A sidelink communication method, device and system

Abstract

This application provides a sidelink communication method, apparatus, and system. The method may include: if a first terminal device determines that the HARQ feedback attribute of the LCH in a newly transmitted MAC PDU on an SL grant is disabled, and the network-side device has configured PUCCH resources for the first terminal device and associated PSFCH resources for the SL grant used to send the MAC PDU, then the first terminal device may request a second terminal device to perform HARQ feedback on this MAC PDU to avoid unnecessary retransmissions and save resources.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a sidelink communication method, device and system. Background Art

[0002] In the new radio (NR) sidelink (SL), for the user equipment (UE) pre-configured or the network side configured for the UE for SL communication resource pool, a resource pool is a collection of time-frequency resources. The resources for the UE to communicate on the SL are determined from the resource pool configured by the network side.

[0003] When the transmitting UE (TX UE) performs initial transmission on the sidelink grant (sl grant), the TX UE sends a medium access control packet data unit (MAC PDU). If the TX UE is configured with a physical uplink control channel (PUCCH) resource and the sl grant has an associated physical sidelink feedback channel (PSFCH) resource, but the hybrid automatic retransmission request (HARQ) feedback attribute of the MAC PDU is disabled, there will be unnecessary retransmissions and waste of resources due to the lack of HARQ information feedback on the PUCCH. Summary of the invention

[0004] The present application provides a side link communication method, device and system to avoid unnecessary retransmission and save resources.

[0005] In a first aspect, the present application provides a sidelink communication method, the method comprising: if a first terminal device determines that the HARQ feedback attribute of a logical channel (logic channel, LCH) in a MAC PDU is disabled, and the network side device configures PUCCH resources for the first terminal device and an sl grant for sending the MAC PDU has been configured with associated PSFCH resources, the first terminal device may send a first request message to a second terminal device to request the second terminal device to perform HARQ feedback on the MAC PDU.

[0006] In the present application, the above-mentioned MAC PDU is the initial transmission (initial transmission) on the above-mentioned sl grant, that is, the MAC PDU is the new data transmitted by the first terminal device on the sl grant.

[0007] Through the above method, if the LCH in the MAC PDU newly transmitted by the first terminal device on the sl grant does not support HARQ feedback, but the network side device configures the first terminal device with PUCCH resources and PSFCH resources associated with the above sl grant, then the first terminal device can request the second terminal device to perform HARQ feedback on the MAC PDU, thereby avoiding unnecessary retransmission and saving resources.

[0008] Based on the first aspect, in some possible implementations, the first request message may include: control information; accordingly, the above method may also include: the first terminal device configures the HARQ feedback attribute in the control information to be enabled.

[0009] In the present application, the HARQ feedback attribute may be indicated by one or more bits in the control information. Then, the first terminal device sets the bit in the control information for indicating the HARQ feedback attribute to enable.

[0010] Based on the first aspect, in some possible implementations, the above-mentioned control information may be sidelink control information (SCI), that is, the first terminal device sends SCI to the second terminal device to request the second terminal device to perform HARQ feedback on the MAC PDU.

[0011] Based on the first aspect, in some possible implementations, the above method may also include: the first terminal device receives HARQ feedback information sent by the second terminal device, that is, a response message of the second terminal device to the first request information; if the HARQ feedback information is positive acknowledgment information (ACK), the first terminal device sends positive acknowledgment information to the network side device on the PUCCH resource; or, if the HARQ feedback information is negative acknowledgment information, the first terminal device sends negative acknowledgment information to the network side device on the PUCCH resource, thereby avoiding unnecessary retransmission and saving resources.

[0012] In a second aspect, the present application provides a sidelink communication method, the method comprising: a second terminal device receives a first request message; the second terminal device responds to the first request message, and performs HARQ feedback on the MAC PDU on the PSFCH.

[0013] Based on the second aspect, in some possible implementations, the second terminal device responds to the first request message, and performs HARQ feedback on the MAC PDU on the PSFCH, including: the second terminal device responds to the first request message, and sends HARQ feedback information to the first terminal device.

[0014] Based on the second aspect, in some possible implementations, the first request message may include: control information; further, the above control information may be SCI, that is, the second terminal device receives the SCI from the second terminal device, and performs HARQ feedback on the MAC PDU to the first terminal device based on the SCI.

[0015] In a third aspect, the present application provides a sidelink communication method, the method comprising: if the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device ignores the sl grant.

[0016] In the present application, the above-mentioned MAC PDU is the initial transmission on the above-mentioned sl grant.

[0017] Through the above method, if the LCH in the MAC PDU sent by the first terminal device on the sl grant supports HARQ feedback, it means that the MAC PDU expects HARQ feedback, but the sl grant is not configured with associated PSFCH resources. At this time, since the sl grant does not support HARQ feedback, the first terminal device ignores the sl grant, thereby avoiding the mismatch between the HARQ feedback attributes of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0018] Based on the third aspect, in some possible implementations, the first terminal device ignores the sidelink authorization, including: the first terminal device does not send a MAC PDU to the third terminal device through the sl grant.

[0019] In a fourth aspect, the present application provides a sidelink communication method, the method comprising: if the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device sends a second request message to the network side device, and the second request message is used to request the network side device to allocate PSFCH resources.

[0020] In the present application, the above MAC PDU is the initial transmission on sl grant.

[0021] Through the above method, if the LCH in the MAC PDU sent by the first terminal device on the sl grant supports HARQ feedback, it means that the MAC PDU expects HARQ feedback, but the sl grant is not configured with associated PSFCH resources. At this time, the first terminal device requests the network side device to allocate PSFCH resources, so that the second terminal device can perform HARQ feedback on the MAC PDU on the newly configured PSFCH resources, thereby avoiding the mismatch between the HARQ feedback attributes of the MAC PDU and the resources configured by the UE, and thus avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0022] Based on the fourth aspect, in some possible implementations, the second request message may include the HARQ feedback attribute of the MAC PDU; the first terminal device sends the second request message to the network side device, including: the first terminal device sends the HARQ feedback attribute of the MAC PDU to the network side device.

[0023] Based on the fourth aspect, in some possible implementations, the second request message may include a MAC control element (CE) or a radio resource control (RRC) signaling. Of course, other signaling may also be included, which is not specifically limited in the embodiments of the present application.

[0024] In the present application, the second request message directly instructs the network side device to allocate PSFCH resources by signaling, and may also indicate the HARQ feedback attributes of the MAC PDU by signaling, so that the network side device can allocate PSFCH resources according to the HARQ feedback attributes of the MAC PDU.

[0025] Based on the fourth aspect, in some possible implementations, the second request message is used to request the network side device to reconfigure the PSFCH resources associated with the sl grant; or, the second request message is used to request the network side device to reallocate the resource pool, and the reallocated resource pool is configured with PSFCH resources, that is, the first terminal device can request the network side device to allocate PSFCH resources to the current resource pool so that the PSFCH resources associated with the sl grant configuration are used to transmit the MAC PDU, or the first terminal device can request the network side device to reselect a new resource pool for the first terminal device, and the new resource pool is configured with PSFCH resources, which can also make the sl grant used to transmit the MAC PDU configured with associated PSFCH resources, and then the second terminal device can perform HARQ feedback on the MAC PDU on the newly configured PSFCH resources.

[0026] In a fifth aspect, the present application provides a sidelink communication method, the method comprising: a network side device receives a second request message from a first terminal device; the network side device responds to the second request message and allocates PSFCH resources to the first terminal device.

[0027] Based on the fifth aspect, in some possible implementations, the second request message may include the HARQ feedback attribute of the MAC PDU; the network side device receives the second request message from the first terminal device, including: the network side device receives the HARQ feedback attribute of the MAC PDU from the first terminal device.

[0028] Based on the fifth aspect, in some possible implementations, the second request message may include MA CE or RRC signaling. Of course, other signaling may also be included, which is not specifically limited in the embodiments of the present application.

[0029] In the present application, the second request message directly instructs the network side device to allocate PSFCH resources by signaling, and may also indicate the HARQ feedback attributes of the MAC PDU by signaling, so that the network side device can allocate PSFCH resources according to the HARQ feedback attributes of the MAC PDU.

[0030] Based on the fifth aspect, in some possible implementations, the second request message is used to request the network side device to reconfigure the PSFCH resources associated with the sl grant; or, the second request message is used to request the network side device to reallocate the resource pool, and the reallocated resource pool is configured with PSFCH resources, that is, the first terminal device can request the network side device to allocate PSFCH resources to the current resource pool so that the PSFCH resources associated with the sl grant configuration are used to transmit the MAC PDU, or the first terminal device can request the network side device to reselect a new resource pool for the first terminal device, and the new resource pool is configured with PSFCH resources, which can also make the sl grant used to transmit the MAC PDU configured with associated PSFCH resources, and then the second terminal device can perform HARQ feedback on the MAC PDU on the newly configured PSFCH resources.

[0031] In a sixth aspect, the present application provides a side link communication method, the method comprising: if the HARQ feedback attribute of at least one LCH configured by the network side device for the first terminal device is enabled, the network side device configures a resource pool for the first terminal device, and at least one resource pool in the configured resource pool is configured with PSFCH resources.

[0032] Through the above method, when the network side device configures resources for the first terminal device, if the configured LCH supports HARQ feedback, it is necessary to configure PSFCH resources for the first terminal device accordingly, that is, the network side device configures a resource pool for the first terminal device, and at least one of the configured resource pools is configured with PSFCH resources. Then, the second terminal device can perform HARQ feedback on the MAC PDU on the configured PSFCH resources to avoid the mismatch between the HARQ feedback attributes of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0033] In the present application, if the network side device configures a resource pool for the first terminal device, then the resource pool is correspondingly configured with PSFCH resources. If the network side device configures multiple resource pools for the first terminal device, then at least one of the multiple resource pools is correspondingly configured with PSFCH resources. In this way, the first terminal device can be configured with an LCH supporting HARQ feedback and having corresponding PSFCH resources. Corresponding can also be understood as corresponding, or can be understood as having an associated relationship.

[0034] In the seventh aspect, the present application provides a side link communication method, which includes: if the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device enters an idle state or a third (inactive) state, and performs resource reselection, and the reselected resource pool is configured with PSFCH resources.

[0035] In the present application, the above-mentioned MAC PDU is the initial transmission on the above-mentioned sl grant.

[0036] Through the above method, if the LCH in the MAC PDU sent by the first terminal device on the sl grant supports HARQ feedback, it means that the MAC PDU is expected to perform HARQ feedback, but the sl grant is not configured with associated PSFCH resources. At this time, the first terminal device can enter the idle state or the third state to perform resource reselection, so that the reselected resource pool is configured with PSFCH resources. Then, the second terminal device can perform HARQ feedback on the MAC PDU on the reselected PSFCH resources to avoid the mismatch between the HARQ feedback attributes of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0037] Based on the seventh aspect, in some possible implementations, the method further includes: after the first terminal device enters the idle state or the third state, switching to the sidelink mode 2

[0038] In an eighth aspect, the present application provides a sidelink communication method, the method comprising: if the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device reselects DST.

[0039] In the present application, the above-mentioned MAC PDU is the initial transmission on the above-mentioned sl grant.

[0040] Through the above method, if the LCH in the MAC PDU sent by the first terminal device on the sl grant supports HARQ feedback, it means that the MAC PDU expects HARQ feedback, but the sl grant is not configured with associated PSFCH resources. At this time, the first terminal device can reselect DST, and the LCH associated with the reselected DST may not support HARQ feedback. In this way, the mismatch between the HARQ feedback attributes of the MAC PDU and the resources configured by the UE is avoided, thereby avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0041] Based on the eighth aspect, in some possible implementations, the DST is a DST determined according to the LCH or MAC CE, and the LCH or MAC CE is the highest priority among multiple LCHs or MAC CEs that meet preset conditions; the preset conditions include at least: the HARQ feedback attributes of multiple LCHs or MAC CEs are disabled.

[0042] In a ninth aspect, the present application provides a sidelink communication method, the method comprising: if the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device sends a third request message to the second terminal device, and the third request message is used to request the second terminal device not to perform HARQ feedback on the MAC PDU.

[0043] In the present application, the above-mentioned MAC PDU is the initial transmission on the above-mentioned sl grant.

[0044] Based on the ninth aspect, in some possible implementations, the third request message may include: control information; accordingly, the above method may also include: the first terminal device configures the HARQ feedback attribute in the control information to be disabled.

[0045] In the present application, the HARQ feedback attribute may be indicated by one or more bits in the control information. Then, the first terminal device sets the bit in the control information used to indicate the HARQ feedback attribute to disable.

[0046] Through the above method, if the LCH in the MAC PDU sent by the first terminal device on the sl grant supports HARQ feedback, it means that the MAC PDU expects HARQ feedback, but the sl grant is not configured with associated PSFCH resources. At this time, the first terminal device requests the second terminal device not to perform HARQ feedback on the MAC PDU, so as to avoid the mismatch between the HARQ feedback attributes of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmission or packet loss due to lack of retransmission.

[0047] In the tenth aspect, the present application provides a side link communication method, the method comprising: a second terminal device receives a third request message sent by a first terminal device, the third request message being used to request the second terminal device not to perform HARQ feedback on the MAC PDU; the second terminal device responds to the third request information and does not perform HARQ feedback on the MAC PDU.

[0048] Based on the tenth aspect, in some possible implementations, the third request message may include: control information; the HARQ feedback attribute in the control information is configured as disabled.

[0049] In the eleventh aspect, the present application provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the first aspect or any possible implementation method thereof. The communication device may include: a sending module and a processing module; the sending module is used to send a first request message to a second terminal device if the processing module determines that the HARQ feedback attribute of the LCH in the MAC PDU is not enabled, and the network side device is configured with PUCCH resources for the first terminal device and the sl grant used to send the MAC PDU has been configured with associated PSFCH resources, the first request message is used to request the second terminal device to perform HARQ feedback on the MAC PDU, the first terminal device performs sidelink communication with the second terminal device, and the MAC PDU is the initial transmission on the sl grant.

[0050] Based on the eleventh aspect, in some possible implementations, the first request message includes: control information; and a processing module, further configured to configure a HARQ feedback attribute in the control information to be enabled.

[0051] Based on the eleventh aspect, in some possible implementations, the control information is SCI.

[0052] Based on the eleventh aspect, in some possible implementations, the communication device also includes: a receiving module for receiving HARQ feedback information sent by the second terminal device; a sending module, further for sending positive acknowledgment information on PUCCH resources if the HARQ feedback information is positive acknowledgment information; or, if the HARQ feedback information is negative acknowledgment information, sending negative acknowledgment information on PUCCH resources.

[0053] In a twelfth aspect, the present application provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the second aspect or any possible implementation method thereof. The communication device may include: a sending module and a processing module; the sending module is used to ignore the sl grant if the processing module determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the MAC PDU is an initial transmission on the sl grant.

[0054] Based on the twelfth aspect, in some possible implementations, the sending module is specifically used to send the MAC PDU to the second terminal device without using the sl grant.

[0055] Based on the twelfth aspect, in some possible implementations, the processing module is further used to not generate a corresponding MAC PDU for the sl grant if the HARQ feedback attribute of the LCH to be packaged is determined to be enabled before package assembly, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources; or, the processing module is further used to stop screening the LCH if the HARQ attribute of the LCH with the highest priority is enabled when determining the DST according to the priority of the LCH.

[0056] In a thirteenth aspect, the present application provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the third aspect or any possible implementation method thereof. The communication device may include: a sending module and a processing module; the sending module is used to send a second request message to a network side device if the processing module determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the second request message is used to request allocation of PSFCH resources for the first terminal device, and the MAC PDU is an initial transmission on the sl grant.

[0057] Based on the thirteenth aspect, in some possible implementations, the second request message includes the HARQ feedback attribute of the MAC PDU; the sending module is specifically used to send the HARQ feedback attribute of the MAC PDU to the network side device.

[0058] Based on the thirteenth aspect, in some possible implementations, the second request message includes MAC control element CE or radio resource control RRC signaling.

[0059] Based on the thirteenth aspect, in some possible implementations, the second request message is used to request the network side device to allocate PSFCH resources associated with the sl grant; or, the second request message is used to request the network side device to reallocate a resource pool, and the resource pool is configured with PSFCH resources.

[0060] In a fourteenth aspect, the present application provides a communication device, which may be a chip or a system on chip in a network side device, or a functional module in a first terminal device for implementing the fourth aspect or any possible implementation method thereof. The communication device may include: a processing module, configured to configure a resource pool for the first terminal device if the HARQ feedback attribute of at least one LCH configured for the first terminal device is enabled, and at least one resource pool in the resource pool is configured with a PSFCH resource.

[0061] In a fifteenth aspect, the present application provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the fifth aspect or any possible implementation method thereof. The communication device may include: a processing unit, for entering an idle state or a third state if it is determined that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and performing resource reselection, the reselected resource pool is configured with PSFCH resources, and the MAC PDU is an initial transmission on the sl grant.

[0062] Based on the fifteenth aspect, in some possible implementations, the processing unit is also used to switch to side link mode 2 after entering the idle state or the third state.

[0063] In a sixteenth aspect, the present application provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the sixth aspect or any possible implementation method thereof. The communication device may include: a processing unit for reselecting a communication target DST if it is determined that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the MAC PDU is an initial transmission on the sl grant.

[0064] Based on the sixteenth aspect, in some possible implementations, the DST is a DST determined according to the LCH or MAC CE, and the LCH or MAC CE is the highest priority among multiple LCHs or MAC CEs that meet preset conditions; the preset conditions include at least: the HARQ feedback attributes of multiple LCHs or MAC CEs are disabled.

[0065] In a seventeenth aspect, the present application provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the seventh aspect or any possible implementation method thereof. The communication device may include: a sending unit and a processing unit; the sending unit is used to send a third request message to a second terminal device if the processing unit determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the third request message is used to request the second terminal device not to perform HARQ feedback on the MAC PDU.

[0066] Based on the seventeenth aspect, in some possible implementations, the third request message may include: control information; accordingly, the processing unit is further used to configure the HARQ feedback attribute in the control information to be disabled.

[0067] In the eighteenth aspect, the present application provides a communication device, comprising: a processor and a memory; the processor is coupled to the memory, and the processor is configured to read and execute instructions in the memory to implement the side link communication method as described in the above-mentioned first to tenth aspects or any possible implementation manner thereof.

[0068] In the nineteenth aspect, the present application provides a communication device, comprising: a processor and a memory; the processor is coupled to the memory, and the processor is configured to read and execute instructions in the memory to implement the side link communication method as described in the fourth to sixth aspects above or any possible implementation manner thereof.

[0069] In the twentieth aspect, the present application provides a side link communication system, comprising: a first terminal device and a second terminal device as described in the first to tenth aspects above or any possible implementation manner thereof, the first terminal device performing side link communication with the second terminal device.

[0070] In the twenty-first aspect, the present application provides a side link communication system, comprising: a first terminal device and a second terminal device as described in the first to tenth aspects above or any possible implementation manner thereof, and a network side device as described in the fourth to sixth aspects above or any possible implementation manner thereof.

[0071] In aspect 22, the present application provides a computer-readable storage medium, which stores instructions, and when the instructions are executed on a computer, is used to execute the side link communication method as described in aspect 1 to aspect 10 above or any possible implementation manner thereof.

[0072] In the twenty-third aspect, the present application provides a computer program or a computer program product. When the computer program or the computer program product is executed on a computer, it enables the computer to implement the side link communication method as described in the first to tenth aspects above or any possible implementation manner thereof.

[0073] It should be understood that aspects 11 to 23 of the present application are consistent with the technical solutions of aspects 1 to 10 of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0075] Figure 1 is a schematic diagram of an SL communication system in an embodiment of the present application;

[0076] Figure 2 The side link communication method in the embodiment of the present application is shown in FIG. Figure 1 ;

[0077] Figure 3 The side link communication method in the embodiment of the present application is shown in FIG. Figure 2 ;

[0078] Figure 4 The side link communication method in the embodiment of the present application is shown in FIG. Figure 3 ;

[0079] Figure 5 The side link communication method in the embodiment of the present application is shown in FIG. Figure 4 ;

[0080] Figure 6 The side link communication method in the embodiment of the present application is shown in FIG. Figure 5 ;

[0081] Figure 7 The side link communication method in the embodiment of the present application is shown in FIG. Figure 6 ;

[0082] Figure 8 The side link communication method in the embodiment of the present application is shown in FIG. Figure 7 ;

[0083] Fig. 9 The structure of the communication device in the embodiment of the present application is shown in FIG. Figure 1 ;

[0084] Fig.10 The structure of the communication device in the embodiment of the present application is shown in FIG. Figure 2 . DETAILED DESCRIPTION

[0085] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application. In the following description, reference is made to the drawings that form a part of the present application and show specific aspects of the embodiments of the present application or specific aspects of the embodiments of the present application in an illustrative manner. It should be understood that the embodiments of the present application can be used in other aspects and may include structural or logical changes not depicted in the drawings. For example, it should be understood that the disclosure of the described method in conjunction with the disclosed content can also be applied to the corresponding device or system for performing the method, and vice versa. For example, if one or more specific method steps are described, the corresponding device may include one or more units such as functional units to perform the one or more method steps described (for example, one unit performs one or more steps, or multiple units, each of which performs one or more of the multiple steps), even if such one or more units are not explicitly described or illustrated in the drawings. On the other hand, for example, if a specific device is described based on one or more units such as functional units, the corresponding method may include a step to perform the functionality of one or more units (for example, one step performs the functionality of one or more units, or multiple steps, each of which performs the functionality of one or more units in multiple units), even if such one or more steps are not explicitly described or illustrated in the drawings. Further, it should be understood that, unless explicitly stated otherwise, features of the various exemplary embodiments and / or aspects described herein may be combined with each other.

[0086] The present application embodiment provides a SL communication system, Figure 1 This is a schematic diagram of the SL communication system in the embodiment of the present application, see Figure 1As shown, in the SL system 100, it can include: a network side device 101 and a terminal device 102. The terminal device can communicate with other terminal devices while communicating with the network side device. The network side device can configure, schedule, coordinate, etc. resources for the side link (sidelink) for communication between terminal devices, and assist the terminal devices to communicate directly. The terminal device can also configure, schedule, coordinate, etc. resources for the side link for communication between other terminal devices by itself, which is not specifically limited in the embodiments of the present application.

[0087] The above-mentioned network side equipment can be a device on the access network side used to support the terminal to access the wireless communication system, for example, it can be a next-generation base station (gNB, next generation NodeB), a transmission reception point (TRP, Transmission Reception Point), a relay node (Relay Node), an access point (AP, Access Point), a roadside device (road site unit, RSU), etc. in a 5G access technology communication system.

[0088] The terminal device may be a device that provides voice or data connectivity to a user, for example, it may also be called UE, mobile station, subscriber unit, station or terminal (TE, Terminal Equipment), etc. The terminal device may be a cellular phone, a personal digital assistant (PDA, Personal Digital Assistant), a wireless modem, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL, Wireless Local Loop) station or a tablet computer (pad), etc. With the development of wireless communication technology, devices that can access a wireless communication system, communicate with the network side of a wireless communication system, or communicate with other devices through a wireless communication system can all be terminal devices in the embodiments of the present application, for example, terminals and cars in intelligent transportation, household appliances in smart homes, power meter reading instruments, voltage monitoring instruments, environmental monitoring instruments in smart grids, video monitoring instruments in intelligent security networks, cash registers, etc. The terminal device may be statically fixed or mobile.

[0089] In NR SL, network-side equipment, such as a base station, configures a resource pool for the UE's SL communication. A resource pool is a collection of time-frequency resources. The resources for the UE to communicate on the SL link are determined from a resource pool pre-configured or configured on the base station side. Specifically, there are two modes for the Tx UE to determine the transmission resources for communication on the SL link from the resource pool, namely mode1 and mode2. Among them, the above-mentioned pre-configured resources can be obtained from the network elements of the core network, or they can be preset in the UE.

[0090] In mode1, the base station allocates SL transmission resources to the Tx UE through scheduling. In this mode, when the Tx UE has SL data to be transmitted, it reports the SL buffer status report (BSR) MAC CE to the base station through the Uu port to inform the base station of the current amount of data to be transmitted by the Tx UE at the PC5 port. The base station can dynamically allocate transmission resources for the Tx UE.

[0091] In mode 2, the UE selects transmission resources from a pre-configured or base station-configured resource pool as needed, without the need for scheduling by the base station. The SL resources determined by the UE are configured by the base station (such as through RRC signaling configuration or system information block (SIB) configuration) or pre-configured. The pre-configuration mentioned here can be obtained from the network element of the core network or preset in the UE.

[0092] When allocating uplink radio resources based on SL grant, the UE needs to determine the total amount of data for each LCH contained in the newly transmitted MAC PDU, and if necessary, allocate resources for MAC CE. In other words, the uplink resources allocated to a UE by the network side device through SL grant are determined, and the UE decides which LCH data to place and how much data to place in the MAC PDU for each LCH logical channel based on the configured LCH attributes and the rules specified by the existing protocol.

[0093] Specifically, when the TX UE transmits new data on the sl grant, if the TX UE has established connections with multiple RX UEs at the same time, and the LCHs with data belong to different DSTs, then the TX UE first needs to determine which DST this sl grant is used to communicate with. For this sl grant, the TX UE selects the LCH or MAC CE with the highest priority (i.e., the first LCH or the first MAC CE) from the LCHs or MAC CEs that meet the following first condition, and then the TX UE determines the DST for communication based on the selected first LCH or the first MAC CE.

[0094] Here, the first condition may include:

[0095] 1. There is SL data waiting to be transmitted;

[0096] 2. SB j >0

[0097] 3. If the current sl grant is configured grant type1, and LCH is configured with sl-configuredSLGrantType1Allowed, this value is true.

[0098] Among them, configured grant type1 is used to indicate sidelink configuration grant type 1;

[0099] Among them, sl-configuredSLGrantType1Allowed is used to indicate whether the data of the LCH can be transmitted on the resources of the side link configuration authorization type 1.

[0100] Here, the UE uses an algorithm similar to the token bucket to implement the encapsulation of the MAC PDU. The UE determines whether to send the data of a certain LCH based on whether there is a token in the token bucket and the number of tokens, and controls the amount of data of the logical channel encapsulated in the MAC PDU. The UE maintains a variable SB for the jth LCH j , j is an integer greater than or equal to 1 and less than or equal to the number of tokens in the token bucket, SB j Indicates the number of tokens currently available in the token bucket, and each token corresponds to 1 Byte of data. j Initialized to 0 when LCH is established and increased by sPBR×T every T, where T is SB j The time that has passed since the last increment. SB j The value cannot exceed the maximum capacity of the token bucket.

[0101] Secondly, after the TX UE determines the DST according to the above first condition, the TX UE needs to screen out the first LCHs that meet the following second condition from the first LCHs associated with the DST, and then the TX UE performs resource allocation among all the selected first LCHs.

[0102] Here, the second condition may include:

[0103] 1. There is SL data waiting to be transmitted;

[0104] 2. If the sl grant is configured grant type1, and LCH is configured with sl-configuredSLGrantType1Allowed, this value is true;

[0105] 3. The HARQ feedback attribute of the LCH is the same as the HARQ feedback attribute of the first LCH.

[0106] Finally, the TX UE encapsulates the data of the LCHs belonging to the same source and destination pair and having the same HARQ attribute in one MAC PDU.

[0107] In an embodiment of the present application, on the one hand, when the network side device configures a resource pool for the UE, the network side device configures a physical sidelink shared channel (PSSCH) resource for the UE, and the UE transmits data on the PSSCH resource.

[0108] When the RX UE receives the data sent by the TX UE through the PSSCH, it can feedback the HARQ response message (such as a positive response message (ACK) or a negative response message (NACK)) on the PSFCH resource. However, when configuring the resource pool, the network side device may configure PSFCH resources for the resource pool or may not configure PSFCH resources for the resource pool. If the network side configures PSFCH resources for the resource pool, each sl grant in the resource pool has an associated PSFCH resource. Conversely, if the network side does not configure PSFCH resources for the resource pool, each sl grant in the resource pool has no associated PSFCH resource.

[0109] On the other hand, when the network side device configures the LCH that can be used for SL communication for the UE, it can configure the HARQ attribute of the SL LCH through the sl-HARQ-feedback-enable field, where the HARQ attribute of the SL LCH is per UE. If it is configured to enable, it indicates that the SL LCH supports HARQ feedback, and if it is configured to disable, it indicates that the SL LCH does not support HARQ feedback.

[0110] It can be seen from this that if the HARQ attribute of the LCH in the newly transmitted MAC PDU is disable, the RX UE will not send HARQ feedback to the TX UE, and the TX UE will not be able to provide HARQ feedback to the network side on the PUCCH resources, causing the network side to believe that the TX UE has not received any HARQ feedback, and then believe that the decoding on the RX UE side has failed, so the RX UE is frequently scheduled for retransmission, wasting resources. Alternatively, if the HARQ attribute of the LCH in the newly transmitted MAC PDU is enable, but the UE has not configured PSFCH resources, at this time, the HARQ feedback attribute of the MAC PDU does not match the resources configured by the UE, which will cause unnecessary retransmissions or packet loss due to lack of retransmissions.

[0111] Then, in order to solve the above problem, an embodiment of the present application provides a sidelink communication method, which can be applied to the above sidelink communication system, and the above UE may include a first terminal device and a second terminal device. In the embodiment of the present application, the first terminal device can be used as a transmitting end device (ie, TX UE), and the second terminal device can be used as a receiving end device (ie, RX UE).

[0112] Since the resource pool configured by the network side device for the TX UE can be divided into one configured with PSFCH resources and one not configured with PSFCH resources, the above side link communication method is described below based on the above two situations respectively.

[0113] In the first case, the network side device configures a resource pool with PSFCH resources for the TX UE, then the sl grant used to send the MAC PDU has been configured with associated PSFCH resources.

[0114] Figure 2 The side link communication method in the embodiment of the present application is shown in FIG. Figure 1 , see Figure 2 As shown, the method may include:

[0115] S201: If the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is disable, and the network side device configures the first terminal device with PUCCH resources and the sl grant used to send the MAC PDU has been configured with associated PSFCH resources, the first terminal device may send a first request message to the second terminal device;

[0116] The first request information is used to request the second terminal device to perform HARQ feedback on the MAC PDU. That is, the first terminal device requests the second terminal device to perform HARQ feedback on the MAC PDU through the first request information.

[0117] S202: The second terminal device responds to the first request message and sends HARQ feedback information to the first terminal device.

[0118] Here, the second terminal device responding to the first request message can be understood as the second terminal device performing HARQ feedback on the MAC PDU after receiving the MAC PDU according to the first request message.

[0119] After the first terminal device performs MAC PDU grouping by the above method, the HARQ feedback attribute of each LCH in the MAC PDU can be determined. If the HARQ feedback attribute of these LCHs is disable, and the network side device configures PUCCH resources for the first terminal device and the sl grant used to send the MAC PDU has been configured with associated PSFCH resources, then the first terminal device can request the second terminal device to perform HARQ feedback on the MAC PDU through a first request message. After receiving the first request message, the second terminal device responds to the first request message and sends HARQ feedback information, such as an ACK message or a NACK message, to the first terminal device on the PSFCH resource. The first terminal device receives the HARQ feedback information. Then, the first terminal device sends a response message to the network side device on the PUCCH resource according to the received HARQ feedback information.

[0120] It should be noted that the MAC PDU described in the embodiment of the present application is the initial transmission on the sl grant, that is, the new transmission data on the sl grant, which will not be repeated in the following embodiments.

[0121] In some possible implementations, the first request message may include, but is not limited to, control information, wherein the control information may be the SCI corresponding to the newly transmitted MAC PDU.

[0122] Accordingly, before S201, the above method may include: the first terminal device configures the HARQ feedback attribute in the control information to be enabled. That is, the first terminal device may configure one or more bits (bits) in the control information used to represent the HARQ feedback attribute to enable. Then, after receiving the control information, the second terminal device can perform HARQ feedback on the corresponding MAC PDU according to the bits (bits). In practical applications, the bit used to represent the HARQ feedback attribute in the control information can be set to 0 to indicate disable. It is easy to understand that the bit can also be set to 1 to indicate enable. Of course, there may be other ways of representing the bit used to represent the HARQ feedback attribute in the control information, which is not specifically limited in the embodiments of the present application.

[0123] In the embodiment of the present application, when the network side device configures resources for the TX UE, it will also configure corresponding PUCCH resources, so that the TX UE can perform HARQ feedback to the network side device on the PUCCH resources.

[0124] Then, the above method may also include: the first terminal device receives HARQ feedback information sent by the second terminal device, that is, the response message of the second terminal device to the first request information; if the HARQ feedback information is ACK, the first terminal device sends ACK to the network side device on the PUCCH resource; or, if the HARQ feedback information is NACK, the first terminal device sends NACK to the network side device on the PUCCH resource. After the network side device receives the response message sent by the first terminal device, it will not frequently schedule retransmission for the RX UE, saving resources.

[0125] In the second case, the network side device configures the resource pool for the TX UE but does not configure PSFCH resources. Then, the SL grant used to send the MAC PDU is not configured with associated PSFCH resources. At this time, if the HARQ feedback attribute of the LCH in the MAC PDU is enabled, since there are no PSFCH resources, there will be a mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE, which will cause unnecessary retransmissions or packet loss due to lack of retransmissions.

[0126] To this end, in the second case, the following solutions can be used but are not limited to solve the above problems.

[0127] Solution 1:

[0128] Figure 3 The side link communication method in the embodiment of the present application is shown in FIG. Figure 2 , see Figure 3 As shown, the method may include:

[0129] S301: The first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources;

[0130] S302: The first terminal device ignores the sl grant.

[0131] When the first terminal device performs MAC PDU packetization through the above method, it can determine the HARQ feedback attribute of each LCH in the MAC PDU. If the LCH in the MAC PDU sent by the first terminal device on the sl grant supports HARQ feedback, it means that the MAC PDU expects HARQ feedback, but the sl grant is not configured with associated PSFCH resources. At this time, the first terminal device ignores the sl grant to avoid the mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmission or packet loss due to lack of retransmission.

[0132] In some possible implementations, in the above S302, since the MAC PDU has been packaged, at this time, the first terminal device ignoring the sl grant can be understood as the first terminal device not sending the MAC PDU on the sl grant, or the first terminal device discarding the changed MAC PDU. Then, S301 may include: the first terminal device does not send the MAC PDU to the second terminal device through the sl grant.

[0133] After the multiplexing and assembly entity in the first terminal device encapsulates the LCH data belonging to the same source and destination pair and having the same HARQ attribute in a MAC PDU, the MAC entity in the first terminal may send the MAC PDU to the second terminal device without using sl grant.

[0134] In another embodiment of the present application, the first terminal device may also ignore the slgrant before MAC PDU assembly. Then, if the first terminal device determines that the HARQ feedback attribute of the LCH to be encapsulated is enable, and the sl grant used for transmission is not configured with associated PSFCH resources, the first terminal device may ignore the sl grant, that is, the multiplexing and assembly entity does not generate a corresponding MAC PDU for the sl grant; or, when the first terminal device determines the DST according to the priority of the LCH, if the HARQ attribute of the LCH with the highest priority is enable, the multiplexing and assembly entity stops screening the LCH.

[0135] Option 2:

[0136] Figure 4 The side link communication method in the embodiment of the present application is shown in FIG. Figure 3 , see Figure 4 As shown, the method may include:

[0137] S401: If the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device sends a second request message to the network side device;

[0138] The second request message is used to request allocation of PSFCH resources for the terminal device (the first terminal device and / or the second terminal device). That is, the first terminal device requests the PSFCH resources associated with the sl grant for sending the MAC PDU from the network side device through the second request message.

[0139] S402: The network side device responds to the second request message and allocates PSFCH resources.

[0140] When the first terminal device performs MAC PDU packetization through the above method, it can determine the HARQ feedback attribute of each LCH in the MAC PDU. If the HARQ feedback attribute of these LCHs is enable, but the slgrant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device sends a second request message to the network side device, and the network side device can allocate PSFCH resources to the terminal device according to the second request message, so that the second terminal device can perform HARQ feedback on the MAC PDU on the newly configured PSFCH resources, thereby avoiding the mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE, and thus avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0141] Here, the network side device responding to the second request message can be understood as the network side device determining to allocate PSFCH resources to the first terminal device according to the second request message.

[0142] In some possible implementations, the second request message may include the HARQ feedback attribute of the MAC PDU; the first terminal device sends the second request message to the network side device, including: the first terminal device sends the HARQ feedback attribute of the MAC PDU to the network side device.

[0143] In some possible implementations, the second request message may include MAC CE or RRC signaling. Of course, other signaling may also be included, which is not specifically limited in the embodiments of the present application.

[0144] In an embodiment of the present application, the second request message directly instructs the network side device to allocate PSFCH resources by signaling, and may also indicate the HARQ feedback attributes of the MAC PDU by signaling, so that the network side device can allocate PSFCH resources according to the HARQ feedback attributes of the MAC PDU.

[0145] In some possible implementations, S402 may include: the network side device reconfiguring the PSFCH resources associated with the sl grant; or the network side device reallocating the resource pool, and the reallocated resource pool is configured with the PSFCH resources.

[0146] Option 3:

[0147] Figure 5 The side link communication method in the embodiment of the present application is shown in FIG. Figure 4 , see Figure 5 As shown, the method may include:

[0148] S501: The HARQ feedback attribute of at least one LCH configured by the network side device for the terminal device (the first terminal device and / or the second terminal device) is enable;

[0149] S502: The network side device configures a resource pool for the terminal device.

[0150] Here, at least one of the resource pools configured this time is configured with PSFCH resources. In other words, when configuring a resource pool, if the attribute of at least one LCH is enable, at least one resource pool has PSFCH resources; or, when configuring an LCH, if the attribute of at least one LCH is enable, at least one resource pool has PSFCH resources; or, when configuring an LCH, if at least one resource pool has PSFCH resources, the attribute of one or more LCHs can be configured to enable.

[0151] When the network side device configures a resource pool for a terminal device, if the terminal device is configured with at least one LCH with a HARQ feedback attribute of enable, then at least one resource pool has PSFCH resources. In other words, if the network side device configures at least one resource pool with PSFCH resources for the terminal device, the network side device can configure an LCH with a HARQ feedback attribute of enable for the terminal device. Or when the network side device configures an LCH for a terminal device, if the attribute of at least one LCH is enable, then at least one resource pool has PSFCH resources. Then, if the network side device configures a resource pool for the terminal device, and at least one of the configured resource pools is configured with PSFCH resources, the second terminal device can perform HARQ feedback on the MAC PDU on the configured PSFCH resources, thereby avoiding the mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0152] In the embodiment of the present application, if the network side device configures a resource pool for the terminal device, then the resource pool is correspondingly configured with PSFCH resources, and if the network side device configures multiple resource pools for the terminal device, then at least one of the multiple resource pools must be configured with PSFCH resources. Then, if the terminal device determines that the HARQ attribute of the LCH of the MAC PDU is enable, the second terminal device can send the HARQ feedback information of the MAC PDU to the first terminal device on the PSFCH resource.

[0153] Option 4:

[0154] Figure 6 The side link communication method in the embodiment of the present application is shown in FIG. Figure 5 , see Figure 6 As shown, the method may include:

[0155] S601: The first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources;

[0156] S602: The first terminal device enters an idle state or a third inactive state and performs resource reselection;

[0157] The reselected resource pool is configured with PSFCH resources.

[0158] When the first terminal device performs MAC PDU grouping by the above method, it can determine the HARQ feedback attribute of each LCH in the MAC PDU. If the HARQ feedback attribute of these LCHs is enable, but the slgrant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device can enter the idle state or the third state by itself. In the idle state or the third state, also known as the inactive state, the first terminal device can reselect resources to select a resource pool configured with PSFCH resources. In this way, after receiving the MAC PDU, the second terminal device can send HARQ feedback on the PSFCH resources corresponding to the reselected resource pool, avoiding the mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmissions or packet loss due to lack of retransmissions.

[0159] In some possible implementations, the method further includes: after the first terminal device enters the idle state or the third state, switching to sidelink mode 2. Since in sidelink mode 2, the first terminal device can select resources by itself without the need for scheduling by a network-side device, the first terminal device can autonomously reselect resources after entering the idle state or the third state.

[0160] Option 5:

[0161] Figure 7 The side link communication method in the embodiment of the present application is shown in FIG. Figure 6 , see Figure 7 As shown, the method may include:

[0162] S701: The first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources;

[0163] S702: The first terminal device reselects DST.

[0164] When the first terminal device performs MAC PDU packetization through the above method, it can determine the HARQ feedback attribute of each LCH in the MAC PDU. If the HARQ feedback attribute of these LCHs is enable, but the slgrant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device reselects DST, and the HARQ feedback attribute of the LCH associated with the reselected DST can be disable. In this way, the mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE is avoided, thereby avoiding unnecessary retransmission or packet loss due to lack of retransmission.

[0165] In a possible implementation manner, the process of the first terminal device reselecting the DST is as follows:

[0166] First, the first terminal device selects the LCH or MAC CE with the highest priority (ie, the second LCH or the second MAC CE) from among the LCH or MAC CE that satisfy the following third condition, and determines the DST of the communication according to this LCH.

[0167] Here, the third condition may include: the HARQ attribute of the LCH is disable;

[0168] Furthermore, the third condition may include at least one of the following:

[0169] 1. There is SL data to be transmitted;

[0170] 2. SB j >0;

[0171] 3. If the current sl grant is configured grant type1, and LCH is configured with sl-configuredSLGrantType1Allowed, this value is true.

[0172] Among them, configured grant type1 is used to indicate sidelink configuration grant type 1;

[0173] Among them, sl-configuredSLGrantType1Allowed is used to indicate whether the data of the LCH can be transmitted on the resources of the side link configuration authorization type 1.

[0174] It should be noted that in an embodiment of the present application, the first terminal device can select an LCH or MAC CE from the LCH or MAC CE that satisfies the third condition above that "the HARQ attribute of the LCH is disable", or can select an LCH or MAC CE from the LCH or MAC CE that satisfies the condition "the HARQ attribute of the LCH is disable" and satisfies some or all of the three conditions 1 to 3 above.

[0175] In an embodiment of the present application, after the first terminal device determines the DST, if there are LCHs among the LCHs associated with this DST that meet the following fourth condition, these LCHs need to be screened out, and then resources need to be allocated among all selected LCHs.

[0176] Here, the fourth condition may include at least one of the following:

[0177] 1. There is SL data waiting to be transmitted;

[0178] 2. If the sl grant is configured grant type1, and LCH is configured with sl-configuredSLGrantType1Allowed, this value is true;

[0179] 3. The HARQ feedback attributes of the LCH are the same as the HARQ feedback attributes of the second LCH.

[0180] It should be noted that, in an embodiment of the present application, the first terminal device may filter the LCH from the LCH associated with the above-mentioned DST according to all or part of the conditions in the above-mentioned fourth condition.

[0181] Finally, the first terminal device encapsulates the LCH data belonging to the same source and destination pair and having the same HARQ feedback attribute in one MAC PDU.

[0182] In some possible implementation schemes, the third condition and the fourth condition mentioned above may also include other conditions, which are not specifically limited in the embodiments of the present application.

[0183] Option 6:

[0184] Figure 8 The side link communication method in the embodiment of the present application is shown in FIG. Figure 7 , see Figure 8 As shown, the method may include:

[0185] S801: If the first terminal device determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device sends a third request message to the second terminal device;

[0186] The third request message is used to request the second terminal device not to perform HARQ feedback on the MAC PDU. That is, the first terminal device requests the second terminal device not to perform HARQ feedback on the MAC PDU through the third request message.

[0187] S802: The second terminal device responds to the third request message, and does not perform HARQ feedback on the MAC PDU after receiving the MAC PDU.

[0188] When the first terminal device performs MAC PDU grouping through the above method, it can determine the HARQ feedback attribute of each LCH in the MAC PDU. If the HARQ feedback attribute of these LCHs is enable, but the slgrant used to send the MAC PDU is not configured with associated PSFCH resources, the first terminal device can send a third request message to the second terminal device to request the second terminal device not to perform HARQ feedback on the MAC PDU, so as to avoid the mismatch between the HARQ feedback attribute of the MAC PDU and the resources configured by the UE, thereby avoiding unnecessary retransmission or packet loss due to lack of retransmission.

[0189] Here, the second terminal device responding to the third request message can be understood as the second terminal device not performing HARQ feedback on the MAC PDU after receiving the MAC PDU according to the third request message.

[0190] In the embodiment of the present application, the third request message may include, but is not limited to, control information, wherein the control information may be SCI.

[0191] Accordingly, before S801, the above method may include: the first terminal device configures the HARQ feedback attribute in the control information to disable. That is, the first terminal device may configure one or more bits (such as 1 bit) in the control information used to represent the HARQ feedback attribute to disable. Then, after receiving the control information, the second terminal device may not perform HARQ feedback on the corresponding MAC PDU according to the bit.

[0192] Based on the same inventive concept, an embodiment of the present application further provides a communication device, which may be a chip or a system on chip in a first terminal device, or a functional module in the first terminal device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, in which instructions are stored, and when the instructions are called by the system on chip or the chip, the above method is executed. Fig. 9 The structure of the communication device in the embodiment of the present application is shown in FIG. Figure 1 , see Fig. 9 As shown, the communication device 900 may include: a sending module 901 and a processing module 902; the sending module 901 is used to send a first request message to the second terminal device if the processing module 902 determines that the HARQ feedback attribute of the LCH in the MAC PDU is disabled, and the sl grant used to send the MAC PDU has been configured with associated PSFCH resources, the first request message is used to request the second terminal device to perform HARQ feedback on the MAC PDU, the first terminal device performs sidelink communication with the second terminal device, and the MAC PDU is the initial transmission on the sl grant.

[0193] In some possible implementations, the first request message includes: control information; and a processing module, further configured to configure the HARQ feedback attribute in the control information to be enabled.

[0194] In some possible implementations, the control information is SCI.

[0195] In some possible implementations, see Fig. 9 As shown, the communication device 900 also includes: a receiving module 903, which is used to receive HARQ feedback information sent by the second terminal device; a sending module, which is also used to send positive acknowledgement information on the PUCCH resource if the HARQ feedback information is positive acknowledgement information; or, if the HARQ feedback information is negative acknowledgement information, send negative acknowledgement information on the PUCCH resource.

[0196] It should be noted that the above-mentioned sending module can be a sending interface, a sending circuit or a transmitter, etc.; the above-mentioned receiving module can be a receiving interface, a receiving circuit or a receiver, etc.; the above-mentioned processing module can be one or more processors.

[0197] Based on the same inventive concept, the embodiment of the present application also provides a communication device, which can be a chip or a system on chip in the first terminal device, or a functional module in the first terminal device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, and the memory stores instructions. When the instructions are called by the system on chip or the chip, the above method is executed. Fig. 9 As shown, the communication device 900 may include: a sending module 901 and a processing module 902; the sending module 901 is used to ignore the sl grant if the processing module 902 determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the MAC PDU is the initial transmission on the sl grant.

[0198] In some possible implementations, the sending module is specifically configured to send the MAC PDU to the second terminal device without using the SL grant.

[0199] In some possible implementations, the above method may further include: if the processing module determines that the HARQ feedback attribute of the LCH to be packaged is enabled before packaging, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the processing module may ignore the sl grant, such as the processing module does not generate a corresponding MAC PDU for the sl grant, that is, does not package the sl grant; or, when the processing module determines the DST according to the priority of the LCH, if the HARQ attribute of the LCH with the highest priority is enabled, then stop screening the LCH.

[0200] It should be noted that the above-mentioned sending module may be a sending interface, a sending circuit or a transmitter, etc.; the above-mentioned processing module may be one or more processors.

[0201] Based on the same inventive concept, the embodiment of the present application also provides a communication device, which can be a chip or a system on chip in the first terminal device, or a functional module in the first terminal device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, and the memory stores instructions. When the instructions are called by the system on chip or the chip, the above method is executed. Fig. 9As shown, the communication device 900 may include: a sending module 901 and a processing module 902; the sending module 901 is used to send a second request message to the network side device if the processing module 902 determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the second request message is used to request allocation of PSFCH resources for the first terminal device, and the MAC PDU is the initial transmission on the sl grant.

[0202] In some possible implementations, the second request message may include the HARQ feedback attribute of the MAC PDU; the first terminal device sends the second request message to the network side device, including: the first terminal device sends the HARQ feedback attribute of the MAC PDU to the network side device.

[0203] In some possible implementations, the second request message may include MAC CE or RRC. Of course, other signaling may also be included, which is not specifically limited in the embodiments of the present application.

[0204] In some possible implementations, the second request message is used to request the network side device to allocate PSFCH resources associated with the sl grant; or, the second request message is used to request the network side device to reallocate a resource pool, and the resource pool is configured with PSFCH resources.

[0205] It should be noted that the above-mentioned sending module may be a sending interface, a sending circuit or a transmitter, etc.; the above-mentioned processing module may be one or more processors.

[0206] Based on the same inventive concept, the embodiment of the present application also provides a communication device, which can be a chip or system on chip in a network side device, or a functional module in a network side device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, and the memory stores instructions. When the instructions are called by the system on chip or chip, the above method is executed. Fig. 9 As shown, the communication device may include: a processing module 902, configured to configure a resource pool for the first terminal device if the HARQ feedback attribute of at least one LCH configured for the first terminal device is enabled, and at least one of the resource pools is configured with PSFCH resources.

[0207] It should be noted that the above processing module may be one or more processors.

[0208] Based on the same inventive concept, the embodiment of the present application also provides a communication device, which can be a chip or a system on chip in the first terminal device, or a functional module in the first terminal device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, and the memory stores instructions. When the instructions are called by the system on chip or the chip, the above method is executed. Fig. 9 As shown, the communication device 900 may include: a processing unit 902, which is used to enter an idle state or a third state and perform resource reselection if it is determined that the HARQ feedback attribute of the LCH in the MAC PDU is enabled and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the reselected resource pool is configured with PSFCH resources, and the MAC PDU is the initial transmission on the sl grant.

[0209] In some possible implementations, the processing unit is further configured to switch to side link mode 2 after entering an idle state or a third state.

[0210] It should be noted that the above processing module may be one or more processors.

[0211] Based on the same inventive concept, the embodiment of the present application also provides a communication device, which can be a chip or a system on chip in the first terminal device, or a functional module in the first terminal device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, and the memory stores instructions. When the instructions are called by the system on chip or the chip, the above method is executed. Fig. 9 As shown, the communication device 900 may include: a processing unit 902, which is used to reselect the communication target DST if it is determined that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the MAC PDU is the initial transmission on the sl grant.

[0212] In some possible implementations, the DST is a DST determined according to the LCH or MAC CE, and the LCH or MAC CE is the highest priority among multiple LCHs or MAC CEs that meet preset conditions; the preset conditions at least include: the HARQ feedback attributes of multiple LCHs or MAC CEs are disabled.

[0213] It should be noted that the above processing module may be one or more processors.

[0214] Based on the same inventive concept, the embodiment of the present application also provides a communication device, which can be a chip or a system on chip in the first terminal device, or a functional module in the first terminal device for implementing the method described in any of the above possible implementations. The chip or system on chip includes a memory, and the memory stores instructions. When the instructions are called by the system on chip or the chip, the above method is executed. Fig. 9 As shown, the communication device 900 may include: a sending module 901 and a processing module 902; the sending module 901 is used to send a third request message to the second terminal device if the processing module determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the third request message is used to request the second terminal device not to perform HARQ feedback on the MAC PDU.

[0215] In some possible implementations, the third request message may include: control information; and a processing module, configured to configure the HARQ feedback attribute in the control information to be disabled.

[0216] Based on the same inventive concept, an embodiment of the present application provides a communication device, which may be a terminal device, and the terminal device may be consistent with the first terminal device described in one or more of the above embodiments. Fig.10 The structure of the terminal device in the embodiment of the present application is shown in FIG. Figure 2 , see Fig.10 As shown, the communication device 1000 includes: a processor 1001 and a memory, the processor 1001 is coupled to the memory 1002, and the processor 1001 is configured to read and execute instructions in the memory 1002; the processor 1001 is configured to send a first request message to the second terminal device if the processor 1001 determines that the HARQ feedback attribute of the LCH in the MAC PDU is not enabled, and the network side device configures PUCCH resources for the terminal device and the sl grant used to send the MAC PDU has been configured with associated PSFCH resources, the first request message is used to request the second terminal device to perform HARQ feedback on the MAC PDU, and the MAC PDU is the initial transmission on the sl grant.

[0217] In some possible implementations, the first request message includes: control information; and a processor further configured to configure a HARQ feedback attribute in the control information to be enabled.

[0218] In some possible implementations, the control information is SCI.

[0219] In some possible implementations, the processor is further configured to receive HARQ feedback information sent by the second terminal device; and to send affirmative acknowledgment information on PUCCH resources if the HARQ feedback information is affirmative acknowledgment information; or to send negative acknowledgment information on PUCCH resources if the HARQ feedback information is negative acknowledgment information.

[0220] Based on the same inventive concept, an embodiment of the present application provides a communication device, which may be a terminal device, and the terminal device may be consistent with the first terminal device described in one or more of the above embodiments. Fig.10 As shown, the terminal device 1000 includes: the communication device 1000 includes: a processor 1001 and a memory, the processor 1001 is coupled to the memory 1002, the processor 1001 is configured to read and execute instructions in the memory 1002; the processor 1001 is configured to ignore the sl grant if the processor 1001 determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the MAC PDU is the initial transmission on the sl grant.

[0221] In some possible implementations, the processor 1001 is configured to send a MAC PDU to the second terminal device not through an sl grant.

[0222] In some possible implementations, the processor 1001 is further configured to not generate a corresponding MAC PDU for the sl grant if the HARQ feedback attribute of the LCH to be packaged is determined to be enabled before package packaging, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources; or, the processor 1001 is further configured to stop screening the LCH if the HARQ attribute of the LCH with the highest priority is enabled when determining the DST according to the priority of the LCH.

[0223] Based on the same inventive concept, an embodiment of the present application provides a terminal device, which may be consistent with the first terminal device described in one or more of the above embodiments. Fig.10As shown, the terminal device 1000 includes: a processor 1001, a memory 1002 and a communication interface 1003, the processor 1001 is coupled to the memory 1002, and the communication interface 1003 is configured to send a second request message to the network side device if the processor 1001 determines that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, the second request message is used to request allocation of PSFCH resources for the first terminal device, and the MAC PDU is the initial transmission on the sl grant.

[0224] In some possible implementations, the second request message includes a HARQ feedback attribute of the MAC PDU; and the communication interface 1003 is configured to send the HARQ feedback attribute of the MAC PDU to the network side device.

[0225] In some possible implementations, the second request message includes MAC control element CE or radio resource control RRC signaling.

[0226] In some possible implementations, the second request message is used to request the network side device to allocate PSFCH resources associated with the sl grant; or, the second request message is used to request the network side device to reallocate a resource pool, and the resource pool is configured with PSFCH resources.

[0227] Based on the same inventive concept, an embodiment of the present application provides a communication device, which may be a network side device, and the network side device may be consistent with the network side device described in one or more of the above embodiments. Fig.10 As shown, the communication device 1000 includes: a processor 1001 and a memory 1002, the processor 1001 is coupled to the memory 1002, and the processor 1001 is configured to read and execute instructions in the memory 1002; the processor 1101 is configured to configure a resource pool for the first terminal device if the HARQ feedback attribute of at least one LCH configured for the first terminal device is enabled, and at least one of the resource pools is configured with a PSFCH resource.

[0228] Based on the same inventive concept, an embodiment of the present application provides a communication device, which may be a terminal device, and the terminal device may be consistent with the first terminal device described in one or more of the above embodiments. Fig.10As shown, the communication device 1000 includes: a processor 1001 and a memory 1002, and the processor 1001 is coupled to the memory 1002. The processor 1001 is configured to read and execute instructions in the memory 1002; the processor 1001 is configured to enter an idle state or a third state if it is determined that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and perform resource reselection, the reselected resource pool is configured with PSFCH resources, and the MAC PDU is an initial transmission on the sl grant.

[0229] In some possible implementations, the processor 1001 is further configured to switch to the sidelink mode 2 after entering the idle state or the third state.

[0230] Based on the same inventive concept, an embodiment of the present application provides a communication device, which may be a terminal device, and the terminal device may be consistent with the first terminal device described in one or more of the above embodiments. Fig.10 As shown, the communication device 1000 includes: a processor 1001 and a memory 1002, and the processor 1001 is coupled to the memory 1002. The processor 1001 is configured to read and execute instructions in the memory 1002; the processor 1101 is configured to reselect a communication target DST if it is determined that the HARQ feedback attribute of the LCH in the MAC PDU is enabled, and the sl grant used to send the MAC PDU is not configured with an associated PSFCH resource, and the MAC PDU is an initial transmission on the sl grant.

[0231] In some possible implementations, the DST is a DST determined according to the LCH or MAC CE, and the LCH or MAC CE is the highest priority among multiple LCHs or MAC CEs that meet preset conditions; the preset conditions at least include: the HARQ feedback attributes of multiple LCHs or MAC CEs are disabled.

[0232] Based on the same inventive concept, an embodiment of the present application provides a communication device, which may be a terminal device, and the terminal device may be consistent with the first terminal device described in one or more of the above embodiments. Fig.10As shown, the communication device 1000 includes: a processor 1001 and a memory 1002, the processor 1001 is coupled to the memory 1002; the processor 1001 is configured to read and execute instructions in the memory 1102; the processor 1101 is configured to send a third request message to the second terminal device if the processor 1001 determines that the HARQ feedback attribute of the LCH in the MAC PDU is enable, and the sl grant used to send the MAC PDU is not configured with associated PSFCH resources, and the third request message is used to request the second terminal device not to perform HARQ feedback on the MAC PDU.

[0233] In some possible implementations, the third request message may include: control information; accordingly, the communication interface 1003 is further configured to configure the HARQ feedback attribute in the control information to be disabled.

[0234] Based on the same inventive concept, the present application provides a sidelink communication system, comprising: a first terminal device and a second terminal device as described in any possible implementation manner described above, and a network side device as described in any possible implementation manner described above.

[0235] Based on the same inventive concept, the present application provides a computer-readable storage medium, which stores instructions. When the instructions are executed on a computer, the sidelink communication method as described in any possible implementation manner described above is executed.

[0236] Based on the same inventive concept, the present application provides a computer program or a computer program product. When the computer program or the computer program product is executed on a computer, the computer implements the sidelink communication method as described in any possible implementation manner described above.

[0237] Those skilled in the art will appreciate that the functions described in conjunction with the various illustrative logic blocks, modules, and algorithm steps disclosed herein can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions described in the various illustrative logic blocks, modules, and steps can be stored or transmitted as one or more instructions or codes on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to tangible media, such as data storage media, or includes any communication media that facilitates the transfer of computer programs from one place to another (e.g., according to a communication protocol). In this manner, computer-readable media may generally correspond to (1) non-temporary tangible computer-readable storage media, or (2) communication media, such as signals or carrier waves. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures for implementing the techniques described in this application. A computer program product may include computer-readable media.

[0238] As an example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer. Also, any connection is properly referred to as a computer-readable medium. For example, if instructions are transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwave are included in the definition of media. However, it should be understood that the computer-readable storage media and data storage media do not include connections, carrier waves, signals or other temporary media, but are actually directed to non-temporary tangible storage media. As used herein, disks and optical disks include compact disks (CDs), laser optical disks, optical optical disks, digital versatile disks (DVDs), and Blu-ray disks, where disks typically reproduce data magnetically, while optical disks reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0239] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Thus, the term "processor" as used herein may refer to any of the aforementioned structures or any other structures suitable for implementing the techniques described herein. Additionally, in some aspects, the functions described by the various illustrative logic blocks, modules, and steps described herein may be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated in a combined codec. Moreover, the techniques may be fully implemented in one or more circuits or logic elements.

[0240] The techniques of the present application may be implemented in a variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC), or a set of ICs (e.g., a chipset). Various components, modules, or units are described in this application to emphasize functional aspects of devices for performing the disclosed techniques, but do not necessarily need to be implemented by different hardware units. In fact, as described above, the various units may be combined in a codec hardware unit in conjunction with appropriate software and / or firmware, or provided by interoperating hardware units (including one or more processors as described above).

[0241] In the above embodiments, the description of each embodiment has different emphases. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0242] The above is only an exemplary embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A sidelink communication method, characterized in that: include: If the first terminal device determines that the hybrid automatic repeat request HARQ feedback attribute of the logical channel LCH in the medium access control layer packet data unit MAC PDU is disabled, and the network side device configures the first terminal device with a physical uplink control channel PUCCH resource and the sidelink grant used to send the MAC PDU has been configured with associated physical sidelink feedback channel PSFCH resources, then the first terminal device sends a first request message to the second terminal device, and the first request message is used to request the second terminal device to perform HARQ feedback on the MAC PDU, the first terminal device performs sidelink communication with the second terminal device, and the MAC PDU is the initial transmission on the sidelink grant.

2. The method according to claim 1, characterized in that The first request message includes: control information; the method further includes: The first terminal device configures the HARQ feedback attribute in the control information to be enabled.

3. The method according to claim 2, characterized in that The control information is sidelink control information SCI.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: The first terminal device receives HARQ feedback information sent by the second terminal device; If the HARQ feedback information is positive acknowledgment information, the first terminal device sends the positive acknowledgment information on the PUCCH resource; or, If the HARQ feedback information is negative acknowledgment information, the first terminal device sends negative acknowledgment information on the PUCCH resource.

5. A communication device, characterized in that: include: Processor and memory; The processor is coupled to the memory, and is configured to read and execute instructions in the memory to implement the sidelink communication method according to any one of claims 1 to 4.

6. A communication device, characterized in that: The communication device is a chip or a system on chip, and the chip or the system on chip includes a memory, in which instructions are stored. When the instructions are called by the system on chip or the chip, the side link communication method according to any one of claims 1 to 4 is executed.

7. A sidelink communication system, characterized in that: include: The communication device according to claim 5 or the communication device according to claim 6.

8. A computer-readable storage medium having a computer program or instruction stored thereon, characterized in that: When the computer program or instructions are executed, the computer is caused to perform the sidelink communication method according to any one of claims 1 to 4.

9. A computer program product, characterized in that When the computer program product is executed on a computer, the computer is caused to execute the sidelink communication method according to any one of claims 1 to 4.

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