A sidelink unlicensed channel resource selection method and device

Abstract

The application discloses a sidelink unlicensed channel resource selection method, which comprises the following steps: in the sidelink communication of an NR system, unlicensed channels are listened to, and channel resources are selected according to the listening; when a backoff process overlaps with an NR SL reserved resource time, the backoff process is continued in response to a condition that a SCI message in the reserved resource is determined; and access is performed on the selected resource after the backoff ends. The application also comprises a device applying the method. The application solves the conflict problem when an LBT backoff process encounters an NR SL reserved resource.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication, and in particular to a sidelink unlicensed channel resource selection method and device. BACKGROUND

[0002] For SL unlicensed communication, a terminal selects a channel resource based on channel listening, i.e., resource selection in NR Mode2 mode. For the selected resource, LBT (Listen Before Talk) channel listening is required, and data transmission can be performed on the selected resource only after the channel is idle and the unlicensed LBT principle is met.

[0003] In fact, the resource selected by Mode2 may also appear on the same time slot as the NR SL reserved data or after the time slot. At this time, how to handle the LBT contention window length backoff on the time slot corresponding to the NR SL reserved resource needs to be designed to solve the problem, so as to ensure the channel access of the terminal on the selected resource. For example, as shown in Figure 1 illustrated, how to handle the LBT contention backoff between the NR reserved resources t1-t2, and how to combine the LBT on the selected resource to perform channel access on the selected resource if the terminal selects the resource on t1-t2 all need to be designed to solve the corresponding solution. SUMMARY

[0004] The present application proposes a sidelink unlicensed channel resource selection method and device to solve the conflict problem when the LBT backoff process encounters the NR SL reserved resource.

[0005] In a first aspect, the present application proposes a sidelink unlicensed channel resource selection method, which includes the following steps in the NR system sidelink communication:

[0006] Listen to the unlicensed channel and select the channel resource according to the listening;

[0007] When the backoff process overlaps with the NR SL reserved resource time, continue the backoff process in response to determining the condition of the SCI message in the reserved resource;

[0008] Access on the selected resource after the backoff ends.

[0009] Preferably, the condition of determining the SCI message in the reserved resource includes: receiving the SCI message in the reserved resource, detecting and determining the SCI message; or generating the SCI message and sending it in the reserved resource.

[0010] Preferably, the selected resource is the available channel resource on the first time slot after the end of the backoff window length.

[0011] Preferably, the method further comprises the following step: if the time difference between the selected resource starting time and the current time is less than the backoff window length, triggering resource reselection.

[0012] Preferably, the method further comprises the following step: if the interval between the current backoff window length end time and the selected resource starting time is greater than the first set time length, performing LBT for the first set time length before the selected resource starting time, determining channel idle and then accessing, otherwise, if it is determined that the channel is not idle, triggering resource reselection.

[0013] Preferably, the method further comprises the following step: if the interval between the current backoff window length end time and the selected resource starting time is less than the second set time length, performing access in the selected resource in the extended CP mode.

[0014] Preferably, the method further comprises the following step: if the interval between the current backoff window length end time and the selected resource starting time is greater than the second set time length and less than or equal to the first set time length, performing LBT for the second set time length before the selected resource starting time, determining channel idle and then accessing, otherwise, if it is determined that the channel is not idle, triggering resource reselection.

[0015] Preferably, the method further comprises the following step: the selected resource is time slot n, there is SL reserved resource transmission in time slot n-1, if the SCI information in time slot n-1 can be correctly detected or the channel is idle, and the LBT backoff ends before the selected resource starting time, data transmission is performed in the selected time slot n.

[0016] Preferably, in the method of any one of the embodiments of the application, when the backoff process overlaps with the NR SL reserved resource time, in response to the condition of determining the SCI message in the reserved resource, the way of continuing the backoff is that: the time length of continuing the backoff when the data transmission indicated by the SCI in the reserved resource ends is the remaining backoff time length at the beginning of the SCI minus the total time length occupied by the SCI in the reserved resource and the data transmission indicated by the SCI.

[0017] In a second aspect, the application further provides a terminal device for implementing the method of any one of the embodiments of the application. At least one module in the terminal device is configured to perform at least one of the following functions: channel listening; selecting, reselecting, and determining a selected resource; receiving and detecting an SCI message in a reserved resource; generating and sending an SCI message in a reserved resource; determining whether a channel is idle; determining the interval between the current backoff window length end time and the selected resource starting time; in response to the condition of determining the SCI message in the reserved resource, performing a backoff process; and initiating channel access.

[0018] Preferably, at least one module of the terminal device is further configured to perform at least one of the following functions:

[0019] if the time difference between the selected resource start time and the current time is less than the backoff window length, triggering resource reselection;

[0020] if the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the first set time length, performing LBT for the first set time length before the start time of the selected resource, judging channel idle for access, otherwise if the channel is judged to be not idle, triggering resource reselection.

[0021] if the interval between the end time of the current backoff window length and the start time of the selected resource is less than or equal to the second set time length, performing access in the selected resource in the extended CP mode.

[0022] if the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the second set time length and less than or equal to the first set time length, performing LBT for the second set time length before the start time of the selected resource, judging channel idle for access, otherwise if the channel is judged to be not idle, triggering resource reselection.

[0023] In a third aspect, the present application further provides a communication device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, and the computer program is executed by the processor to implement the steps of the method according to any one of the embodiments of the first aspect of the present application.

[0024] In a fourth aspect, the present application further provides a computer readable medium, and the computer readable medium 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 first aspect of the present application.

[0025] The above at least one technical scheme adopted by the embodiments of the present application can achieve the following beneficial effects:

[0026] The problem of how to back off the LBT when it encounters the NR SL reserved resource contention window length can be effectively solved, and when the channel access is supported based on LBT, the resource selected by the terminal and the NR SL reserved resource are simultaneously transmitted in the same slot. BRIEF DESCRIPTION OF DRAWINGS

[0027] 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:

[0028] Figure 1 for the application scenario of LBT in NR reserved resources;

[0029] Figure 2 for the flowchart of the embodiment of the method of the present application;

[0030] Figure 3 is an embodiment diagram of selecting resource;

[0031] Figure 4 is an embodiment diagram of expanding the first set time length LBT and the second set time length CP;

[0032] Figure 5 is an embodiment diagram of the backoff window length and the SCI time domain overlap;

[0033] Figure 6 is an embodiment diagram of the terminal side device;

[0034] Figure 7 is a block diagram of the terminal side device of another embodiment of the present application. DETAILED DESCRIPTION

[0035] 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 specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only a part 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.

[0036] The technical solutions provided by the embodiments of the present application will be described in detail below in combination with the drawings.

[0037] Figure 1 is an application scenario of LBT in NR reserved resources.

[0038] In the NR standard definition, LBT contains type1\type2A\type2B\type2C several channel listening modes, among which type1 requires the most stringent, where LBT type1 is generally used for initial channel access and channel access without COT sharing. The basic access process is that the terminal first performs channel listening for a Td duration, and if it is judged that the channel is idle, it enters a random backoff, and the backoff window length is N0xTd, where N0 is a random number selected with equal probability between 0 and CWp, during the backoff process, if a Td channel idle duration is passed, then the backoff count N is reduced by 1 (N initial value is N0), when N backoff to 0, the channel is idle, then access the channel for data transmission, otherwise the backoff process is suspended until the channel detection is idle. Type2A\type2B\type2C is used for channel access in COT sharing situation, type2A is used for the scenario that the start time of channel access and the end time of the previous data transmission within COT are not less than 25us, type2B is used for the scenario that the start time of channel access and the end time of the previous data transmission within COT are 16us, and type2C is used for the scenario that the start time of channel access and the end time of the previous data transmission within COT are not more than 16us.

[0039] Since LBT type1 is based on random selection of the contention window, the length of the backoff window cannot be specifically determined, which brings some uncertainty to the resource selection of Mode2, and the following situations may occur:

[0040] The selected channel resource start time has a certain time interval with the backoff end time of the LBT window length, and needs to be transmitted immediately after the backoff ends, or needs to perform a certain duration of channel listening before the selected channel resource to judge the channel state, and only when it is idle, the transmission is performed.

[0041] The selected channel resource start time is before the backoff end time of the LBT window length, and needs to be reselected.

[0042] In fact, the resource selected by Mode2 may also appear on the same time slot as the NR SL reserved data or after the time slot, at this time, how to handle the contention window length backoff of LBT on the time slot corresponding to the NR SL reserved resource needs to be designed to solve the problem to ensure that the terminal can access the channel on the selected resource. As shown in the figure, how to handle the contention backoff of LBT between NR reserved resources t1-t2, and if the terminal selects the resource on t1-t2, how to combine with LBT to access the channel on the selected resource needs to be designed to solve the corresponding solution. Figure 1

[0043] Figure 2 The embodiment flowchart of the method of the present application.

[0044] ​The application provides a sidelink unlicensed channel resource selection method, which comprises the following steps in the sidelink communication of an NR system:

[0045] Step 10: Listen to the unlicensed channel and select the channel resource according to the listening.

[0046] In this step, the NR SL terminal performs channel listening for a Td duration according to the unlicensed channel access criterion and LBT type 1, and if it is judged that the channel is idle, the terminal enters random backoff, and the backoff window length is N0x Td, wherein N0 is a random number selected with equal probability between the competition window 0 and CWp, and during the backoff process, if the channel is idle for a Td duration, the backoff counter N is reduced by 1 (N is initially N0).

[0047] Preferably, the selected resource is the available channel resource in the first time slot after the end of the backoff window length.

[0048] Meanwhile, the NR SL terminal listens to and detects the SCI (Sidelink Control Information) information on the channel to obtain the reserved resource information on the channel.

[0049] The terminal selects the channel resource according to the current backoff window length Nx Td (N is initially N0) and the channel reservation resource information listened to.

[0050] Preferably, the method further comprises at least one of steps 11-13.

[0051] Step 11: If the time difference between the start time of the selected resource and the current time is lower than the backoff window length, the resource reselection is triggered.

[0052] Step 12: If the interval between the end time of the current backoff window length and the start time of the selected resource is determined to be not idle by LBT, the resource reselection is triggered.

[0053] Step 13: If the interval between the end time of the current backoff window length and the start time of the selected resource is greater than a first set duration, LBT is performed for the first set duration before the start time of the selected resource, and if it is determined that the channel is not idle, the resource reselection is triggered. The method in this step is referred to as first set duration LBT.

[0054] Step 14: If the interval between the end time of the current backoff window length and the start time of the selected resource is greater than a second set duration and less than or equal to the first set duration, LBT is performed for the second set duration before the start time of the selected resource, and if it is determined that the channel is not idle, the resource reselection is triggered. The method in this step is referred to as second set duration LBT.

[0055] Step 20, in response to determining the condition of the SCI message in the reserved resource, continuing the backoff process when the backoff process overlaps with the NR SL reserved resource time.

[0056] Preferably, the determining the condition of the SCI message in the reserved resource comprises: receiving the SCI message in the reserved resource, detecting to determine the SCI message; or, generating the SCI message and sending in the reserved resource.

[0057] Preferably, in the method of any one of the embodiments of the application, when the backoff process overlaps with the NR SL reserved resource time, in response to determining the condition of the SCI message in the reserved resource, the way of continuing the backoff is: continuing the backoff for the time length of the end of the data transmission indicated by the SCI on the reserved resource, which is the remaining backoff time length at the beginning of the SCI minus the total time length occupied by the SCI and the data transmission indicated by the SCI on the reserved resource.

[0058] Step 30, accessing on the selected resource after the backoff ends.

[0059] In step 30, the NR SL terminal determines to access on the selected channel resource according to the SCI decoding state on the reserved resource and the LBT competition backoff timing.

[0060] Preferably, if the interval between the end time of the current backoff window length and the start time of the selected resource is greater than a first set time length, then performing LBT for the first set time length before the start time of the selected resource, and accessing after judging that the channel is idle.

[0061] Preferably, if the interval between the end time of the current backoff window length and the start time of the selected resource is less than or equal to a second set time length, then accessing on the selected resource in an extended CP manner.

[0062] Preferably, if the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the second set time length and less than or equal to the first set time length, then performing LBT for the second set time length before the start time of the selected resource, and accessing after judging that the channel is idle.

[0063] Preferably, the selected resource is slot n, there is SL reserved resource transmission in slot n-1, if the SCI information in slot n-1 can be correctly detected or the channel is idle, and the LBT backoff ends before the start time of the selected resource, then performing data transmission on the selected slot n.

[0064] In this step, it is assumed that the terminal selects the time slot n where the resource is located. If there is a reserved channel resource indicated by SCI in time slot n-1, according to the description in step 20, if the LBT backoff is completed before time slot n (i.e., N=0) according to the detection of SCI in time slot n-1, the terminal accesses the selected channel resource in time slot n.

[0065] It needs to be further explained that if the LBT backoff is completed before time slot n, if the terminal correctly detects SCI information or sends SCI in time slot n-1, the terminal accesses the selected channel resource in time slot n. If there is a gap between the end time of data transmission indicated by SCI information in time slot n-1 and the start time of time slot n, the terminal accesses the selected channel resource in time slot n in the manner of 25us LBT (first set time length LBT), 16us LBT (second set time length LBT) or extended CP as described in step 10.

[0066] If there is no reserved channel resource indicated by SCI in time slot n-1, according to the description in step 20, if the LBT backoff is completed before time slot n (i.e., N=0), the terminal accesses the selected channel resource in time slot n. It needs to be further explained that if there is a gap between the LBT backoff completion time and the start time of time slot n, the terminal accesses the selected channel resource in time slot n in the manner of 25us LBT (first set time length LBT), 16us LBT (second set time length LBT) or extended CP as described in step 10.

[0067] It needs to be further explained that if the LBT backoff is completed before time slot n, if time slot n-1 is configured with PSFCH resource, if the terminal sends PSFCH or correctly detects PSFCH in time slot n-1, the terminal accesses the selected channel resource in time slot n.

[0068] It also needs to be explained that the above steps are used for a network entity of a wireless communication system, including a terminal side device; can also be used for a service device for providing information processing for the network entity device; the above steps can also be used for any one of a device, system, subsystem, circuit, chip or software entity for providing information receiving, sending, identifying and processing for the terminal side device.

[0069] Figure 3 The figure is for selecting a resource. According to the embodiment of the application step 10, combined with the attached Figure 3 For example, the principles for specifically selecting a channel resource can include the following:

[0070] According to the current backoff window length N x Td, the selected channel resource needs to be after the current time N x Td length. The terminal preferentially selects the channel resource available in the first time slot after the current backoff window length N x Td.

[0071] If the time difference between the selected channel resource start time and the current time is lower than the current expected minimum backoff window length N x Td, resource reselection is triggered.

[0072] The time relationship between the channel resource selected by the terminal and the current contention backoff window length and the reserved channel resource indicated in the overheard SCI information is as follows: the terminal-selected resource is after the current N x Td and before the time when the reserved channel resource indicated in the SCI information starts, or the terminal-selected resource is after the current N x Td and after the time when the reserved channel resource indicated in the SCI information starts.

[0073] Figure 4 The first set time length LBT and the second set time length CP are expanded.

[0074] In the embodiments of the present application, the first set time length can be 25 us, and the second set time length can be 16 us. The 25 us LBT, 16 us LBT and extended CP (CPE, CP extension) are as shown in Figure 4

[0075] Suppose that the start time of the channel resource selected by the terminal is t0, the terminal performs backoff according to the LBT type 1 rule, and after a Td channel idle time, the backoff counter N is reduced by 1 (N0 is the initial value of N), and when N is reduced to 0, if there is a certain time interval (such as Figure 4 shown, the time interval is te-t0), the channel access is performed according to the specification requirements, which includes (but is not limited to) the following methods:

[0076] If the time interval is greater than 25 us, 25 us LBT is performed before the start time of the selected channel resource, and the channel is accessed after the channel is judged to be idle. Otherwise, if the time interval is greater than 16 us and lower than 25 us, 16 us LBT is performed before the start time of the selected channel resource, and the channel is accessed after the channel is judged to be idle. Otherwise, if the time interval is lower than 16 us, the extended CP is used to access the selected channel resource. If the LBT judges that the channel is not idle, resource reselection is triggered.

[0077] The 25 us LBT is to perform channel detection for 9 us before and after the 25 us detection time, and if both are idle, the channel is judged to be idle. The 16 us LBT is to perform channel detection for 9 us after the 16 us detection time, and the detection time is not less than 5 us, and if the channel detection is idle for more than 4 us, the channel is considered to be idle. The extended CP is to form a CP according to the traditional CP and send the data prepared in the time slot where the selected resource is located.

[0078] ​Figure 5 Figure 2 shows a diagram of a backoff window length and SCI time domain overlap.

[0079] The terminal selects a resource after the current N x Td, in the second time slot and after the reserved channel resource indicated by the SCI information, at which time the NR SL terminal performs backoff according to the LBT type 1 rule, and after a Td channel idle time, the backoff counter N is reduced by 1 (N initial value is N0). During the backoff process, channel sensing needs to be performed on the time slot where the SCI indicates the reserved resource, and the LBT backoff is performed according to the method described in step 20 of the embodiment. After the backoff is completed, i.e., N = 0, channel access is performed on the selected channel resource as in step 30.

[0080] During the backoff process, the NR SL terminal encounters channel sensing on the time slot where the SCI indicates the reserved resource, i.e., the backoff process overlaps with the time where the SCI indicates the reserved resource. The NR SL terminal performs SCI reception or transmission on the time slot, and if it is determined that there is no SCI transmission on the time slot, it continues LBT contention window backoff according to the LBT channel sensing rule. If it is determined that the SCI on the time slot is successfully detected or transmitted, the current LBT backoff window length is reduced by the total time length of the SCI and the data transmission indicated by the SCI in the time slot (i.e., the time length of continuing backoff after the data transmission indicated by the SCI on the reserved resource ends, which is the remaining backoff time length at the start of the SCI minus the total time length of the SCI and the data transmission indicated by the SCI on the reserved resource.

[0081] It should be noted that the terminal can receive and detect multiple SCIs in one time slot, and the data transmission time length indicated by each SCI can be different, resulting in different total data transmission time lengths of each SCI and the data transmission indicated by the SCI. The total data transmission time length of the SCI and the data transmission indicated by the SCI in the time slot that needs to be reduced from the backoff window length is the maximum value of the total data transmission time lengths of the multiple SCIs and the data transmission indicated by the SCIs.

[0082] For example, Figure 5 As shown in the figure, the terminal encounters the time slot n-1 corresponding to the reserved channel resource during the LBT backoff process, receives and detects the SCI on the time slot n-1, and if it is determined that there is no SCI transmission, the LBT backoff is normal. If it is determined that the SCI on the time slot is successfully detected, it is assumed that the total time length of the SCI and the data transmission indicated by the SCI in the time slot is 10 x Td, and the contention backoff window length N is reduced by 10. If the value of N is 10, then N = N-10 = 0.

[0083] It needs to be further explained that the reserved resource of the n-1 time slot can also be the resource reserved by the terminal itself. If the terminal transmits SCI information and data in the self-reserved resource in the time slot n-1, the LBT continues to back off, and the current LBT backoff window length is reduced by the total time length of the SCI and the data transmission indicated by the SCI in the time slot.

[0084] It needs to be further explained that the backoff method can also be used for the PSFCH channel. If the backoff process overlaps with the PSFCH resource in a time slot, if the terminal transmits or correctly detects the PSFCH in the time slot, the LBT backoff window length is reduced by the time length of the PSFCH resource in the time slot, that is, the LBT continues to back off for the time length of the PSFCH in the time slot. The time length of the remaining backoff at the beginning of the SCI is reduced by the time length of the PSFCH resource in the time slot.

[0085] It needs to be further explained that the present scheme is mainly aimed at the problem of how to back off LBT when the LBT backoff process overlaps with the transmission time of the SCI and the data transmission indicated by the SCI in the NR system. The resource occupied by the transmission of the SCI and the data transmission indicated by the SCI is referred to as reserved resource in the present case.

[0086] Figure 6 is an embodiment schematic diagram of a terminal side device.

[0087] The present application also proposes a terminal side device using the method of any one of the embodiments of the present application. At least one module in the terminal device is used for at least one of the following functions: channel listening; selecting, reselecting, and determining selected resources; receiving and detecting SCI messages in reserved resources; generating and transmitting SCI messages in reserved resources; determining whether a channel is idle; determining the interval between the end time of the current backoff window length and the start time of the selected resource; performing a backoff process in response to determining the condition of the SCI message in the reserved resource; and initiating an access request.

[0088] To implement the above technical solutions, the present application proposes a terminal side device 500, which comprises a terminal sending module 501, a terminal determining module 502, and a terminal receiving module 503 connected to each other.

[0089] The terminal receiving module is used for receiving and detecting SCI messages in reserved resources and detecting LBT signals.

[0090] The terminal sending module is used for generating and transmitting SCI messages in reserved resources and issuing an access request.

[0091] The terminal determination module is configured to select, reselect, and determine the selected resource (selected resource); determine the interval between the end time of the current backoff window length and the start time of the selected resource; determine the condition of the SCI message in the reserved resource; determine whether the channel is idle; and determine to initiate channel access.

[0092] Further, the terminal determination module is further configured to perform at least one of the following:

[0093] determine that the time difference between the start time of the selected resource and the current time is lower than the backoff window length, and trigger resource reselection;

[0094] determine that the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the first set time length, trigger a timer to perform LBT for the first set time length before the start time of the selected resource, determine whether the channel is idle to trigger channel access, and determine whether the channel is not idle to trigger resource reselection.

[0095] determine that the interval between the end time of the current backoff window length and the start time of the selected resource is less than or equal to the second set time length, and trigger access to the selected resource in an extended CP mode.

[0096] determine that the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the second set time length and less than or equal to the first set time length, trigger a timer to perform LBT for the second set time length before the start time of the selected resource, determine whether the channel is idle to trigger channel access, and determine whether the channel is not idle to trigger resource reselection.

[0097] Other specific functions and methods are described in the method embodiments of the present application, which will not be described here.

[0098] The terminal side device described in the present application can refer to a user equipment (UE), a personal mobile terminal, a smart terminal, a mobile phone, a computer with communication function, and can also be a system for providing services for the above devices, and can also be any kind of system, subsystem, module, circuit, chip or software running device for providing information receiving, sending, identification and processing for the above devices.

[0099] Figure 7 is a block diagram of a terminal side device according to another embodiment of the present application. The terminal side 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 side device 700 are coupled together through a bus system. The bus system is used to realize the connection communication between the components. The bus system includes a data bus, a power supply bus, a control bus, and a state signal bus.

[0100] The user interface 703 can include a display, a keyboard, or a pointing device, such as a mouse, trackball, touchpad, or touchscreen, etc.

[0101] The memory 702 stores executable modules or data structures. The memory can store an operating system and application programs. The operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., for implementing various basic services and processing hardware-based tasks. The application programs include various application programs, such as a media player, a browser, etc., for implementing various application services.

[0102] 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.

[0103] The memory 702 contains a computer readable storage medium, and the processor 701 reads information in the memory 702, in combination with hardware thereof, to complete the steps of the above method. Specifically, the computer readable storage medium has a computer program stored thereon, and the computer program is executed by the processor 701 to implement each step of the method embodiments of any one of the above embodiments.

[0104] The processor 701 can be an integrated circuit chip with a processing capability. In the implementation process, each step of the method of 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 ready programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. Each method, step and logic block diagram disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware coding processor for execution, or a combination of hardware and software modules in the coding processor for execution.

[0105] 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 one typical configuration, the device of the present application includes one or more processors (CPUs), input / output user interfaces, network interfaces, and memories.

[0106] In addition, the present application can take the form of a computer program product embodied in one or more computer usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) having computer usable program code embodied therein.

[0107] Therefore, the present application also provides 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 random access memory (RAM) and / or non-volatile memory, etc., such as read-only memory (ROM) or flash memory (flash RAM).

[0108] Based on the above-mentioned embodiments of the device of the present application, the present application also provides a mobile communication system, which comprises at least one terminal side device according to any one of the embodiments of the present application and / or at least one network side device according to any one of the embodiments of the present application.

[0109] 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 device 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 device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0110] It should also be noted that "first", "second" and the like in the present application are used to distinguish a plurality of objects with the same name, and have no order or size meaning if not specifically stated.

[0111] The above only describes the embodiments of the present application and is not intended to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method of sidelink unlicensed channel resource selection, in a NR system sidelink communication, characterized in that, Comprising the following steps: Listen to the unlicensed channel, and select the channel resource according to the listening; When the backoff process overlaps with the NR SL reserved resource time, in response to determining the condition of the SCI message in the reserved resource, continue the backoff process; Access on the selected resource after the end of the backoff, satisfying any one of the following: If the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the first set time length, then before the start time of the selected resource, perform LBT for the first set time length, judge the channel to be idle and then access, otherwise if the channel is determined to be not idle, trigger resource reselection; If the interval between the end time of the current backoff window length and the start time of the selected resource is greater than the second set time length and less than or equal to the first set time length, then before the start time of the selected resource, perform LBT for the second set time length, judge the channel to be idle and then access, otherwise if the channel is determined to be not idle, trigger resource reselection; If the interval between the end time of the current backoff window length and the start time of the selected resource is less than or equal to the second set time length, then use the extended CP to access on the selected resource.

2. The sidelink unlicensed channel resource selection method of claim 1, wherein, The condition of determining the SCI message in the reserved resource includes: Receive the SCI message in the reserved resource, and determine the SCI message through detection; or generate the SCI message and send it in the reserved resource.

3. The sidelink unlicensed channel resource selection method of claim 1, wherein the selected resource is the first available channel resource on the time slot after the end of the backoff window length. Further comprising the following steps:

4. The sidelink unlicensed channel resource selection method of claim 1, wherein, If the time difference between the start time of the selected resource and the current time is lower than the backoff window length, trigger resource reselection. Further comprising the following steps:

5. The sidelink unlicensed channel resource selection method of claim 1, wherein, The selected resource is time slot n, there is SL reserved resource transmission in time slot n-1, if n-1 time slot can correctly detect SCI information or the listening channel is idle, and the LBT backoff ends before the start time of the selected resource, then perform data transmission on the selected time slot n. Further comprising the following steps:

6. The sidelink unlicensed channel resource selection method of claim 1, wherein, When the backoff process overlaps with the NR SL reserved resource time, in response to determining the condition of the SCI message in the reserved resource, the continuation of the backoff is: the continuation of the backoff at the end of the data transmission indicated by the SCI on the reserved resource is the remaining backoff time at the beginning of the SCI minus the total time length occupied by the SCI and the data transmission indicated by the SCI.

7. The sidelink unlicensed channel resource selection method of claim 1, wherein if the LBT backoff is completed before time slot n, if time slot n-1 is configured with PSFCH resource, if the terminal transmits PSFCH on time slot n-1 or correctly detects PSFCH, then the terminal accesses on time slot n using the selected channel resource.

8. A terminal device for implementing the method of any one of claims 1-7, wherein ​ ​ The at least one module of the terminal device is configured to perform at least one of the following functions: channel sensing; selecting, reselecting, or determining selected resources; receiving or detecting SCI messages in the reserved resources; generating or sending SCI messages in the reserved resources; determining whether a channel is idle; determining an interval between an end time of a current backoff window length and a start time of the selected resources. In response to determining a condition of the SCI messages in the reserved resources, performing a backoff procedure; and initiating channel access.

9. The terminal device of claim 8, wherein, The at least one module of the terminal device is further configured to perform at least one of the following functions: If a time difference between the start time of the selected resources and a current time is less than a backoff window length, triggering resource reselection; If the interval between the end time of the current backoff window length and the start time of the selected resources is greater than a first set time length, triggering a timer to perform LBT for the first set time length before the start time of the selected resources; if the channel is determined to be idle, triggering channel access; and if the channel is determined to be not idle, triggering resource reselection; If the interval between the end time of the current backoff window length and the start time of the selected resources is less than or equal to a second set time length, triggering access to the selected resources in an extended CP mode; If the interval between the end time of the current backoff window length and the start time of the selected resources is greater than the second set time length and less than or equal to the first set time length, triggering the timer to perform LBT for the second set time length before the start time of the selected resources; if the channel is determined to be idle, triggering channel access; and if the channel is determined to be not idle, triggering resource reselection.

10. A communication device, characterized by The computer program is stored in the memory and executable on the processor, and when executed by the processor, implements the steps of the method according to any one of claims 1-7.

11. A computer readable medium, the computer readable medium storing a computer program, the computer program being executable on a processor to implement the steps of the method according to any one of claims 1-7. ​

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