A method and apparatus for sidelink communication channel access contention window length adjustment

Abstract

The application discloses a sidelink communication channel access contention window length adjusting method, and contains the following steps: obtaining configuration information, wherein the configuration information is used for determining contention window length configuration parameters under different access levels and / or different channel busy states; and updating the contention window length according to HARQ feedback information and a channel busy state. The application also contains a device applying the method. The scheme of the application proposes a new contention window length adjusting mechanism for sidelink SL communication, and solves the problem that channel access does not meet fairness caused by the inconsistency of the contention window length adjusting mechanism of the terminal under the HARQ feedback mechanism or without the HARQ feedback mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, in particular to a sidelink communication channel access contention window length adjustment method and device. BACKGROUND

[0002] Currently, sidelink communication based on unlicensed is being developed in cellular systems. Channel access will be based on Listen Before Talk (LBT) technology. There are various types of LBT technology, among which LBT type 1 is generally used for initial channel access and channel access in the absence of Channel Occupation Time (COT) sharing. The basic access process is that the terminal first performs channel listening for a set time Td, and if it is judged that the channel is idle, it enters a random backoff, and the backoff window length is N0 x Td, where N0 is a random number selected with equal probability between 0 and CWp (p represents the access level). During the backoff process, if a Td channel idle time elapses, the backoff count N decreases by 1 (N initially is N0), and when N backoff is 0, the channel is idle and the channel is accessed for data transmission, otherwise the backoff process is suspended until the channel is detected to be idle.

[0003] The channel access time of this type is related to the backoff window length N0 x Td (N0 = randn (0 ~ CWp)), and the contention window length (Contention Window) CWp of the access level p is configured with a minimum value of CWmin_p and a maximum value of CWmax_p. Generally, when the channel access receives ACK feedback during data transmission, CWp is reset to CWmin_p, and when there is no retransmission or new data transmission within the transmission time, CWp window length remains unchanged, otherwise, when NACK feedback is received, CWp is updated to the next higher value until CWmax_p. When CWp = CWmax_p is used to generate N0 for K consecutive times, CWp is reset to CWmin_p.

[0004] For sidelink SL communication without HARQ feedback, the CWp adjustment mechanism for unlicensed channel access is not clear, and the contention window length adjustment mechanism based on HARQ feedback cannot be used, so a new mechanism needs to be designed. In the WiFi system and the Uu port of the cellular network, the CWp adjustment mechanism is consistent among various nodes, which is conducive to ensuring the fairness of channel access. However, in SL communication, when SL communication without HARQ feedback and SL communication with HARQ feedback use different CWp adjustment mechanisms, the fairness of channel access will be lost to some extent. Moreover, when multiple CWp adjustment mechanisms are designed in the system, it is not clear under what conditions a terminal specifically uses which CWp mechanism, so certain criteria need to be designed, and the criteria should try to ensure the fairness of channel access by various nodes. SUMMARY

[0005] The application provides a sidelink communication channel access contention window length adjustment method and device, and a new CWp adjustment mechanism for sidelink SL communication is provided, and through specific criteria for nodes working in multiple CWp adjustment mechanisms, the problem of not meeting fairness in channel access of nodes is solved.

[0006] In a first aspect, the application provides a sidelink communication channel access contention window length adjustment method, comprising the following steps:

[0007] Obtaining configuration information, wherein the configuration information is used to determine the contention window length configuration parameters under different access levels and / or different channel busy states;

[0008] Updating the contention window length according to the HARQ feedback information and the channel busy state.

[0009] Preferably, the configuration information includes contention window length configuration values CW_mp under different access levels p and different channel busy state levels m.

[0010] Preferably, the configuration information includes a first time length; the channel busy state is determined and it is determined whether to update the contention window length with the first time length as a period.

[0011] Preferably, the channel busy state level m is determined according to the channel busy state, the contention window length configuration value CW_mp under the access level p and the channel busy state level m is determined according to the configuration information, and the value CWp of the contention window length is determined in at least one of the following ways: the larger one of the contention window length configuration value CW_mp and the current value of the contention window length; and one of the contention window length configuration value CW_mp and the current value of the contention window length is selected according to a set probability.

[0012] Preferably, the value of the contention window length CWp is reset to the minimum contention window length CWmin_p under the access level p in response to at least one of the following conditions:

[0013] The value of the contention window length CWp uses the contention window length configuration value CW_Mp of the highest level channel busy state M of the access level p for K consecutive times, and is used to generate a backoff window length;

[0014] The value of the contention window length CWp uses the contention window length configuration value CW_Mp of the highest level channel busy state M of the access level p for a second time length, and is used to generate a backoff window length;

[0015] The value of the contention window length CWp uses the highest contention window length configuration value CWmax_p of the access level p for K consecutive times, and is used to generate a backoff window length;

[0016] The value of the contention window length CWp is configured as the maximum contention window length configuration value CWmax_p of the access level p for a second time length, and is used to generate the backoff window length.

[0017] Preferably, when an ACK corresponding to the data transmission feedback of the access level p is received, the channel contention window length corresponding to the access level p is reset as CWmin_p. Alternatively, when a NACK corresponding to the data transmission feedback of the access level p is received, the contention window length CWp is increased to a higher value in the configuration value list of the access level p until CWmax_p.

[0018] Preferably, in response to the indication information from the sending end, the receiving end updates the channel access contention window length value corresponding to the access level p of the receiving end according to the current value CWp of the contention window length of the access level p of the sending end contained in the indication information, wherein the sending end is a transmission terminal enabling HARQ feedback.

[0019] In a second aspect, the present application further provides a terminal device for implementing the method of any one of the embodiments, comprising a receiving module and a determining module.

[0020] The receiving module is configured to receive the configuration information. The determining module is configured to determine the contention window length according to the HARQ feedback information and the channel busy state.

[0021] Preferably, the receiving module is further configured to receive the indication information of the sidelink. The determining module is further configured to update the channel access contention window length value corresponding to the access level p of the receiving end according to the current value CWp of the contention window length of the access level p of the sending end contained in the indication information, wherein the sending end is a transmission terminal enabling HARQ feedback.

[0022] Preferably, the receiving module is further configured to receive a NACK or an ACK corresponding to the data transmission feedback of the sidelink access level p. The determining module is further configured to reset the data transmission channel access contention window length CWp corresponding to the access level p as CWmin_p when an ACK corresponding to the data transmission feedback of the sidelink access level p is received. Further, the determining module is further configured to increase the contention window length CWp to a higher value in the configuration value list of the access level p until CWmax_p when a NACK corresponding to the data transmission feedback of the sidelink access level p is received.

[0023] Further, the terminal device further comprises a sending module. Preferably, the sending module is configured to send an ACK corresponding to the data transmission feedback of the sidelink access level p. The determining module is further configured to reset the channel contention window length corresponding to the access level p as CWmin_p when an ACK corresponding to the data transmission feedback of the sidelink access level p is sent.

[0024] In a third aspect, the present application also provides a communication device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the computer program is executed by the processor, the steps of the sidelink communication channel access contention window length adjustment method according to any one of the embodiments of the first aspect of the present application are implemented.

[0025] In a fourth aspect, the present application also provides a computer readable medium, wherein a computer program is stored in the computer readable medium, and when the computer program is executed by a processor, the steps of the sidelink communication channel access contention window length adjustment method according to any one of the embodiments of the first aspect of the present application are implemented.

[0026] The above at least one technical solution adopted by the embodiments of the present application can achieve the following beneficial effects:

[0027] The new CWp adjustment mechanism for unlicensed SL communication proposed in the present application effectively determines the specific condition method of CWp through the specific criteria of the node working under multiple CWp adjustment mechanisms, and improves the fairness of the node accessing the channel. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which are included to provide a further understanding of the present application, constitute a part of the present application and illustrate the illustrative embodiments of the present application and their description serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0029] Figure 1 The flowchart is for an embodiment of the method of the present application;

[0030] Figure 2 The flowchart is for an embodiment of the flowchart of the specific update;

[0031] Figure 3 The schematic diagram is for an embodiment of the terminal device;

[0032] Figure 4 The block diagram is for a terminal device of another embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] Among them, the existing Uu interface CWmin_p, CWmax_p, CWp configuration is shown in Table 1.

[0035] Table 1

[0036]

[0037] When the sidelink (SL) introduces unlicensed LBT-based channel access, a mechanism is also needed to determine its backoff window length (CWp). In the existing standard development discussion, for SL-enabled HARQ feedback unicast communication, the adjustment mechanism of CWp is the same as that of the above-mentioned Uu interface unlicensed channel access CWp adjustment mechanism. For SL communication without HARQ feedback, further discussion is needed.

[0038] The technical solutions provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0039] Figure 1 The embodiment flowchart of the method of the present application.

[0040] In a first aspect, the present application provides a sidelink communication channel access contention window length adjustment method, comprising the following steps:

[0041] Step 101, obtain configuration information, the configuration information is used to determine the contention window length configuration parameter under different access levels and / or different channel busy state levels;

[0042] Preferably, the configuration information includes the contention window length configuration value CW_mp under different access levels p and different channel busy state levels m.

[0043] Preferably, the configuration information includes a first time length; with the first time length as the period, judge the channel busy state and determine whether to update the contention window length.

[0044] For example, the configuration information contains contention window length configuration parameters under different access levels and / or different channel busy state levels, wherein the contention window length configuration parameters under different access levels include minimum contention window length CWmin_p, maximum contention window length CWmax_p under different levels p, and contention window length CWp configuration value list, the minimum value in the list is CWmin_p and the maximum value is CWmax_p, as shown in Table 2.

[0045] Table 2

[0046]

[0047] The contention window length configuration parameters under different channel busy state levels corresponding to different access levels include contention window length CW_mp under different access levels p and different channel busy state (CBR) levels m, as shown in Table 3.

[0048] Table 3 CW_mp configuration under different access levels and channel busy state levels

[0049]

[0050]

[0051] The configuration information further includes a first time length for contention window length maintenance, i.e., the terminal updates the access contention window length according to the channel busy state every first time length.

[0052] It should be noted that the contention window length CW_mp under different access levels p and different channel busy state (CBR) levels m can also be understood as the contention window length under different transmission priorities z and different CBR levels m, and there is a certain mapping relationship between different transmission priorities z and different access levels p. Configuring the contention window length under different transmission priorities z and different CBR levels m is equivalent to configuring the contention window length under different access levels p and different channel busy state (CBR) levels m. The contention window length under different transmission priorities z and different CBR levels m can be used as a transmission parameter determined by SL congestion control.

[0053] Step 102, the terminal device determines the initial value of the contention window length CWp.

[0054] The method of determining the initial value can be that the channel access contention window length CWp is the corresponding CWmin_p (first window length) of the access level p according to the access level, or the channel access contention window length CWp is the corresponding CW_mp based on the access level p and the CBR level m. Optionally, the terminal uses the larger value of CWmin_p and CW_mp, or autonomously selects CWmin_p or CW_mp, or selects CWmin_p or CW_mp as the initial value of CWp with a set probability.

[0055] Step 103, updating the contention window length according to the HARQ feedback information and the channel busy state level.

[0056] For example, the channel busy state level m is determined according to the measured channel busy state, the contention window length configuration value CW_mp under the access level p and the channel busy state level m is determined according to the configuration information, and the value CWp of the contention window length is determined in at least one of the following ways: the larger one of the contention window length configuration value CW_mp and the current value of the contention window length; one of the contention window length configuration value CW_mp and the current value of the contention window length is selected according to a set probability.

[0057] The determination of the contention window length update mechanism includes at least one of the following features:

[0058] Step 103A, when the contention window length CWp is updated, within the first time duration, if the HARQ ACK feedback is received, the contention window length CWp is reset to CWmin_p; each time the HARQ NACK feedback is received, the contention window length CWp is increased to a higher value in the access level p configuration value list (such as the CWp configuration value list in Table 2) until CWmax_p. Optionally, the terminal feeds back ACK to the sidelink access level p transmission data, and the access level p service transmission channel contention window length is reset to CWmin_p.

[0059] Step 103B, after the CWp is updated, within the first time duration, the CBR level m is determined according to the channel busy ratio (CBR), and the configured window length CW_mp (second window length) under the access level p and the CBR level m is further determined according to the configuration.

[0060] Optionally, the second window length is compared with the current CWp window length, if CW_mp is greater than CWp, then CWp is set to CW_mp, otherwise CWp remains unchanged;

[0061] Optionally, the terminal autonomously determines to select CWp as the current value or CW_mp;

[0062] Optionally, the terminal selects CWp as the current value or CW_mp with a set probability.

[0063] Figure 2 is a specific update flow embodiment.

[0064] A specific update flow example is shown in the following figure, the SL sending end accesses the channel based on the contention window length CWp = CWmin_p at t0, within the first time duration, the HARQ NACK feedback is received at t1, then the CWp is updated to the next higher value in the access level p corresponding contention window length list, within the first time duration, CW_mp is determined according to the measured CBR level m and the access level p, the terminal selects the larger value between the current CWp and CW_mp according to the above description method, or selects CWp or CW_mp to update CWp with a set probability, the HARQ ACK feedback is received at t3 in the transmission, then CWp is reset to CWmin_p, at the next first time duration t4, CW_mp is determined according to the measured CBR level m and the access level p. If the terminal transmission does not enable HARQ feedback, the steps related to updating CWp based on HARQ ACK / NACK feedback are not involved in the update flow.

[0065] It should be noted that the terminal updates the contention window length according to the channel busy state according to the first time length. The first time length can be that the terminal updates the contention window length according to the channel busy state every first time length after initially accessing the channel, or that the terminal updates the contention window length according to the channel busy state every first time length starting from the first system frame superimposed with a time offset. Here, the specific starting point of the terminal for updating the contention window length according to the channel busy state using the first time length is not limited.

[0066] Further, in response to at least one of the following conditions, the value of the contention window length CWp is reset to the minimum contention window length CWmin_p of the access level p:

[0067] The value of the contention window length CWp uses the contention window length configuration value CW_Mp of the highest level channel busy degree M of the access level p for K consecutive times to generate the backoff window length;

[0068] The value of the contention window length CWp is the contention window length configuration value CW_Mp of the highest level channel busy degree M of the access level p for a second time length to generate the backoff window length;

[0069] The value of the contention window length CWp uses the highest contention window length configuration value CWmax_p of the access level p for K consecutive times to generate the backoff window length;

[0070] The value of the contention window length CWp is the highest contention window length configuration value CWmax_p of the access level p for a second time length to generate the backoff window length.

[0071] The K and the second time length can be indicated to the terminal in the configuration information in step 101.

[0072] The backoff window length N0xTd (N0=randn (0~CWp), N0 is a randomly generated integer between 0 and CWP) of the data transmission channel access of the access level p is related, where Td is a system configured time unit.

[0073] Optionally, the receiving end obtains indication information from the sending end, and the receiving end updates the contention window length value of the corresponding data transmission of the receiving end access level p according to the current value CWp of the contention window length of the sending end access level p contained in the indication information, where the sending end is a transmission terminal enabling HARQ feedback.

[0074] Optionally, when the receiving terminal feeds back ACK to the transmission of the sending terminal access level p, the receiving terminal resets the channel access CWp of the corresponding access level p to CWmin_p. For example, as shown in Figure 2 In t3, the receiving terminal feeds back ACK to the sending terminal, and the receiving terminal resets the data transmission channel access contention window length CWp of the corresponding access level p to CWmin_p.

[0075] Figure 3 is an embodiment schematic diagram of a terminal device.

[0076] The application also proposes a terminal device for implementing the method of any one of the embodiments of the application, and the terminal device is configured to: determine a CWp initial value, and determine a channel access CWp for an access level p corresponding to a CWmin_p (a first window length); determine a CWp update mechanism, and the CWp update mechanism specifically includes at least one of the following features: configuring a first time length, and if a HARQ ACK feedback is received within the first time length after the CWp is updated, resetting the CWp to the CWmin_p; if a HARQ NACK feedback is determined, increasing the CWp to a next higher value until the CWmax_p; and after the CWp is updated and the first time length is experienced, determining a CBR level m according to a channel busy ratio (CBR), and further determining a configured window length CW_mp under the access level p and the CBR level m according to the configuration, and using the configured window length CW_mp to update the CWp.

[0077] To implement the above technical solutions, the application proposes a terminal device 500, and the application also proposes a terminal device for implementing the method described in any one of the embodiments of the application, and the terminal device includes a receiving module, a determining module and a sending module.

[0078] The receiving module is configured to receive the configuration information, and the determining module is configured to determine the contention window length according to the HARQ feedback information and the channel busy state.

[0079] Preferably, the receiving module is further configured to receive indication information of sidelink, and the determining module is further configured to update a contention window length value of a receiving end access level according to a current contention window length value CWp of a sending end access level p included in the indication information, wherein the sending end is a transmission terminal that enables HARQ feedback.

[0080] Further, the terminal device further includes a sending module configured to send indication information of sidelink, and the indication information includes a current contention window length value CWp of an access level p, wherein the terminal device that sends the indication information is a transmission terminal that enables HARQ feedback.

[0081] Preferably, the sending module is further configured to send an ACK of data transmission feedback of the access level p, and the determining module is further configured to reset a data transmission channel access contention window length corresponding to the access level p to the CWmin_p after the ACK of the data transmission feedback of the access level p is sent.

[0082] Preferably, the receiving module is further configured to receive a NACK or an ACK corresponding to the sidelink access level p data transmission feedback; the determining module is further configured to determine that the contention window length CWp is increased to a higher value in the access level p configuration value list until CWmax_p when a NACK corresponding to the sidelink access level p data transmission feedback is sent; and the determining module is further configured to determine that the data transmission channel access contention window length CWp corresponding to the access level p is reset to CWmin_p when an ACK corresponding to the sidelink access level p data transmission feedback is received.

[0083] The specific method for implementing the terminal sending module and the determining module and the receiving module is further described in the method embodiments of the present application, which will not be described herein.

[0084] The terminal device described in the present application can refer to a personal mobile terminal device.

[0085] Figure 4 FIG. 7 is a block diagram of a terminal device according to another embodiment of the present application. The terminal device 700 includes at least one processor 701, a memory 702, a user interface 703, and at least one network interface 704. The various components in the terminal device 700 are coupled together by a bus system. The bus system is configured to implement the connection communication between the components. The bus system includes a data bus, a power bus, a control bus, and a status signal bus.

[0086] The user interface 703 can include a display, a keyboard, or a pointing device, such as a mouse, a trackball, a touchpad, or a touch screen.

[0087] The memory 702 stores executable modules or data structures. The memory can store an operating system and an application program. The operating system includes various system programs, such as a framework layer, a core library layer, and a driver layer, for implementing various basic services and processing hardware-based tasks. The application program includes various application programs, such as a media player and a browser, for implementing various application services.

[0088] In the embodiments of the present application, the memory 702 contains a computer program for executing any one of the embodiments of the present application, which is run on or changed by the processor 701.

[0089] The memory 702 contains a computer readable storage medium, and the processor 701 reads the information in the memory 702 to complete the steps of the above method in combination with the hardware. Specifically, the computer readable storage medium stores a computer program, and the computer program is executed by the processor 701 to implement the steps of the method embodiments of any one of the above embodiments.

[0090] The processor 701 can be an integrated circuit chip with processing capability. In the implementation process, the steps of the method disclosed in the present application can be completed by the integrated logic circuit or the instruction in the form of software in the processor 701. The processor 701 can be a general processor, a digital signal processor, an application-specific integrated circuit, a readymade programmable gate array, or other programmable logic device, discrete gate or transistor logic device, discrete hardware component. The methods, steps and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution.

[0091] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. In a typical configuration, the device of the present application includes one or more processors (CPU), input / output user interfaces, network interfaces and memories.

[0092] In addition, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage and the like) containing computer-usable program code.

[0093] Therefore, the present application also proposes a computer readable medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the method according to any one of the embodiments of the present application. For example, the memory 603, 702 of the present application can include a non-permanent memory in the computer readable medium, such as a random access memory (RAM) and / or a non-volatile memory, etc., such as a read-only memory (ROM) or a flash memory (flash RAM). The computer readable medium includes permanent and non-permanent, removable and non-removable media, which can be implemented by any method or technology to store information. The information can be computer readable instructions, data structures, program modules or other data. Examples of the storage medium of the computer include, but are not limited to, a phase change memory (PRAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), other types of random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory or other memory technology, a compact disc read-only memory (CD-ROM), a digital versatile disc (DVD) or other optical storage, a magnetic cassette, a magnetic tape, a magnetic disk storage or other magnetic storage device, or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0094] It should also be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or apparatus that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0095] The above only describes the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method for sidelink communication channel access contention window length adjustment, the method comprising: determining a sidelink communication channel access contention window length; and adjusting the sidelink communication channel access contention window length based on a sidelink communication channel access contention window length adjustment factor. The method comprises the following steps: Obtaining configuration information, which is used to determine the contention window length configuration parameters under different access levels and / or different channel busy state levels; Determining the channel busy state and determining whether to update the contention window length in a first time period; If a HARQ ACK feedback is received within the first time period after the contention window length CWp is updated, resetting the contention window length CWp to CWmin_p; In response to at least one of the following conditions, the value of the contention window length CWp is reset to the minimum contention window length CWmin_p under the access level p: The value of the contention window length CWp continuously adopts the contention window length configuration value CW_Mp of the highest level channel busy state M of the access level p for K times, which is used to generate the backoff window length; The value of the contention window length CWp continuously adopts the contention window length configuration value CW_Mp of the highest level channel busy state M of the access level p for a second time period, which is used to generate the backoff window length.

2. The method of claim 1, wherein the configuration information comprises contention window length configuration values CW_mp under different access levels p and different channel busy state levels m.

3. The method of claim 1, wherein the configuration information comprises a first time period.

4. The method of claim 1, wherein the channel busy state level m is determined according to the channel busy state, the contention window length configuration value CW_mp under the access level p and the channel busy state level m is determined according to the configuration information, and the value CWp of the contention window length is determined in at least one of the following manners: the larger one of the contention window length configuration value CW_mp and the current value of the contention window length; one of the contention window length configuration value CW_mp and the current value of the contention window length is selected according to a set probability.

5. The method of claim 1, wherein the CBR level m is determined according to the channel busy state after the contention window length CWp is updated and experiences the first time period, and the configuration window length CW_mp under the access level p and the CBR level m is further determined according to the configuration.

6. The method of claim 1, wherein the channel contention window length corresponding to the access level p is reset to CWmin_p when an ACK corresponding to the data transmission feedback of the access level p is received. Or, the contention window length CWp is increased to a higher value in the configuration value list of the access level p until CWmax_p when a NACK corresponding to the data transmission feedback of the access level p is received.

7. The method of claim 1, wherein in response to indication information from a sending end, a receiving end updates the channel access contention window length value corresponding to the access level p of the receiving end according to the current value CWp of the contention window length of the access level p of the sending end included in the indication information, wherein the sending end is a transmission terminal enabling HARQ feedback. The method comprises a receiving module, a determining module, and a contention window length updating module. The receiving module is configured to receive the configuration information. ​ ​ ​ ​ ​ 8. A terminal device for implementing the method of any one of claims 1 to 7, characterized in that, ​ ​ The determining module is configured to determine the contention window length according to the HARQ feedback information and the channel busy state. 9.The terminal device of claim 8, wherein, The receiving module is further configured to receive the indication information of the sidelink. The determining module is further configured to update the value of the channel access contention window length corresponding to the access class p of the receiving end according to the current value CW p of the contention window length of the access class p of the transmitting end, wherein the transmitting end is a transmission terminal that enables HARQ feedback.

10. The terminal device of claim 8, wherein, The terminal device further comprises a sending module, The sending module is further configured to send ACK of the data transmission feedback corresponding to the access class p of the sidelink. The determining module is further configured to reset the channel access contention window length corresponding to the access class p to CWmin_p when ACK of the data transmission feedback corresponding to the access class p of the sidelink is sent. 11.The terminal device of claim 8, wherein, The receiving module is further configured to receive NACK or ACK of the data transmission feedback corresponding to the access class p of the sidelink. The determining module is further configured to reset the channel access contention window length CW p corresponding to the access class p to CWmin_p when ACK of the data transmission feedback corresponding to the access class p of the sidelink is received. The determining module is further configured to increase the contention window length CW p to a higher value in the list of configuration values of the access class p until CWmax_p when NACK of the data transmission feedback corresponding to the access class p of the sidelink is received.

12. A communication device, characterized by The terminal device comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is executed by the processor to implement the steps of the sidelink communication channel access contention window length adjustment method according to any one of claims 1 to 7. 13.A computer readable medium, wherein a computer program is stored on the computer readable medium, and the computer program is executed by a processor to implement the steps of the sidelink communication channel access contention window length adjustment method according to any one of claims 1 to 7.

Images