention can be used interchangeably in this specification. The term "and / or" in this specification only describes the relationship between related objects, and three relationships can exist, for example, "A and / or B" can indicate three situations: "only A exists", "A and B exist simultaneously", and "only B exists". Note that the symbol " / " in this specification usually indicates that the related objects before and after have an "or" relationship.

[0178] In the embodiment of the present application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, "determining B based on A" does not mean that B is determined based only on A, and B can also be determined based on A and / or other information.

[0179] It is obvious to those skilled in the art that each exemplary unit and algorithm step described in conjunction with the embodiments disclosed herein can be realized by electronic hardware, or a combination of a computer program and electronic hardware. Whether these functions are performed by hardware or software is determined by the specific application of the technical solution, design constraints, etc. Professional technical personnel can use different methods to realize the described functions for each specific application, but these realizations should not be considered as going beyond the scope of the present invention.

[0180] Those skilled in the art can understand that for convenience and concise description, the specific operation processes of the above-mentioned systems, devices and units can refer to the corresponding processes of the above-mentioned method embodiments, and will not be repeated here.

[0181] In some embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be realized in other forms. For example, the device examples described above are merely illustrative. For example, the division of units is merely a division of logical functions, and may have other division forms when actually realized. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not implemented. Furthermore, the illustrated or discussed couplings, direct couplings, and communication connections between each other may be indirect couplings and communication connections of some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0182] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, i.e., they may be located in one place or in multiple network units. Some or all of the units may be selected according to actual requirements to achieve the objective of the technical solution of the embodiment.

[0183] Furthermore, each functional unit of each embodiment of the present invention may be integrated into a single processing unit, each unit may exist physically alone, or two or more units may be integrated into a single unit.

[0184] The functions may be realized as software functional units and stored in a computer-readable recording medium when sold or used as an independent product. According to this understanding, an essential part of the technical solution of the present application, or a part of the technical solution that can contribute to the prior art, may be expressed as a software product. The computer software product is stored in a storage medium and includes a plurality of commands for executing all or part of the steps of the methods according to the embodiments of the present application in a computer (which may be a personal computer, a server, a network device, etc.). The storage medium includes various media capable of storing program codes, such as a flash memory, a portable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0185] The above are only specific embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily think of modifications or replacements within the technical scope disclosed in the present invention, and all of them should be included in the scope of this application. Therefore, the scope of protection of this application should be determined by the claims.

Claims

1. 1. A sidelink monitoring method, comprising: A first terminal device detects mixed automatic repeat request (HARQ) feedback information transmitted from a second terminal device during a first period; and the first terminal device determines whether a sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to a detection result of the HARQ feedback information; The first terminal device determines whether a sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to a detection result of the HARQ feedback information. and determining that the sidelink is in an asynchronous state when a number of consecutive detections of a discontinuous transmission (DTX) state after transmitting sidelink data reaches a threshold value; The DTX state refers to the first terminal device being unable to detect HARQ feedback information transmitted from the second terminal device; A sidelink monitoring method comprising:

2. Before the first terminal device detects HARQ feedback information transmitted from the second terminal device during a first period, the method includes: The first terminal device further includes transmitting sidelink data to the second terminal device. The sidelink monitoring method according to claim 1 .

3. A terminal device, comprising: The terminal device is a first terminal device, the terminal device including a processing unit; The processing unit is used for detecting Hybrid Automatic Repeat Request (HARQ) feedback information sent from a second terminal device during a first period; The processing unit is further used for determining whether a sidelink between the first terminal device and the second terminal device is in a synchronous state or an asynchronous state according to a detection result of the HARQ feedback information; The processing unit is specifically configured to determine that the sidelink is in an asynchronous state when a number of consecutive detections of a discontinuous transmission (DTX) state after transmitting sidelink data reaches a threshold value; and The DTX state refers to the first terminal device being unable to detect HARQ feedback information transmitted from the second terminal device; A terminal device comprising:

4. The first terminal device further includes a transmitting unit; the transmitting unit is used for transmitting sidelink data to the second terminal device; A terminal device according to claim 3 .

5. A computer-readable storage medium used to store a computer program, The computer program causes a computer to carry out the method according to any one of claims 1 to 2. A computer-readable storage medium comprising:

Images