Channel access method, device and terminal

Abstract

The invention provides a channel access method, a channel access device and a terminal. The method is applied to a terminal, and comprises: according to target information, determining the size of a contention window used by first target transmission for channel access, the first target transmission comprising one or more direct link (SL) transmissions; performing channel access for the first target transmission according to the size of the contention window; the target information comprises at least one of the following items: a reference priority of the first target transmission; other SL transmissions except the first target transmission use the latest contention window size for the first type of channel access; the terminal initiates the transmission type within the reference duration occupied by the last channel; and the terminal initiates the feedback type corresponding to the transmission of the direct link shared channel PSSCH in the reference duration occupied by the last channel. Thus, the terminal can adjust the contention window based on the above scheme, and execute channel access for straight-through link transmission according to the adjusted contention window.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a channel access method, device and terminal. Background Art

[0002] The existing NR-U contention window adjustment mechanism is based on the feedback information of unicast data transmission, and adjusts the value of the contention window before the first type (Type 1) channel access. However, in the direct link (Sidelink, SL), transmission types such as direct link feedback information, direct link synchronization information, and direct link positioning reference signal may also require Type 1 channel access before transmission. Therefore, for sidelink terminals working in unlicensed frequency bands, it is necessary to further design corresponding channel access methods for transmission types such as feedback information, synchronization information, and positioning reference signals. Summary of the invention

[0003] The present invention provides a channel access method, device and terminal, which solve the problem that the existing direct link transmission has no corresponding channel access mechanism.

[0004] In a first aspect, an embodiment of the present invention provides a channel access method, applied to a terminal, comprising:

[0005] Determine, according to the target information, a contention window size used by a first target transmission for channel access, wherein the first target transmission includes one or more through link SL transmissions;

[0006] performing channel access for the first target transmission based on the contention window size;

[0007] The target information includes at least one of the following:

[0008] first information, wherein the first information is a reference priority of the first target transmission;

[0009] second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access;

[0010] third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal;

[0011] The fourth information is a feedback type corresponding to a Physical Sidelink Shared Channel (PSSCH) transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

[0012] Optionally, the type of SL transmission includes: at least one of: physical sidelink control channel (PSCCH) transmission, physical sidelink shared channel (PSSCH) transmission, physical sidelink feedback channel (PSFCH) transmission, sidelink synchronization signal block (Sidelink Synchronization Signal Block, S-SSB), and sidelink positioning reference signal (Sidelink Positioning Reference Signal, SL-PRS).

[0013] Optionally, determining, according to the target information, a contention window size used by the first target transmission for channel access includes:

[0014] According to the target information, determine the contention window size for the target channel; the target channel is one or more channels occupied by the first target transmission; wherein one channel corresponds to one contention window size, or multiple channels correspond to one contention window size, or each of the multiple channels corresponds to one contention window size.

[0015] Optionally, when the target information includes the first information, determining the contention window size for the target channel according to the target information includes:

[0016] Determine, according to the first information, an optional value of a contention window corresponding to the first target transmission;

[0017] The contention window size is determined for the target channel according to the contention window optional value.

[0018] Optionally, when the target information includes the second information, determining the contention window size for the target channel according to the target information includes one of the following:

[0019] Determine the latest contention window size used by the first SL transmission for first type channel access as the contention window size used by the target channel;

[0020] The first SL transmission satisfies at least one of the following:

[0021] Occupying the same channel as the first target transmission;

[0022] is of the same type as the first target transmission;

[0023] having the same reference priority as the first target transmission;

[0024] The transmission corresponding to the maximum contention window in the second target transmission;

[0025] The transmission corresponding to the minimum contention window in the second target transmission;

[0026] any transmission of the second target transmission;

[0027] The second target transmission satisfies at least one of the following:

[0028] Occupying the same channel as the first target transmission;

[0029] is of the same type as the first target transmission;

[0030] The same as the reference priority of the first target transmission.

[0031] Optionally, in the case that the first target transmission occupies multiple channels, the multiple channels uniformly maintain a contention window, or each of the multiple channels independently maintains a contention window.

[0032] Optionally, when the first target transmission includes multiple SL transmissions, the reference priority corresponding to the first target transmission is the highest priority among the multiple priorities, or the lowest priority among the multiple priorities.

[0033] Optionally, when the target information includes the third information and / or the fourth information, determining the contention window size for the target channel according to the target information includes one of the following:

[0034] When the first condition is met, determining the minimum value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0035] When the second condition is met, determining the next larger allowed value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0036] The first condition includes: the transmission type is unicast and the feedback type is positive acknowledgment, or the transmission type is multicast and at least one positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is greater than or equal to a first threshold;

[0037] The second condition includes: the transmission type is unicast and the feedback type is a negative acknowledgment, or the transmission type is multicast and no positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is less than the first threshold.

[0038] Optionally, performing channel access for the first target transmission according to the contention window size includes:

[0039] If a third condition is met, performing multi-channel access for the first target transmission according to the contention window size;

[0040] The third condition includes at least one of the following:

[0041] The first target transmission is a PSFCH transmission performed by the terminal on multiple channels;

[0042] The first target transmission is an S-SSB transmission performed by the terminal on an S-SSB opportunity on multiple channels;

[0043] The first target transmission is one or more direct link positioning reference signal SL-PRS transmissions performed by the terminal on multiple channels;

[0044] The first target transmission is one or more PSCCH transmissions performed by the terminal on multiple channels;

[0045] The first target transmission is one or more PSSCH transmissions performed by the terminal on multiple channels;

[0046] The transmission of the terminal on the multiple channels is expected to be performed at the same time;

[0047] The reference priorities of the first target transmission transmitted on multiple channels are the same.

[0048] Optionally, the reference priority of the first target transmission includes: at least one of: channel access priority, short distance communication data packet priority (ProSe Per-Packet Priority, PPPP), synchronization priority and positioning priority.

[0049] Optionally, after performing multi-channel access for the first target transmission, the method further includes:

[0050] When it is determined that the terminal has successfully accessed multiple channels, performing the first target transmission on the multiple channels; or

[0051] When it is determined that the terminal has successfully accessed some of the multiple channels, the first target transmission is performed on the channels where the access has been successful, and the first target transmission is not performed on the channels where the access has failed.

[0052] In a second aspect, an embodiment of the present invention provides a terminal, comprising: a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the channel access method described in the first aspect when executing the computer program.

[0053] In a third aspect, an embodiment of the present invention provides a channel access device, applied to a terminal, including:

[0054] A first determination module, configured to determine, according to target information, a contention window size used by a first target transmission for channel access, wherein the first target transmission includes one or more straight-through link SL transmissions;

[0055] a first processing module, configured to perform channel access for the first target transmission according to the contention window size;

[0056] The target information includes at least one of the following:

[0057] first information, wherein the first information is a reference priority of the first target transmission;

[0058] second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access;

[0059] third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal;

[0060] Fourth information, where the fourth information is a feedback type corresponding to a direct link shared channel PSSCH transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

[0061] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the channel access method described in the first aspect.

[0062] The beneficial effects of the above technical solution of the present invention are: the terminal determines the contention window size used for channel access by the first target transmission according to the target information, and the first target transmission includes one or more direct link SL transmissions; according to the contention window size, channel access is performed for the first target transmission; wherein the target information includes at least one of the following: the reference priority of the first target transmission; the latest contention window size used for the first type of channel access by other SL transmissions other than the first target transmission; the transmission type within the reference duration of the most recent channel occupancy initiated by the terminal; the feedback type corresponding to the direct link shared channel PSSCH transmission within the reference duration of the most recent channel occupancy initiated by the terminal. In this way, the terminal can adjust the contention window based on the above scheme, and perform channel access for the direct link transmission according to the adjusted contention window. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 One of the flow charts showing the channel access method according to an embodiment of the present invention;

[0064] Figure 2 A transmission schematic diagram showing an embodiment of the present invention;

[0065] Figure 3 A structural block diagram showing a channel access device according to an embodiment of the present invention;

[0066] Figure 4 A schematic diagram showing the hardware structure of a terminal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail in conjunction with the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided only to help fully understand the embodiments of the present invention. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, for clarity and brevity, the description of known functions and structures is omitted.

[0068] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0069] In various embodiments of the present invention, it should be understood that the size of the serial numbers of the following processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0070] Additionally, the terms "system" and "network" are often used interchangeably herein.

[0071] In the embodiments provided in the present application, it should be understood that "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0072] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0073] The following first introduces the contents involved in the solution provided in the embodiment of the present application.

[0074] 1. Channel access process of NR-U (New Radio Unlicensed Band)

[0075] The channel access process on the shared spectrum is a sensing-based process that evaluates the availability of the channel for performing transmission. The basic unit of sensing is a T sl = 9us sensing slot. If an eNB / gNB or a UE senses in a sensing slot and determines that at least 4us of the monitored energy in the sensing slot is below the energy detection threshold X Thresh , the sensing slot is considered idle, otherwise the sensing slot duration (sensing slot duration) T sl busy.

[0076] The channel access process of the NR-U system is divided into Type 1 and Type 2, of which Type 2 is further divided into Type 2A, 2B and 2C channel access methods. The following introduces the above two channel access processes using the downlink channel access method as an example.

[0077] 1) Type 1:

[0078] The eNB / gNB can sense that the channel is idle within the sensing slot duration of the backoff time Td and send a transmission after the value of the counter N in step 4 is 0. The counter N is adjusted by sensing the additional sensing slot duration according to the following steps:

[0079] Step 1: Set N = Ninit, where Ninit is a random number uniformly distributed between 0 and CWp, and jump to step 4;

[0080] Step 2: If N>0 and the eNB / gNB chooses to decrease the counter, set N=N-1;

[0081] Step 3: Detect the channel within an additional sensing slot duration. If the additional sensing slot duration is idle, jump to step 4; otherwise, jump to step 5.

[0082] Step 4: If N=0, stop; otherwise, jump to step 2;

[0083] Step 5: Detect the channel until a busy sensing slot is detected within an additional backoff time Td, or all sensing slots within the additional backoff time Td are idle;

[0084] Step 6: If all sensing slot channels within Td are idle, jump to step 4; otherwise, jump to step 5.

[0085] Among them, Td is composed of Tf = 16us and the following m p Tf is composed of consecutive sensing slot duration Tsl, and Tf includes an idle sensing slot duration Tsl located at the beginning of Tf.

[0086] CW min,p ≤CW p ≤CW max,p It is a competition window, CW p Adjustments are made according to the competition window adjustment mechanism.

[0087] CW min,p and CW max,p Before step 1, select m p ,CW min,p and CW max,pBased on the channel access priority p associated with the eNB / gNB transmission, the eNB / gNB shall not exceed the channel occupancy time T mcotp transmitted on the channel.

[0088]

[0089] Table 1. Channel Access Priority (CAPC)

[0090] 2) Type 2:

[0091] Type 2A channel access applies only to the following transmissions performed by the eNB / gNB:

[0092] Transmissions initiated by the eNB, including discovery bursts, excluding PDSCH, and with a maximum transmission duration of 1 ms

[0093] Transmissions initiated by gNBs with only discovery bursts or discovery bursts multiplexed with non-unicast information, with a maximum transmission duration of 1ms and a discovery burst duty cycle of at most 1 / 20

[0094] The transmission of the eNB / gNB is 25us after the transmission of the UE on the shared channel

[0095] Type 2B or 2C channel access applies to gNB transmissions 16us or at most 16us after the UE’s transmission on the shared channel, respectively.

[0096] (1) Type 2A:

[0097] The eNB / gNB can sense that the channel is idle for at least one sensing interval T short_dl = DL transmission is sent immediately after 25us. T short_dl It consists of Tf = 16us and one sensing slot immediately following it, and Tf includes a sensing slot at the beginning of Tf. short_dl If both sensing slots of T are idle, the channel is considered to be short_dl is free.

[0098] (2) Type 2B

[0099] The base station (gNB) can sense that the channel is idle for one T f= 16us before the DL transmission is sent immediately. Tf includes a sensing slot at the end of Tf for 9us. If the channel is sensed to be idle for at least 5us and at least 4us is in the sensing slot, the channel is considered idle for the duration Tf.

[0100] (3) Type 2C

[0101] The gNB does not perform channel sensing before downlink transmission, and the maximum downlink transmission time is 584us.

[0102] 2. NR-U contention window adjustment process

[0103] If the eNB / gNB sends transmissions including PDSCH that are associated with channel access priority level p, the eNB / gNB maintains the contention window value CWp and adjusts the CWp of these transmissions as follows before step 1 of Type 1 channel access.

[0104] Step 1. For each priority class p∈{1,2,3,4}, set CW p =CW min,p

[0105] Step 2: If there is HARQ-ACK feedback after the last update of CWp, jump to step 3. Otherwise, if the transmission after the Type 1 channel access does not include retransmission, or the transmission is within duration Tw starting from the end of the reference duration corresponding to the earliest DL channel occupation after the last update of CWp, go to step 5; otherwise, please execute step 4.

[0106] Step 3. During the reference duration of the latest DL channel occupancy for which HARQ-ACK feedback is available, the HARQ-ACK feedback corresponding to the PDSCH(s) is as follows:

[0107] If at least one HARQ-ACK feedback is "ACK" for the PDSCH(s) with TB-based feedback, or at least 10% of the HARQ-ACK feedback is "ACK" for the PDSCH CBGs at least partially transmitted on the channel with code block group-based feedback, go to step 1; otherwise, execute step 4.

[0108] Step 4. For each priority class p∈{1,2,3,4}, increase CWp to the next higher allowed value;

[0109] Step 5. For each priority class p∈{1,2,3,4}, keep CWp and jump to step 2.

[0110] The reference duration corresponds to a channel occupation initiated by the gNB, including the transmission of PDSCH(s), and is defined as the duration from the start of the channel occupation to the end of the first slot in which at least one unicast PDSCH is transmitted on all resources allocated for the PDSCH, or to the end of the first transmission brust of the gNB containing unicast PDSCH(s) transmitted on all resources allocated for the PDSCH, whichever occurs first. If the channel occupation includes one unicast PDSCH but does not include all resource allocated PDSCHs transmitted on any unicast PDSCH, then the time of the first transmission brust of the gNB containing unicast PDSCH(s) within the unicast PDSCH is the reference time adjustment for the CWS.

[0111] T w =max(T A ,T B +1ms), where T B It is the duration of the transmission burst starting from the reference duration, in ms. If it cannot be guaranteed in the long term that there is no other technology sharing the channel (for example, by regulatory levels), TA = 5ms. Otherwise, TA = 10ms.

[0112] If the gNB sends a transmission using a Type 1 channel access procedure associated with a channel access priority p on a channel and the transmission is not associated with explicit HARQ-ACK feedback from the corresponding UE(s), the gNB adjusts the CWp before step 1 and uses the latest CWp for any DL transmission on the channel using the Type 1 channel access procedure associated with the channel access priority p. If the corresponding channel access priority p is not used for any DL transmission on the channel, the CWp used p =CW min,p .

[0113] If CW p =CW max,p , C.W. p The next higher available value is CW max,p If N is generated init , CW was used K times in a row p =CW max,p , then only for priority class p, CW p Reset to CW min,p, K is selected by the eNB / gNB from the set {1,2,…,8} for each priority class p∈{1,2,3,4}.

[0114] Based on the above, the existing NR-U contention window adjustment mechanism adjusts the contention window value before Type 1 channel access based on the feedback information of unicast data transmission. For direct link UEs working in unlicensed frequency bands, it is necessary to further consider the contention window adjustment mechanism for transmission types such as feedback information, synchronization information, and positioning reference signals. In addition, for the situation of occupying multiple channels for transmission at the same time, it is also necessary to further consider the contention window adjustment mechanism for multi-channel access to ensure that direct link services can be transmitted in a timely and reliable manner.

[0115] Specifically, the embodiments of the present invention provide a channel access method, device and terminal, which solve the problem that the existing direct link transmission has no corresponding channel access mechanism.

[0116] First embodiment

[0117] like Figure 1 As shown, an embodiment of the present invention provides a channel access method, which specifically includes the following steps:

[0118] Step 101: determining a contention window size used by a first target transmission for channel access according to target information, wherein the first target transmission includes one or more direct link SL transmissions;

[0119] The target information includes at least one of the following:

[0120] first information, wherein the first information is a reference priority of the first target transmission;

[0121] second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access;

[0122] third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal;

[0123] Fourth information, where the fourth information is a feedback type corresponding to a direct link shared channel PSSCH transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

[0124] Optionally, the types of SL transmission include: at least one of: physical direct link control channel PSCCH transmission, physical direct link shared channel PSSCH transmission, physical direct link feedback channel PSFCH transmission, direct link synchronization signal block S-SSB, and direct link positioning reference signal SL-PRS.

[0125] It should be noted that when the first target transmission includes multiple SL transmissions, the multiple SL transmissions may be multiple transmissions of different types or multiple transmissions of the same type. For example, the multiple SL transmissions may include: one or more types of PSCCH transmission, PSSCH transmission, PSFCH transmission, S-SSB, and SL-PRS.

[0126] Optionally, the reference priority of the first target transmission includes at least one of: channel access priority, short distance communication data packet priority PPPP, synchronization priority and positioning priority.

[0127] When the first target transmission includes multiple SL transmissions, the reference priority corresponding to the first target transmission is the highest priority among the multiple priorities, or the lowest priority among the multiple priorities.

[0128] It should be noted that when the first target transmission includes multiple SL transmissions, if each channel independently determines the contention window size, then there is no need to select a priority, and the priority corresponding to the transmission on each channel can be used as the reference priority; if multiple channels uniformly determine a contention window size, in this case, it is necessary to determine one SL transmission from multiple SL transmissions to determine the reference priority, which may include the following methods:

[0129] a) If the multiple priorities corresponding to the multiple SL transmissions in the first target transmission are of the same type of priorities (such as all corresponding to channel access priorities), the values ​​of the same priority can be compared and the highest or lowest priority can be selected as the reference priority.

[0130] b) If the multiple priorities corresponding to the multiple SL transmissions in the first target transmission are different types of priorities (such as some corresponding to channel access priorities, some corresponding to positioning priorities, and some corresponding to PPPP), it is necessary to first determine which type of priority to use as a reference, and then compare the same priority values, and finally select the highest or lowest priority as the reference priority.

[0131] Optionally, other SL transmissions except the first target transmission refer to SL transmissions occupying the same channel as the first target transmission.

[0132] Optionally, the feedback type corresponding to the PSSCH transmission includes: positive acknowledgement and / or negative acknowledgement.

[0133] Optionally, the transmission type within the reference duration of the most recent channel occupancy initiated by the terminal includes: unicast, multicast and broadcast.

[0134] Step 102: Perform channel access for the first target transmission according to the contention window size;

[0135] In the above embodiment, a corresponding channel access method is designed for direct link transmission, so that the terminal can adjust the contention window size based on the embodiment and perform channel access for direct link transmission according to the adjusted contention window size.

[0136] In one embodiment, in the above step 101, determining the contention window size used by the first target transmission for channel access according to the target information includes:

[0137] According to the target information, determine the contention window size for the target channel; the target channel is one or more channels occupied by the first target transmission; wherein one channel corresponds to one contention window size, or multiple channels correspond to one contention window size, or each of the multiple channels corresponds to one contention window size.

[0138] In this embodiment, the contention window size can be determined for a certain channel (such as a channel corresponding to single-channel access, or any channel corresponding to multi-channel access) for the first target transmission, so that one channel corresponds to one contention window size; or a contention window size can be uniformly determined for multiple channels for the first target transmission, so that multiple channels correspond to one contention window size.

[0139] In one embodiment, when the first target transmission occupies multiple channels, the multiple channels uniformly maintain a contention window, or each of the multiple channels independently maintains a contention window.

[0140] When the target channel includes one channel, the channel independently maintains a contention window size.

[0141] It should be pointed out that multiple channels uniformly maintain a contention window, or each of the multiple channels independently maintains a contention window, which refers to the contention window maintenance status of the multiple channels accessed by the terminal for the first target transmission before multi-channel access is performed for the first target transmission. That is, before multi-channel access is performed for the first target transmission, if the terminal uniformly maintains a contention window for multiple channels, then when determining the contention window size for the first target transmission, a contention window size can be uniformly determined for the multiple channels, or a contention window size can be determined for each of the multiple channels; similarly, before multi-channel access is performed for the first target transmission, if the terminal independently maintains a contention window for each of the multiple channels, then when determining the contention window size for the first target transmission, a contention window size can be uniformly determined for the multiple channels, or a contention window size can continue to be determined for each of the multiple channels.

[0142] In view of the difference in target information, determining the contention window size for a target channel according to the target information is introduced below.

[0143] Case 1: Target information includes first information

[0144] In one embodiment, when the target information includes the first information, determining the contention window size for the target channel according to the target information includes:

[0145] Determine, according to the first information, an optional value of a contention window corresponding to the first target transmission;

[0146] The contention window size is determined for the target channel according to the contention window optional value.

[0147] Optionally, determining the contention window size for the target channel according to the contention window optional value includes one of the following:

[0148] Determine a contention window size of a target channel as a random value among the optional values ​​of the contention window;

[0149] Determine the contention window size of the target channel as the minimum value among the optional values ​​of the contention window;

[0150] The contention window size of the target channel is determined to be the maximum value among the optional values ​​of the contention window.

[0151] The following is an introduction through specific application scenario examples.

[0152] Exemplary application scenario 1: The terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and for each channel c in the multiple channels i ∈C, the contention window size is independently determined according to the first information, and C refers to a set of multiple channels occupied by the first target transmission.

[0153] It should be noted that in the first application scenario, the priority corresponding to the transmission on each channel is used as the reference priority.

[0154] Example 1: The reference priority corresponding to the first target transmission is the only channel access priority, and the channel access priority corresponding to the first target transmission is p=1. According to the mapping relationship between the channel access priority and the contention window size, the optional value of the contention window is {3, 7}. The terminal can determine channel c or channel c in the following way: i ∈C uses the contention window size:

[0155] Mode 1: Randomly select one from the optional values ​​of the contention window corresponding to the channel access priority of the first target transmission, that is, randomly select one from {3, 7} as channel c or channel c i ∈C, the contention window size used.

[0156] Mode 2: Select the minimum value from the optional values ​​of the contention window corresponding to the channel access priority of the first target transmission, that is, select CWp=3 from {3, 7} as channel c or channel c i ∈C is the contention window size used.

[0157] Mode 3: Select the maximum value from the optional values ​​of the contention window corresponding to the channel access priority of the first target transmission, that is, select CWp=7 from {3, 7} as channel c or channel c i ∈C is the contention window size used.

[0158] Example 2: The reference priority corresponding to the first target transmission includes a unique channel access priority and a unique target priority, and the target priority is at least one of the short-range communication data packet priority PPPP, the synchronization priority, and the positioning priority. The optional value of the contention window is determined according to the channel access priority and the target priority. Optionally, if the first target transmission is PSCCH / PSSCH transmission, the corresponding target priority is PPPP; if the first target transmission is PSFCH transmission, the target priority is the short-range communication data packet priority PPPP of the PSCCH / PSSCH transmission fed back by it; if the first target transmission is S-SSB transmission, the corresponding target priority is the synchronization priority; if the first target transmission is SL-PRS transmission, the corresponding target priority is the priority of the positioning service (i.e., the positioning priority).

[0159] Exemplarily, the mapping relationship between the channel access priority, the target priority and the optional value of the contention window is shown in the following Table 2:

[0160]

[0161] Table 2

[0162] Based on Table 2 above, assuming that the channel access priority of the first target transmission is p=1 and the target priority is 3, the optional value of the contention window is {3}, and the terminal can determine the contention window size for the target channel in the following manner:

[0163] Method 1: Determine channel c or channel c i The contention window size used by ∈C is a random value among the optional values ​​of the contention window, that is, the contention window CWp=3;

[0164] Method 2: Determine channel c or channel c iThe contention window size used by ∈C is the minimum value among the optional values ​​of the contention window, that is, CWp=3;

[0165] Method 3: Determine channel c or channel c i The contention window size used by ∈C is the maximum value among the optional values ​​of the contention window, that is, CWp=3.

[0166] Exemplary application scenario 2: the terminal performs multi-channel access for the first target transmission, and before performing multi-channel access for the first target transmission, the terminal independently maintains a contention window for each of the multiple channels, then according to the first information, uniformly determines a contention window size for the multiple channels, including the following examples:

[0167] Example 1: Assuming that the first target transmission is expected to occupy 3 channels (C=3), and the channel access priority p=1, the first target transmission corresponds only to a unique channel access priority, and the reference priority is p=1, and the corresponding optional value of CWp is {3, 7}, then the terminal can determine that the contention window values ​​of multiple channels are all minimum values, that is, CWp=3

[0168] Example 2: Assuming that the first target transmission is expected to occupy 3 channels (C=3), and the channel access priorities of the transmissions performed on the three channels are different, namely p=1, 2, and 3. Then, the reference priority of the first target transmission can be taken as the lowest priority among the multiple priorities as the reference priority, that is, the reference priority is p=1, and the corresponding contention window optional value is {3, 7}. Then, the terminal can determine that the contention window values ​​of multiple channels are all minimum values, that is, CWp=3.

[0169] Example 3: Assuming that the first target transmission is expected to occupy 3 channels (C=3), the channel access priority p=1, and the target priority is 3, the first target transmission only corresponds to a unique channel access priority and target priority, see Table 2, and the corresponding contention window optional value is {3}. The terminal can determine that the contention window values ​​of multiple channels are all minimum values, that is, CWp=3.

[0170] Example 4: Assuming that the first target transmission is expected to occupy 3 channels (C=3), and the target priorities executed on the three channels are different, namely 1, 2, and 3, then the highest priority value among the multiple priorities corresponding to the first target transmission can be taken, that is, the reference priority is p=3, and the corresponding contention window optional value is {3, 7}, then the terminal can determine that the contention window values ​​of multiple channels are all minimum values, that is, CWp=3

[0171] It should be noted that, for the first target transmission performed on multiple channels, when the values ​​of the channel access priority and the target priority are different, the use of this embodiment may lead to increased complexity.

[0172] Optionally, when the first target transmission includes multiple SL transmissions, one SL transmission corresponds to a group of contention window optional values, and the contention window optional values ​​corresponding to each SL transmission may be the same or may be different.

[0173] It should be noted that when the first target transmission includes multiple SL transmissions, if multiple channels uniformly determine a contention window size, in this case, it is necessary to determine one SL transmission from the multiple SL transmissions for determining the reference priority, which may specifically include the following methods:

[0174] a) If the multiple priorities corresponding to the multiple SL transmissions in the first target transmission are of the same type of priorities (such as corresponding to different channel access priorities), the values ​​of the same priority can be compared and the highest or lowest priority can be selected as the reference priority.

[0175] b) If the multiple priorities corresponding to the multiple SL transmissions in the first target transmission are different types of priorities (such as some corresponding to channel access priorities, some corresponding to positioning priorities, and some corresponding to PPPP), it is necessary to first determine which type of priority to use as a reference, and then compare the same priority values, and finally select the highest or lowest priority as the reference priority.

[0176] Exemplary application scenario three, the terminal performs multi-channel access for the first target transmission, and before performing multi-channel access for the first target transmission, the terminal uniformly maintains a contention window for multiple channels, then according to the first information, uniformly determines a contention window size for the multiple channels, including the following examples:

[0177] Example 1: A random value among optional contention window values ​​corresponding to a reference priority of a first target transmission is determined as a contention window size corresponding to a plurality of channels.

[0178] Example 2: Determine the maximum value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size corresponding to the multiple channels.

[0179] Example 3: Determine the minimum value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size corresponding to the multiple channels.

[0180] In the above example, the reference priority of the first target transmission includes at least one of: channel access priority, short distance communication data packet priority PPPP, synchronization priority and positioning priority.

[0181] It should be pointed out that in the scheme of uniformly determining a contention window size for multiple channels (such as application scenarios 2 and 3 mentioned above), when the first target transmission includes multiple SL transmissions, if the multiple priorities corresponding to the multiple SL transmissions in the first target transmission are the same type of priorities (such as all corresponding to channel access priorities), then the values ​​of the same priority level can be compared, and the highest or lowest priority can be selected as the reference priority; if the multiple priorities corresponding to the multiple SL transmissions in the first target transmission are different types of priorities (such as some corresponding to channel access priorities, some corresponding to positioning priorities, and some corresponding to PPPP), it is necessary to first determine which type of priority is to be used as a reference, and then compare the values ​​of the same priority level, and finally select the highest or lowest priority as the reference priority.

[0182] Case 2: Target information includes second information

[0183] In one embodiment, when the target information includes the second information, determining the contention window size for the target channel according to the target information includes one of the following:

[0184] Determine the latest contention window size used by the first SL transmission for first type channel access as the contention window size used by the target channel;

[0185] The first SL transmission satisfies at least one of the following:

[0186] Occupying the same channel as the first target transmission;

[0187] is of the same type as the first target transmission;

[0188] having the same reference priority as the first target transmission;

[0189] The transmission corresponding to the maximum contention window in the second target transmission;

[0190] The transmission corresponding to the minimum contention window in the second target transmission;

[0191] any transmission of the second target transmission;

[0192] The second target transmission satisfies at least one of the following:

[0193] Occupying the same channel as the first target transmission;

[0194] is of the same type as the first target transmission;

[0195] The same as the reference priority of the first target transmission.

[0196] It should be noted that the first SL transmission belongs to other SL transmissions except the first target transmission.

[0197] Among them, under the condition that the first SL transmission and the first target transmission occupy the same channel, the first SL transmission can be of the same type as the first target transmission or of a different type, and the first SL transmission can have the same reference priority as the first target transmission or a different reference priority.

[0198] It should also be noted that the second target transmission includes multiple SL transmissions.

[0199] It should also be pointed out that the second target transmission and the first target transmission occupying the same channel includes: the channel occupied by the second target transmission and the first target transmission are completely or partially the same.

[0200] The following is an introduction through specific application scenario examples.

[0201] Exemplary application scenario 1: The terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and for each channel c in the multiple channels i ∈C, independently determine the contention window size, where C refers to the set of multiple channels occupied by the first target transmission.

[0202] Example 1: According to the second information, it is channel c or channel c i ∈C determines the contention window size to be used, which can include the following methods:

[0203] Mode 1: The latest contention window size used for channel access by other SL transmissions occupying the same channel as the first target transmission is determined as channel c or channel c i ∈C corresponds to the contention window size used;

[0204] For example, determine channel c or channel c i The contention window size used by ∈C is the latest contention window used by the first SL transmission for Type 1 channel access. The first SL transmission and the first target transmission occupy the same channel. In this way, the transmission type of the first SL transmission is not distinguished, and the latest contention window in other SL transmissions is directly used as the contention window size used by the first target transmission.

[0205] Optionally, if there is no SL transmission before the first target transmission, the minimum value of the contention window optional values ​​corresponding to the channel access priority of the first target transmission is used as the contention window size used for the first target transmission, that is, CW p =CW min,p .

[0206] Mode 2: The latest contention window size used for channel access by other SL transmissions of the same type as the first target transmission is determined as channel c or channel c i ∈C corresponds to the contention window size used;

[0207] For example, the terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and performs multi-channel access on each channel c in the plurality of channels. i ∈C, independently determine the contention window size, and if the transmission type of the first target transmission is PSFCH or S-SSB transmission, determine channel c or channel c i The contention window size used by ∈C is: the latest CWp used by other PSFCH or S-SSB transmissions of the same type as the first target transmission for Type 1 channel access. In this way, only the CWp used by PSFCH or S-SSB transmissions for Type 1 channel access is referenced, and the latest CWp used by other PSFCH or S-SSB transmissions for Type 1 channel access is used as channel c or channel c i ∈C is the contention window size used.

[0208] Optionally, if there is no PSFCH or S-SSB transmission before the current transmission, the minimum value of the contention window size corresponding to the channel access priority of the current transmission is used as channel c or channel c i ∈C is the contention window size used.

[0209] For example, the terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and performs multi-channel access on each channel c in the plurality of channels. i ∈C, independently determine the contention window size, and if the transmission type of the first target transmission is PSCCH / PSSCH transmission, determine channel c or channel c i The contention window size used by ∈C is; the latest CWp used by other PSCCH / PSSCH transmissions of the same type as the first target transmission for Type 1 channel access. In this way, only the CWp used by PSCCH / PSSCH transmissions for Type 1 channel access is referenced, and the latest CWp used by other PSCCH / PSSCH transmissions for Type 1 channel access is used as the contention window size for the current transmission.

[0210] Optionally, if there is no PSCCH / PSSCH transmission before the current transmission, the minimum value of the contention window size corresponding to the channel access priority of the current transmission is used as the contention window size of the current transmission.

[0211] For example, the terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and performs multi-channel access on each channel c in the plurality of channels. i ∈C, independently determine the contention window size, and if the transmission type of the first target transmission is SL-PRS transmission, determine channel c or channel c i The contention window size used by ∈C is; the latest CWp used by other SL-PRS transmissions of the same type as the first target transmission for Type 1 channel access. In this way, only the CWp used by SL-PRS transmission for Type 1 channel access is referenced, and the latest CWp used by other SL-PRS transmissions for Type 1 channel access is used as the contention window size for the current transmission.

[0212] Optionally, if there is no SL-PRS transmission before the current transmission, the minimum value of the contention window size corresponding to the channel access priority of the current transmission is used as the contention window size of the current transmission.

[0213] It should be pointed out that, considering that the energy detection threshold value XThresh for channel access may be different for different SL transmissions, for example, the energy detection threshold value for PSCCH / PSSCH transmission is -80, and the energy detection threshold value for PSFCH transmission is -70, then if PSFCH transmission uses the latest CWp used by PSCCH / PSSCH transmission for channel access, it may lead to differences in the assessment of channel occupancy. In addition, the demodulation performance of different channels will also lead to differences in the assessment of channel status. Therefore, from the perspective of ensuring fairness, only the latest CWp used by other SL transmissions of the same type for Type 1 channel access can be referenced. For example, if the current transmission is PSFCH transmission, only the CWp used by PSFCH transmission for Type 1 channel access is referenced, and the latest CWp used by other PSFCH transmissions for Type 1 channel access is used as the contention window size for the current transmission.

[0214] Exemplary application scenario 2: the terminal performs multi-channel access for the first target transmission, and before performing multi-channel access for the first target transmission, the terminal independently maintains a contention window for each of the multiple channels, then according to the second information, uniformly determines a contention window size for the multiple channels, including the following examples:

[0215] Example 1, see Figure 2, assuming that the current first target transmission is expected to occupy 3 channels (C=3), the channel access priority p=1, the optional value of CWp is {3, 7}, and the UE determines that the latest CWp in the 3 channels is 7, 3, and 7 respectively. Then it can be determined that the CWp used by the current first target transmission is the maximum value of the latest CWp in multiple channels, that is, CWp=7.

[0216] Example 2, see Figure 2 , assuming that the current first target transmission is expected to occupy 3 channels (C=3), the channel access priority p=1, the optional value of CWp is {3, 7}, the UE determines that the latest contention windows CWp in the 3 channels are 7, 3, and 7 respectively, and the type of the first target transmission is PSSCH transmission. If the second target transmission satisfies the same type as the first target transmission, it can be determined that CWp=3 is used by the current first target transmission.

[0217] Exemplary application scenario three, the terminal performs multi-channel access for the first target transmission, and before performing multi-channel access for the first target transmission, the terminal uniformly maintains a contention window for multiple channels, then according to the second information, uniformly determines a contention window size for the multiple channels, including the following examples:

[0218] Example 1: The contention window size used by multiple channels is determined to be the latest CWp used for Type 1 channel access in the most recent SL transmission on the multiple channels;

[0219] Example 2: When the first target transmission is a PSFCH or S-SSB transmission, the contention window size used by multiple channels is determined to be the latest CWp used for Type 1 channel access by the most recent PSFCH or S-SSB transmission on the multiple channels;

[0220] Example 3: When the first target transmission is a PSCCH / PSSCH transmission, the contention window size used by the multiple channels is determined to be the latest CWp used for Type 1 channel access by the most recent PSCCH / PSSCH transmission on the multiple channels;

[0221] Example 4: When the first target transmission is SL-PRS transmission, the contention window size used by multiple channels is determined to be the latest CWp used for Type 1 channel access in the most recent SL-PRS transmission on the multiple channels.

[0222] Case 3: Target information includes third information and / or fourth information

[0223] In one embodiment, when the target information includes the third information and / or the fourth information, determining the contention window size for the target channel according to the target information includes one of the following:

[0224] When the first condition is met, determining the minimum value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0225] When the second condition is met, determining the next larger allowed value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0226] The first condition includes: the transmission type is unicast and the feedback type is positive acknowledgment, or the transmission type is multicast and at least one positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is greater than or equal to a first threshold;

[0227] The second condition includes: the transmission type is unicast and the feedback type is a negative acknowledgment, or the transmission type is multicast and no positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is less than the first threshold.

[0228] Optionally, the reference priority of the first target transmission includes at least one of: channel access priority, short distance communication data packet priority PPPP, synchronization priority and positioning priority.

[0229] It should be noted that when performing single channel access for the first target transmission or determining the contention window size for each of the multiple channels separately, the selection of the reference priority is not involved, and the priority corresponding to the transmission on each channel can be used as the reference priority. For example, the channel access priority corresponding to the transmission on the channel is used as the reference priority, or at least one of the PPPP, synchronization priority and positioning priority corresponding to the transmission on the channel is used as the reference priority.

[0230] The following is an introduction through specific application scenario examples.

[0231] Exemplary application scenario 1: The terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and for each channel c in the multiple channels i ∈C, independently determine the contention window size according to the third information and / or the fourth information, where C refers to the set of multiple channels occupied by the first target transmission. The following examples may be included:

[0232] Example 1: The terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and performs multi-channel access on each channel c in the plurality of channels. i ∈C, independently determine the contention window size. If the terminal is in channel c or channel ci ∈C, the transmission type within the reference duration of the most recent channel occupation initiated on channel c is unicast, and the terminal receives the corresponding feedback. If the received feedback is ACK, the contention window size is determined to be i The minimum value of the contention window size corresponding to the channel access priority transmitted on channel c; if the received feedback is NACK, the contention window size is determined to be i The next higher allowed value of the contention window size corresponding to the channel access priority of the transmission.

[0233] Example 2: The terminal performs single channel access on channel c for the first target transmission, or the terminal performs multi-channel access for the first target transmission and performs multi-channel access on each channel c in the plurality of channels. i ∈C, independently determine the contention window size. If the terminal is in channel c or channel c i ∈C, the transmission type within the reference duration of the most recent channel occupation initiated on channel c is ACK / NACK-based multicast, and the UE receives corresponding feedback, then if at least one ACK is received, or the proportion of received ACKs is greater than or equal to a preconfigured first threshold, the contention window size is determined to be i The minimum value of the contention window size corresponding to the channel access priority transmitted on channel c; otherwise, the contention window size is determined to be the minimum value of the contention window size corresponding to the channel access priority transmitted on channel c i The next higher allowed value of the contention window size corresponding to the channel access priority of the transmission.

[0234] Exemplary application scenario 2: when the terminal performs multi-channel access for the first target transmission, a contention window size is uniformly determined for multiple channels according to the third information and / or the fourth information, including the following examples:

[0235] Example 1: If the transmission type within the reference duration of the most recent channel occupancy initiated by the UE on one or more channels on multiple channels is unicast, and the UE receives corresponding feedback, then: if the received feedback is ACK, the contention window size is determined to be the minimum value of the contention window size corresponding to the reference priority of the current first target transmission; if the received feedback is NACK, the contention window size is determined to be the next higher allowed value of the contention window size corresponding to the reference priority of the current first target transmission.

[0236] Example 2: If the transmission type within the reference duration of the most recent channel occupancy initiated by the UE on one or more channels on multiple channels is ACK / NACK-based multicast, and the UE receives corresponding feedback, then: if at least one ACK is received, or the proportion of received ACKs is greater than or equal to a preconfigured threshold value, the contention window size is determined to be the minimum value of the contention window size corresponding to the reference priority of the current first target transmission; otherwise, the contention window size is determined to be the next higher allowed value of the contention window size corresponding to the reference priority of the current first target transmission.

[0237] It should be noted that in the third application scenario, before the terminal performs multi-channel access for the first target transmission, multiple channels uniformly maintain a contention window, or each of the multiple channels independently determines a contention window.

[0238] In one embodiment, in the above step 102, performing channel access for the first target transmission according to the contention window size includes:

[0239] If a third condition is met, performing multi-channel access for the first target transmission according to the contention window size;

[0240] The third condition includes at least one of the following:

[0241] The first target transmission is a PSFCH transmission performed by the terminal on multiple channels;

[0242] The first target transmission is an S-SSB transmission performed by the terminal on an S-SSB opportunity on multiple channels;

[0243] The first target transmission is one or more direct link positioning reference signal SL-PRS transmissions performed by the terminal on multiple channels;

[0244] The first target transmission is one or more PSCCH transmissions performed by the terminal on multiple channels;

[0245] The first target transmission is one or more PSSCH transmissions performed by the terminal on multiple channels;

[0246] The transmission of the terminal on the multiple channels is expected to be performed at the same time;

[0247] The reference priorities of the first target transmission transmitted on multiple channels are the same.

[0248] Exemplarily, the third condition is PSFCH transmission performed by the terminal on multiple channels.

[0249] Since each PSFCH transmission only occupies one channel, when the UE transmits only one PSFCH, there is no need to perform multi-channel access. However, if the UE needs to transmit multiple PSFCHs on multiple channels, for example, to repeat a PSFCH transmission on different RB sets at the same time, or to provide feedback on different PSCCH / PSSCH transmissions on multiple RB sets, in these cases, the UE can perform multi-channel access for multiple PSFCH transmissions. Optionally, the UE can also perform a single channel access process independently for each PSFCH transmission.

[0250] Exemplarily, the third condition is the transmission of S-SSB by the terminal on S-SSB opportunities on multiple channels.

[0251] When the UE needs to transmit a synchronization signal, occupying one channel can meet the transmission requirements. In this case, only single-channel access is required. However, when the UE wants to increase the coverage, or wants to ensure continuous transmission on multiple channels, it can perform repeated transmission of S-SSB on multiple channels. In this case, multi-channel access should be performed.

[0252] Exemplarily, the third condition is that the terminal transmits one or more direct link positioning reference signals SL-PRS on multiple channels.

[0253] SL-PRS is similar to PSCCH / PSSCH transmission, and a single transmission may occupy multiple channels. In this case, it is more suitable for UE to use multi-channel access. For the case of transmitting multiple SL-PRS or PSCCH / PSSCH transmissions on multiple channels, multi-channel access can be performed for multiple transmissions, or single-channel access and / or multi-channel access can be performed independently for each transmission.

[0254] Exemplarily, the third condition is that the terminal transmits one or more direct link positioning reference signals SL-PRS on multiple channels.

[0255] SL-PRS is similar to PSCCH / PSSCH transmission, and a single transmission may occupy multiple channels. In this case, it is more suitable for UE to use multi-channel access. For the case of transmitting multiple SL-PRS or PSCCH / PSSCH transmissions on multiple channels, multi-channel access can be performed for multiple transmissions, or single-channel access and / or multi-channel access can be performed independently for each transmission.

[0256] Exemplarily, the third condition is that transmissions by the terminal on multiple channels are expected to be performed at the same time.

[0257] If the UE is expected to transmit on multiple channels at the same time, it is more suitable for the UE to perform multi-channel access to ensure that the UE can transmit simultaneously after the channel access.

[0258] It should be noted that if the transmission of multiple channels is not expected to be performed at the same time, the UE can also perform multi-channel access, such as Type A multi-channel access. Since each channel of Type A multi-channel access needs to perform Type 1 LBT, the time when different channels complete channel access may be different. Each channel can perform channel access based on the contention window size and counter N value determined by the transmission on the channel.

[0259] Exemplarily, the reference priority of the first target transmission transmitted on multiple channels is the same.

[0260] If the reference priorities of the transmissions of the UE on multiple channels are the same, for example, the channel access priorities are the same, then the optional values ​​of the corresponding contention window sizes are also the same, which can better ensure the fairness of the UE in performing multi-channel access.

[0261] In one embodiment, after performing multi-channel access for the first target transmission, the method further includes:

[0262] When it is determined that the terminal has successfully accessed multiple channels, performing the first target transmission on the multiple channels; or

[0263] When it is determined that the terminal has successfully accessed some of the multiple channels, the first target transmission is performed on the channels where the access has been successful, and the first target transmission is not performed on the channels where the access has failed.

[0264] In this embodiment, one solution is that the UE transmits only when it has successfully accessed multiple channels. This method is particularly suitable for the case where one transmission occupies multiple channels. If the UE fails to successfully access multiple channels, the transmission cannot be completed, and the UE can reselect resources. Another solution is that the UE can perform transmission on any channel to which the channel access is successful, and does not perform transmission on the channel to which the channel access fails. This method is more suitable for the case where multiple transmissions occupy multiple channels, and each transmission can be regarded as an independent transmission. In order to increase the probability of successful channel access, even if multiple channels are not successfully accessed, the UE can transmit on the channel to which the access is successful, and does not transmit on the channel to which the access fails, thereby ensuring the timely reliability of the transmission.

[0265] In the above scheme, before the direct link UE working in the unlicensed frequency band performs channel access, the influencing factors of different contention window values ​​and the number of channels expected to be occupied by UE transmission are considered, and the contention window is adjusted accordingly, thereby ensuring the fairness of direct link channel access and improving the reliability of direct link UE transmission in the unlicensed frequency band, which is more suitable for channel access of direct link UE working in the unlicensed frequency band.

[0266] Second embodiment

[0267] like Figure 3 As shown, an embodiment of the present invention provides a channel access device 300, which is applied to a terminal and includes:

[0268] A first determination module 301 is used to determine, according to target information, a contention window size used by a first target transmission for channel access, wherein the first target transmission includes one or more direct link SL transmissions;

[0269] A first processing module 302, configured to perform channel access for the first target transmission according to the contention window size;

[0270] The target information includes at least one of the following:

[0271] first information, wherein the first information is a reference priority of the first target transmission;

[0272] second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access;

[0273] third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal;

[0274] Fourth information, where the fourth information is a feedback type corresponding to a direct link shared channel PSSCH transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

[0275] Optionally, the type of SL transmission includes: at least one of: physical direct link control channel PSCCH transmission, physical direct link shared channel PSSCH transmission, physical direct link feedback channel PSFCH transmission, direct link synchronization signal block S-SSB, and direct link positioning reference signal SL-PRS.

[0276] Optionally, the first determining module 301 includes:

[0277] The first determination submodule is used to determine the contention window size for the target channel according to the target information; the target channel is one or more channels occupied by the first target transmission; wherein one channel corresponds to one contention window size, or multiple channels correspond to one contention window size, or each channel in the multiple channels corresponds to one contention window size.

[0278] Optionally, when the target information includes the first information, the first determining submodule includes:

[0279] A first determining unit, configured to determine, according to the first information, an optional contention window value corresponding to the first target transmission;

[0280] The second determining unit is configured to determine the contention window size for the target channel according to the optional value of the contention window.

[0281] Optionally, when the target information includes the second information, the first determining submodule includes one of the following:

[0282] A third determining unit, configured to determine the latest contention window size used by the first SL transmission for first type channel access as the contention window size used by the target channel;

[0283] The first SL transmission satisfies at least one of the following:

[0284] Occupying the same channel as the first target transmission;

[0285] is of the same type as the first target transmission;

[0286] having the same reference priority as the first target transmission;

[0287] The transmission corresponding to the maximum contention window in the second target transmission;

[0288] The transmission corresponding to the minimum contention window in the second target transmission;

[0289] any transmission of the second target transmission;

[0290] The second target transmission satisfies at least one of the following:

[0291] Occupying the same channel as the first target transmission;

[0292] is of the same type as the first target transmission;

[0293] The same as the reference priority of the first target transmission.

[0294] Optionally, in the case that the first target transmission occupies multiple channels, the multiple channels uniformly maintain a contention window, or each of the multiple channels independently maintains a contention window.

[0295] Optionally, when the first target transmission includes multiple SL transmissions, the reference priority corresponding to the first target transmission is the highest priority among the multiple priorities, or the lowest priority among the multiple priorities.

[0296] Optionally, when the target information includes the third information and / or the fourth information, the first determining module 301 includes one of the following:

[0297] A second determination submodule is used to determine, when a first condition is met, a minimum value among optional contention window values ​​corresponding to the reference priority of the first target transmission as a contention window size used by the target channel;

[0298] A third determination submodule is used to determine, when a second condition is met, the next larger allowed value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0299] The first condition includes: the transmission type is unicast and the feedback type is positive acknowledgment, or the transmission type is multicast and at least one positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is greater than or equal to a first threshold;

[0300] The second condition includes: the transmission type is unicast and the feedback type is a negative acknowledgment, or the transmission type is multicast and no positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is less than the first threshold.

[0301] Optionally, the first processing module 302 includes:

[0302] A first processing submodule, configured to perform multi-channel access for the first target transmission according to the contention window size when a third condition is met;

[0303] The third condition includes at least one of the following:

[0304] The first target transmission is a PSFCH transmission performed by the terminal on multiple channels;

[0305] The first target transmission is an S-SSB transmission performed by the terminal on an S-SSB opportunity on multiple channels;

[0306] The first target transmission is one or more direct link positioning reference signal SL-PRS transmissions performed by the terminal on multiple channels;

[0307] The first target transmission is one or more PSCCH transmissions performed by the terminal on multiple channels;

[0308] The first target transmission is one or more PSSCH transmissions performed by the terminal on multiple channels;

[0309] The transmission of the terminal on the multiple channels is expected to be performed at the same time;

[0310] The reference priorities of the first target transmission transmitted on multiple channels are the same.

[0311] Optionally, the reference priority of the first target transmission includes at least one of: channel access priority, short distance communication data packet priority PPPP, synchronization priority and positioning priority.

[0312] Optionally, the apparatus 300 further includes:

[0313] A second processing module is configured to perform the first target transmission on the multiple channels when it is determined that the terminal has successfully accessed the multiple channels; or

[0314] The third processing module is used to, when it is determined that the terminal has successfully accessed some of the multiple channels, perform the first target transmission on the channels on which the access has been successful, and not perform the first target transmission on the channels on which the access has failed.

[0315] The second embodiment of the present invention corresponds to the method of the first embodiment. All implementation means in the first embodiment are applicable to the embodiment of the channel access device and can achieve the same technical effect.

[0316] Third embodiment

[0317] In order to better achieve the above goals, Figure 4 As shown, the third embodiment of the present invention further provides a terminal, including:

[0318] A processor 400; and a memory 420 connected to the processor 400 via a bus interface, the memory 420 being used to store programs and data used by the processor 400 when performing operations, and the processor 400 calling and executing the programs and data stored in the memory 420.

[0319] The transceiver 410 is connected to the bus interface and is used to receive and send data under the control of the processor 400; the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0320] Determine, according to the target information, a contention window size used by a first target transmission for channel access, wherein the first target transmission includes one or more through link SL transmissions;

[0321] performing channel access for the first target transmission based on the contention window size;

[0322] The target information includes at least one of the following:

[0323] first information, wherein the first information is a reference priority of the first target transmission;

[0324] second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access;

[0325] third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal;

[0326] Fourth information, where the fourth information is a feedback type corresponding to a direct link shared channel PSSCH transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

[0327] Among them, Figure 4 In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 400 and various circuits of memory represented by memory 320 are linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 410 may be a plurality of components, namely, a transmitter and a transceiver, providing a unit for communicating with various other devices on a transmission medium. For different terminals, the user interface 430 may also be an interface capable of externally connecting or internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like. The processor 400 is responsible for managing the bus architecture and general processing, and the memory 420 may store data used by the processor 400 when performing operations.

[0328] Optionally, the types of SL transmission include: at least one of: physical direct link control channel PSCCH transmission, physical direct link shared channel PSSCH transmission, physical direct link feedback channel PSFCH transmission, direct link synchronization signal block S-SSB, and direct link positioning reference signal SL-PRS.

[0329] Optionally, the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0330] According to the target information, determine the contention window size for the target channel; the target channel is one or more channels occupied by the first target transmission; wherein one channel corresponds to one contention window size, or multiple channels correspond to one contention window size, or each of the multiple channels corresponds to one contention window size.

[0331] Optionally, the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0332] Determine, according to the first information, an optional value of a contention window corresponding to the first target transmission;

[0333] The contention window size is determined for the target channel according to the contention window optional value.

[0334] Optionally, the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0335] Determine the latest contention window size used by the first SL transmission for first type channel access as the contention window size used by the target channel;

[0336] The first SL transmission satisfies at least one of the following:

[0337] Occupying the same channel as the first target transmission;

[0338] is of the same type as the first target transmission;

[0339] having the same reference priority as the first target transmission;

[0340] The transmission corresponding to the maximum contention window in the second target transmission;

[0341] The transmission corresponding to the minimum contention window in the second target transmission;

[0342] any transmission of the second target transmission;

[0343] The second target transmission satisfies at least one of the following:

[0344] Occupying the same channel as the first target transmission;

[0345] is of the same type as the first target transmission;

[0346] The same as the reference priority of the first target transmission.

[0347] Optionally, in the case that the first target transmission occupies multiple channels, the multiple channels uniformly maintain a contention window, or each of the multiple channels independently maintains a contention window.

[0348] Optionally, when the first target transmission includes multiple SL transmissions, the reference priority corresponding to the first target transmission is the highest priority among the multiple priorities, or the lowest priority among the multiple priorities.

[0349] Optionally, the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0350] When the first condition is met, determining the minimum value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0351] When the second condition is met, determining the next larger allowed value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel;

[0352] The first condition includes: the transmission type is unicast and the feedback type is positive acknowledgment, or the transmission type is multicast and at least one positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is greater than or equal to a first threshold;

[0353] The second condition includes: the transmission type is unicast and the feedback type is a negative acknowledgment, or the transmission type is multicast and no positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is less than the first threshold.

[0354] Optionally, the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0355] If a third condition is met, performing multi-channel access for the first target transmission according to the contention window size;

[0356] The third condition includes at least one of the following:

[0357] The first target transmission is a PSFCH transmission performed by the terminal on multiple channels;

[0358] The first target transmission is an S-SSB transmission performed by the terminal on an S-SSB opportunity on multiple channels;

[0359] The first target transmission is one or more direct link positioning reference signal SL-PRS transmissions performed by the terminal on multiple channels;

[0360] The first target transmission is one or more PSCCH transmissions performed by the terminal on multiple channels;

[0361] The first target transmission is one or more PSSCH transmissions performed by the terminal on multiple channels;

[0362] The transmission of the terminal on the multiple channels is expected to be performed at the same time;

[0363] The reference priorities of the first target transmission transmitted on multiple channels are the same.

[0364] Optionally, the reference priority of the first target transmission includes at least one of: channel access priority, short distance communication data packet priority PPPP, synchronization priority and positioning priority.

[0365] Optionally, the processor 400 is used to read the program in the memory 420 to implement the following steps:

[0366] When it is determined that the terminal has successfully accessed multiple channels, performing the first target transmission on the multiple channels; or

[0367] When it is determined that the terminal has successfully accessed some of the multiple channels, the first target transmission is performed on the channels where the access has been successful, and the first target transmission is not performed on the channels where the access has failed.

[0368] The terminal provided by the present invention determines the contention window size used for channel access by the first target transmission according to the target information, and the first target transmission includes one or more direct link SL transmissions; according to the contention window size, channel access is performed for the first target transmission; wherein the target information includes at least one of the following: the reference priority of the first target transmission; the latest contention window size used for the first type of channel access by other SL transmissions other than the first target transmission; the transmission type within the reference duration of the most recent channel occupancy initiated by the terminal; the feedback type corresponding to the direct link shared channel PSSCH transmission within the reference duration of the most recent channel occupancy initiated by the terminal. In this way, based on the above scheme, the contention window can be adjusted before performing channel access for the direct link transmission.

[0369] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing relevant hardware through a computer program, wherein the computer program includes instructions for executing part or all of the steps of the above method; and the computer program may be stored in a readable storage medium, and the storage medium may be any form of storage medium.

[0370] Those skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing relevant hardware through a computer program, wherein the computer program includes instructions for executing part or all of the steps of the above method; and the computer program may be stored in a readable storage medium, and the storage medium may be any form of storage medium.

[0371] In addition, a specific embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of the method in the first embodiment described above are implemented. The same technical effect can be achieved, and to avoid repetition, it will not be described here.

[0372] In addition, it should be noted that in the apparatus and method of the present invention, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. Moreover, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but it is not necessary to perform them in chronological order, and some steps can be performed in parallel or independently of each other. For those of ordinary skill in the art, it is understood that all or any steps or components of the method and apparatus of the present invention can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices in hardware, firmware, software or a combination thereof, which can be achieved by those of ordinary skill in the art using their basic programming skills after reading the description of the present invention.

[0373] Therefore, the purpose of the present invention can also be achieved by running a program or a group of programs on any computing device. The computing device can be a well-known general device. Therefore, the purpose of the present invention can also be achieved by simply providing a program product containing a program code that implements the method or device. That is to say, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be pointed out that in the device and method of the present invention, it is obvious that each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. In addition, the steps of performing the above-mentioned series of processing can naturally be performed in chronological order according to the order of description, but it is not necessary to perform them in chronological order. Some steps can be performed in parallel or independently of each other.

[0374] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A channel access method, characterized in that: Applied to terminals, including: Determine, according to the target information, a contention window size used by a first target transmission for channel access, wherein the first target transmission includes one or more through link SL transmissions; performing channel access for the first target transmission based on the contention window size; The target information includes at least one of the following: first information, wherein the first information is a reference priority of the first target transmission; second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access; third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal; Fourth information, where the fourth information is a feedback type corresponding to a direct link shared channel PSSCH transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

2. The channel access method according to claim 1, characterized in that: The types of SL transmission include: at least one of: physical direct link control channel PSCCH transmission, physical direct link shared channel PSSCH transmission, physical direct link feedback channel PSFCH transmission, direct link synchronization signal block S-SSB, and direct link positioning reference signal SL-PRS.

3. The channel access method according to claim 1, characterized in that: The determining, according to the target information, a contention window size used by the first target transmission for channel access comprises: According to the target information, determine the contention window size for the target channel; the target channel is one or more channels occupied by the first target transmission; wherein one channel corresponds to one contention window size, or multiple channels correspond to one contention window size, or each of the multiple channels corresponds to one contention window size.

4. The channel access method according to claim 3, characterized in that: In a case where the target information includes the first information, determining the contention window size for the target channel according to the target information includes: Determine, according to the first information, an optional value of a contention window corresponding to the first target transmission; The contention window size is determined for the target channel according to the contention window optional value.

5. The channel access method according to claim 3, characterized in that: In a case where the target information includes the second information, determining the contention window size for the target channel according to the target information includes one of the following: Determine the latest contention window size used by the first SL transmission for first type channel access as the contention window size used by the target channel; The first SL transmission satisfies at least one of the following: Occupying the same channel as the first target transmission; is of the same type as the first target transmission; having the same reference priority as the first target transmission; The transmission corresponding to the maximum contention window in the second target transmission; The transmission corresponding to the minimum contention window in the second target transmission; any transmission of the second target transmission; The second target transmission satisfies at least one of the following: Occupying the same channel as the first target transmission; is of the same type as the first target transmission; The same as the reference priority of the first target transmission.

6. The channel access method according to claim 1, characterized in that: In the case where the first target transmission occupies multiple channels, the multiple channels uniformly maintain a contention window, or each of the multiple channels independently maintains a contention window.

7. The channel access method according to claim 1, characterized in that: When the first target transmission includes multiple SL transmissions, the reference priority corresponding to the first target transmission is the highest priority among the multiple priorities, or the lowest priority among the multiple priorities.

8. The channel access method according to claim 3, characterized in that: In a case where the target information includes the third information and / or the fourth information, determining the contention window size for the target channel according to the target information includes one of the following: When the first condition is met, determining the minimum value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel; When the second condition is met, determining the next larger allowed value among the optional values ​​of the contention window corresponding to the reference priority of the first target transmission as the contention window size used by the target channel; The first condition includes: the transmission type is unicast and the feedback type is positive acknowledgment, or the transmission type is multicast and at least one positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is greater than or equal to a first threshold; The second condition includes: the transmission type is unicast and the feedback type is a negative acknowledgment, or the transmission type is multicast and no positive acknowledgment is received, or the transmission type is multicast and the proportion of positive acknowledgments received is less than the first threshold.

9. The channel access method according to claim 1, characterized in that: The performing channel access for the first target transmission according to the contention window size includes: If a third condition is met, performing multi-channel access for the first target transmission according to the contention window size; The third condition includes at least one of the following: The first target transmission is a PSFCH transmission performed by the terminal on multiple channels; The first target transmission is an S-SSB transmission performed by the terminal on an S-SSB opportunity on multiple channels; The first target transmission is one or more direct link positioning reference signal SL-PRS transmissions performed by the terminal on multiple channels; The first target transmission is one or more PSCCH transmissions performed by the terminal on multiple channels; The first target transmission is one or more PSSCH transmissions performed by the terminal on multiple channels; The transmission of the terminal on the multiple channels is expected to be performed at the same time; The reference priorities of the first target transmission transmitted on multiple channels are the same.

10. The channel access method according to claim 1 or 5 or 7 or 8 or 9, characterized in that: The reference priority of the first target transmission includes at least one of: channel access priority, short distance communication data packet priority PPPP, synchronization priority and positioning priority.

11. The channel access method according to claim 1, characterized in that: After performing multi-channel access for the first target transmission, the method further includes: When it is determined that the terminal has successfully accessed multiple channels, performing the first target transmission on the multiple channels; or When it is determined that the terminal has successfully accessed some of the multiple channels, the first target transmission is performed on the channels where the access has been successful, and the first target transmission is not performed on the channels where the access has failed.

12. A terminal, comprising: A transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the channel access method as claimed in any one of claims 1 to 11 when executing the computer program.

13. A channel access device, characterized in that: Applied to terminals, including: A first determination module, configured to determine, according to target information, a contention window size used by a first target transmission for channel access, wherein the first target transmission includes one or more straight-through link SL transmissions; a first processing module, configured to perform channel access for the first target transmission according to the contention window size; The target information includes at least one of the following: first information, wherein the first information is a reference priority of the first target transmission; second information, where the second information is the latest contention window size used by other SL transmissions other than the first target transmission for first type channel access; third information, where the third information is a transmission type within a reference duration of the most recent channel occupancy initiated by the terminal; Fourth information, where the fourth information is a feedback type corresponding to a direct link shared channel PSSCH transmission within a reference duration of the most recent channel occupancy initiated by the terminal.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the channel access method according to any one of claims 1 to 11 are implemented.

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