Mode 1 resource allocation for sidelink transmissions in unlicensed spectrum

Abstract

Systems and processes are described for resource allocation for new radio (NR) sidelink transmissions in an unlicensed spectrum (NR-U). More specifically, the resource allocation is performed for mode 1 sidelink transmission. The methods and systems include a time slot field configured to indicate a time slot between a downlink control information (DCI) format 350 transmission and a physical sidelink control channel (PSCCH) or a physical sidelink shared channel (PSSCH) transmission.

Description

Technical Field

[0001] The present disclosure generally relates to sidelink (SL) transmissions in wireless communications. Background Art

[0002] The use of wireless communication systems is growing rapidly. In addition, wireless communication technology has evolved from voice-only communications to also include the transmission of data (such as the Internet and multimedia content) to various devices. In order to accommodate the increasing number of devices that transmit both voice and data signals, many wireless communication systems share available communication channel resources between devices. Summary of the invention

[0003] This specification describes a process for resource allocation of new radio (NR) sidelink transmissions in unlicensed spectrum (NR-U). More specifically, resource allocation is performed for mode 1 sidelink transmissions. The method and system include a time gap field, which is configured to indicate the time gap between downlink control information (DCI) format 3_0 transmission and physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH) transmission. In another example, DCI 3_0 includes a field specifying a physical sidelink feedback channel to a hybrid automatic repeat request (PSFCH to HARQ) feedback timing indicator. In another example, the system and process include a resource reassessment or preemption process that is forced before resource allocation. If necessary, add additional time gaps. The systems and operations described herein may be related to Release 18 of the fifth generation (5G) of the third generation partnership project (3GPP).

[0004] Typically, unlicensed spectrum or idle frequency bands can be used for transmission. For example, these frequency bands may include 2.4 and 5 GHz. The Listen Before Talk (LBT) protocol enables user equipment (UE) to use unlicensed spectrum while maintaining fair access relative to WiFi devices. In particular, the processes herein are intended to avoid conflicts with WiFi transmissions. The systems and processes described in this specification are configured for Mode 1, where Uu operations for Mode 1 use only licensed spectrum (e.g., RAN1, RAN2, and RAN4). Typically, the channel access mechanism from NR-U is reused for unlicensed sidelink operations.

[0005] Typically, sidelink mode 1 resource allocation (RA) includes dynamic grants. Each of the grants of type 1 and type 2 configurations is supported as a baseline for sidelink operation in a shared carrier, subject to applicable regional rules. At least in dynamic channel access, the SL UE performs one of type 1 or type 2 LBT operations before using the allocated resources for SL transmission. Due to potential conflicts with WiFi transmissions, the UE still performs LBT operation. LBT operation is performed in compliance with transmission gap and LBT sensing idle time requirements (such as those specified in TS137.213).

[0006] The systems and methods described in this specification achieve one or more advantages. The systems and methods described herein enhance Mode 1 resource allocation on shared spectrum channel access to prevent conflicts such as with WiFi transmissions. The enhanced resource tolerance for unlicensed SL transmissions in Mode 1 includes timeline considerations for LBT sensing to allow LBT operation in dynamic allocation. For scenarios including multiple PSFCH opportunities, SL HARQ reports are generated for nodes (e.g., base stations, next generation nodes gNB, access points, etc.). The enhanced resource allocation updates the authorization of the SL configuration. The enhanced resource allocation accommodates timeline restrictions on resource reassessment and preemption on shared spectrum channel access. For example, the SL UE performs a Type 1 LBT operation or a Type 2 LBT operation prior to SL transmission. For Type 1 LBT, which is a more general LBT, the LBT sensing duration is flexible based on the channel access priority level (CAPC) value. The transmitted two-bit value indicates which channel access priority the initiating UE is using to obtain the channel occupancy time (COT) for SL transmission. For Type 2 LBT, the sensing duration (eg, 0 microseconds (μs) - 25 μs) is selected based on the specific LBT operation being performed. The enhanced resource margin enables different LBT operations to be performed without conflict.

[0007] One or more advantages may be achieved by at least one or more of the following embodiments described in the Examples section below.

[0008] In some implementations, the process is performed by a network element, a UE, or a base station, such as a next generation node (gNB). In some implementations, one or more non-transitory computer-readable media store instructions that, when executed by at least one processing device, cause the at least one processing device (or another device in communication with the at least one processing device) to perform the process.

[0009] The details of one or more specific implementations are set forth in the drawings and description below. Other features and advantages will be apparent from the detailed description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A wireless network according to some embodiments is illustrated.

[0011] Figure 2 An illustration of an example transmission timeline for a UE for SL transmission is shown.

[0012] Figure 3 An illustration of an example transmission timeline for a UE for SL transmission in an unlicensed spectrum is shown.

[0013] Figure 4 An illustration of an example transmission timeline for a UE for SL transmission is shown.

[0014] Figure 5 An illustration of an example transmission timeline for a UE for configured Grant Type 1 SL transmissions is shown.

[0015] Figure 6 An illustration of an example transmission timeline for a UE for SL transmission is shown.

[0016] Figure 7 A flow chart of an example process for resource allocation for Mode 1 SL transmission by a UE in unlicensed spectrum is shown.

[0017] Figure 8 A flow chart of an example process for resource allocation for Mode 1 SL transmission by a UE in unlicensed spectrum is shown.

[0018] Fig. 9 A flow chart of an example process for resource allocation for Mode 1 SL transmission by a UE in unlicensed spectrum is shown.

[0019] Fig.10 A flow chart of an example process for resource allocation for Mode 1 SL transmission by a UE in unlicensed spectrum is shown.

[0020] Fig.11 A flow chart of an example process for resource allocation for Mode 1 SL transmission by a UE in unlicensed spectrum is shown.

[0021] Fig.12 A user equipment (UE) according to some embodiments is illustrated.

[0022] Fig.13 An access node according to some embodiments is illustrated.

[0023] According to various embodiments herein, like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION

[0024] This specification describes systems and processes that enable enhanced sidelink (SL) resource allocation for transmissions in mode 1 when unlicensed spectrum (NR-U) is used, such as by a user equipment (UE). Typically, a SL UE performs a type 1 LBT operation or one of one or more sets of type 2 LBT operations before performing an SL transmission. Different LBTs have different corresponding configurations. Type 1 LBT includes a flexible LBT sensing duration based on an associated CAPC value, as shown in Table 1 or Table 2 below. A two-bit value is generated that indicates which channel access priority the initiating device is using to obtain a COT for SL transmission. Typically, a downlink (DL) CAPC value from Table 1 or an uplink (UL) CAPC value from Table 2 can be used for SL resource allocation. Typically, the maximum LBT sensing idle time is 1023*9μs (e.g., sensing slot duration), which is approximately 9 milliseconds (ms), or several time slots. For type two, the following configuration is typically used. Type 2A LBT is associated with an LBT sensing duration of 25μs. Type 2B LBT is associated with a sensing duration between 16 μs and 25 μs. Type 2CLBT does not include a channel sensing operation before transmission. Instead, if the spectrum is idle, the spectrum is used without countdown or calculation of CW. The time gap to the previous transmission is less than 16 μs. The duration of the corresponding transmission is less than or equal to 584 μs.

[0025] Table 1: NR-U (gNB) downlink configuration for Type 1 LBT

[0026]

[0027] As shown in Table 1, m p is the maximum number of transmission attempts for priority level p. CW p is the contention window for a given priority level p. CW max,p is the maximum contention window for a given priority level p. CW min,p is the minimum contention window for a given priority level p. cot,pm is the maximum channel occupancy time for a given priority level p. According to the 3GPP standard, a device mcot,p The longer periods of time are not continuously transmitted in the unlicensed spectrum. Table 1 shows the allowed CW size for each priority level for DL.

[0028] Table 2: Uplink configuration of NR-U (UE) for Type 1 LBT

[0029]

[0030] As shown in Table 2, m pis the maximum number of transmission attempts for priority level p. CW p is the contention window for a given priority level p. CW max,p is the maximum contention window for a given priority level p. CW min,p is the minimum contention window for a given priority level p. cot,pm is the maximum channel occupancy time for a given priority level p. According to the 3GPP standard, a device mcot,p Longer periods of time are not continuously transmitted in the unlicensed spectrum. Table 2 shows the allowed CW size for each priority level for UL.

[0031] Enhanced resource allocation for SL transmission using unlicensed spectrum in Mode 1 is based on the following process for SL transmission. A node (e.g., a gNB) is configured to schedule NR sidelink resources for use by a UE for sidelink transmission. First, a request for sidelink scheduling is sent by an initiating device (e.g., a UE). The request may include a scheduling request (SR) and a buffer status report (BSR). Typically, an SR report notifies the node that there is data to be transmitted at the UE. Typically, a BSR is a MAC control element (CE) from the UE to the node (network) that carries information about how much data is in the UE buffer for transmission.

[0032] Based on the SR and / or BSR, the node may then perform a SL authorization operation. For SL authorization, the node may perform dynamic authorization, configured authorization type 1, or configured authorization type 2. Typically, the SL authorization includes an allocation of PSCCH and / or PSSCH resources. In some implementations, DCI format 3_0 is used for SL authorization. The UE sends SL data to a device (e.g., another UE) and receives HARQ feedback from the other UE. The UE sends a received SL HARQ feedback report to the node. This occurs if the node provides physical uplink control channel (PUCCH) resources for feedback in the allocation. A node may perform SL authorization for a retransmission, such as in response to receiving a negative acknowledgment (NACK) for a previous transmission.

[0033] Typically, in NR SL transmission, for SL dynamic or SL configured grant type 2, there is a delay greater than T between DCI 3_0 transmissions from the node to the UE. proc time gap. UE SL transmission occurs and there is a gap until SL HARQ is received. There is a time slot offset between SL HARQ and SL HARQ report from UE to node. This is not multiplexed with uplink control information (UCI). When NACK is performed, there is a dynamic grant for SL ReTx.

[0034] The node and / or UE may perform SL resource allocation for mode 1 in an unlicensed spectrum by adjusting the SL resource allocation process in one or more of the following ways. In an example, a timeline restriction is imposed in the mode 1 resource allocation. The method described in more detail later includes using the time gap field in the DCI 3_0 format to indicate the gap between DCI 3_0 and PSCCH / PSSCH. In another example, the SL HARQ report in the mode 1 resource allocation is modified. DCI 3_0 includes a field for the PSFCH to HARQ feedback timing indicator. In this example, for the case of multiple PSFCH transmission opportunities (in order to solve the LBT failure problem), the last PSFCH opportunity is used by the UE to determine the timing of PUCCH transmission in the case of SL HARQ reporting to the node. In some specific implementations, multiple PUCCH opportunities are allocated, and each opportunity corresponds to a candidate PSFCH transmission opportunity. Multiple PUCCH opportunities are determined using the same or multiple different PSFCH to HARQ feedback timing indicator values ​​in DCI 3_0. In another example, the authorization of the SL configuration is used for SL resource allocation for mode 1 in an unlicensed spectrum. In another example, for unlicensed spectrum (NR-U), the UE uses the timing of resource re-evaluation and preemption process for SL resource allocation in Mode 1. Each of these examples is described in more detail subsequently. Each of these examples enhances Mode 1 resource allocation on shared spectrum channel access by providing timeline considerations for LBT sensing, SL HARQ reporting to the base station in the case of multiple PSFCH opportunities, and authorization configuration of SL configuration.

[0035] Figure 1 A wireless network 100 is illustrated according to some embodiments. The wireless network 100 includes UEs 102 and base stations 104 connected via one or more channels 106A, 106B across an air interface 108. The UEs 102 and base stations 104 communicate using a system that supports control for managing access of the UEs 102 to the network via the base stations 104.

[0036] For convenience and not for purposes of limitation, the wireless network 100 is described in the context of Long Term Evolution (LTE) and fifth generation (5G) New Radio (NR) communication standards, as defined by the Third Generation Partnership Project (3GPP) technical specifications. More specifically, the wireless network 100 is described in the context of a non-standalone (NSA) network that combines both LTE and NR (e.g., an E-UTRA (Evolved Universal Terrestrial Radio Access)-NR Dual Connectivity (EN-DC) network and a NE-DC network). However, the wireless network 100 may also be a standalone (SA) network that combines only NR. In addition, other types of communication standards are possible, including future 3GPP systems (e.g., sixth generation (6G)) systems, Institute of Electrical and Electronics Engineers (IEEE) 802.11 technologies (e.g., IEEE 802.11a; IEEE 802.11b; IEEE 802.11g; IEEE 802.11-2007; IEEE 802.11n; IEEE 802.11-2012; IEEE 802.11ac; or other currently or future developed IEEE 802.11 technologies), IEEE 802.16 protocols (e.g., WMAN, WiMAX, etc.), etc. Although various aspects may be described herein using terms generally associated with 5G NR, various aspects of the present disclosure may be applied to other systems, such as 3G, 4G, and / or systems after 5G (e.g., 6G).

[0037] In the wireless network 100, UE 102 and any other UE in the system can be, for example, a laptop computer, a smart phone, a tablet computer, a machine type device such as a smart meter or a dedicated device for healthcare monitoring, remote security monitoring, an intelligent transportation system, or any other wireless device with or without a user interface. In the network 100, a base station 104 provides a network connection to a wider network (not shown) to UE 102. The UE 102 connection is provided via an air interface 108 in a base station service area provided by the base station 104. In some embodiments, this wider network can be a wide area network operated by a cellular network provider, or it can be the Internet. Each base station service area associated with the base station 104 is supported by an antenna integrated with the base station 104. The service area is divided into a plurality of sectors associated with certain antennas. Such sectors can be physically associated with fixed antennas, or can be assigned to physical areas with tunable antennas or antenna settings, which can be adjusted in a beamforming process for directing signals to a specific sector.

[0038] UE 102 includes control circuitry 110 coupled to transmission circuitry 112 and reception circuitry 114. Transmission circuitry 112 and reception circuitry 114 may each be coupled to one or more antennas. Control circuitry 110 may be adapted to perform operations associated with selection of a codec for communication and to adapt the codec for wireless communication as part of system congestion control. Control circuitry 110 may include various combinations of dedicated circuitry and baseband circuitry. Transmission circuitry 112 and reception circuitry 114 may be adapted to transmit and receive data, respectively, and may include radio frequency (RF) circuitry or front end module (FEM) circuitry, including communications using the codecs described herein.

[0039] In various embodiments, aspects of the transmission circuit 112, the receiving circuit 114, and the control circuit 110 can be integrated in various ways to implement the circuits described herein. The control circuit 110 may be adapted or configured to perform various operations, such as UE-related operations described elsewhere in this disclosure. The transmission circuit 112 may transmit multiple multiplexed uplink physical channels. The multiple uplink physical channels may be multiplexed according to time division multiplexing (TDM) or frequency division multiplexing (FDM) and carrier aggregation. The transmission circuit 112 may be configured to receive block data from the control circuit 110 for transmission across the air interface 108. Similarly, the receiving circuit 114 may receive multiple multiplexed downlink physical channels from the air interface 108 and relay these physical channels to the control circuit 110. The multiple downlink physical channels may be multiplexed according to TDM or FDM and carrier aggregation. The transmission circuit 112 and the receiving circuit 114 may transmit and receive both control data and content data (e.g., messages, images, videos, etc.) structured within the data blocks carried by the physical channels.

[0040] Figure 1 A base station 104 is also illustrated. In an embodiment, the base station 104 may be an NG radio access network (RAN) or a 5G RAN, an E-UTRAN, a non-terrestrial cell, or a traditional RAN such as a UTRAN or a GERAN. As used herein, the term "NG RAN" or the like may refer to a base station 104 operating in an NR or 5G wireless network 100, and the term "E-UTRAN" or the like may refer to a base station 104 operating in an LTE or 4G wireless network 100. The UE 102 utilizes connections (or channels) 106A, 106B, each of which includes a physical communication interface or layer.

[0041] Base station 104 circuitry may include control circuitry 116 coupled to transmission circuitry 118 and reception circuitry 120. Transmission circuitry 118 and reception circuitry 120 may each be coupled to one or more antennas that may be used to enable communications over air interface 108.

[0042] The control circuit 116 may be adapted to perform the following operations: analyze and select a codec, manage congestion control and bandwidth limit communications from a base station, determine whether a base station is aware of a codec, and communicate with a base station that is aware of a codec to manage codec selection for various communication operations described herein. The transmission circuit 118 and the reception circuit 120 may be adapted to transmit and receive data to any UE connected to the base station 104, respectively, using data generated by the various codecs described herein. The transmission circuit 118 may transmit a downlink physical channel including a plurality of downlink subframes. The reception circuit 120 may receive a plurality of uplink physical channels from various UEs including the UE 102.

[0043] In this example, one or more channels 106A, 106B are shown as air interfaces that implement communication coupling, and may conform to cellular communication protocols, such as GSM protocols, CDMA network protocols, PTT protocols, POC protocols, UMTS protocols, 3GPP LTE protocols, Advanced Long Term Evolution (LTE-A) protocols, LTE-based unlicensed spectrum access (LTE-U), 5G protocols, NR protocols, NR-based unlicensed spectrum access (NR-U) protocols, and / or any other communication protocols discussed herein. In an embodiment, UE 102 may directly exchange communication data via the ProSe interface. The ProSe interface may alternatively be referred to as a SL interface, and may include one or more logical channels, including but not limited to PSCCH, PSSCH, PSDCH, and PSBCH.

[0044] Figure 2 A UE (eg, Figure 1 102). The UE is configured to perform SL resource allocation based on the timeline restriction in mode 1 resource allocation. In timeline 200, a time gap 206 between DCI 3_0 reception 202 and PSCCH / PSSCH transmission 204 performed by the UE is shown. The length of the time gap 206 is specified in a field of the DCI 3_0 data. The time gap field indicates the time gap 206 between the DCI 3_0 data reception and the PSCCH / PSSCH transmission. Specifically, the value of the time gap field indicates the value of the index of the table "sl-DCI-ToSL-Trans", which stores the value of the time gap 206 associated with the index value. When the UE is to perform an LBT operation before an initial PSCCH / PSSCH transmission, the time gap 206 can be extended to enable the UE to perform an LBT operation (e.g., type 1 or type 1 LBT).

[0045] The UE can determine the time value of the time gap in different ways. In the example, the value of the time gap is equal to the value indicated by the table "sl-DCI-ToSL-Trans". In this case, each time gap specified in the table is used as specified in the table, and there is no adjustment made to the value by the UE specifically for LBT operation. On the contrary, it is not expected that the UE has a time gap 206 size less than the threshold value based on the LBT type and CAPC index. In this example, the length of the time gap 206 specified by the table is long enough to accommodate the LBT operation of the given LBT type and CAPC index value. In some specific implementations, the value of the time gap 206 specified in the table "sl-DCI-ToSL-Trans" is lengthened relative to the traditional value to accommodate the LBT operation of the UE, thereby ensuring that each time gap is longer than the time threshold required for LBT operation. In some specific implementations, if the time gap 206 specified by the DCI 3_0 transmission 202 is less than the threshold, the resource allocation is rejected.

[0046] Instead of using the time gap value directly, the UE may be configured to add an offset 210 time length to the time gap 208 specified by the table "sl-DCI-ToSL-Trans". The time gap 206 used by the UE is equal to the offset 210 added to the time gap value 208 indicated by the "sl-DCI-ToSL-Trans" table. In this example, the time gap value specified in the table may be the same for conventional operation. The added offset ensures that the UE has allocated time for the LBT operation. The offset value 210 depends on the value of the CAPC index of the LBT operation of the UE (e.g., as previously shown in Tables 1 and 2). In the example, for a larger CAPC index, a larger offset value is provided. The value of the CAPC index is included in the DCI 3_0 transmission 202. The value of the offset 210 may be stored in the table together with the CAPC index value. In some embodiments, the offset 210 may be a function of the CAPC index value. For example, the offset value 208 may be a function of the CW or other values ​​of Tables 1 and 2. In some implementations, the mapping between each CAPC index and the offset value 210 is (pre-)configured for each resource pool.

[0047] Figure 3 A UE (eg, Figure 1102). The timeline 300 shows a feedback configuration based on resource allocation. The SL HARQ report 306 in the Mode 1 resource allocation is used to determine the resource allocation for the SL transmission. Typically, because the UE is operating using unlicensed spectrum, LBT failure is possible and multiple PSFCH transmission opportunities 302a, 302b may be required. This is in contrast to licensed spectrum where a single PSFCH opportunity is used.

[0048] The timing of the UE reporting HARQ feedback to the base station is as follows: For multiple PSFCH feedback opportunities 302a-b, a time gap 304 is configured based on the PSFCH to HARQ feedback timing indicator value. The time gap 304 is usually measured between the last possible PSFCH opportunity 302b and feedback 306.

[0049] The UE may determine the time slot 304 based on the last PSFCH opportunity. The time slot 304 specifies the time between the UE and the base station (e.g., Figure 1 The timing of the PUCCH transmission in the case of a SL HARQ report 306 to the base station 104). Typically, the content of the SL HARQ report 306 to the base station depends on the multiple PSFCH feedback opportunities 302a-b associated with the PSCCH / PSSCH transmission 204. Typically, if the PSFCH opportunities 302a-b are within a time window, the last PSFCH opportunity 302b is the end of the time window. The end of the time window is the beginning of the determined time gap 304.

[0050] The UE may perform SL unicast. In this case, if the UE receives a HARQ ACK in any of the PSFCH opportunities 302a-b, the UE sends a SL HARQ report 306 as an "ACK" transmission to the base station. If the UE does not receive a HARQ ACK in any of the PSFCH opportunities 302a-b, the UE sends a SL HARQ report 306 as a "NACK" transmission to the base station. Although two PSFCH opportunities 302a-b are shown, the number of PSFCH opportunities may be greater than two, and subsequent opportunities and corresponding transmission allocations may be configured in a similar manner as for the PSFCH opportunities 302a-b.

[0051] The UE may perform SL groupcast ACK / NACK transmissions. In this case, if a HARQ ACK is received for each of the receiver UEs in any of the PSFCH opportunities 302a-b, the UE sends a SL HARQ report 306 as an "ACK" transmission to the base station. If any of the PSFCH opportunities 302a-b received by the UE does not include a HARQ ACK, the UE sends a SL HARQ report 306 as a "NACK" transmission to the base station.

[0052] The UE may perform SL multicast NACK-only transmissions. In this case, if the UE receives a HARQ NACK for any of the PSFCH opportunities 302a-b, the UE sends the SL HARQ report 306 as a "NACK" transmission to the base station. If none of the PSFCH opportunities 302a-b received by the UE include a HARQ NACK, the UE sends the SL HARQ report 306 as an "ACK" transmission to the base station. The UE reports to the base station is ACK / NACK, but the UE-UE transmission is NACK-only. This is because the base station determines whether to schedule a retransmission based on the ACK / NACK data received in the report 306.

[0053] Figure 4 A UE (eg, Figure 1 102). The timeline 400 shows a feedback configuration for the UE, including a first SL HARQ report 406a for a first PSFCH opportunity 302a and a second SL HARQ report 406b for a retransmission of the PSFCH opportunity 302b. Typically, because the UE is operating using unlicensed spectrum, LBT failures are possible and multiple PSFCH transmission opportunities 302a, 302b may be required. This is in contrast to licensed spectrum where a single PSFCH opportunity is used.

[0054] The UE determines each of the candidate PSFCH opportunities 302a-b. For example, the UE determines each SL HARQ report 406a-b for each corresponding PSFCH opportunity 306a-b. The UE obtains a first time gap 404a between a first PSFCH opportunity 302a and a first SL HARQ report to a base station 406a. This may be done in the same manner as previously described with respect to Figure 3 The time gap 404a is determined in a similar manner to the time gap 304 described above. The UE determines a second time gap 404b between the second PSFCH opportunity 302b and the second SL HARQ report to the base station 406b. Figure 3 The time slot 404b is determined in a similar manner to the time slot 304.

[0055] The UE may determine each of the time slots 404a, 404b individually. For example, when there are multiple PSFCH transmission opportunities 302a-b to solve the LBT failure problem, multiple PUCCH opportunities 406a-b are allocated, each opportunity 406a-b corresponds to a corresponding candidate PSFCH transmission opportunity 302a-b. The UE may use multiple different PSFCH to HARQ feedback timing indicator values ​​in the DCI 3_0 data 202 to determine the time slots 404a-b for multiple PUCCH opportunities 406a-b. In some specific implementations, a single value for the PSFCH to HARQ feedback timing indicator is received in the DCI 3_0. In this example, the UE determines each time slot 404a-b to be the same length.

[0056] In some implementations, to a base station (e.g., Figure 1 The content of each SL HARQ report 406a-b of the base station 104) depends on the corresponding PSFCH feedback of the opportunity 302a-b. For example, the UE can perform SL unicast. In this case, if the UE receives a HARQ ACK in the PSFCH opportunity 302a or 302b, the UE sends the SL HARQ report 406a or 406b as an "ACK" transmission to the base station, respectively. If the UE does not receive a HARQ ACK in either of the PSFCH opportunities 302a or 302b, the UE sends the SL HARQ report 406a or 406b as a "NACK" transmission to the base station, respectively.

[0057] The UE may perform SL multicast ACK / NACK transmissions. In this case, if the UE receives a HARQ ACK for each of the PSFCH opportunities 302a or 302b, the UE sends a SL HARQ report 406a or 406b, respectively, as an "ACK" transmission to the base station. If any PSFCH opportunity 302a or 302b received by the UE does not include a HARQ ACK, the UE sends a SL HARQ report 406a or 406b, respectively, as a "NACK" transmission to the base station.

[0058] The UE may perform SL multicast NACK-only transmissions. In this case, if the UE receives a HARQ NACK for either of the PSFCH opportunities 302a or 302b, the UE sends a SL HARQ report 406a or 406b, respectively, as a "NACK" transmission to the base station. If neither of the PSFCH opportunities 302a or 302b received by the UE includes a HARQ NACK, the UE sends a SL HARQ report 406a or 406b, respectively, as an "ACK" transmission to the base station.

[0059] The UE may change the content or transmission of the second report 406b based on the content of the first report 406a. In an example, if the UE reports the SL HARQ ACK in the earlier PUCCH opportunity 406a, the UE does not use a later PUCCH opportunity, such as report 406b. In another example, if the UE reports the SL HARQ ACK in the earlier report 406a, the UE also reports the SL HARQ ACK for a subsequent PUSCH opportunity (such as for report 406b). In another example, if the UE reports the SL HARQ ACK in the earlier PUSCH opportunity 406a, the content of the SL HARQ report 406b depends on the corresponding PSFCH feedback opportunity 302b. Therefore, reports 406a-b correspond to the results of the corresponding PSFHCH opportunities 302a-b.

[0060] Figure 5 1 shows a UE configured for Grant Type 1 SL transmission (eg, Figure 1 302a-b). The timeline 500 is not based on a DCI 3_0 message, but rather on an RRC message. The configured authorized transmission is in response to an LBT failure that may occur in an unlicensed spectrum. A list of fields called "sl-PSFCH-ToPUCCH-CG-Type1" may be configured for the UE. When multiple PUCCH opportunities 302a-b are allocated to the UE, a configured authorized transmission opportunity time slot 502a-b is allocated for each corresponding candidate PSFCH transmission opportunity 302a-b. The time slot 502a-b represents the time between the UE receiving the PSFCH opportunity 302a-b and the UE sending the corresponding report 406a-b. Typically, the length of the list is equal to the number of candidate PSFCH opportunities 302a-b.

[0061] In some implementations, the lists of fields "sl-TimeResourceCG-Type1" and "sl-FreqResourceCG-Type1" are configured by the UE. These configure the time and frequency resources, respectively, for each PSFCH opportunity 302a-b and any response transmission 406a-b by the UE.

[0062] Multiple PSCCH / PSSCH transmission opportunities mitigate the negative consequences from LBT failures. As previously described for the time slots used to send reports 406a-b to the base station in response to PSFCH opportunities 302a-b, the time slots 502a-b can be configured together (and possibly the same) or they can each be independently configured and each have a different length than one or more other time slots.

[0063] Figure 6A UE (eg, Figure 1 1 and 2. An illustration of example transmission timelines 600a-b for a UE 102 of the same spectrum as the ...

[0064] As shown in timeline 600a, re-evaluation or preemption of resources 602 for time slot 604 is mandatory performed at a specified time T3 before the time slot 604 occurs. For the NR side link on the unlicensed spectrum, the time gap of T3 before the time slot 602 is not enough because the LBT operation performed before the SL transmission takes some additional time. As shown in timeline 600b, for the unlicensed spectrum, the time gap T3 for resource re-evaluation and preemption of the time slot 602 is increased in length by a time gap T4. Adding T4 to the time gap T3 enables the UE to perform the LBT operation before the SL transmission in addition to other functions for preparing the UE to use the allocated time slot 602.

[0065] The value of T4 is configured by the UE as follows. The value of T4 may depend on the value of the CAPC index of the data transmission. For example, a larger CAPC index may correspond to a larger value of adding time T4 to time slot T3 for resource reassessment and preemption. In some implementations, the value of T4 is (pre)configured by resource pool. In some implementations, the value of T4 is predefined and / or static. In some implementations, the value of T4 depends on the subcarrier spacing. For example, if the subcarrier spacing (SCS) is large, the value of T4 is correspondingly large. In some implementations, the LBT operation may fail for the UE. In this case, time slot 602 is discarded and the next time slot 604 is allocated. Then time slot T3 plus T4 is used for resource preemption or reassessment before time slot 604.

[0066] Figure 7 , Figure 8 , Fig. 9 , Fig.10 and Fig.11 An example process performed by a UE for resource allocation for sidelink transmissions in unlicensed spectrum for Mode 1 is shown. In some embodiments, Figures 1 to 6 The electronic device, network, system, chip or component of some other figures or parts or specific implementations thereof may be configured to perform one or more processes, techniques or methods or parts thereof as described herein. Figure 7 One such process 700 is depicted in FIG. The process 700 may be performed by a UE such as Figure 1 UE 102) executes.

[0067] for Figure 7 In the process 700 shown in FIG. 7 , a UE receives ( 702 ) a DCI transmission. As previously described, the DCI transmission includes a field that specifies a time gap value. The time gap value indicates a time gap between receiving the DCI transmission by the UE and transmitting a PSCCH / PSSCH signal by the UE. The time gap specified by the DCI transmission is large enough to allow the UE to perform an LBT operation.

[0068] The UE is configured to determine (704) a time gap between receiving a DCI transmission and sending a PSCCH / PSSCH transmission based on the DCI transmission. The time gap may be the same as the time gap value specified in the DCI time gap field. In some specific implementations, the time gap may be adjusted. For example, the process may include determining (706) a time offset value based on a channel access priority level (CPAC) value in the DCI transmission. The offset value enables the UE to perform an LBT operation. In some specific implementations, the offset value is related to a CAPC index such that when the CAPC index value is larger, the offset is larger. The mapping between the CAPC index value and the corresponding offset value may be predefined or configured per resource pool. The UE is configured to determine (708) a total time gap between receiving a DCI transmission and sending a PSCCH / PSSCH transmission based on the time offset value.

[0069] Figure 8 An example process 800 is shown for resource allocation performed by a UE for sidelink transmission in unlicensed spectrum for Mode 1. Process 800 may be performed by a UE such as Figure 1 UE 102) executes.

[0070] Process 800 includes receiving (802) a DCI transmission indicating a PSFCH to HARQ feedback timing value. The PSFCH to HARQ feedback timing value indicates a PSFCH to HARQ feedback timing value relative to a UE to a base station (eg, Figure 1 The UE may configure a single time gap between the last PSFCH opportunity in the time window and the corresponding SL HARQ feedback report to the base station.

[0071] The UE is configured to determine (806) a time gap between the last PSFCH transmission opportunity and the transmission of the SL HARQ report to the base station based on the last PSFCH transmission opportunity within the timing window. The UE is configured to transmit (806) the SL HARQ report after the time gap from the last PSFCH opportunity. The content of the SL HARQ report is based on the content of at least one of the PSFCH opportunities. For example, the UE can perform SL unicast. In this case, if the UE receives a HARQ ACK in any of the PSFCH opportunities, the UE sends the SL HARQ report as an "ACK" transmission to the base station. If the UE does not receive a HARQ ACK in any of the PSFCH opportunities, the UE sends the SL HARQ report as a "NACK" transmission to the base station.

[0072] The UE may perform SL groupcast ACK / NACK transmissions. In this case, if the UE receives a HARQ ACK for each of the PSFCH opportunities, the UE sends the SL HARQ report as an "ACK" transmission to the base station. If any PSFCH opportunity received by the UE does not include a HARQ ACK, the UE sends the SL HARQ report as a "NACK" transmission to the base station.

[0073] The UE can perform SL multicast NACK-only transmission. In this case, if the UE receives a HARQ NACK for any of the PSFCH opportunities, the UE sends the SL HARQ report as a "NACK" transmission to the base station. If none of the PSFCH opportunities received by the UE include a HARQ NACK, the UE sends the SL HARQ report as an "ACK" transmission to the base station. The UE report to the base station is ACK / NACK, but the UE-UE transmission is NACK-only. This is because the base station determines whether to schedule a retransmission based on the ACK / NACK data received in the report.

[0074] Fig. 9 An example process 900 is shown for resource allocation performed by a UE for sidelink transmission in unlicensed spectrum for Mode 1. Process 900 may be performed by a UE such as Figure 1102) is performed by the UE. The UE is configured to receive (902) a DCI transmission indicating a PSFCH to HARQ feedback timing value. The UE is configured to determine (904) that a resource allocation includes multiple PSFCH transmission opportunities. In some specific implementations, multiple PSFCH opportunities are included to accommodate potential LBT failures and, therefore, subsequent PSFCH retransmissions. The UE is configured to determine (906) a time gap between each PSFCH opportunity and a corresponding transmission of a SL HARQ report to a base station based on each PSFCH transmission opportunity allocation. In some specific implementations, the time gap is the same length for each associated PSFCH opportunity. In some specific implementations, the time gap associated with each PSFCH opportunity is configured independently of other PSFCH opportunities. In some specific implementations, the time gap associated with the corresponding PSFCH opportunity has a different length. The UE is configured to transmit (908) at least one SL HARQ report after a specific PSFCH opportunity. The content of the SL HARQ report (e.g., ACK / NACK) is based on the content of the specific corresponding PSFCH opportunity.

[0075] Fig.10 An example process 1000 is shown for resource allocation performed by a UE for sidelink transmission in unlicensed spectrum for Mode 1. Process 1000 may be performed by a UE such as Figure 1 1000 is performed by a UE 102). Process 1000 is performed by RRC messaging. The UE is configured to receive (1002) an RRC transmission indicating an authorization timing value for a SL PSFCH to PUCCH configuration. The UE is configured to determine (1004) that a resource allocation includes multiple PSFCH transmission opportunities. In some specific implementations, multiple PSFCH opportunities are included to accommodate potential LBT failures of the UE and to enable subsequent PSFCH retransmissions. The UE is configured to determine (1006) a configured authorization time gap between each PSFCH opportunity and a corresponding transmission of a SL HARQ report to a base station based on each PSFCH transmission opportunity allocation. In some specific implementations, the configured authorization time gap is the same length for each associated PSFCH opportunity. In some specific implementations, the configured authorization time gap associated with each PSFCH opportunity is configured independently of other PSFCH opportunities. In some specific implementations, the configured authorization time gap associated with the corresponding PSFCH opportunity has different lengths. The UE is configured to transmit (1008) at least one SL HARQ report after a specific PSFCH opportunity based on a configured grant time gap. The content of the SL HARQ report (eg, ACK / NACK) is based on the content of the specific corresponding PSFCH opportunity.

[0076] Fig.11An example process 1100 performed by a UE for resource allocation in an unlicensed spectrum for mode 1 sidelink transmission is shown. The process 1100 may be performed by a UE such as Figure 1 The UE 102) performs a resource allocation reassessment or preemption of an extended time slot. The resource allocation reassessment extended time slot includes an offset time slot added to a basic time slot. The basic time slot depends on the value of the CAPC index. The basic time slot enables the UE to prepare for transmission or reception of a given time slot. In addition to the resource allocation reassessment or preemption for the time slot, the added offset time slot enables the UE to perform an LBT operation. The UE performs (1104) resource allocation reassessment or preemption on the time slot based on the extended time slot at a time before the time slot occurs.

[0077] Fig.12 An access node 1200 (e.g., a base station or gNB) according to some embodiments is illustrated. Access node 1200 may be similar to and substantially interchangeable with base station 104. Access node 1200 may include a processor 1202, RF interface circuitry 1204, core network (CN) interface circuitry 1206, memory / storage circuitry 1208, and antenna structures 1210.

[0078] The components of access node 1200 may be coupled to various other components via one or more interconnects 1212. Processor 1202, RF interface circuitry 1204, memory / storage circuitry 1208 (including communication protocol stack 1214), antenna structures 1210, and interconnects 1212 may be similar to those described above. Figure 8 Like-named elements are shown and described.For example, processor 1202 may include processor circuits such as baseband processor circuit (BB) 1216A, central processor unit circuit (CPU) 1216B, and graphics processor unit circuit (GPU) 1216C.

[0079] The CN interface circuit 1206 may provide connectivity to a core network (e.g., a 5GC using a 5th Generation Core Network (5GC) compatible network interface protocol such as a Carrier Ethernet protocol or some other suitable protocol). Network connectivity may be provided to / from the access node 1200 via optical fiber or wireless backhaul. The CN interface circuit 1206 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuit 1206 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0080] As used herein, the terms "access node", "access point", etc. may be described as equipment that provides radio baseband functionality for data and / or voice connections between a network and one or more users. These access nodes may be referred to as BS, gNB, RAN node, eNB, NodeB, RSU, TRxP or TRP, etc., and may include ground stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell). As used herein, the terms "NG RAN node", etc. may refer to an access node 1200 (e.g., a gNB) operating in an NR or 5G system, and the terms "E-UTRAN node", etc. may refer to an access node 1200 (e.g., an eNB) operating in an LTE or 4G system. According to various embodiments, the access node 1200 may be implemented as one or more of a dedicated physical device such as a macrocell base station and / or a low power (LP) base station for providing a femtocell, picocell or other similar cell with a smaller coverage area, smaller user capacity or higher bandwidth than a macrocell.

[0081] In some embodiments, all or part of the access node 1200 may be implemented as one or more software entities running on a server computer as part of a virtual network that may be referred to as a CRAN and / or a virtual baseband unit pool (vBBUP). In these embodiments, the CRAN or vBBUP may implement a RAN functional split, such as a PDCP split, where the RRC and PDCP layers are operated by the CRAN / vBBUP and other L2 protocol entities are operated by the access node 1200; a MAC / PHY split, where the RRC, PDCP, RLC, and MAC layers are operated by the CRAN / vBBUP and the PHY layer is operated by the access node 1200; or a "lower PHY" split, where the RRC, PDCP, RLC, MAC layers, and upper portions of the PHY layers are operated by the CRAN / vBBUP and the lower portions of the PHY layers are operated by the access node 1200.

[0082] In the V2X scenario, the access node 1200 may be an RSU or act as an RSU. The term "road side unit" or "RSU" may refer to any traffic infrastructure entity used for V2X communication. The RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, wherein an RSU implemented in or by a UE may be referred to as a "UE-type RSU", an RSU implemented in or by an eNB may be referred to as an "eNB-type RSU", an RSU implemented in or by a gNB may be referred to as a "gNB-type RSU", and so on.

[0083] Fig.13 UE 1300 according to some embodiments is illustrated. UE 1300 may be similar to Figure 1UE 102 is substantially interchangeable with UE 102. UE 1300 may be any mobile or non-mobile computing device, such as, for example, a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a carbon dioxide sensor, a pressure sensor, a humidity sensor, a thermometer, a motion sensor, an accelerometer, a laser scanner, a fluid level sensor, an inventory sensor, a voltage / current meter, an actuator, etc.), a video surveillance / monitoring device (e.g., a camera, a camcorder, etc.), a wearable device (e.g., a smart watch), a loose IoT device.

[0084] UE 1300 may include a processor 1302, an RF interface circuit 1304, a memory / storage 1306, a user interface 1308, a sensor 1310, a driver circuit 1312, a power management integrated circuit (PMIC) 1314, antenna structures 1316, and a battery 1318. The components of UE 1300 may be implemented as an integrated circuit (IC), a portion of an integrated circuit, a discrete electronic device or other module, logic component, hardware, software, firmware, or a combination thereof. Fig.13 The block diagram of UE 1300 is intended to show a high-level view of certain of the components of UE 1300. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other implementations.

[0085] Components of UE 1300 may be coupled to various other components via one or more interconnects 1320, which may represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, optical connection, etc., which allows various circuit components (on a common or different chip or chipset) to interact with each other.

[0086] The processor 1302 may include processor circuits such as a baseband processor circuit (BB) 1322A, a central processor unit circuit (CPU) 1322B, and a graphics processor unit circuit (GPU) 1322C. The processor 1302 may include any type of circuit or processor circuit that executes or otherwise operates computer-executable instructions (such as program codes, software modules, or functional processes from the memory / storage device 1306) to cause the UE 1300 to perform operations as described herein.

[0087] In some embodiments, the baseband processor circuit 1322A can access the communication protocol stack 1324 in the memory / storage device 1306 to communicate through a 3GPP compatible network. Generally speaking, the baseband processor circuit 1322A can access the communication protocol stack to: perform user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer; and perform control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access layer. In some embodiments, the PHY layer operation may be additionally / alternatively performed by components of the RF interface circuit 1304. The baseband processor circuit 1322A may generate or process a baseband signal or waveform that carries information in a 3GPP compatible network. In some embodiments, the waveform for NR may be based on cyclic prefix OFDM ("CP-OFDM") in the uplink or downlink, and discrete Fourier transform spread OFDM ("DFT-S-OFDM") in the uplink.

[0088] The memory / storage 1306 may include one or more non-transitory computer-readable media including instructions (e.g., the communication protocol stack 1324) that may be executed by one or more processors in the processor 1302 to cause the UE 1300 to perform various operations described herein. The memory / storage 1306 includes any type of volatile or non-volatile memory that may be distributed throughout the UE 1300. In some embodiments, some of the memory / storage 1306 may be located on the processor 1302 itself (e.g., L1 cache and L2 cache), while other memory / storage 1306 is located external to the processor 1302 but can be accessed via a memory interface. The memory / storage 1306 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0089] The RF interface circuit 1304 may include a transceiver circuit and a radio frequency front end module (RFEM) that allows the UE 1300 to communicate with other devices through a radio access network. The RF interface circuit 1304 may include various elements arranged in a transmission or reception path. These elements may include, for example, switches, mixers, amplifiers, filters, synthesizer circuits, control circuits, etc.

[0090] In the receive path, the RFEM can receive the radiated signal from the air interface via the antenna structure 1316 and proceed to filter and amplify the signal (using a low noise amplifier). The signal can be provided to the receiver of the transceiver, which down-converts the RF signal to a baseband signal, which is provided to the baseband processor of the processor 1302.

[0091] In the transmit path, the transmitter of the transceiver up-converts the baseband signal received from the baseband processor and provides an RF signal to the RFEM. The RFEM may amplify the RF signal through a power amplifier before the signal is radiated across the air interface via the antenna 1316.

[0092] In various embodiments, the RF interface circuit 1304 may be configured to transmit / receive signals in a manner compatible with NR access technology.

[0093] Antenna 1316 may include antenna elements to convert electrical signals into radio waves to travel through the air and convert received radio waves into electrical signals. These antenna elements may be arranged into one or more antenna panels. Antenna 1316 may have an antenna panel that is omnidirectional, directional, or a combination thereof to achieve beamforming and multiple-input, multiple-output communications. Antenna 1316 may include a microstrip antenna, a printed antenna manufactured on the surface of one or more printed circuit boards, a patch antenna, a phased array antenna, etc. Antenna 1316 may have one or more panels that are designed for a specific frequency band including a frequency band in FRI or FR2.

[0094] The user interface 1308 includes various input / output (I / O) devices designed to enable a user to interact with the UE 1300. The user interface 1308 includes input device circuits and output device circuits. The input device circuit includes any physical or virtual components for accepting input, including in particular one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touch screen, a microphone, a scanner, or a headset, etc. The output device circuit includes any physical or virtual components for displaying information or otherwise delivering information (such as sensor readings, actuator positions, or other similar information). The output device circuit may include any number or combination of audio or visual displays, including in particular one or more simple visual outputs / indicators (e.g., binary state indicators (such as light emitting diodes "LEDs") and multi-character visual outputs) or more complex outputs (such as display devices or touch screens (e.g., liquid crystal displays "LCDs", LED displays, quantum dot displays, projectors, etc.)), where the output of characters, graphics, multimedia objects, etc. is generated or produced by the operation of the UE 1300.

[0095] Sensors 1310 may include devices, modules, or subsystems whose purpose is to detect events or changes in their environment and to send information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others: an inertial measurement unit, including an accelerometer, gyroscope, or magnetometer; a microelectromechanical system or nanoelectromechanical system, including a three-axis accelerometer, a three-axis gyroscope, or a magnetometer; a level sensor; a flow sensor; a temperature sensor (e.g., a thermistor); a pressure sensor; a barometric pressure sensor; a gravity meter; an altimeter; an image capture device (e.g., a camera or a lensless aperture); a light detection and ranging sensor; a proximity sensor (e.g., an infrared radiation detector, etc.); a depth sensor; an ambient light sensor; an ultrasonic transceiver; a microphone or other similar audio capture device; and the like.

[0096] The driver circuit 1312 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1300. The driver circuit 1312 may include various drivers to allow other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 1300. For example, the driver circuit 1312 may include a display driver for controlling and allowing access to a display device, a touch screen driver for controlling and allowing access to a touch screen interface, a sensor driver for obtaining sensor readings of the sensor circuit 1328 and controlling and allowing access to the sensor circuit 1328, a driver for obtaining an actuator position of an electromechanical component or controlling and allowing access to an electromechanical component, a camera driver for controlling and allowing access to an embedded image capture device, and an audio driver for controlling and allowing access to one or more audio devices.

[0097] The PMIC 1314 may manage the power provided to various components of the UE 1300. Specifically, with respect to the processor 1302, the PMIC 1314 may control power source selection, voltage scaling, battery charging, or DC to DC conversion.

[0098] In some embodiments, the PMIC 1314 may control or otherwise be part of various power saving mechanisms of the UE 1300, including DRX, as discussed herein. The battery 1318 may power the UE 1300, but in some examples, the UE 1300 may be mounted to be deployed in a fixed location and may have a power source coupled to the grid. The battery 1318 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some implementations, such as in vehicle-based applications, the battery 1318 may be a typical lead-acid automotive battery.

[0099] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods described in the following example section. For example, the baseband circuit described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. For another example, the circuits associated with the UE, base station, network element, etc. described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below in the example section.

[0100] Example

[0101] In the following sections, additional exemplary embodiments are provided.

[0102] Embodiment 1 includes a method for performing sidelink (SL) communication, the method comprising receiving a downlink control information (DCI) transmission by a user equipment (UE). The method comprises determining an initial time gap between reception of the DCI transmission and transmission of a physical sidelink control channel or a physical sidelink shared channel (PSCCH / PSSCH) allocated to the UE based on the DCI transmission. The method comprises determining a time offset value based on a channel access priority level (CPAC) value included in the DCI transmission. The method comprises determining a total time gap between receiving the DCI transmission at the UE and sending the PSCCH or PSSCH transmission by the UE based on the initial time gap and the time offset. The method comprises sending the PSCCH or PSSCH transmission based on the total time gap.

[0103] Embodiment 2 includes the method of at least Embodiment 1, wherein the DCI transmission includes a field storing a value representing the initial time gap.

[0104] Embodiment 3 includes a method according to embodiment 1 or 2, wherein the DCI transmission includes a field indicating an index value, and the index value is associated with an sl-DCI-ToSL-Trans table storing the value of the time gap.

[0105] Embodiment 4 includes the method of embodiments 1 to 3, wherein the total time gap enables the UE to perform a listen-before-talk (LBT) operation.

[0106] Embodiment 5 includes the method of embodiments 1 to 4, wherein the CAPC value is pre-mapped to the offset value for each resource pool.

[0107] Embodiment 6 includes a method for performing sidelink (SL) communication, the method comprising receiving, by a user equipment (UE), a downlink control information (DCI) transmission indicating a physical sidelink feedback channel to hybrid automatic repeat request (PSFCH to HARQ) feedback timing indicator value. The method includes determining a time gap between a PSFCH opportunity of the UE and a transmission time of a sidelink (SL) HARQ report of the UE to a base station based on the PSFCH to HARQ feedback timing indicator value. The method includes transmitting the SL HARQ report after the PSFCH opportunity based on the time gap.

[0108] Embodiment 7 includes the method according to embodiment 6, and further includes determining that the PSFCH opportunity is one of multiple PSFCH opportunities. The method also includes determining a last scheduled PSFCH opportunity among the multiple PSFCH opportunities. The method also includes determining the transmission time of the SL HARQ report of the UE to the base station based on the time gap and the last PSFCH opportunity.

[0109] Embodiment 8 includes the method according to embodiments 6 to 7, wherein the content of the SL HARQ feedback is based on the content of the PSFCH opportunity.

[0110] Embodiment 9 includes the method of embodiments 6 to 8, wherein the content of the SL HARQ feedback includes an ACK signal in response to at least one PSFCH opportunity among a plurality of PSFCH opportunities including an ACK signal.

[0111] Embodiment 10 includes the method of embodiments 6 to 9, wherein the content of the SL HARQ feedback includes an ACK signal in response to each of a plurality of PSFCH opportunities including a corresponding ACK signal.

[0112] Embodiment 11 includes the method of embodiments 6 to 10, wherein the content of the SL HARQ feedback includes a NACK signal in response to at least one PSFCH opportunity among a plurality of PSFCH opportunities including a NACK signal.

[0113] Embodiment 12 includes the method according to embodiments 6 to 11, the method further comprising determining that the PSFCH opportunity is one of a plurality of PSFCH opportunities. The method further comprises determining a first time gap between a first PSFCH opportunity in the plurality of PSFCH opportunities and a first SL HARQ report of the UE based on a first PSFCH to HARQ feedback timing indicator value included in the DCI transmission. The method further comprises determining a second time gap between a second PSFCH opportunity in the plurality of PSFCH opportunities and a second SL HARQ report of the UE based on a second PSFCH to HARQ feedback timing indicator value included in the DCI transmission. The method further comprises determining a first transmission time for the first SL HARQ report of the UE to the base station based on the first time gap. The method further comprises determining a second transmission time for the second SL HARQ report of the UE to the base station based on the second time gap. The method comprises transmitting the first SL HARQ report based on the first time gap. The method comprises transmitting the second SL HARQ report based on the second time gap.

[0114] Embodiment 13 includes the method of embodiment 12, wherein the first time gap and the second time gap are the same length.

[0115] Embodiment 14 includes the method of embodiments 12-13, wherein the first time gap and the second time gap are different lengths.

[0116] Embodiment 15 includes the method according to embodiments 12 to 14, the method further comprising determining that the first SL HARQ report includes an ACK signal, wherein the second SL HARQ report is not transmitted in response to the determination.

[0117] Embodiment 16 includes a method for performing sidelink (SL) communications. The method includes receiving, by a user equipment (UE), a radio resource control (RRC) transmission indicating a grant timing value configured for a sidelink physical sidelink feedback channel to a physical uplink control channel (PSFCH to PUCCH). The method includes determining, based on a PSFCH transmission opportunity and the configured grant timing value, a configured grant time gap between the PSFCH opportunity and a corresponding transmission of a SL HARQ report by the UE to a base station. The method includes transmitting the SL HARQ report based on the configured grant time gap.

[0118] Embodiment 17 includes the method of embodiment 16, further comprising transmitting at least one SL HARQ report after the PSFCH opportunity based on the configured grant time gap.

[0119] Embodiment 18 includes the method of embodiments 16 to 17, wherein the configured grant time gap is long enough to enable the UE to perform listen-before-talk (LBT) operation.

[0120] Embodiment 19 includes the method according to embodiments 16 to 18, further comprising determining a resource re-evaluation or preemption time gap for a time slot.

[0121] Embodiment 20 includes a method according to embodiments 16 to 19, wherein the resource reassessment or preemption time gap includes an offset extension configured to enable LBT operation by the UE.

[0122] Embodiment 21 may include an apparatus comprising means for performing one or more elements of a method as described or related to any of Embodiments 1 to 20, or any other method or process described herein.

[0123] Embodiment 22 may include one or more non-transitory computer-readable media, which include instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of a method described or related to any one of Embodiments 1 to 20 or any other method or process described herein.

[0124] Embodiment 23 may include an apparatus comprising logic components, modules, or circuits for performing one or more elements of a method as described or related to any of Embodiments 1 to 20, or any other method or process described herein.

[0125] Embodiment 24 may include methods, techniques or processes described or related to any one of Embodiments 1 to 20, or parts or components thereof.

[0126] Embodiment 25 may include a device comprising: one or more processors and one or more computer-readable media, wherein the one or more computer-readable media include instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process, or a portion thereof, described in or related to any one of Embodiments 1 to 20.

[0127] Embodiment 26 may include a signal as described or related to any one of Embodiments 1 to 25, or a portion or component thereof.

[0128] Embodiment 27 may include a datagram, packet, frame, segment, protocol data unit (PDU) or message, or a portion or component thereof, as described or associated with any of Embodiments 1 to 26, or as otherwise described in the present disclosure.

[0129] Embodiment 28 may include a signal encoded with data as described or associated with any one of Embodiments 1 to 26, or a portion or component thereof, or otherwise described in this disclosure.

[0130] Embodiment 29 may include a signal encoded with a datagram, packet, frame, segment, protocol data unit (PDU) or message as described or associated with any of Embodiments 1 to 26, or a portion or component thereof, or otherwise described in the present disclosure.

[0131] Embodiment 30 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors will cause the one or more processors to perform a method, technique, or process, or a portion thereof, as described or related to any one of Embodiments 1 to 20.

[0132] Embodiment 31 may include a computer program comprising instructions, wherein execution of the program by a processing element causes the processing element to perform a method, technique, or process, or a portion thereof, as described or related to any one of Embodiments 1 to 20.

[0133] Embodiment 32 may include signals in a wireless network as shown and described herein.

[0134] Embodiment 33 may include a method of communicating in a wireless network as shown and described herein.

[0135] Embodiment 34 may include a system for providing wireless communications as shown and described herein.

[0136] Embodiment 35 may include an apparatus for providing wireless communications as shown and described herein.

[0137] Embodiment 36 may include an apparatus according to or related to any one of embodiments 1 to 26, wherein the apparatus or any part thereof is implemented in or by a user equipment (UE).

[0138] Embodiment 37 may include a method according to or related to any one of embodiments 1 to 26, wherein the method or any part thereof is implemented in or by a user equipment (UE).

[0139] Embodiment 38 may include an apparatus according to or related to any one of embodiments 1 to 26, wherein the apparatus or any part thereof is implemented in or by a base station (BS).

[0140] Embodiment 39 may include a method according to or related to any one of embodiments 1 to 26, wherein the method or any part thereof is implemented in or by a base station (BS).

[0141] Embodiment 40 may include an apparatus as described in or related to any one of embodiments 1 to 26, wherein the apparatus or any part thereof is implemented in or by a network element.

[0142] Unless explicitly stated otherwise, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations are possible in view of the above teachings or may be obtained from the practice of various embodiments.

[0143] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to include all such variations and modifications.

[0144] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

Claims

1. A method for performing sidelink (SL) communication, the method comprising: Receiving a downlink control information (DCI) transmission by a user equipment (UE); determining, based on the DCI transmission, an initial time gap between reception of the DCI transmission and transmission of a physical sidelink control channel or a physical sidelink shared channel (PSCCH / PSSCH); determining a time offset value based on a channel access priority level (CPAC) value included in the DCI transmission; determining a total time gap between receiving the DCI transmission at the UE and sending the PSCCH or PSSCH transmission by the UE based on the initial time gap and the time offset; as well as The PSCCH or PSSCH transmission is sent based on the total time slot.

2. The method of claim 1, wherein the DCI transmission includes a field storing a value representing the initial time gap.

3. The method of claim 1 , wherein the DCI transmission includes a field indicating an index value associated with an sl-DCI-ToSL-Trans table storing a value of the time slot.

4. The method of claim 1, wherein the total time gap enables the UE to perform a listen-before-talk (LBT) operation.

5. The method of claim 1, wherein the CAPC value is pre-mapped to the offset value for each resource pool.

6. A method for performing sidelink (SL) communication, the method comprising: receiving, by a user equipment (UE), a downlink control information (DCI) transmission indicating a physical sidelink feedback channel to hybrid automatic repeat request (PSFCH to HARQ) feedback timing indicator value; determining a time gap between a PSFCH opportunity of the UE and a transmission time of a sidelink (SL) HARQ report of the UE to a base station based on the PSFCH to HARQ feedback timing indicator value; and The SL HARQ report is transmitted after the PSFCH opportunity based on the time gap.

7. The method according to claim 6, further comprising: Determining that the PSFCH opportunity is one of a plurality of PSFCH opportunities; determining a last scheduled PSFCH opportunity among the plurality of PSFCH opportunities; as well as The transmission time of the SL HARQ report of the UE to the base station is determined based on the time gap and the last PSFCH opportunity.

8. The method of claim 6, wherein the content of the SL HARQ feedback is based on the content of the PSFCH opportunity. 9 . The method of claim 8 , wherein the content of the SL HARQ feedback comprises an ACK signal in response to at least one PSFCH opportunity among a plurality of PSFCH opportunities including an ACK signal.

10. The method of claim 8, wherein the content of the SL HARQ feedback comprises an ACK signal in response to each of a plurality of PSFCH opportunities including a corresponding ACK signal. 11 . The method of claim 8 , wherein the content of the SL HARQ feedback includes a NACK signal in response to at least one PSFCH opportunity among a plurality of PSFCH opportunities including a NACK signal.

12. The method according to claim 6, further comprising: Determining that the PSFCH opportunity is one of a plurality of PSFCH opportunities; determining, based on a first PSFCH to HARQ feedback timing indicator value included in the DCI transmission, a first time gap between a first PSFCH opportunity of the plurality of PSFCH opportunities and a first SL HARQ report of the UE; determining a second time gap between a second PSFCH opportunity of the plurality of PSFCH opportunities and a second SL HARQ report of the UE based on a second PSFCH to HARQ feedback timing indicator value included in the DCI transmission; determining a first transmission time for the first SL HARQ report from the UE to the base station based on the first time gap; as well as determining a second transmission time for the second SL HARQ report from the UE to the base station based on the second time gap; as well as transmitting the first SL HARQ report based on the first time slot; as well as The second SL HARQ report is transmitted based on the second time slot.

13. The method of claim 12, wherein the first time gap and the second time gap are the same length. The method of claim 12 , wherein the first time gap and the second time gap are different lengths.

15. The method according to claim 12, further comprising: Determine that the first SL HARQ report includes an ACK signal, wherein the second SL HARQ report is not sent in response to the determination.

16. A method for performing sidelink (SL) communication, the method comprising: receiving, by a user equipment (UE), a radio resource control (RRC) transmission indicating a grant timing value for a sidelink physical sidelink feedback channel to physical uplink control channel (PSFCH to PUCCH) configuration; as well as determining, based on a PSFCH transmission opportunity and the configured grant timing value, a configured grant time gap between the PSFCH opportunity and a corresponding transmission of a SL HARQ report by the UE to a base station; as well as The SL HARQ report is transmitted based on the configured granted time interval.

17. The method of claim 16, further comprising transmitting at least one SL HARQ report after the PSFCH opportunity based on the configured grant time gap.

18. The method of claim 16, wherein the configured grant time gap is long enough to enable the UE to perform a listen-before-talk (LBT) operation.

19. The method of claim 16, further comprising determining a resource re-evaluation or preemption time gap for a time slot.

20. The method of claim 19, wherein the resource reassessment or preemption time gap comprises an offset extension configured to enable LBT operation by the UE.

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