Resource selection method and device, communication equipment and readable storage medium

Abstract

Disclosed are a resource selection method and apparatus, a communication device and a readable storage medium, belonging to the technical field of communications, the resource selection method of the embodiment of the present application comprising: when a UE fails to access a channel, executing at least one of the following items according to a first resource: executing resource reselection for the first resource; the selected straight-through link grant (sidelink grant) is updated, and the selected straight-through link grant is updated; the selected sidelink grant is maintained, and the selected sidelink grant is maintained; the selected sidelink grant is cleared away, and the selected sidelink grant is cleared away; abandoning the first resource; wherein the first resource is a transmission resource which cannot execute transmission due to channel access failure.

Description

Technical Field

[0001] The present application belongs to the field of communication technology, and specifically relates to a resource selection method, device, communication equipment and readable storage medium. Background Art

[0002] In order to support direct communication between user equipment (UE), a sidelink (also called secondary link, side link or side link, etc.) communication mode is introduced, so that UEs can directly transmit without going through network devices.

[0003] In the related art, the resource selection method of the direct link is mainly applicable to the scenario where the UE works on a dedicated carrier, and is difficult to be applied to the resource selection of the direct link transmission on the unlicensed frequency band. Summary of the invention

[0004] The embodiments of the present application provide a resource selection method, apparatus, communication device, and readable storage medium, which improve the resource selection process for direct link transmission on an unlicensed frequency band.

[0005] In a first aspect, a resource selection method is provided, which is applied to a user equipment UE. The method includes:

[0006] When the UE fails to access the channel, performing at least one of the following according to the first resource:

[0007] performing resource reselection for the first resource;

[0008] Update the selected sidelink grant;

[0009] maintaining the selected sidelink grant;

[0010] clearing the selected sidelink grant;

[0011] abandoning the first resource;

[0012] The first resource is a transmission resource that cannot be transmitted due to a channel access failure.

[0013] In a second aspect, a resource selection device is provided, which is applied to a user equipment UE, and the device includes:

[0014] An execution module, configured to execute at least one of the following according to the first resource when the access channel fails:

[0015] performing resource reselection for the first resource;

[0016] Update the selected sidelink grant;

[0017] maintaining the selected sidelink grant;

[0018] clearing the selected sidelink grant;

[0019] abandoning the first resource;

[0020] The first resource is a transmission resource that cannot be transmitted due to a channel access failure.

[0021] According to a third aspect, a communication device is provided, comprising a processor and a memory, wherein the memory stores a program or instruction that can be executed on the processor, and when the program or instruction is executed by the processor, the steps of the method described in the first aspect are implemented.

[0022] In a fourth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented.

[0023] In a fifth aspect, a chip is provided, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the method described in the first aspect.

[0024] In a sixth aspect, a computer program / program product is provided, wherein the computer program / program product is stored in a storage medium, and the program / program product is executed by at least one processor to implement the steps of the method described in the first aspect.

[0025] In an embodiment of the present application, considering that for an unlicensed frequency band, the UE needs to complete channel access before transmission, otherwise it is impossible to perform transmission on the selected resources. This application improves the sidelink resource selection process on the unlicensed frequency band and improves the reliability of service transmission in the unlicensed frequency band by enabling the UE to perform resource reselection or abandon the first resource when channel access fails, or to update, maintain or clear the selected sidelink grant. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of a perception window and a selection window for resource allocation in the related art;

[0027] Figure 2 is a schematic diagram of a perception window and a selection window of a re-evaluation mechanism in the related art;

[0028] Figure 3is a schematic diagram of a perception window and a selection window of a preemption mechanism in the related art;

[0029] Figure 4 is a flowchart of a resource selection method in an embodiment of the present application;

[0030] Figure 5 is a schematic diagram of a resource reselection process in an embodiment of the present application;

[0031] Figure 6 is a schematic diagram of an implementation process of resource selection in an embodiment of the present application;

[0032] Figure 7 is a schematic diagram of another implementation process of resource selection in an embodiment of the present application;

[0033] Figure 8 is a schematic diagram of another implementation process of resource selection in an embodiment of the present application;

[0034] Fig. 9 is a schematic diagram of another implementation process of resource selection in an embodiment of the present application;

[0035] Fig.10 is a schematic diagram of another implementation process of resource selection in an embodiment of the present application;

[0036] Fig.11 is a schematic diagram of another implementation process of resource selection in an embodiment of the present application;

[0037] Fig.12 is a structural block diagram of a resource selection device in an embodiment of the present application;

[0038] Fig.13 It is a structural block diagram of a communication device in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of this application.

[0040] The terms "first", "second", etc. of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of one type, and the number of objects is not limited, for example, the first object can be one or more. In addition, "or" in the present application represents at least one of the connected objects. For example, "A or B" covers three schemes, namely, Scheme 1: including A but not including B; Scheme 2: including B but not including A; Scheme 3: including both A and B. The character " / " generally indicates that the objects associated with each other are in an "or" relationship. It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA) or other systems. The terms "system" and "network" in the embodiments of the present application are often used interchangeably, and the described technology can be used for the systems and radio technologies mentioned above as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for illustrative purposes, and the NR terminology is used in most of the following descriptions, but these technologies can also be applied to systems other than NR systems, such as the 6th generation (6 th Generation, 6G) communication system.

[0041] First, in order to facilitate understanding of the resource selection method of the embodiment of the present application, the following contents are now introduced.

[0042] 1. Channel access process of New Radio in Unlicensed Spectrum (NR-U) working in unlicensed frequency band

[0043] 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 length T sl If an evolved Node B (eNB) or the next generation Node B (gNB), or a UE senses in a sensing slot and determines that the monitoring energy in the sensing slot is at least 4us lower than the energy detection threshold XThresh, the sensing slot is considered idle. Otherwise, the sensing slot is considered idle in length T. sl Duration T sl ) is busy inside.

[0044] The channel access process of the NR-U system is divided into Type 1 and Type 2. Type 2 is further divided into Type 2A, 2B and 2C. The following takes the downlink channel access method as an example to introduce the above two channel access processes.

[0045] (1) Type 1

[0046] The eNB or gNB may 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 in the channel access process (such as the counter N in step 4 below) is 0. The counter N is adjusted by sensing the additional sensing slot duration according to the following steps, which are as follows:

[0047] 1) Set N=Ninit, where Ninit is a random number uniformly distributed between 0 and CWp (contention window), and jump to step 4;

[0048] 2) If N>0 and the eNB or gNB chooses to decrease the counter, set N=N-1;

[0049] 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;

[0050] 4) If N=0, stop; otherwise, jump to step 2;

[0051] 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;

[0052] 6) If all sensing slot channels within Td are idle, jump to step 4; otherwise, jump to step 5.

[0053] The backoff time Td is equal to the time length T of 16us. f and the following mp consecutive sensing slot duration T sl Composition, mp is a positive integer, and T f Including a T f The beginning of the idle sensing slot duration T sl ;, C.W. min,p ≤CW p ≤CW max,p , C.W. max,p is the maximum window, CW min,p is the minimum window, CW p Adjust according to the competition window adjustment mechanism, CW min,p and CW max,p Before step 1, select the parameter value m p ,CW min,p and CW max,p Based on the channel access priority p associated with the eNB or gNB transmission, the eNB or gNB shall not exceed the channel occupancy time T mcot,p transmitted on the channel.

[0054] Exemplarily, the channel access priority class (CAPC) may be as shown in Table 1 below.

[0055]

[0056] Table 1

[0057] (2) Type 2

[0058] Type 2A channel access applies only to the following transmissions performed by the eNB or gNB:

[0059] ① Transmission initiated by the eNB, including discovery burst, excluding Physical Downlink Shared Channel (PDSCH), and the maximum transmission duration is 1 millisecond (ms);

[0060] ② Transmission initiated by a gNB multiplexed with a discovery burst with only discovery burst or non-unicast information, with a maximum transmission duration of 1ms and a discovery burst duty cycle of at most 1 / 20;

[0061] ③The transmission of the eNB or gNB comes 25us after the transmission of the UE on the shared channel.

[0062] Type 2B or 2C channel access applies to the gNB’s transmission 16us or at most 16us after the UE’s transmission on the shared channel, respectively.

[0063] Type 2A:

[0064] The eNB or gNB may sense that the channel is idle for at least one sensing interval (T) short_dl (eg, 25us), immediately send a downlink (DL) transmission.

[0065] Among them, T short_dl The time length T is equal to 16us f and the next sensing slot, and T f Including a T f The starting sensing slot. If T short_dl If both sensing slots of are idle, the channel is considered to be short_dl is free.

[0066] Type 2B:

[0067] The gNB can sense that the channel is idle for a time length T equal to 16us f After that, DL transmission is sent immediately. f Including a T f If the channel is perceived to be idle for at least 5us and at least 4us is within the sensing slot, the channel is considered to be idle for duration T f The inside is free.

[0068] Type 2C:

[0069] The gNB does not perform channel sensing before downlink transmission, and the maximum downlink transmission time is 584us.

[0070] 2. New Radio Vehicle to everything (NR-V2X) Mode 2 Resource Allocation

[0071] NR-V2X Mode 2 resource allocation is designed to support enhanced application requirements that cannot be supported by the protocol version 15 (Release 15, Rel-15) Long Term Evolution Vehicle to everything (LTE-V2X), and adopts a distributed resource scheduling method (that is, the UE independently selects transmission resources). Since there is no unified scheduling by the base station, the UE needs to determine the resource occupancy of other UEs through the perception mechanism and select resources based on the perception results. The resource selection process of NR-V2X Mode 2 is:

[0072] a) Candidate single slot resource R x,y is the time t in [n+T1, n+T2] y There are x+j consecutive sub-channels on a slot, such as Figure 1 As shown. Where 0≤T1≤T proc,1 , T proc,1 Indicates the UE's transmission processing delay (including the perception-based resource selection time, the transmission preparation time of the physical sidelink control channel (PSCCH) and the transmission preparation time of the physical sidelink shared channel (PSSCH). The value can be {3, 5, 9, 17} physical slots, corresponding to the subcarrier spacing (SCS) {15, 30, 60, 120} kHz, respectively. T 2min ≤T2≤remaining Packet Delay Budget (remaining PDB), T 2min The minimum T2 value configured for the high-level parameter t2min_SelectionWindow. The total number of candidate slot resources is the set parameter value Mtotal.

[0073] b) UE continuously monitors the perception window [n-T0, nT proc,0) slot, performs PSCCH, PSSCH decoding and PSSCH or Physical Sidelink Control CHannel Reference Signal Receiving Power (PSCCH-RSRP) measurement. T0 is the perception window length configured by the high-level layer, T proc,0 It is the time for UE to process the previous perception result. The value can be {1, 1, 2, 4} physical slots, corresponding to SCS {15, 30, 60, 120} kHz respectively.

[0074] c)Th(p i , p j ) indicates the i-th RSRP field in the higher layer parameter sl-ThresPSSCH-RSRP-List-r16, i=p i +(p j -1)*8,p i Indicates the priority indicated in the received sidelink control information (SCI), p j Indicates the priority of the UE transmission, p j =prio TX (Setting priority).

[0075] d) Initialize S A It is the collection of all candidate single slot resources.

[0076] e) Exclude candidate slots corresponding to skip slots. Skip slots are slots that cannot be sensed due to half-duplex (such as y). For all periods configured by the system (such as 20ms, 50ms, 100ms), exclude all candidate slots at the corresponding positions (i.e. y, y+20*2 μ ,y+40*2 μ ,y+50*2 μ ,y+60*2 μ ,y+80*2 μ ,y+100*2 μ ...and other slots that fall within the selection window).

[0077] f) Eliminate candidate single slot resources that meet the following two conditions:

[0078] i. The PSSCH-RSRP measurement value indicated by the SCI is higher than Th(prio RX ,prio TX );

[0079] ii. The reserved resources indicated by the SCI will be sent on the candidate resource y or on the subsequent y+x*P step *2 μ The TBs sent by the candidate resources on P are partially or completely overlapped. step It is the period of service generation in milliseconds. x is an integer representing the number of subsequent periods.

[0080] g) If S A The remaining resources in are less than X*M total , then Th(p i , p j ) are all increased by 3dB and return to step d; for a given prio TX , X is determined by the high-level parameter sl-xPercentage (prio TX ) configuration;

[0081] h) UE reports SA to higher layers;

[0082] i) The higher layer randomly selects the initial transmission and retransmission resources for the current TB in the SA under the constraint of the Hybrid Automatic Repeat reQuest (HARQ) round-trip time (RTT).

[0083] On this basis, in order to solve the resource collision caused by non-periodic burst services and to ensure the reliability of high-priority services, the re-evaluation mechanism and pre-emption mechanism are added respectively, such as Figure 2 and Figure 3 As shown. Among them, the re-evaluation mechanism is mainly for unreserved resources. Before sending resources, it determines whether the selected resources have collided based on the latest perception results. If a collision occurs, reselection can be performed to reduce the probability of resource collision; the preemption mechanism is mainly for reserved resources. If it is found that the reserved resources are preempted by high-priority UEs, it is necessary to trigger low-priority UEs to reselect resources to avoid collisions between high and low priorities, thereby ensuring the performance of high-priority services.

[0084] In the related technologies, the sidelink resource allocation process such as NR-V2X Mode 2 is mainly designed based on the scenario where the UE works on a dedicated carrier (i.e., the sidelink UE can ensure that the transmission is completed on the reserved resources (i.e., the selected resources) without worrying about the channel being occupied by other technologies). However, for unlicensed frequency bands, since the UE needs to complete channel access before transmission, if the channel access fails, the transmission cannot be performed on the selected resources (i.e., the transmission cannot be guaranteed to be completed on the reserved resources), and if the channel access is successful, the UE can only occupy the channel continuously for a period of time. If the transmission is interrupted in the middle, the channel may be occupied by other technologies and subsequent transmission cannot be completed. For this reason, the concept of continuous multi-slot transmission (MCSt) is also introduced in the sidelink unlicensed frequency band (SideLink Unlicensed Spectrum, SL-U).

[0085] However, the current resource selection methods such as mode 2 are mainly designed based on the scenario where the UE works on a dedicated carrier, and only define the transmission of a single time slot. For the MCSt transmission method, how to perform resource selection or reselection processes to ensure the reliability of transmission still needs further consideration.

[0086] In response to the problems existing in the related technology, an embodiment of the present application provides a resource selection method, which enables the sidelink UE operating in the unlicensed frequency band to perform resource reselection or determine whether to abandon transmission based on the transmission situation (such as whether it is a continuous multi-slot transmission, etc.) when channel access fails, and updates or clears the direct link authorization (sidelinkgrant) accordingly, thereby improving the sidelink resource selection process on the unlicensed frequency band and improving the reliability of service transmission in the unlicensed frequency band, which is more suitable for sidelink UE operating in the unlicensed frequency band.

[0087] The resource selection method provided in the embodiment of the present application is described in detail below through some embodiments and their application scenarios in combination with the accompanying drawings.

[0088] In a first aspect, an embodiment of the present application provides a resource selection method, which is applied to a user equipment UE, such as Figure 4 As shown, the method may include the following steps:

[0089] Step 101: When the UE fails to access the channel, the UE performs at least one of the following according to the first resource: performs resource reselection for the first resource; updates the selected through link authorization sidelink grant; maintains the selected sidelink grant; clears the selected sidelink grant; and abandons the first resource.

[0090] The first resource is a transmission resource that cannot be transmitted due to a channel access failure.

[0091] The sidelink grant records the transmission resources selected by the UE to perform transmission. By performing operations such as updating, maintaining, or clearing the sidelink grant, the transmission resources used by the current transmission block (Transport Block, TB) and / or the subsequent TBs of the current TB (such as subsequent periods in periodic transmission) can be adjusted.

[0092] In specific implementation, for unlicensed frequency bands, the UE will first perform channel access before performing transmission (such as performing PSSCH transmission). If the channel access fails, the PSSCH transmission cannot be performed, that is, the UE cannot perform transmission on the selected resources. Therefore, an embodiment of the present application provides a resource selection method, so that the UE can trigger the execution of the resource selection process when the channel access fails. Specifically, the UE will perform resource reselection on the transmission resources (i.e., the first resource) that cannot be transmitted due to the channel access failure, such as using a new resource to replace the first resource to perform transmission, or abandoning the first resource, such as abandoning the first resource to abandon transmission, or updating, maintaining, or clearing the selected sidelink grant. Operations, such as triggering and executing the above-mentioned resource selection process, can reduce the impact of the UE's access channel failure on the unlicensed frequency band service transmission (such as the current TB and subsequent TB transmissions), thereby improving the reliability of the UE's unlicensed frequency band service transmission.

[0093] It can be seen from the above steps that, considering that for the unlicensed frequency band, the UE needs to complete channel access before transmission, otherwise it cannot perform transmission on the selected resources. The embodiment of the present application improves the sidelink resource selection process on the unlicensed frequency band and improves the reliability of service transmission in the unlicensed frequency band by enabling the UE to perform resource reselection or abandon the first resource when channel access fails, or to update, maintain or clear the selected sidelink grant.

[0094] Optionally, the first resource may include at least one of the following:

[0095] Item A-1: ​​Transmission resources for single-slot transmission;

[0096] Item A-2: Transmission resources for continuous multi-slot transmission;

[0097] Item A-3: the first M transmission resources among the transmission resources for continuous multi-slot transmission, where M is a positive integer.

[0098] For item A-1, considering that when the UE performs single-slot transmission, the current channel access failure only affects the transmission resources of the current single-slot, the UE can reselect or abandon the transmission resources of the current single-slot, remove the transmission resources of the current single-slot from the sidelink grant, or use the reselected resources to replace the transmission resources of the current single-slot in the sidelink grant, and so on. For the remaining transmission resources that are not affected by the current channel access failure, the UE can flexibly determine whether to make adjustments.

[0099] For item A-2, considering that when the UE performs continuous multi-slot transmission, the current channel access failure will affect the entire current continuous multi-slot transmission (such as causing the UE to be unable to perform transmission on three consecutive time slots), the UE can perform one or more operations such as resource reselection or abandonment of the transmission resources of the entire current continuous multi-slot transmission (such as three consecutive time slots), or remove the continuous multi-slot transmission resources from the sidelink grant, or use the reselected resources to replace the continuous multi-slot transmission resources in the sidelink grant, so as to reduce the impact of the channel access failure on the continuous multi-slot transmission.

[0100] For item A-3, considering that when the UE performs continuous multi-slot transmission, if the UE fails to access the channel before the transmission of the first resource (such as time slot) in the transmission resources of the continuous multi-slot transmission, the channel access may still be successful before the transmission of the subsequent time slots of the first time slot. Therefore, the UE can, according to the time required for channel access, only reselect or abandon the first M transmission resources in the transmission resources of the continuous multi-slot transmission, or remove the first M transmission resources from the sidelink grant, or use the reselected resources to replace the first M transmission resources, and other one or more operations to reduce the impact of channel access failure on the continuous multi-slot transmission.

[0101] Optionally, the first resource should not be indicated by the SCI to avoid other UEs performing channel perception from causing system performance loss due to incorrect assessment of channel occupancy after receiving the SCI indication of the current UE.

[0102] It can be understood that in the direct link service transmission, a TB can have an initial transmission and a retransmission. When the UE sends the initial transmission of the TB (such as sending the initial transmission in time slot 1), it will indicate the location of the retransmission to other UEs through the SCI (such as indicating that the retransmission is sent in time slots 2 and 3). Time slots 2 and 3 are the transmission resources indicated by the SCI. In order to avoid the UE reselecting or abandoning the transmission resources including time slots 2 and 3 as the first resources due to channel access failure, so that other UEs fail to obtain accurate transmission information (such as the UE originally indicated that it would retransmit in time slots 2 and 3 but did not retransmit, or retransmitted in other time slots), resulting in resource collision or confusion and other problems, the above-mentioned first resources can be limited to transmission resources not indicated by the SCI.

[0103] Implementation Method 1

[0104] This implementation describes an example in which the UE performs resource reselection for the first resource. Figure 5 As shown, the resource reselection process may include the following steps:

[0105] Step 201: Determine a candidate resource set;

[0106] Step 202: Select a transmission resource from a candidate resource set.

[0107] In step 201, the physical layer of the UE may select multiple single-slot candidate resources as a candidate resource set through the single-slot resource selection mechanism in the traditional resource allocation process such as the above-mentioned NR-V2X Mode 2 resource allocation, or may determine the candidate resource set according to the length L of continuous multi-slot transmission, where L is not less than 1.

[0108] For example, when the transmission type of the UE is continuous multi-slot transmission, the physical layer of the UE first determines the length L of the continuous multi-slot transmission, then determines one or more continuous multi-slot candidate resources with a length of L, and finally determines the one or more continuous multi-slot candidate resources with a length of L as a candidate resource set and reports it to the UE's media access control (MAC) layer.

[0109] In step 202, the MAC layer of the UE may select resources from the candidate resource set reported by the physical layer in the following two ways.

[0110] Method 1: Randomly select a transmission resource from the candidate resource set.

[0111] In this embodiment, the candidate resource set may be a single-time slot candidate resource set or a multi-time slot candidate resource set. The MAC layer of the UE may randomly select a transmission resource from the candidate resource set to use the selected resource instead of the first resource for transmission.

[0112] As a possible implementation manner, the selected transmission resource needs to meet the restriction of HARQ RTT so that the UE can use the selected transmission resource to perform normal transmission.

[0113] Mode 2: Select transmission resources that are continuous with other reserved resources of the current TB from the candidate resource set.

[0114] In this embodiment, the candidate resource set can be a single-time slot candidate resource set or a multi-time slot candidate resource set. Considering that when the transmission type of the UE is continuous multi-time slot transmission, the selected resources should be continuous with other reserved resources of the current TB to meet the requirements of MCSt transmission. For example, the current TB should meet the requirements of transmission on three consecutive time slots (time slots 1, 2 and 3). When performing resource reselection using time slot 1 as the first resource, time slot 4 continuous with time slots 2 and 3 can be selected, so that the UE can transmit the current TB on time slots 2, 3 and 4 to meet the requirements of transmission on three consecutive time slots.

[0115] For example, Figure 6 As shown, the UE performs continuous multi-slot transmission, and channel access fails before the transmission of the first slot of MCSt, and performs resource reselection for the resources of the first slot, and continues to perform Listen Before Talk (LBT) for the resources of the second slot. If LBT is still unsuccessful (i.e., channel access fails before the transmission of the second slot), the UE needs to continue to perform resource reselection for the resources of the second slot.

[0116] Specifically, for the first slot, the UE can adopt method 1 and perform resource reselection in a random selection manner to obtain the reselected resources for the first slot. For the second slot, the UE can adopt method 2 and select transmission resources that are continuous with other reserved resources of the current TB (such as the resources reselected for the first slot) from the candidate resource set to obtain the reselected resources for the second slot.

[0117] Implementation Method 2

[0118] This implementation describes an example of updating a selected sidelink grant.

[0119] The sidelink grant selected for the update may include at least one of the following:

[0120] removing the first resource from the selected sidelink grant;

[0121] replacing the first resource in the selected sidelink grant with a reselected resource;

[0122] For the current TB, removing the first resource from the selected sidelink grant;

[0123] For the current TB, the first resource in the selected sidelink grant is replaced with the reselected resource.

[0124] In this embodiment, the selected sidelink grant may be updated for subsequent periods of periodic transmission (eg, the first resource is removed or replaced), so that subsequent transmissions all use the resources recorded by the updated sidelink grant.

[0125] Considering that the reserved resources of the TB after updating the sidelink grant are not necessarily continuous, such as the reselected resources are discontinuous with other reserved resources of the TB, if the reselected resources are used to replace the first resource in the selected sidelink grant, the reserved resources of the TB after updating the sidelink grant will be discontinuous. Therefore, the UE can also update the sidelink grant only for the current period (i.e., the current TB) of non-periodic transmission or periodic transmission. At this time, the UE maintains the selected sidelink grant as follows: For subsequent TBs, maintain the selected sidelink grant. So that the subsequent periods still use the initially selected resources for transmission, thereby maintaining MCSt as much as possible.

[0126] It should be noted that the above-mentioned "replacing the first resource in the selected sidelink grant with the reselected resources" and "for the current TB, replacing the first resource in the selected sidelink grant with the reselected resources" are only performed in the process of the UE updating the selected sidelink grant under the condition that the UE has not executed the abandonment of the first transmission resource. Under the condition that the UE has executed the abandonment of the first transmission resource, the process of the UE updating the selected sidelink grant does not include the above-mentioned "replacing the first resource in the selected sidelink grant with the reselected resources" and "for the current TB, replacing the first resource in the selected sidelink grant with the reselected resources".

[0127] For example, Figure 7As shown, the UE performs continuous multi-slot transmission and channel access fails before the transmission of the first slot of MCSt. If the UE needs 2 time slots to perform channel access, the UE can use only the first 2 resources of MCSt as the first resources and remove them from the selected sidelink grant, and perform resource reselection for the first resource, using the reselected resource to replace the first resource in the selected sidelink grant.

[0128] It can be understood that, in this example, the UE performs resource reselection and updates the sidelink grant accordingly, so that subsequent transmissions all use the initial retransmission resources in the updated sidelink grant.

[0129] For example, Figure 8 As shown, the UE performs continuous multi-slot transmission, and the channel access fails before the MCSt transmission, then the UE can remove the entire MCSt from the sidelink grant and reselect resources for it. When reselecting resources, the UE randomly selects transmission resources from the candidate resource set (the candidate set is determined according to the length of the continuous multi-slot transmission), and only updates the sidelink grant for the transmission of the current TB, and uses the reselected resources for transmission, and maintains the selected sidelink grant for subsequent TBs, so that subsequent periodic transmissions still use the primary resources.

[0130] Implementation Method 3

[0131] This embodiment describes an example of reselecting resources for the entire TB.

[0132] In this embodiment, after the UE clears the selected sidelink grant, it will lose the record of all initially selected resources, thereby triggering resource reselection for the entire TB.

[0133] As a possible implementation, after clearing the selected sidelink grant, the UE can re-determine the transmission type (single time slot transmission or continuous multi-time slot transmission), that is, the UE can reselect to perform single time slot transmission or continuous multi-time slot transmission each time it reselects resources for the entire TB.

[0134] It should be noted that, when the transmission type re-determined by the UE is single-slot transmission, there is no need to indicate the length L, and resource reselection can be performed according to the traditional resource selection process. When the transmission type re-determined by the UE is continuous multi-slot transmission, the UE needs to determine the length L of the continuous multi-slot transmission, and after determining the length L, perform resource reselection according to the length L to meet the transmission requirements of MCSt, specifically including the following two methods:

[0135] Mode 1: The physical layer of the UE determines a candidate resource set according to the length L, and the MAC layer of the UE performs random resource selection from the candidate resource set.

[0136] In method 1, the physical layer can adopt the method of determining the candidate resource set according to the length L as described in the relevant embodiment of step 201 above, so that each candidate resource in the determined candidate resource set is a continuous multi-slot candidate resource with a length of L. The MAC layer randomly selects resources from the candidate resource set to ensure that the selected transmission resources can meet the transmission requirements of MCSt.

[0137] Mode 2: The physical layer of the UE determines a candidate resource set according to a traditional resource selection mechanism, and the MAC layer of the UE determines the transmission resource according to L when performing resource selection.

[0138] In method 2, the physical layer can adopt a traditional resource selection mechanism (such as the single-slot resource selection mechanism described in the relevant embodiment of step 201 above) to determine a set of candidate resources for a single time slot, and the MAC layer can then select multiple single-slot candidate resources with a total length of L from the candidate resource set, thereby ensuring that the selected transmission resources can meet the transmission requirements of MCSt.

[0139] Optionally, the length L is not greater than the maximum number of transmissions Nmax that the SCI can indicate, and Nmax can take values ​​{2, 3}.

[0140] In one embodiment, after completing resource reselection for the entire TB, the UE selects a transmission opportunity according to the reselected resources, and determines the selected transmission as the selected sidelink grant.

[0141] In this embodiment, the transmission opportunity includes at least the initial transmission opportunity, and if the UE chooses to perform retransmission, it may also include the retransmission opportunity. For example, for non-periodic transmission, the transmission opportunity only includes the initial retransmission opportunity of the current TB, and for periodic transmission, the transmission opportunity includes the initial retransmission opportunity of the current TB and the initial retransmission opportunity of subsequent TBs separated by the resource reservation period.

[0142] For example, Fig. 9 As shown, when the UE fails to access the channel, if it chooses to clear the sidelink grant, it will trigger the UE to reselect resources for the entire TB. In other words, the UE needs to re-execute the resource selection process. For the current TB, the UE determines to perform continuous multi-slot transmission, and the length L of the continuous multi-slot transmission is 2. Then, the MAC layer of the UE selects resources from the candidate resource set reported by the physical layer under the premise of ensuring MCSt, and regards the reselected initial transmission and retransmission timing as the selected sidelink grant.

[0143] Implementation Method 4

[0144] This embodiment describes an example of abandoning the first resource.

[0145] In this embodiment, abandoning the first resource means that the transmission corresponding to the first resource will not be performed. For example, TB will be transmitted three times in time slots 1, 2 and 3. If time slot 1 is abandoned, TB will only be transmitted twice in time slots 2 and 3.

[0146] As a possible implementation manner, the UE abandons the first resource when a first condition is met, where the first condition includes at least one of the following:

[0147] Item B-1: the first resource is a transmission resource for continuous multi-slot transmission;

[0148] Item B-2: TB currently has other reserved resources;

[0149] B-3: The resource selection window T or resource reselection window T is less than the length L of continuous multi-slot transmission;

[0150] Item B-4: It is impossible to reselect transmission resources for the first resource.

[0151] For item B-1, the first resource is the transmission resource for continuous multi-slot transmission, which means that the UE performs continuous multi-slot transmission. Then, channel access failure will have an impact on the transmission of the entire MCSt. Therefore, the UE can abandon the transmission resources of the entire continuous multi-slot transmission to abandon the transmission of the entire MCSt (that is, the first resource is the transmission resource of the entire MCSt), or it can only abandon the first M transmission resources of MCSt (that is, the first resource is the first M transmission resources) so as to continue to perform channel access for the remaining MCSt transmission resources.

[0152] For item B-2, if the UE abandons the current transmission resources and the current TB still has other reserved resources, then the UE's abandonment of the current transmission resources will have little impact on the transmission of the entire TB, and the UE still has the opportunity to complete the transmission on other reserved resources subsequent to the current TB, so the first resource can be abandoned at this time.

[0153] For item B-3, if the resource selection (or reselection) window is smaller than the length L of MCSt, the UE cannot select L consecutive transmission resources. In this case, the UE can abandon the transmission of the entire MCSt or only abandon N transmissions (if one transmission only occupies one resource, then N resources are abandoned) by abandoning the corresponding first resource, where N is the difference between L and the length T of the resource selection (or reselection) window.

[0154] For item B-4, the UE may not be able to select suitable resources even if resource selection is performed because it cannot meet the HARQ RTT limit or the maximum length indicated by the SCI. In this case, the UE can abandon the current transmission resource (ie, the first resource).

[0155] Implementation Method 5

[0156] This implementation describes an example of the behavior after giving up the first resource. Depending on whether the current TB has other reserved resources, it can be divided into the following two situations.

[0157] Case 1: When the current TB has other reserved resources, the UE performs at least one of the following:

[0158] performing channel access for the other reserved resources;

[0159] updating the selected sidelink grant;

[0160] The selected sidelink grant is maintained.

[0161] In case 1, if the UE abandons the current transmission resource (i.e., the first resource) and the current TB still has other reserved resources, the UE can continue to perform channel access for the other reserved resources, and can choose to maintain the selected sidelink grant, that is, for periodic services, the UE transmits subsequent TBs according to the original sidelink grant, or can choose to update the sidelink grant, that is, the UE removes the abandoned resources (i.e., the first resource) from the selected sidelink grant, and for periodic services, the UE only transmits according to the updated sidelink grant. For example, if the selected sidelink grant includes 3 resources, the UE removes the first 2 resources of the 3 resources from the sidelink grant, and the updated sidelink grant only includes the last 1 resource.

[0162] For example, Fig.10 As shown, assuming that the UE performs MCSt transmission and the channel access fails before the first group of MCSt transmission, since there are other reserved resources for the current TB later, the UE can abandon the first group of MCSt transmission and continue to perform channel access for the second group of MCSt transmission in the cycle. After abandoning the current first MCSt transmission, the UE can choose to still maintain the selected sidelink grant to ensure the transmission opportunity of the next TB, that is, for the next TB, the original sidelink grant is still used for transmission.

[0163] Case 2: When there are no other reserved resources in the current TB, the UE maintains the selected sidelink grant.

[0164] In case 2, if the current TB has no other reserved resources after the UE abandons the current transmission resources, the UE maintains the selected sidelink grant so that the UE performs subsequent TB transmissions (such as subsequent periodic transmissions of periodic transmissions) according to the original sidelink grant.

[0165] As a possible implementation, in situation 2, the UE reduces the value of the counter (eg, counter) of the resource selection process by 1.

[0166] It should be noted that in the resource selection process, for periodic transmission, the UE will confirm the value of the counter counter. According to the traditional resource selection mechanism, the value of the counter counter will be reduced by 1 only when the initial transmission and retransmission of the current TB are completed. However, considering that if the value of the counter counter is not reduced by 1, it will not reach the value of zero and trigger resource reselection, the embodiment of the present application is set to reduce the value of the counter counter by 1 when the last transmission of the current TB is abandoned (that is, the current TB has no other reserved resources after abandonment) to avoid the situation where resource reselection cannot be triggered by the value of the counter counter.

[0167] For example, Fig.11 As shown in the figure, it is assumed that the UE performs MCSt transmission with a length of 3 slots, and the channel access fails before the transmission. Since the size of the resource reselection window is 2 slots, which is smaller than the length of MCSt, the UE chooses to abandon the current transmission. To ensure the normal subsequent periodic transmission, the UE does not clear the sidelink grant, that is, it keeps the previously selected sidelink grant, and reduces the counter value by 1 after the LBT fails, to prevent the subsequent transmission from being unable to perform resource reselection because the counter value has not been reduced to 0.

[0168] Implementation Method 6

[0169] This embodiment describes an example of maintaining the selected sidelink grant.

[0170] In one embodiment, if the current transmission is periodic transmission, the UE maintains the selected sidelink grant for subsequent periodic transmissions.

[0171] In this embodiment, the UE may update the sidelinkgrant only for the current period of non-periodic transmission or periodic transmission, that is, if the current transmission is periodic transmission, for the subsequent periodic transmissions, the UE maintains the selected sidelinkgrant unchanged, so that the UE only uses the updated sidelink grant resources for transmission for the current TB, and for subsequent TBs, still uses the initially selected resources for transmission to maintain MCSt as much as possible.

[0172] As described in the relevant embodiments of Implementation Method 2, considering that the reserved resources of the TB may not be continuous after the sidelink grant is updated, the UE maintains the selected sidelink grant for subsequent TBs so that the initial selected resources are still used for transmission in subsequent periods. This can avoid the situation where the reserved resources of the TB are discontinuous after the sidelink grant is updated, thereby maintaining MCSt as much as possible.

[0173] In one embodiment, after the UE abandons the current transmission resource (ie, the first resource), the UE maintains the selected sidelink grant.

[0174] In this embodiment, as in the related embodiment described in Implementation Mode 5, if the current TB has no other reserved resources after the UE abandons the current transmission resources, and the current transmission is a periodic transmission, the UE maintains the selected sidelink grant so that subsequent TBs can be transmitted according to the selected sidelink grant. If the current TB still has other reserved resources after the UE abandons the current transmission resources, the UE can choose to maintain and / or update the selected sidelink grant. For periodic services, when the UE chooses to maintain the selected sidelink grant, the UE will transmit subsequent TBs according to the selected sidelink grant.

[0175] The resource selection method provided in the embodiment of the present application can be executed by a resource selection device. In the embodiment of the present application, the resource selection device provided in the embodiment of the present application is described by taking the resource selection method executed by the resource selection device as an example.

[0176] In a second aspect, an embodiment of the present application provides a resource selection device, which is applied to a user equipment UE, such as Fig.12 As shown, the resource selection device 100 includes the following modules:

[0177] The execution module 101 is configured to execute at least one of the following according to the first resource when the access channel fails:

[0178] performing resource reselection for the first resource;

[0179] Update the selected sidelink grant;

[0180] maintaining the selected sidelink grant;

[0181] clearing the selected sidelink grant;

[0182] abandoning the first resource;

[0183] The first resource is a transmission resource that cannot be transmitted due to a channel access failure.

[0184] Optionally, the first resource includes at least one of the following: a transmission resource for single time slot transmission, a transmission resource for continuous multi-time slot transmission, and first M transmission resources of the transmission resource for continuous multi-time slot transmission, where M is a positive integer.

[0185] Optionally, the execution module 101 includes:

[0186] The first reselection module is used to randomly select a transmission resource from the candidate resource set, or to select a transmission resource that is continuous with other reserved resources of the current TB from the candidate resource set.

[0187] Optionally, the first resource is not indicated by direct link control information SCI.

[0188] Optionally, the execution module 101 includes:

[0189] An update module is configured to perform at least one of the following:

[0190] removing the first resource from the selected sidelink grant;

[0191] replacing the first resource in the selected sidelink grant with a reselected resource;

[0192] For the current TB, removing the first resource from the selected sidelink grant;

[0193] For the current TB, the first resource in the selected sidelink grant is replaced with the reselected resource.

[0194] Optionally, the execution module 101 includes:

[0195] The first maintaining module is used to maintain the selected sidelink grant for subsequent TBs.

[0196] Optionally, the device further comprises:

[0197] The first processing module is used to re-determine the transmission type after clearing the selected sidelink grant.

[0198] Optionally, the device further comprises:

[0199] A second processing module, configured to determine a length L of continuous multi-slot transmission when the transmission type re-determined by the UE is continuous multi-slot transmission;

[0200] The third processing module is used to perform resource reselection according to the length L.

[0201] Optionally, the execution module 101 includes:

[0202] A abandonment module is used to abandon the first resource when a first condition is met, and the first condition includes at least one of the following:

[0203] The first resource is a transmission resource for continuous multi-slot transmission;

[0204] Currently TB has other reserved resources;

[0205] The resource selection window T or the resource reselection window T is smaller than the length L of the continuous multi-slot transmission;

[0206] It is impossible to reselect a transmission resource for the first resource.

[0207] Optionally, the device further comprises:

[0208] The second maintaining module is used to maintain the selected sidelink grant when the current TB has no other reserved resources.

[0209] Optionally, the device further comprises:

[0210] The fourth processing module is used to reduce the value of the counter by 1.

[0211] Optionally, the device further comprises:

[0212] A fifth processing module is configured to, after the UE abandons the first resource, if the current TB has other reserved resources, cause the UE to perform at least one of the following:

[0213] performing channel access for the other reserved resources;

[0214] updating the selected sidelink grant;

[0215] The selected sidelink grant is maintained.

[0216] The resource selection device provided in the embodiment of the present application can implement the various processes implemented by the method embodiment of the first aspect and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0217] like Fig.13 As shown, the embodiment of the present application further provides a communication device 500, including a processor 501 and a memory 502, the memory 502 stores a program or instruction that can be run on the processor 501, for example, when the communication device 500 is a user equipment, the program or instruction is executed by the processor 501 to implement each step of the above resource selection method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0218] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned resource selection method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0219] The processor is the processor in the user equipment described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0220] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned resource selection method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0221] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0222] The embodiments of the present application further provide a computer program / program product, which is stored in a storage medium and is executed by at least one processor to implement the various processes of the above-mentioned resource selection method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described here.

[0223] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises one..." does not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0224] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general hardware platform, and of course, can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, disk, CD, etc.), including several instructions to enable a terminal or a network-side device to execute the methods described in each embodiment of the present application.

[0225] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of the present application and the scope of protection of the claims, and these implementation methods are all within the protection of the present application.

Claims

1. A resource selection method, characterized in that: Applied to user equipment UE, including: When the UE fails to access the channel, performing at least one of the following according to the first resource: performing resource reselection for the first resource; Update the selected sidelink grant; maintaining the selected sidelink grant; clearing the selected sidelink grant; abandoning the first resource; The first resource is a transmission resource that cannot be transmitted due to a channel access failure.

2. The method according to claim 1, characterized in that The first resource includes at least one of the following: a transmission resource for single time slot transmission, a transmission resource for continuous multi-time slot transmission, and the first M transmission resources of the transmission resource for continuous multi-time slot transmission, where M is a positive integer.

3. The method according to claim 1, characterized in that The UE performing resource reselection for the first resource includes: The UE randomly selects a transmission resource from the candidate resource set, or the UE selects a transmission resource from the candidate resource set that is continuous with other reserved resources of the current TB.

4. The method according to claim 3, characterized in that: The first resource is not indicated by direct link control information SCI.

5. The method according to claim 1, characterized in that: The UE updates the selected sidelink grant, including at least one of the following: removing the first resource from the selected sidelink grant; replacing the first resource in the selected sidelink grant with a reselected resource; For the current TB, removing the first resource from the selected sidelink grant; For the current TB, the first resource in the selected sidelink grant is replaced with the reselected resource.

6. The method according to claim 1, characterized in that Maintaining, by the UE, the selected sidelink grant, includes: For subsequent TBs, the selected sidelink grant is maintained.

7. The method according to claim 1, characterized in that After the UE clears the selected sidelink grant, the method further includes: The UE re-determines the transmission type.

8. The method according to claim 7, characterized in that Also includes: In a case where the transmission type re-determined by the UE is continuous multi-slot transmission, the UE determines a length L of the continuous multi-slot transmission; The UE performs resource reselection according to the length L.

9. The method according to claim 1, characterized in that: The abandoning the first resource comprises: The UE abandons the first resource when a first condition is met, where the first condition includes at least one of the following: The first resource is a transmission resource for continuous multi-slot transmission; Currently TB has other reserved resources; The resource selection window T or the resource reselection window T is smaller than the length L of the continuous multi-slot transmission; It is impossible to reselect a transmission resource for the first resource.

10. The method according to claim 1, characterized in that After the UE abandons the first resource, the method further includes: When there are no other reserved resources in the current TB, the UE maintains the selected sidelink grant.

11. The method according to claim 10, characterized in that Also includes: The UE reduces the value of the counter by 1.

12. The method according to claim 1, characterized in that After the UE abandons the first resource, the method further includes: In the case that the current TB has other reserved resources, the UE performs at least one of the following: performing channel access for the other reserved resources; updating the selected sidelink grant; The selected sidelink grant is maintained.

13. A resource selection device, characterized in that: Applied to user equipment UE, the device includes: An execution module, configured to execute at least one of the following according to the first resource when the access channel fails: performing resource reselection for the first resource; Update the selected sidelink grant; maintaining the selected sidelink grant; clearing the selected sidelink grant; abandoning the first resource; The first resource is a transmission resource that cannot be transmitted due to a channel access failure.

14. A communication device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the resource selection method according to any one of claims 1 to 12 are implemented.

15. A readable storage medium, characterized in that: The readable storage medium stores a program or an instruction, and when the program or the instruction is executed by a processor, the resource selection method according to any one of claims 1 to 12 is implemented.

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