METHOD AND APPARATUS FOR CHANNEL OCCUPANCY INDICATION ON SIDELINK

Methods and apparatuses for channel occupancy indication on a sidelink (SL) in a wireless communication system. A method of operating user equipment (UE) includes receiving a SL control information (SCI) format over a sidelink channel; determining, from the SCI format, at least one of: time domain information for a channel occupancy, frequency domain information for the channel occupancy, and a SL channel access procedure. The method further includes performing the SL channel access procedure before a sidelink transmission; and transmitting, upon successfully performing the sidelink channel access procedure, the SL transmission over the SL channel within the channel occupancy based on the time domain information or the frequency domain information for the channel occupancy.

TECHNICAL FIELD

The present disclosure relates generally to wireless communication systems and, more specifically, the present disclosure relates to a channel occupancy indication on a sidelink (SL) in a wireless communication system.

BACKGROUND

SUMMARY

The present disclosure relates to wireless communication systems and, more specifically, the present disclosure relates to a channel occupancy indication on a SL in a wireless communication system.

In one embodiment, a user equipment (UE) in a wireless communication system operating with a shared spectrum channel access is provided. The UE includes a transceiver configured to receive a sidelink control information (SCI) format over a sidelink channel and a processor operably coupled to the transceiver. The processor configured to determine, from the SCI format, at least one of: time domain information for a channel occupancy, frequency domain information for the channel occupancy, and a sidelink channel access procedure; and perform the sidelink channel access procedure before a sidelink transmission. The transceiver is further configured to transmit, upon successfully performing the sidelink channel access procedure, the sidelink transmission over the sidelink channel within the channel occupancy based on the time domain information or the frequency domain information for the channel occupancy.

In another embodiment, a method of UE in a wireless communication system operating with a shared spectrum channel access is provided. The method includes receiving a SCI format over a sidelink channel; determining, from the SCI format, at least one of: time domain information for a channel occupancy, frequency domain information for the channel occupancy, and a sidelink channel access procedure. The method further includes performing the sidelink channel access procedure before a sidelink transmission; and transmitting, upon successfully performing the sidelink channel access procedure, the sidelink transmission over the sidelink channel within the channel occupancy based on the time domain information or the frequency domain information for the channel occupancy.

DETAILED DESCRIPTION

The following documents are hereby incorporated by reference into the present disclosure as if fully set forth herein: 3GPP TS 38.211 v16.6.0, “NR; Physical channels and modulation”; 3GPP TS 38.212 v16.6.0, “NR; Multiplexing and Channel coding”; 3GPP TS 38.213 v16.6.0, “NR; Physical Layer Procedures for Control”; 3GPP TS 38.214 v16.6.0, “NR; Physical Layer Procedures for Data”; and 3GPP TS 38.331 v16.5.0, “NR; Radio Resource Control (RRC) Protocol Specification.”

In another example, the UE116may be within network coverage and the other UE may be outside network coverage (e.g., UEs111A-111C). In yet another example, both UE are outside network coverage. In some embodiments, one or more of the gNBs101-103may communicate with each other and with the UEs111-116using 5G/NR, LTE, LTE-A, WiMAX, WiFi, or other wireless communication techniques.

As described in more detail below, one or more of the UEs111-116include circuitry, programing, or a combination thereof, for an inter-UE co-ordination signaling in a wireless communication system. In certain embodiments, and one or more of the gNBs101-103includes circuitry, programing, or a combination thereof, for an inter-UE co-ordination signaling in a wireless communication system.

As discussed in greater detail below, the wireless network100may have communications facilitated via one or more devices (e.g., UEs111A to111C) that may have a SL communication with the UE111. The UE111can communicate directly with the UEs111A to111C through a set of SLs (e.g., SL interfaces) to provide sideline communication, for example, in situations where the UEs111A to111C are remotely located or otherwise in need of facilitation for network access connections (e.g., BS102) beyond or in addition to traditional fronthaul and/or backhaul connections/interfaces. In one example, the UE111can have direct communication, through the SL communication, with UEs111A to111C with or without support by the BS102. Various of the UEs (e.g., as depicted by UEs112to116) may be capable of one or more communication with their other UEs (such as UEs111A to111C as for UE111).

The controller/processor225is also capable of executing programs and other processes resident in the memory230, such as processes for a channel occupancy indication on a sidelink in a wireless communication system. The controller/processor225can move data into or out of the memory230as required by an executing process.

The transceiver(s)310receives, from the antenna305, an incoming RF signal transmitted by a gNB of the network100. The transceiver(s)310down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in the transceiver(s)310and/or processor340, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuitry sends the processed baseband signal to the speaker330(such as for voice data) or is processed by the processor340(such as for web browsing data).

The processor340is also capable of executing other processes and programs resident in the memory360, such as processes for a channel occupancy indication on a sidelink in a wireless communication system.

The processor340is also coupled to the input350and the display355mwhich includes for example, a touchscreen, keypad, etc., The operator of the UE116can use the input350to enter data into the UE116. The display355may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and/or at least limited graphics, such as from web sites.

FIG.4andFIG.5illustrate example wireless transmit and receive paths according to this disclosure. In the following description, a transmit path400may be described as being implemented in a gNB (such as the gNB102), while a receive path500may be described as being implemented in a UE (such as a UE116). However, it may be understood that the receive path500can be implemented in a gNB and that the transmit path400can be implemented in a UE. In some embodiments, the receive path500is configured to support the codebook design and structure for systems having 2D antenna arrays as described in embodiments of the present disclosure.

As illustrated inFIG.4, the channel coding and modulation block405receives a set of information bits, applies coding (such as a low-density parity check (LDPC) coding), and modulates the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols.

The serial-to-parallel block410converts (such as de-multiplexes) the serial modulated symbols to parallel data in order to generate N parallel symbol streams, where N is the IFFT/FFT size used in the gNB102and the UE116. The size N IFFT block415performs an IFFT operation on the N parallel symbol streams to generate time-domain output signals. The parallel-to-serial block420converts (such as multiplexes) the parallel time-domain output symbols from the size N IFFT block415in order to generate a serial time-domain signal. The add cyclic prefix block425inserts a cyclic prefix to the time-domain signal. The up-converter430modulates (such as up-converts) the output of the add cyclic prefix block425to an RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to the RF frequency.

A transmitted RF signal from the gNB102arrives at the UE116after passing through the wireless channel, and reverse operations to those at the gNB102are performed at the UE116.

A unit for DL signaling or for UL signaling on a cell is referred to as a slot and can include one or more symbols. A bandwidth (BW) unit is referred to as a resource block (RB). One RB includes a number of sub-carriers (SCs). For example, a slot can have duration of one millisecond and an RB can have a bandwidth of 180 KHz and include 12 SCs with inter-SC spacing of 15 KHz. A slot can be either full DL slot, or full UL slot, or hybrid slot similar to a special subframe in time division duplex (TDD) systems.

DL signals include data signals conveying information content, control signals conveying DL control information (DCI), and reference signals (RS) that are also known as pilot signals. A gNB transmits data information or DCI through respective physical DL shared channels (PDSCHs) or physical DL control channels (PDCCHs). A PDSCH or a PDCCH can be transmitted over a variable number of slot symbols including one slot symbol. A UE can be indicated a spatial setting for a PDCCH reception based on a configuration of a value for a transmission configuration indication state (TCI state) of a control resource set (CORESET) where the UE receives the PDCCH. The UE can be indicated a spatial setting for a PDSCH reception based on a configuration by higher layers or based on an indication by a DCI format scheduling the PDSCH reception of a value for a TCI state. The gNB can configure the UE to receive signals on a cell within a DL bandwidth part (BWP) of the cell DL BW.

A gNB transmits one or more of multiple types of RS including channel state information RS (CSI-RS) and demodulation RS (DMRS). A CSI-RS is primarily intended for UEs to perform measurements and provide channel state information (CSI) to a gNB. For channel measurement, non-zero power CSI-RS (NZP CSI-RS) resources are used. For interference measurement reports (IMRs), CSI interference measurement (CSI-IM) resources associated with a zero power CSI-RS (ZP CSI-RS) configuration are used. A CSI process consists of NZP CSI-RS and CSI-IM resources. A UE can determine CSI-RS transmission parameters through DL control signaling or higher layer signaling, such as an RRC signaling from a gNB. Transmission instances of a CSI-RS can be indicated by DL control signaling or configured by higher layer signaling. A DMRS is transmitted only in the BW of a respective PDCCH or PDSCH and a UE can use the DMRS to demodulate data or control information.

UL signals also include data signals conveying information content, control signals conveying UL control information (UCI), DMRS associated with data or UCI demodulation, sounding RS (SRS) enabling a gNB to perform UL channel measurement, and a random access (RA) preamble enabling a UE to perform random access. A UE transmits data information or UCI through a respective physical UL shared channel (PUSCH) or a physical UL control channel (PUCCH). A PUSCH or a PUCCH can be transmitted over a variable number of slot symbols including one slot symbol. The gNB can configure the UE to transmit signals on a cell within an UL BWP of the cell UL BW.

UCI includes hybrid automatic repeat request acknowledgement (HARQ-ACK) information, indicating correct or incorrect detection of data transport blocks (TBs) in a PDSCH, scheduling request (SR) indicating whether a UE has data in the buffer of UE, and CSI reports enabling a gNB to select appropriate parameters for PDSCH or PDCCH transmissions to a UE. HARQ-ACK information can be configured to be with a smaller granularity than per TB and can be per data code block (CB) or per group of data CBs where a data TB includes a number of data CBs.

A CSI report from a UE can include a channel quality indicator (CQI) informing a gNB of a largest modulation and coding scheme (MCS) for the UE to detect a data TB with a predetermined block error rate (BLER), such as a 10% BLER, of a precoding matrix indicator (PMI) informing a gNB how to combine signals from multiple transmitter antennas in accordance with a multiple input multiple output (MIMO) transmission principle, and of a rank indicator (RI) indicating a transmission rank for a PDSCH. UL RS includes DMRS and SRS. DMRS is transmitted only in a BW of a respective PUSCH or PUCCH transmission. A gNB can use a DMRS to demodulate information in a respective PUSCH or PUCCH. SRS is transmitted by a UE to provide a gNB with an UL CSI and, for a TDD system, an SRS transmission can also provide a PMI for DL transmission. Additionally, in order to establish synchronization or an initial higher layer connection with a gNB, a UE can transmit a physical random-access channel.

In the present disclosure, a beam is determined by either of: (1) a TCI state, which establishes a quasi-colocation (QCL) relationship between a source reference signal (e.g., synchronization signal/physical broadcasting channel (PBCH) block (SSB) and/or CSI-RS) and a target reference signal; or (2) spatial relation information that establishes an association to a source reference signal, such as SSB or CSI-RS or SRS. In either case, the ID of the source reference signal identifies the beam.

The TCI state and/or the spatial relation reference RS can determine a spatial Rx filter for reception of downlink channels at the UE, or a spatial Tx filter for transmission of uplink channels from the UE.

In Rel-16 NR V2X, transmission and reception of SL signals and channels are based on resource pool(s) confined in the configured SL bandwidth part (BWP). In the frequency domain, a resource pool consists of a (pre-)configured number (e.g., sl-NumSubchannel) of contiguous sub-channels, wherein each sub-channel consists of a set of contiguous resource blocks (RBs) in a slot with size (pre-)configured by higher layer parameter (e.g., sl-SubchannelSize). In time domain, slots in a resource pool occur with a periodicity of 10240 ms, and slots including S-SSB, non-UL slots, and reserved slots are not applicable for a resource pool. The set of slots for a resource pool is further determined within the remaining slots, based on a (pre-)configured bitmap (e.g., sl-TimeResource). An illustration of a resource pool is shown inFIG.6.

FIG.6illustrates an example of resource pool in Rel-16 NR V2X600according to embodiments of the present disclosure. The embodiment of the resource pool in Rel-16 NR V2X600illustrated inFIG.6is for illustration only.

A transmission and reception of physical sidelink shared channel (PSSCH), physical a sidelink control channel (PSCCH), and a physical sidelink feedback channel (PSFCH) are confined within and associated with a resource pool, with parameters (pre-)configured by higher layers (e.g., SL-PSSCH-Config, SL-PSCCH-Config, and SL-PSFCH-Config, respectively).

A UE may transmit the PSSCH in consecutive symbols within a slot of the resource pool, and PSSCH resource allocation starts from the second symbol configured for sidelink, e.g., startSLsymbol+1, and the first symbol configured for sidelink is duplicated from the second configured for sidelink, for AGC purpose. The UE may not transmit PSSCH in symbols not configured for sidelink, or in symbols configured for PSFCH, or in the last symbol configured for sidelink, or in the symbol immediately preceding the PSFCH. The frequency domain resource allocation unit for PSSCH is the sub-channel, and the sub-channel assignment is determined using the corresponding field in the associated SCI.

For transmitting a PSCCH, the UE can be provided a number of symbols (either 2 symbols or 3 symbols) in a resource pool (e.g., sl-TimResourcePSCCH) starting from the second symbol configured for sidelink, e.g., startSLsymbol+1; and further provided a number of RBs in the resource pool (e.g., sl-FreqResourcePSCCH) starting from the lowest RB of the lowest sub-channel of the associated PSSCH.

The UE can be further provided a number of slots (e.g., sl-PSFCH-Period) in the resource pool for a period of PSFCH transmission occasion resources, and a slot in the resource pool is determined as containing a PSFCH transmission occasion if the relative slot index within the resource pool is an integer multiple of the period of PSFCH transmission occasion. PSFCH is transmitted in two contiguous symbols in a slot, wherein the second symbol is with index startSLsymbols+lengthSLsymbols−2, and the two symbols are repeated. In frequency domain, PSFCH is transmitted in a single RB, wherein OCC can be applied within the RB for multiplexing, and the location of the RB is determined based on an indication of a bitmap (e.g., sl-PSFCH-RB-Set), and the selection of PSFCH resource is according to the source ID and destination ID.

The first symbol including PSSCH and PSCCH is duplicated for AGC purpose. An illustration of the slot structure including PSSCH and PSCCH is shown in701ofFIG.7, and the slot structure including PSSCH, PSCCH and PSFCH is shown in702ofFIG.7.

FIG.7illustrates an example of slot structure for SL transmission and reception700according to embodiments of the present disclosure. The embodiment of the slot structure for SL transmission and reception700illustrated inFIG.7is for illustration only.

For a sidelink operation on unlicensed or shared spectrum, there is a need to indicate channel occupancy information, in both time and frequency domain, such that another node not initializing the channel occupancy can receive the channel occupancy information and share the channel. Meanwhile, there is also a need to indicate the number of PSCCH candidate locations to monitor, which can be used for sidelink operating on unlicensed or shared spectrum, but not limited to sidelink operating on unlicensed or shared spectrum.

The present disclosure provides embodiments for supporting indication of channel occupancy related information in a sidelink control information. More precisely, the following components are focused on the present disclosure: (1) a time domain channel occupancy indication; (2) a frequency domain channel occupancy indication; (3) a PSCCH configuration indication; and (4) an SCI format to include the indication(s).

In one embodiment, an indication of time domain information on channel occupancy can be included in a sidelink control information (SCI) format, wherein the SCI format can be according to an example of another embodiment in this disclosure.

In one example, the time domain information can be a remaining channel occupancy duration in the unit of symbols from a first symbol of the slot where a UE detects the SCI format.

In another example, the time domain information can be a remaining channel occupancy duration in the unit of slots from the slot where a UE detects the SCI format.

In one embodiment, the time domain information on the channel occupancy can be associated with a source ID (e.g., a ID of a source transmitter UE).

For one instance, when a UE receives a SCI format (e.g. SCI format 2-A and/or format 2-B and/or format 2-C), the time domain information on the channel occupancy can be associated with a source ID given by the “source ID” field as included in the SCI format. A UE that receives the time domain information on the channel occupancy can determine such time domain information is applicable for the channel occupancy utilized for SL transmission from the transmitter UE with the identity provided by the “source ID” field.

For another instance, when a UE receives a SCI format, the time domain information on the channel occupancy can be associated with a source ID field as included in the same SCI format that includes the time domain information. A UE that receives the time domain information on the channel occupancy can determine such time domain information is applicable for the channel occupancy utilized for SL transmission from the transmitter UE with the identity provided by the source ID field included in the same SCI format that includes the time domain information.

For yet another instance, when a UE receives a SCI format, the time domain information on the channel occupancy can be associated with a source ID included in a RNTI that scrambles the SCI format. A UE that receives the time domain information on the channel occupancy can determine such time domain information is applicable for the channel occupancy utilized for SL transmission from the transmitter with the identity provided by the source ID included in the RNTI. In one aspect, the SCI format can be included in the PSCCH. In another aspect, the SCI format can be included in the PSSCH.

For yet another instance, when a UE initiates a channel occupancy by completing a channel access procedure, the source ID associated with the time domain information on the channel occupancy is associated with the UE itself (e.g., the source ID is associated with the UE initiates the channel occupancy).

For yet another instance, the source ID associated with the time domain information on the channel occupancy may not have to refer to the transmitter of the transmission including the SCI. For a sub-instance, the source ID associated with the time domain information on the channel occupancy can refer to a first UE (e.g., the UE initializing the channel occupancy), and the SCI including the time domain information on the channel occupancy can be transmitted from a second UE to a third UE, wherein the second UE uses the shared channel occupancy from the first UE and performs sidelink transmission to the third UE.

In another embodiment, the time domain information on the channel occupancy can be associated with a CO-sharing ID.

For one instance, when a UE receives a SCI format (e.g., SCI format 2-A and/or format 2-B and/or format 2-C), the time domain information on the channel occupancy can be associated with the “destination ID” field as included in the SCI format (e.g., the CO-sharing ID can be represented by the “destination ID”). A UE that receives the time domain information on the channel occupancy can determine such time domain information is applicable for the channel occupancy utilized for SL transmission to the receiver(s) with the identity provided by the “destination ID” field.

For another instance, when a UE receives a SCI format, the time domain information on the channel occupancy can be associated with a CO-sharing ID field as included in the same SCI format that includes the time domain information (e.g., the CO-sharing ID field may be different from “destination ID” field). A UE that receives the time domain information on the channel occupancy can determine such time domain information is applicable for the channel occupancy utilized for SL transmission to the receiver(s) with the identity provided by the CO-sharing ID field included in the same SCI format that includes the time domain information.

For yet another instance, when a UE receives a SCI format, the time domain information on the channel occupancy can be associated with a CO-sharing ID included in a RNTI that scrambles the SCI format. A UE that receives the time domain information on the channel occupancy can determine such time domain information is applicable for the channel occupancy utilized for SL transmission to the receiver(s) with the identity provided by CO-sharing ID. In one aspect, the SCI format can be included in the PSCCH. In another aspect, the SCI format can be included in the PSSCH.

For yet another instance, when a UE initializes a channel occupancy by performing a channel access procedure, the CO-sharing ID associated with the time domain information on the channel occupancy is the one or more UEs as the receiver(s) of the SL transmissions performed by the UE.

In yet another embodiment, a UE that receives the time domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission within the remaining duration of the channel occupancy, if a condition on at least one ID is satisfied.

For one instance, the UE that receives the time domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission within the remaining duration of the channel occupancy, if the CO-sharing ID associated with the channel occupancy (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE.

For another instance, the UE that receives the time domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission within the remaining duration of the channel occupancy, if the CO-sharing ID associated with the channel occupancy corresponds to the UE (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE, and/or the source ID associated with the channel occupancy corresponds to or is included in the receiver(s) of the new SL transmission.

In yet another embodiment, a UE can receive multiple time domain information on the channel occupancy included in multiple SCIs at the same time, and determine a combined time domain information on the channel occupancy based on multiple received time domain information on the channel occupancy.

In one instance, the UE determines the combined remaining channel occupancy duration for a channel as the minimum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs.

In another instance, the UE determines the combined remaining channel occupancy duration for a channel as the maximum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the minimum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the maximum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the minimum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same, and the CO-sharing ID associated with the remaining channel occupancy durations at least includes the UE.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the maximum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same, and the CO-sharing ID associated with the remaining channel occupancy durations at least includes the UE.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the minimum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated the received multiple the remaining channel occupancy durations are the same, and the CO-sharing ID associated with the remaining channel occupancy durations at least includes the UE, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the maximum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same, and the CO-sharing ID associated with the remaining channel occupancy durations at least includes the UE, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the minimum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined remaining channel occupancy duration for a channel as the maximum of remaining channel occupancy duration determined based on the received multiple remaining channel occupancy durations for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple remaining channel occupancy durations are the same, and the cast type included in and/or associated with the multiple SCIs are the same.

In one embodiment, if a UE is performing SL transmission on a channel with a first remaining channel occupancy duration, and received a SCI including a second remaining channel occupancy duration for the channel, the UE can determine the updated time domain information on the channel occupancy based on the first and second remaining channel occupancy durations.

In one instance, the UE determines the updated remaining channel occupancy duration for the channel as the minimum value of the first and second remaining channel occupancy durations.

In another instance, the UE determines the updated remaining channel occupancy duration for the channel as the maximum value of the first and second remaining channel occupancy durations.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the minimum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the maximum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the minimum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration, and the CO-sharing ID associated with the second remaining channel occupancy durations at least includes the UE.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the maximum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration, and the CO-sharing ID associated with the second remaining channel occupancy durations at least includes the UE.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the minimum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration, and the CO-sharing ID associated with the second remaining channel occupancy durations at least includes the UE, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the maximum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration, and the CO-sharing ID associated with the second remaining channel occupancy durations at least includes the UE, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the minimum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated remaining channel occupancy duration for the channel as the maximum value of the first and second remaining channel occupancy durations, if the source ID associated with the second remaining channel occupancy duration is the same as the source ID associated with the first remaining channel occupancy duration, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In one embodiment, the time domain information on the channel occupancy can be utilized for validation of SL transmissions.

In one instance, a UE does not expect to receive any SL transmission outside the duration (e.g., remaining channel occupancy) determined by the time domain information on the channel occupancy.

In another instance, a UE expects SL signal(s)/channel(s) to be transmitted (e.g., scheduled to be transmitted or configured to be transmitted) within the duration (e.g., remaining channel occupancy) determined by the time domain information on the channel occupancy are actually transmitted.

In yet another instance, if a UE is provided with multiple candidate locations in time domain to receive SL signal(s)/channel(s), and also provided with the time domain information on the channel occupancy, the UE expects the SL signal(s)/channel(s) is actually transmitted in at least one of the multiple candidate locations in time domain confined within the duration (e.g., remaining channel occupancy) determined by the time domain information on the channel occupancy.

In yet another instance, if a UE is provided with multiple candidate locations in time domain to receive SL signal(s)/channel(s), and also provided with the time domain information on the channel occupancy, the UE does not expect the SL signal(s)/channel(s) is actually transmitted in any candidate location in time domain outside the duration (e.g., remaining channel occupancy) determined by the time domain information on the channel occupancy.

In one embodiment, the time domain information on the channel occupancy can be utilized for resource selection on sidelink.

In one instance, when a UE receives a SCI including the information on reserved resource for SL transmission, the UE assumes such reserved resource can be used for actual transmission if the actual transmission is within the duration of the channel occupancy provided by the time domain information on the channel occupancy.

In another instance, when a UE receives a SCI including the information on reserved resource for transmission, the UE assumes such reserved resource may not be used for actual transmission if the actual transmission is outside the duration of the channel occupancy provided by the time domain information on the channel occupancy, and the UE can reserve such resource for its own transmission.

In yet another instance, when a UE receives a SCI including the information on reserved resource for transmission, the UE may need to perform channel access procedure in order to determine whether a reserved resource is available to be used for transmission if the transmission is outside the duration of the channel occupancy provided by the time domain information on the channel occupancy.

In one embodiment, the indication of the time domain information on channel occupancy can be forwarded.

In one example, when the SCI corresponds to groupcast SL transmission or broadcast SL transmission, any UE in the group for groupcast SL transmission or as a receiver of the broadcast SL transmission can receive the SCI, update the time domain information on the channel occupancy, and transmit such information in another SCI in the channel occupancy.

In another example, when the SCI corresponds to groupcast SL transmission or broadcast SL transmission, only one UE in the group (e.g., the groupcast leader) for groupcast SL transmission or only one UE (e.g., leader) for broadcast SL transmission can update the time domain information on the channel occupancy, and transmit such information in a SCI in the channel occupancy.

In yet another example, when the SCI corresponds to unicast SL transmission, either of the UEs in the unicast SL transmission can receive the SCI, update the time domain information on the channel occupancy, and transmit such information in another SCI in the channel occupancy.

In yet another example, when the SCI corresponds to unicast SL transmission, only one UE in the group (e.g., the UE initializing the channel occupancy) for unicast SL transmission can update the time domain information on the channel occupancy, and transmit such information in a SCI in the channel occupancy.

In one embodiment, an indication of frequency domain information on channel occupancy can be included in an SCI format.

In one example, the frequency domain information can be a bitmap, wherein each bit corresponds to an RB-set. For instance, the bit taking value of 1 indicates the corresponding RB-set can be available for SL transmission and/or reception. For another instance, the bit taking value of 0 indicates the corresponding RB-set may not be available for SL transmission and/or reception.

In another example, the frequency domain information can be an indication of sub-channel-sets available for SL transmission, e.g., using a bitmap and each bit corresponding to a sub-channel-set.

In one embodiment, the frequency domain information on the channel occupancy can be associated with a source ID (e.g., an ID associated with a source transmitter UE).

For one instance, when a UE receives a SCI format (e.g., SCI format 2-A and/or format 2-B and/or format 2-C), the frequency domain information on the channel occupancy can be associated with a source ID given by the “source ID” field as included in the SCI format. A UE that receives the frequency domain information on the channel occupancy can determine such frequency domain information is applicable for the channel occupancy utilized for SL transmission from the transmitter UE with the identity provided by the “source ID” field.

For another instance, when a UE receives a SCI format, the frequency domain information on the channel occupancy can be associated with a source ID field as included in the same SCI format that includes the frequency domain information. A UE that receives the frequency domain information on the channel occupancy can determine such frequency domain information is applicable for the channel occupancy utilized for SL transmission from the transmitter with the identity provided by the source ID field included in the same SCI format that includes the frequency domain information.

For yet another instance, when a UE receives a SCI format, the frequency domain information on the channel occupancy can be associated with a source ID included in a RNTI that scrambles the SCI format. A UE that receives the frequency domain information on the channel occupancy can determine such frequency domain information is applicable for the channel occupancy utilized for SL transmission from the transmitter with the identity provided by the source ID included in the RNTI. In one aspect, the SCI format can be included in the PSCCH. In another aspect, the SCI format can be included in the PSSCH.

For yet another instance, when a UE initiates a channel occupancy by completing a channel access procedure, the source ID associated with the frequency domain information on the channel occupancy is the UE itself (e.g., the source ID is associated with the UE initiates the channel occupancy).

For yet another instance, the source ID associated with the frequency domain information on the channel occupancy may not have to refer to the transmitter of the transmission including the SCI. For a sub-instance, the source ID associated with the frequency domain information on the channel occupancy can refer to a first UE (e.g., the UE initializing the channel occupancy), and the SCI including the frequency domain information on the channel occupancy can be transmitted from a second UE to a third UE, wherein the second UE uses the shared channel occupancy from the first UE and performs sidelink transmission to the third UE.

In another embodiment, the frequency domain information on the channel occupancy can be associated with a CO-sharing ID.

For one instance, when a UE receives a SCI format (e.g., SCI format 2-A and/or format 2-B and/or format 2-C), the frequency domain information on the channel occupancy can be associated with the “destination ID” field as included in the SCI format(e.g., the CO-sharing ID can be represented by the “destination ID”). A UE that receives the frequency domain information on the channel occupancy can determine such frequency domain information is applicable for the channel occupancy utilized for SL transmission to the receiver(s) with the identity provided by the “destination ID” field.

For another instance, when a UE receives a SCI format, the frequency domain information on the channel occupancy can be associated with a CO-sharing ID field as included in the same SCI format that includes the frequency domain information (e.g., the CO-sharing ID field may be different from “destination ID” field). A UE that receives the frequency domain information on the channel occupancy can determine such frequency domain information is applicable for the channel occupancy utilized for SL transmission to the receiver(s) with the identity provided by the CO-sharing ID field included in the same SCI format that includes the frequency domain information.

For yet another instance, when a UE receives a SCI format, the frequency domain information on the channel occupancy can be associated with a CO-sharing ID included in a RNTI that scrambles the SCI format. A UE that receives the frequency domain information on the channel occupancy can determine such frequency domain information is applicable for the channel occupancy utilized for SL transmission to the receiver(s) with the identity provided by CO-sharing ID. In one aspect, the SCI format can be included in the PSCCH. In another aspect, the SCI format can be included in the PSSCH.

For yet another instance, when a UE initializes a channel occupancy by performing a channel access procedure, the CO-sharing ID associated with the frequency domain information on the channel occupancy is the one or more UEs as the receiver(s) of the SL transmissions performed by the UE.

In yet another embodiment, a UE that receives the frequency domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission over the available RB-set(s), if a condition on at least one ID is satisfied.

For one instance, the UE that receives the frequency domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission over the available RB-set(s), if the CO-sharing ID associated with the channel occupancy (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE.

For another instance, the UE that receives the frequency domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission over the available RB-set(s), if the CO-sharing ID associated with the channel occupancy corresponds to the UE (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE, and/or the source ID associated with the channel occupancy corresponds to or is included in the receiver(s) of the new SL transmission.

For one instance, the UE that receives the frequency domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission over the available sub-channel-set(s), if the CO-sharing ID associated with the channel occupancy (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE.

For another instance, the UE that receives the frequency domain information on the channel occupancy can further share the channel occupancy to start a new SL transmission over the available sub-channel-set(s), if the CO-sharing ID associated with the channel occupancy corresponds to the UE (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE, and/or the source ID associated with the channel occupancy corresponds to or is included in the receiver(s) of the new SL transmission.

In yet another embodiment, a UE can receive multiple frequency domain information on the channel occupancy included in multiple SCIs at the same time, and determine a combined frequency domain information on the channel occupancy based on multiple received frequency domain information on the channel occupancy.

In one instance, the UE determines the combined available RB-set for a channel as the intersection of the received multiple available RB-sets for the channel included in the multiple SCIs.

In another instance, the UE determines the combined available RB-set for a channel as the union of the received multiple available RB-sets for the channel included in the multiple SCIs.

In yet another instance, the UE determines the combined available RB-set for a channel as the intersection of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same.

In yet another instance, the UE determines the combined available RB-set for a channel as the union of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same.

In yet another instance, the UE determines the combined available RB-set for a channel as the intersection of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same, and the CO-sharing ID associated with the available RB-sets at least includes the UE.

In yet another instance, the UE determines the combined available RB-set for a channel as the union of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same, and the CO-sharing ID associated with the available RB-sets at least includes the UE.

In yet another instance, the UE determines the combined available RB-set for a channel as the intersection of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated the received multiple the available RB-sets are the same, and the CO-sharing ID associated with the available RB-sets at least includes the UE, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined available RB-set for a channel as the union of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same, and the CO-sharing ID associated with the available RB-sets at least includes the UE, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined available RB-set for a channel as the intersection of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined available RB-set for a channel as the union of the received multiple available RB-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available RB-sets are the same, and the cast type included in and/or associated with the multiple SCIs are the same.

In one instance, the UE determines the combined available sub-channel-set for a channel as the intersection of the received multiple available sub-channel-sets for the channel included in the multiple SCIs.

In another instance, the UE determines the combined available sub-channel-set for a channel as the union of the received multiple available sub-channel-sets for the channel included in the multiple SCIs.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the intersection of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the union of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the intersection of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same, and the CO-sharing ID associated with the available sub-channel-sets at least includes the UE.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the union of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same, and the CO-sharing ID associated with the available sub-channel-sets at least includes the UE.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the intersection of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated the received multiple the available sub-channel-sets are the same, and the CO-sharing ID associated with the available sub-channel-sets at least includes the UE, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the union of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same, and the CO-sharing ID associated with the available sub-channel-sets at least includes the UE, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the intersection of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another instance, the UE determines the combined available sub-channel-set for a channel as the union of the received multiple available sub-channel-sets for the channel included in the multiple SCIs, wherein the source ID associated with the received multiple available sub-channel-sets are the same, and the cast type included in and/or associated with the multiple SCIs are the same.

In yet another embodiment, if a UE is performing SL transmission on a channel with a first available RB-set, and received a SCI including a second available RB-set for the channel, the UE can determine the updated frequency domain information on the channel occupancy based on the first and second available RB-sets.

In one instance, the UE determines the updated available RB-set for the channel as the intersection of the first and second available RB-sets.

In another instance, the UE determines the updated available RB-set for the channel as the union of the first and second available RB-sets.

In yet another instance, the UE determines the updated available RB-set for the channel as the intersection of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set.

In yet another instance, the UE determines the updated available RB-set for the channel as the union of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set.

In yet another instance, the UE determines the updated available RB-set for the channel as the intersection of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set, and the CO-sharing ID associated with the second available RB-sets at least includes the UE.

In yet another instance, the UE determines the updated available RB-set for the channel as the union of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set, and the CO-sharing ID associated with the second available RB-sets at least includes the UE.

In yet another instance, the UE determines the updated available RB-set for the channel as the intersection of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set, and the CO-sharing ID associated with the second available RB-sets at least includes the UE, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated available RB-set for the channel as the union of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set, and the CO-sharing ID associated with the second available RB-sets at least includes the UE, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated available RB-set for the channel as the intersection of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated available RB-set for the channel as the union of the first and second available RB-sets, if the source ID associated with the second available RB-set is the same as the source ID associated with the first available RB-set, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In one instance, the UE determines the updated available sub-channel-set for the channel as the intersection of the first and second available sub-channel-sets.

In another instance, the UE determines the updated available sub-channel-set for the channel as the union of the first and second available sub-channel-sets.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the intersection of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the union of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the intersection of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set, and the CO-sharing ID associated with the second available sub-channel-sets at least includes the UE.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the union of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set, and the CO-sharing ID associated with the second available sub-channel-sets at least includes the UE.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the intersection of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set, and the CO-sharing ID associated with the second available sub-channel-sets at least includes the UE, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the union of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set, and the CO-sharing ID associated with the second available sub-channel-sets at least includes the UE, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the intersection of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another instance, the UE determines the updated available sub-channel-set for the channel as the union of the first and second available sub-channel-sets, if the source ID associated with the second available sub-channel-set is the same as the source ID associated with the first available sub-channel-set, and the cast type of the SL transmission being performed by the UE and cast type of the SL transmission received by the UE are the same.

In yet another embodiment, the frequency domain information on the channel occupancy can be utilized for validation of SL transmissions.

In one instance, a UE does not expect to receive any SL transmission over RB-set(s) other than the available RB-set(s) determined by the frequency domain information on the channel occupancy.

In another instance, a UE expects SL signal(s)/channel(s) to be transmitted (e.g., scheduled to be transmitted or configured to be transmitted) over the available RB-set(s) determined by the frequency domain information on the channel occupancy are actually transmitted.

In yet another instance, if a UE is provided with multiple candidate locations in frequency domain to receive SL signal(s)/channel(s), and also provided with the frequency domain information on the channel occupancy, the UE expects the SL signal(s)/channel(s) is actually transmitted in at least one of the multiple candidate locations in frequency domain confined within the available RB-set(s) determined by the frequency domain information on the channel occupancy.

In yet another instance, if a UE is provided with multiple candidate locations in frequency domain to receive SL signal(s)/channel(s), and also provided with the frequency domain information on the channel occupancy, the UE does not expect the SL signal(s)/channel(s) is actually transmitted in any candidate location in frequency domain over RB-set(s) other than the available RB-set(s) determined by the frequency domain information on the channel occupancy.

In one instance, a UE does not expect to receive any SL transmission over sub-channel-set(s) other than the available sub-channel-set(s) determined by the frequency domain information on the channel occupancy.

In another instance, a UE expects SL signal(s)/channel(s) to be transmitted (e.g., scheduled to be transmitted or configured to be transmitted) over the available sub-channel-set(s) determined by the frequency domain information on the channel occupancy are actually transmitted.

In yet another instance, if a UE is provided with multiple candidate locations in frequency domain to receive SL signal(s)/channel(s), and also provided with the frequency domain information on the channel occupancy, the UE expects the SL signal(s)/channel(s) is actually transmitted in at least one of the multiple candidate locations in frequency domain confined within the available sub-channel-set(s) determined by the frequency domain information on the channel occupancy.

In yet another instance, if a UE is provided with multiple candidate locations in frequency domain to receive SL signal(s)/channel(s), and also provided with the frequency domain information on the channel occupancy, the UE does not expect the SL signal(s)/channel(s) is actually transmitted in any candidate location in frequency domain over sub-channel-set(s) other than the available sub-channel-set(s) determined by the frequency domain information on the channel occupancy.

In yet another embodiment, the frequency domain information on the channel occupancy can be utilized for resource selection on a sidelink.

In one instance, when a UE receives a SCI including the information on reserved resource for SL transmission, the UE assumes such reserved resource can be used for actual transmission if the resource is within the available RB-set(s) provided by the frequency domain information on the channel occupancy.

In another instance, when a UE receives a SCI including the information on reserved resource for transmission, the UE assumes such reserved resource may not be used for actual transmission if the resource is outside the available RB-set(s) provided by the frequency domain information on the channel occupancy, and the UE can reserve such resource for its own transmission.

In one instance, when a UE receives a SCI including the information on reserved resource for SL transmission, the UE assumes such reserved resource can be used for actual transmission if the resource is within the available sub-channel-set(s) provided by the frequency domain information on the channel occupancy.

In another instance, when a UE receives a SCI including the information on reserved resource for transmission, the UE assumes such reserved resource may not be used for actual transmission if the resource is outside the available sub-channel-set(s) provided by the frequency domain information on the channel occupancy, and the UE can reserve such resource for its own transmission.

In one embodiment, the indication of the frequency domain information on channel occupancy can be forwarded.

In one example, when the SCI corresponds to groupcast SL transmission or broadcast SL transmission, any UE in the group for groupcast SL transmission or as a receiver of the broadcast SL transmission can receive the SCI, update the frequency domain information on the channel occupancy, and transmit such information in another SCI in the channel occupancy.

In another example, when the SCI corresponds to groupcast SL transmission or broadcast SL transmission, only one UE in the group (e.g., the groupcast leader) for groupcast SL transmission or only one UE (e.g., leader) for broadcast SL transmission can update the frequency domain information on the channel occupancy, and transmit such information in a SCI in the channel occupancy.

In yet another example, when the SCI corresponds to unicast SL transmission, either of the UEs in the unicast SL transmission can receive the SCI, update the frequency domain information on the channel occupancy, and transmit such information in another SCI in the channel occupancy.

In yet another example, when the SCI corresponds to unicast SL transmission, only one UE in the group (e.g., the UE initializing the channel occupancy) for unicast SL transmission can update the frequency domain information on the channel occupancy, and transmit such information in a SCI in the channel occupancy.

In one embodiment, an indication of at least one configuration on the PSCCH can be included in a SCI format.

For one example, N≥1 sets of configurations on the PSCCH can be provided by pre-configuration and/or configuration from higher layer parameters and/or fixed in the specification, and an indication of the index of the set of configurations can be included in the SCI format. A UE receives the PSCCH according to the set of configurations on PSCCH indicated by the SCI format. For one sub-example, N=2, and one bit in the SCI format can be used to indicate one of the two sets of configurations on the PSCCH.

For one instance, the set of configurations on the PSCCH at least includes the index(es) of starting symbol(s) for PSCCH (e.g., or in general for SL transmissions and the starting symbol for PSCCH is determined based on the starting symbol for SL transmissions).

For another instance, the set of configurations on the PSCCH at least includes a number of symbols for PSCCH.

For yet another instance, the set of configurations on the PSCCH at least includes a number of locations to monitor for receiving PSCCH.

For another example, an indication of the index(es) of starting symbol(s) for PSCCH can be included in the SCI format. A UE receives the PSCCH according to the index(es) of starting symbol(s) for PSCCH indicated by the SCI format.

For yet another example, an indication of a number of symbols for PSCCH can be included in the SCI format. A UE receives the PSCCH according to the number of symbols for PSCCH indicated by the SCI format.

For yet another example, an indication of a number of locations to monitor for receiving PSCCH can be included in the SCI format. A UE receives the PSCCH according to the number of locations to monitor for receiving PSCCH indicated by the SCI format.

In one embodiment, the PSCCH configuration can be associated with a source ID.

For one instance, when a UE receives a SCI format (e.g., SCI format 2-A and/or format 2-B and/or format 2-C), the PSCCH configuration can be associated with a source ID given by the “source ID” field as included in the SCI format.

For another instance, when a UE receives a SCI format, the PSCCH configuration can be associated with a source ID field as included in the same SCI format that includes the frequency domain information.

For yet another instance, when a UE receives a SCI format, the PSCCH configuration can be associated with a source ID included in a RNTI that scrambles the SCI format. In one aspect, the SCI format can be included in the PSCCH. In another aspect, the SCI format can be included in the PSSCH.

For yet another instance, the source ID associated with the PSCCH configuration may not have to refer to the transmitter of the transmission including the SCI. For a sub-instance, the source ID associated with the PSCCH configuration can refer to a first UE (e.g., the UE initializing the channel occupancy), and the SCI including the PSCCH configuration can be transmitted from a second UE to a third UE, wherein the second UE uses the shared channel occupancy from the first UE and perform sidelink transmission to the third UE.

In another embodiment, the PSCCH configuration can be associated with a CO-sharing ID.

For one instance, when a UE receives a SCI format (e.g., SCI format 2-A and/or format 2-B and/or format 2-C), the PSCCH configuration can be associated with a CO-sharing ID given by the “destination ID” field as included in the SCI format 2-A and/or format 2-B.

For another instance, when a UE receives a SCI format, the PSCCH configuration can be associated with a CO-sharing ID field as included in the same SCI format that includes the frequency domain information (e.g., the CO-sharing ID field may be different from “destination ID” field).

For yet another instance, when a UE receives a SCI format, the PSCCH configuration can be associated with a CO-sharing ID included in a RNTI that scrambles the SCI format. In one aspect, the SCI format can be included in the PSCCH. In another aspect, the SCI format can be included in the PSSCH.

In yet another embodiment, a UE that receives the PSCCH configuration can receive the PSCCH according to the PSCCH configuration, if a condition on at least one ID is satisfied.

For one instance, the UE receives the PSCCH according to the PSCCH configuration, if the CO-sharing ID associated with the PSCCH configuration (e.g., according to the instance of this disclosure) corresponds to the UE or includes the UE.

In yet another embodiment, there can be a delay (e.g., denoted as Pswitch,SL) for a UE receiving the SCI including the PSCCH configuration to switch from the previous PSCCH configuration to the new PSCCH configuration. In one instance, the delay (e.g., Pswitch,SL) can be determined based on a SCS associated with the SL resource pool. In another instance, the delay (e.g., Pswitch,SL) can correspond to the same absolute time duration for at least two of the SCSs supported for the SL resource pool, e.g., the number of symbols/slots scale reciprocally with the SCS.

In one embodiment, the indication of PSCCH configuration can be forwarded.

In one example, when the SCI corresponds to groupcast SL transmission or broadcast SL transmission, any UE in the group for groupcast SL transmission or as a receiver of the broadcast SL transmission can receive the SCI, update the PSCCH configuration, and transmit the PSCCH configuration in another SCI in the channel occupancy.

In another example, when the SCI corresponds to groupcast SL transmission or broadcast SL transmission, only one UE in the group (e.g., the groupcast leader) for groupcast SL transmission or only one UE (e.g., leader) for broadcast SL transmission can update the PSCCH configuration, and transmit the PSCCH configuration in a SCI in the channel occupancy.

In yet another example, when the SCI corresponds to unicast SL transmission, either of the UEs in the unicast SL transmission can receive the SCI, update the PSCCH configuration, and transmit the PSCCH configuration in another SCI in the channel occupancy.

In yet another example, when the SCI corresponds to unicast SL transmission, only one UE in the group (e.g., the UE initializing the channel occupancy) for unicast SL transmission can update the PSCCH configuration, and transmit the PSCCH configuration in a SCI in the channel occupancy.

In one embodiment, at least one of the time domain channel occupancy, frequency domain channel occupancy, or PSCCH configuration indications can be included in a SCI format.

In one example, the following information is transmitted by means of the SCI format 1-A: time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In another example, the following information is transmitted by means of the SCI format 2-A: time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In yet another example, the following information is transmitted by means of the SCI format 2-B: time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B): (1) a source ID; and (2) time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B): (1) a source ID, (2) a CO-sharing ID, and (3) time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B): (1) a CO-sharing ID and (2) time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B) with CRC scrambled by a new sidelink RNTI (wherein the new sidelink RNTI can be generated based on at least one of the source ID or the CO-sharing ID): time domain channel occupancy 1, time domain channel occupancy 2, . . . , time domain channel occupancy N1.

In one embodiment, in the examples of this disclosure, the “time domain channel occupancy 1,” “time domain channel occupancy 2,” . . . , “time domain channel occupancy N1” included in the SCI format can be further subject to a higher layer parameter being configured, and the value of N1 can be determined based on the higher layer parameter.

In another embodiment, in the examples of this disclosure, N1 can be fixed in the specification and/or pre-configured, e.g., N1=1.

In one example, the following information is transmitted by means of the SCI format 1-A: (1) frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In another example, the following information is transmitted by means of the SCI format 2-A: frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In yet another example, the following information is transmitted by means of the SCI format 2-B: frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B): (1) a source ID and (2) frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B): (1) source ID, (2) CO-sharing ID, and (3) frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B): (1) CO-sharing ID and (2) frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B) with CRC scrambled by a new sidelink RNTI (wherein the new sidelink RNTI can be generated based on at least one of the source ID or the CO-sharing ID): frequency domain channel occupancy 1, frequency domain channel occupancy 2, . . . , frequency domain channel occupancy N2.

In one embodiment, in the examples of this disclosure, the “frequency domain channel occupancy 1,” “frequency domain channel occupancy 2,” . . . , “frequency domain channel occupancy N2” included in the SCI format can be further subject to a higher layer parameter being configured, and the value of N2 can be determined based on the higher layer parameter.

In another embodiment, in the examples of this disclosure, N2 can be fixed in the specification and/or pre-configured, e.g., N2=1.

In one example, the following information is transmitted by means of the SCI format 1-A: a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In another example, the following information is transmitted by means of the SCI format 2-A: a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In yet another example, the following information is transmitted by means of the SCI format 2-B: a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B, 2-C): (1) a source ID and (2) a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B, 2-C): (1) a source ID, (2) a CO-sharing ID, and (3) a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B, 2-C): (1) a CO-sharing ID and (2) a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In yet another example, the following information is transmitted by means of a new SCI format (e.g., a SCI format other than 1-A, 2-A, and 2-B, 2-C) with CRC scrambled by a new sidelink RNTI (wherein the new sidelink RNTI can be generated based on at least one of the source ID or the CO-sharing ID): (1) a PSCCH configuration 1, a PSCCH configuration 2, . . . , a PSCCH configuration N3.

In one embodiment, in the examples of this disclosure, the “PSCCH configuration 1,” “PSCCH configuration 2,” . . . , “PSCCH configuration N3” included in the SCI format can be further subject to a higher layer parameter being configured, and the value of N3 can be determined based on the higher layer parameter.

In another embodiment, in the examples of this disclosure, N3 can be fixed in the specification and/or pre-configured, e.g., N3=1.

In time domain, the UE can be further provided a number of slots (e.g., sl-PSFCH-Period) in the resource pool for a period of PSFCH transmission occasion resources, and a slot in the resource pool is determined as containing a PSFCH transmission occasion, if the relative slot index within the resource pool is an integer multiple of the period of PSFCH transmission occasion, and with at least a number of slots provided by sl-MinTimeGapPSFCH after the last slot of the PSSCH reception. PSFCH is transmitted in two contiguous symbols in a slot, wherein the second symbol is with index startSLsymbols+lengthSLsymbols−2, and the two symbols are repeated. An illustration of the time domain resource determination for PSFCH is illustrated inFIG.8.

FIG.8illustrates an example of time domain resource determination for PSFCH800according to embodiments of the present disclosure. The embodiment of the time domain resource determination for PSFCH800illustrated inFIG.8is for illustration only.

In a frequency domain, a PSFCH is transmitted in a single PRB, wherein the PRB is determined from a set of MPRB,setPSFCHPRBs based on an indication of a bitmap (e g sl-PSFCH-RB-Set). The UE determines a mapping from slot i (within NPSSCHPSFCHslots provided by sl-PSFCH-Period) and sub-channel j (within Nsubchsub-channels provided by sl-NumSubchannel) to a subset of PRBs within the set of MPRB,setPSFCH, wherein the subset of PRBs are with index from (i+j·NPSSCHPSFCH)·Msubch,slotPSFCHto (i+1+j·NPSSCHPSFCH)·Msubch,slotPSFCH−1, with Msubch,slotPSFCH=MPRB,setPSFCH/(Nsubch·NPSSCHPSFCH).

FIG.9illustrates an example of frequency domain resource determination for PSFCH900according to embodiments of the present disclosure. The embodiment of the frequency domain resource determination for PSFCH900illustrated inFIG.9is for illustration only.

An illustration of this mapping is shown inFIG.9. The UE determines a number of PSFCH resources available for multiplexing HARQ-ACK information in a PSFCH transmission as RPRB,CSPSFCH=NtypePSFCH·Msubch,slotPSFCH·NCSPSFCH, wherein NtypePSFCHis determined based on the type of resources that the PSFCH is associated with, and NCSPSFCHis a number of cyclic shift pairs for the resource pool provided by sl-NumMuxCS-Pair. The UE determines an index of a PSFCH resource for a PSFCH transmission in response to a PSSCH reception as (PID+MID) mod RPRB,CSPFSCHwhere PIDis the source ID provided by the SCI scheduling the PSSCH, and MIDis the PSSCH receiver ID in groupcast SL transmission with ACK or NACK information in HARQ-feedback.

In Rel-16, NR is supported on unlicensed or shared spectrum, and a channel access procedure and a cyclic prefix extension are jointly coded and indicated using a DCI format, wherein the channel access procedure and the cyclic prefix extension can be applied to an uplink transmission on the unlicensed or shared spectrum.

For a sidelink operation on unlicensed or shared spectrum, there is a need to enhance channel access procedure and/or adjustment of symbol duration (e.g., CP extension) in a DCI and/or SCI. It is noted that the embodiments and/or examples in this disclosure can be used for sidelink operating on unlicensed or shared spectrum, but may not be limited to sidelink operating on unlicensed or shared spectrum. The embodiments and examples in this disclosure can be supported separately or combined.

The present disclosure provides embodiments for indicating channel access procedure related parameter in a downlink control information format and/or a sidelink control information format. More precisely, the following components are provided in the present disclosure: (1) a description of a field for indicating channel access procedure related parameter; (2) an indication using the field in a downlink control information format; (3) an indication using the field in a sidelink control information format; (4) a UE behavior for channel access procedure with scheduled sidelink transmission (e.g., a scheduled sidelink transmission can be a sidelink transmission in Mode 1 resource allocation scheduled by a DCI or a sidelink transmission in Mode 2 resource allocation scheduled by a SCI); and (5) a UE behavior for channel access procedure with configured sidelink transmission (e.g., a configured sidelink transmission can be a sidelink transmission in Mode 2 resource allocation).

In one embodiment, a field can be included in a DCI format and/or an SCI format, wherein the field indicates at least one of a channel access procedure type (e.g., including the CAPC information if not explicitly mentioning) and/or symbol duration adjustment.

For one aspect, the channel access procedure type can include at least one of the following examples.

In one example, in a first type of sidelink channel access procedure (e.g., Type 1), the time duration spanned by the sensing slots that are sensed to be idle before a sidelink transmission is random (e.g., depending on a random number).

In one example, in a second type of sidelink channel access procedure (e.g., Type 2), the time duration spanned by the sensing slots that are sensed to be idle before a sidelink transmission is deterministic as a first positive number (e.g., 25 us).

In one example, in a third type of sidelink channel access procedure (e.g., Type 3), the time duration spanned by the sensing slots that are sensed to be idle before a sidelink transmission is deterministic as a second positive number (e.g., 16 us).

In a fourth type of sidelink channel access procedure (e.g., Type 4), the time duration spanned by the sensing slots that are sensed to be idle before a sidelink transmission is deterministic as zero.

In one example, there can be multiple channel access priority class (CAPC) associated with the sidelink channel access procedure. One example CAPC for Type 1 sidelink channel access procedure is shown in TABLE 1, and another example CAPC for Type 1 sidelink channel access procedure is shown in TABLE 2. In the tables, mpis a parameter for determining the sensing duration, CWmin,pand CWmax,pare minimum and maximum contention window size for the corresponding CAPC, Tmcot,pis the corresponding maximum channel occupancy time, and CWpis the allowed contention window size for the corresponding CAPC.

For another aspect, the symbol duration adjustment can include at least one of the following examples: (1) the symbol duration adjustment can be CP extension of the first symbol of the next sidelink transmission, and the length of the extended CP can be one from multiple pre-defined cases; (2) the symbol duration adjustment can be extension of the last symbol of the next sidelink transmission, and the length of the extended symbol can be one form multiple pre-defined cases; (3) the symbol duration adjustment can be repetition of the first symbol of the next sidelink transmission; and (4) the symbol duration adjustment can be repetition of the last symbol of the next sidelink transmission.

One example indication of channel access procedure type and/or symbol duration adjustment by the field is shown in TABLE 3. Another example for selecting entries for the indication of channel access procedure type and/or symbol duration adjustment by the field is shown in TABLE 4. Yet another example for selecting entries for the indication of channel access procedure type and/or symbol duration adjustment by the field is shown in TABLE 5.

TABLE 5Example indication by the fieldBit field mappedto indexCAPC01122334

In one embodiment, at least one field in a DCI format can be utilized to indicate at least one of a channel access procedure type (e.g., including the CAPC information if not explicitly mentioning) and/or symbol duration adjustment, wherein the content of the field can be according to at least one example in this disclosure.

In one aspect, the at least one field is with a positive number as bitwidth for operation with shared spectrum channel access, and with zero bitwidth for operation without shared spectrum channel access.

In another aspect, the at least one field is with the same bitwidth for operation with and without shared spectrum channel access. For one further example, a UE can ignore this field for operation without shared spectrum channel access.

In one aspect, the DCI format can be the DCI format 3_0, which is utilized for scheduling of NR PSSCH and/or NR PSCCH in a cell.

In another aspect, the DCI format can be a new DCI format utilized for sidelink operation (e.g., other than DCI format 3_0 and DCI format 3_1).

In one aspect, the bitwidth of the at least one field can be fixed, when the field is present in the DCI. For one example, the fixed bitwidth can be 2. For another example, the fixed bitwidth can be 3. For yet another example, the fixed bitwidth can be 4. For yet another example, the fixed bitwidth can be 5. For yet another example, the fixed bitwidth can be 6.

In another aspect, the bitwidth of the at least one field can be determined as ┌log2(I)┐, wherein I is the number of entries pre-configured or provided by a higher layer parameter, and the entries are selected from a predefined table.

In yet another aspect, the bitwidth of the at least one field can depend on the format of the DCI. For example, for a first set of DCI formats, the bitwidth of the at least one field can be fixed according to a first example of this disclosure; and for a second set of DCI formats, the bitwidth of the at least one field can be determined as ┌log2(I)┐ according to a second example of this disclosure.

In yet another aspect, the bitwidth of the at least one field can be decided independently for each of the field, when multiple fields are included in the DCI format, and for each of the bitwidth can be determined according to one of the examples of this disclosure.

In one aspect, there is only one field in a DCI format which can be utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment. An illustration is shown inFIG.10, wherein the indicated channel access procedure type (e.g., LBT) and/or symbol duration adjustment (SDA) is applied according to at least one of the following examples.

For one example, the indicated channel access procedure type and/or symbol duration adjustment by the one field can be applicable to the first sidelink transmission after reception of the DCI.

For another example, the indicated channel access procedure type and/or symbol duration adjustment by the one field can be applicable to the first sidelink transmission scheduled by the DCI.

For yet another example, the indicated channel access procedure type and/or symbol duration adjustment by the one field can be applicable to the all the sidelink transmission(s) scheduled by the DCI.

For yet another example, the indicated channel access procedure type (other than the CAPC information) and/or symbol duration adjustment by the one field can be applicable to the sidelink transmission other than the first transmission within the channel occupancy, and the CAPC information can be applicable to the sidelink transmission as the first transmission within the channel occupancy.

For yet another example, multiple of above examples can be supported, and the selection of the examples can be according to at least one of a pre-configuration, a configuration by higher layer parameter, or an indication in the DCI which includes the field.

FIG.10illustrates an example of single field indication in the DCI1000according to embodiments of the present disclosure. The embodiment of the single field indication in the DCI1000illustrated inFIG.10is for illustration only.

In another aspect, there are two fields in a DCI format which can be utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment.

FIG.11illustrates an example of two fields indication in the DCI1100according to embodiments of the present disclosure. The embodiment of the two fields indication in the DCI1100illustrated inFIG.11is for illustration only.

An illustration is shown inFIG.11, wherein the indicated channel access procedure type (e.g., LBT) and/or SDA is applied according to at least one of the following examples.

For one example, the indicated channel access procedure type and/or symbol duration adjustment by one of the two fields can be applicable to the sidelink transmission which is the first transmission within a channel occupancy.

For another example, the indicated channel access procedure type and/or symbol duration adjustment by the other of the two fields can be applicable to the sidelink transmission which is located within a channel occupancy but not the first one.

In yet another aspect, there can be one or multiple fields in a DCI format which can be utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment. An illustration is shown inFIG.12, wherein the indicated channel access procedure type (e.g., LBT) and/or SDA is applied according to at least one of the following examples.

For one example, there can be a one-to-one mapping between a field and a scheduled SL transmission (e.g., PSSCH), and the indicated channel access procedure type (e.g., LBT) and/or SDA from each field can be applicable to the corresponding scheduled SL transmission (e.g., PSSCH).

For another example, the indicated channel access procedure type (e.g., LBT) and/or SDA from each field within the one or multiple fields can be applicable to a set of SL transmissions respectively. For one sub-example, the set of SL transmissions are the ones scheduled by the DCI which includes the one or multiple fields. For another sub-example, the set of SL transmissions are the ones following the reception of the DCI which includes the one or multiple fields.

FIG.12illustrates an example of one or multiple fields indication in the DCI1200according to embodiments of the present disclosure. The embodiment of the one or multiple fields indication in the DCI1200illustrated inFIG.12is for illustration only.

In one aspect, the at least one field in a DCI format utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment can be applicable to Mode 1 sidelink transmission.

In one embodiment, at least one field in a sidelink DCI format can be utilized to indicate at least one of a channel access procedure type (e.g., including the CAPC information if not explicitly mentioning) and/or symbol duration adjustment, wherein the content of the field can be according to at least one example in this disclosure.

In one aspect, the at least one field is with a positive number as bitwidth for operation with shared spectrum channel access, and with zero bitwidth for operation without shared spectrum channel access.

In another aspect, the at least one field is with the same bitwidth for operation with and without shared spectrum channel access. For one example, a UE can ignore this field for operation without shared spectrum channel access.

In one aspect, the SCI format can be the SCI format 1-A, which is utilized for scheduling of NR PSSCH and the second stage SCI on NR PSSCH.

In another aspect, the SCI format can be the SCI format 2-A, which is utilized for decoding PSSCH.

In yet another aspect, the SCI format can be the SCI format 2-B, which is utilized for decoding PSSCH.

In yet another aspect, the SCI format can be the SCI format 2-C, which is utilized for providing or requesting inter-UE coordination information.

In yet another aspect, the SCI format can be a new SCI format utilized for sidelink operation (e.g., other than SCI format 1-A, 2-A, 2-B, and 2-C).

In one aspect, the bitwidth of the at least one field can be fixed, when the field is present in the SCI. For one example, the fixed bitwidth can be 2. For another example, the fixed bitwidth can be 3. For yet another example, the fixed bitwidth can be 4. For yet another example, the fixed bitwidth can be 5. For yet another example, the fixed bitwidth can be 6.

In another aspect, the bitwidth of the at least one field can be determined as ┌log2(I)┐, wherein I is the number of entries pre-configured or provided by a higher layer parameter, and the entries are selected from a predefined table (e.g., a table according to another embodiment of this disclosure).

In yet another aspect, the bitwidth of the at least one field can depend on the format of the SCI. For example, for a first set of SCI formats, the bitwidth of the at least one field can be fixed according to a first example of this disclosure; and for a second set of SCI formats, the bitwidth of the at least one field can be determined as ┌log2(I)┐ according to a second example of this disclosure.

In yet another aspect, the bitwidth of the at least one field can be decided independently for each of the field, when multiple fields are included in the SCI format, and for each of the bitwidth can be determined according to one of the examples of this disclosure.

In one aspect, there is only one field in a SCI format which can be utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment. An illustration is shown inFIG.13, wherein the indicated channel access procedure type (e.g., LBT) and/or SDA is applied according to at least one of the following examples.

For one example, the indicated channel access procedure type and/or symbol duration adjustment by the one field can be applicable to the first sidelink transmission after reception of the SCI.

For another example, the indicated channel access procedure type and/or symbol duration adjustment by the one field can be applicable to the first sidelink transmission scheduled by the SCI.

For yet another example, the indicated channel access procedure type and/or symbol duration adjustment by the one field can be applicable to the all the sidelink transmission(s) scheduled by the SCI.

For yet another example, the indicated channel access procedure type (other than the CAPC information) and/or symbol duration adjustment by the one field can be applicable to the sidelink transmission other than the first transmission within the channel occupancy, and the CAPC information can be applicable to the sidelink transmission as the first transmission within the channel occupancy.

For yet another example, multiple of above examples can be supported, and the selection of the examples can be according to at least one of a pre-configuration, a configuration by higher layer parameter, or an indication in the SCI which includes the field.

FIG.13illustrates an example of single field indication in the DCI1300according to embodiments of the present disclosure. The embodiment of the single field indication in the DCI1300illustrated inFIG.13is for illustration only.

In another aspect, there are two fields in a SCI format which can be utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment. An illustration is shown inFIG.14, wherein the indicated channel access procedure type (e.g., LBT) and/or SDA is applied according to at least one of the following examples.

For one example, the indicated channel access procedure type and/or symbol duration adjustment by one of the two fields can be applicable to the sidelink transmission which is the first transmission within a channel occupancy.

For another example, the indicated channel access procedure type and/or symbol duration adjustment by the other of the two fields can be applicable to the sidelink transmission which is located within a channel occupancy but not the first one.

FIG.14illustrates an example of two fields indication in the DCI1400according to embodiments of the present disclosure. The embodiment of the two fields indication in the DCI1400illustrated inFIG.14is for illustration only.

In yet another aspect, there can be one or multiple fields in a SCI format which can be utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment. An illustration is shown inFIG.15, wherein the indicated channel access procedure type (e.g., LBT) and/or SDA is applied according to at least one of the following examples.

For one example, there can be a one-to-one mapping between a field and a scheduled SL transmission (e.g., PSSCH), and the indicated channel access procedure type (e.g., LBT) and/or SDA from each field can be applicable to the corresponding scheduled sidelink transmission (e.g., PSSCH).

For another example, the indicated channel access procedure type (e.g., LBT) and/or SDA from each field within the one or multiple fields can be applicable to a set of SL transmissions respectively. For one sub-example, the set of SL transmissions are the ones scheduled by the SCI which includes the one or multiple fields. For another sub-example, the set of SL transmissions are the ones following the reception of the SCI which includes the one or multiple fields.

FIG.15illustrates an example of one or multiple fields indication in the DCI1500according to embodiments of the present disclosure. The embodiment of the one or multiple fields indication in the DCI1500illustrated inFIG.15is for illustration only.

In one aspect, the at least one field in a SCI format utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment can be applicable to Mode 1 sidelink transmission.

In another aspect, the at least one field in a SCI format utilized to indicate at least one of a channel access procedure type and/or symbol duration adjustment can be applicable to Mode 2 sidelink transmission.

In one aspect, if a UE fails to access the channel(s) prior to an intended sidelink transmission, layer 1 notifies higher layers about the channel access failure.

In one aspect, a UE uses the indicated type of channel access procedure for accessing the channel before sidelink transmission(s), other than examples which allows other types of channel access procedure(s) as described in this disclosure.

In another aspect, a UE uses the indicated symbol duration adjustment (e.g., CP extension) applied for the sidelink transmission(s), other than examples which allows other symbol duration adjustment (e.g., CP extension) as described in this disclosure.

In one aspect, if a UE is indicated to use Type 1 channel access procedure for a SL transmission as described in the example of this disclosure, and the UE determines the SL transmission is within a channel occupancy from both the time domain and frequency domain perspectives, the UE can switch from Type 1 channel access procedure to Type 2 channel access procedure for that SL transmission.

In another aspect, if a UE is indicated to use Type 1 channel access procedure for a SL transmission as described in the example of this disclosure, and the UE determines the SL transmission is within a channel occupancy from both the time domain and frequency domain perspectives, the UE can switch from Type 1 channel access procedure to Type 3 channel access procedure for that SL transmission.

In yet another aspect, if a UE is indicated to use Type 1 channel access procedure for a SL transmission as described in the example of this disclosure, and the UE determines the SL transmission is within a channel occupancy from both the time domain and frequency domain perspectives, the UE can switch from Type 1 channel access procedure to Type 4 channel access procedure for that SL transmission.

In one aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmissions without any gap, and the UE transmits one of the scheduled sidelink transmissions in the set after accessing the channel according to one of the channel access procedure as described in the example of this disclosure, the UE may continue transmitting the remaining sidelink transmission in the set, if any.

In one aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmissions, and if the UE cannot access the channel for a transmission in the set prior to the last transmission according to Type 1 channel access procedure as described in the example of this disclosure, the UE may attempt to transmit the next transmission according to the channel access type indicated in the corresponding DCI and/or SCI.

In another aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmissions, and if the UE cannot access the channel for a transmission in the set prior to the last transmission according to Type 2 channel access procedure as described in the example of this disclosure, the UE may attempt to transmit the next transmission according to the channel access type indicated in the corresponding DCI and/or SCI.

In yet another aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmissions, and if the UE cannot access the channel for a transmission in the set prior to the last transmission according to Type 3 channel access procedure as described in the example of this disclosure, the UE may attempt to transmit the next transmission according to Type 2 channel access procedure.

In one aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmissions without any gap, the UE is not expected to be indicated with different channel access types in between the contiguous transmissions, expect if Type 2 or Type 3 channel access procedures are identified for the first of the consecutive sidelink transmissions.

In one aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmission without any gap, and if the UE has stopped transmitting during or before one transmission in the set (prior to the last transmission), the UE may resume transmitting a later sidelink transmission in the set using Type 2 channel access procedure as described in this disclosure. In one example, the UE may apply no symbol duration adjustment (e.g., CP extension) to the later sidelink transmission in the set.

In another aspect, if a UE intends (e.g., is scheduled) to transmit a set of contiguous sidelink transmission without any gap, and if the UE has stopped transmitting during or before one transmission in the set (prior to the last transmission), and the channel sensed by the UE is not idle after the UE has stopped transmitting, the UE may resume transmitting a later sidelink transmission in the set using Type 1 channel access procedure as described in this disclosure. In one example, the UE may apply the channel access priority class as indicated in the corresponding DCI and/or SCI. In another further example, the UE may apply no symbol duration adjustment (e.g., CP extension) to the later sidelink transmission in the set. In yet another example, the UE may apply symbol duration adjustment (e.g., CP extension) to the later sidelink transmission in the set as indicated in the corresponding DCI and/or SCI.

In one aspect, if a UE intends (e.g., is scheduled) to transmit a set of non-contiguous sidelink transmissions, and if the UE has stopped transmitting during or before one transmission in the set (prior to the last transmission), the UE may resume transmitting a later sidelink transmission in the set using Type 2 channel access procedure as described in this disclosure, if the channel is sensed by the UE to be continuously idle after the UE has stopped transmitting. In one example, the UE may apply no symbol duration adjustment (e.g., CP extension) to the later sidelink transmission in the set.

In another aspect, if a UE intends (e.g., is scheduled) to transmit a set of non-contiguous sidelink transmission, and if the UE has stopped transmitting during or before one transmission in the set (prior to the last transmission), and the channel sensed by the UE is not idle after the UE has stopped transmitting, the UE may resume transmitting a later sidelink transmission in the set using Type 1 channel access procedure as described in this disclosure. In one example, the UE may apply the channel access priority class as indicated in the corresponding DCI and/or SCI. In another further example, the UE may apply no symbol duration adjustment (e.g., CP extension) to the later sidelink transmission in the set. In yet another example, the UE may apply symbol duration adjustment (e.g., CP extension) to the later sidelink transmission in the set as indicated in the corresponding DCI and/or SCI.

In one aspect, if a UE is indicated, e.g., by a DCI and/or SCI, to perform Type 1 channel access procedure for a scheduled sidelink transmission, and the UE has an ongoing Type 1 channel access procedure prior to the scheduled sidelink transmission starting time, and if the CAPC value corresponding to the ongoing Type 1 channel access procedure is same or larger than the CAPC value indicated, e.g., by the DCI and/or SCI, the UE may transmit the scheduled sidelink transmission by assessing the channel by using the ongoing Type 1 channel access procedure.

In another aspect, if a UE is indicated, e.g., by a DCI and/or SCI, to perform Type 1 channel access procedure for a scheduled sidelink transmission, and the UE has an ongoing Type 1 channel access procedure prior to the scheduled sidelink transmission starting time, and if the CAPC value corresponding to the ongoing Type 1 channel access procedure is less than the CAPC value indicated, e.g., by the DCI and/or SCI, the UE terminates the ongoing Type 1 channel access procedure.

In one aspect, a UE can be indicated, e.g., by a DCI and/or SCI, to perform one from Type 2, Type 3, or Type 4 channel access procedure for a scheduled sidelink transmission, and if the scheduled sidelink transmission(s) occur within the channel occupancy time (e.g., including the gap(s) longer than 25 us).

In another aspect, if a UE can be indicated, e.g., by a DCI and/or SCI, to perform one from Type 2, Type 3, or Type 4 channel access procedure for a scheduled sidelink transmission, the UE can assume the CAPC indicated in the same DCI and/or SCI is associated with the channel access procedure which initializes the channel occupancy.

In yet another aspect, the UE can assume the CAPC indicated in the DCI and/or SCI is associated with the channel access procedure which initializes the channel occupancy.

In one aspect, when gap between SL transmissions is at least 25 us, a UE can be indicated with Type 2 channel access procedure, e.g., by a DCI and/or SCI.

In another aspect, when gap between SL transmissions is equal to 16 us, a UE can be indicated with Type 3 channel access procedure, e.g., by a DCI and/or SCI.

In yet another aspect, when gap between SL transmissions is up to 16 us, a UE can be indicated with Type 4 channel access procedure, e.g., by a DCI and/or SCI.

In one aspect, if a UE received an indication of channel access type and/or symbol duration adjustment for a sidelink transmission from a DCI, and received an indication of channel access type and/or symbol duration adjustment for the same sidelink transmission from a SCI, the UE assume the indicated channel access type and/or symbol duration adjustment is the same in the DCI and the SCI.

In another aspect, if a UE received an indication of channel access type and/or symbol duration adjustment for a sidelink transmission from a DCI, and received an indication of channel access type and/or symbol duration adjustment for the same sidelink transmission from a SCI, the UE assumes the indication from the DCI overrides the indication from the SCI.

In yet another aspect, if a UE received an indication of channel access type and/or symbol duration adjustment for a sidelink transmission from a DCI, and received an indication of channel access type and/or symbol duration adjustment for the same sidelink transmission from a SCI, the UE assumes the indication from the SCI overrides the indication from the DCI.

In one aspect, if a UE received an indication of channel access type and/or symbol duration adjustment for a sidelink transmission from a DCI, and the UE is going to transmit a SCI that schedules the same sidelink transmission, then the UE uses the same information on the channel access type and/or symbol duration adjustment to be included in the SCI.

In one aspect, a UE uses Type 1 channel access procedure for transmitting (e.g., configured) sidelink transmission(s), other than examples which allows other types of channel access procedure(s) as described in this disclosure.

In one aspect, if a UE intends (e.g., is configured) to transmit a set of contiguous sidelink transmissions without any gap, wherein the time domain resource configuration defines multiple transmission occasions, and the UE transmits one of the sidelink transmissions in the set in one of the transmission occasions after accessing the channel according to one of the channel access procedure as described in the example of this disclosure, the UE may continue transmitting the remaining sidelink transmission in the set, if any.

In one aspect, if a UE intends (e.g., is configured) to transmit a set of contiguous sidelink transmissions, wherein the time domain resource configuration defines multiple transmission occasions, and if the UE cannot access the channel for a transmission in the set in a transmission occasion prior to the last transmission according to Type 1 channel access procedure as described in the example of this disclosure, the UE may attempt to transmit the next transmission according to Type 1 channel access procedure.

In one aspect, if a UE intends (e.g., is scheduled) to transmit sidelink transmission(s) starting from symbol i in slot n using Type 1 channel access procedure with a corresponding CAPC, as described in example of this disclosure, wherein for example the sidelink transmission is without symbol duration adjustment (e.g., CP extension), and if the UE starts sidelink transmission before symbol i in slot n using Type 1 channel acces procedure with a corresponding CAPC, and the scheduled sidelink transmission(s) occupies all the RBs of the same channels (e.g., LBT bandwidth or RB-sets) occupied by the configured sidelink transmission(s), or the scheduled sidelink transmission(s) occupies all the RBs of a subset of channels (e.g., LBT bandwidth or RB-sets) occupied by the configured sidelink transmission(s), the UE may directly continue to transmit the scheduled sidelink transmission(s) to from symbol i in slot n without a gap, if the CAPC value of the performed channel access procedure for the configured sidelink transmission(s) is no less than the CAPC value of the channel access procedure for the scheduled sidelink transmission(s).

In one example, the sum of the transmission durations of the configured sidelink transmission(s) and scheduled sidelink transmission(s) does not exceed the maximum channel occupancy time (MCOT) duration corresponding to the CAPC of the performed channel access procedure for the configured sidelink transmission(s).

In another aspect, if a UE intends (e.g., is scheduled) to transmit sidelink transmission(s) starting from symbol i in slot n using Type 1 channel acces procedure with a corresponding CAPC, as described in example of this disclosure, wherein for example the sidelink transmission is without symbol duration adjustment (e.g., CP extension), and if the UE starts configured sidelink transmission before symbol i in slot n using Type 1 channel acces procedure with a corresponding CAPC, and the scheduled sidelink transmission(s) occupies all the RBs of the same channels (e.g., LBT bandwidth or RB-sets) occupied by the configured sidelink transmission(s), or the scheduled sidelink transmission(s) occupies all the RBs of a subset of channels (e.g., LBT bandwidth or RB-sets) occupied by the configured sidelink transmission(s), the UE terminates the configured sidelink transmission(s) by dropping the transmission on symbols of at least the last configured transmission before from symbol i in slot n, and attempts to transmit the scheduled sidelink transmission(s) using channel access procedure with the corresponding CAPC, if the CAPC value of the performed channel access procedure for the configured sidelink transmission(s) is less than the CAPC value of the channel access procedure for the scheduled sidelink transmission(s).

In Rel-16 NR-U, for operation with shared spectrum channel access (e.g., unlicensed or shared spectrum), a transmitter may perform sensing that evaluates the availability of a channel for performing transmissions. For energy detection based sensing, a basic unit for sensing is defined as a sensing slot. A channel with a duration of s sensing slot is declared as idle, if the transmitter senses the channel during the sensing slot duration and determines that the detected power for a given portion of the sensing slot duration is less than a maximum energy detection threshold, or declared as busy otherwise.

For a sidelink operation over an unlicensed spectrum, the transmission of sidelink signals and channels may be subject to the channel access procedure, and the sensing results can also be compared with a maximum energy detection threshold. This disclosure focuses on the adaptation of the energy detection threshold for sidelink operated over an unlicensed spectrum.

The present disclosure provides embodiments for an adaptation of energy detection threshold for sidelink transmission on the unlicensed spectrum. More precisely, the present disclosure provides the following components: (1) an indication of a first type of maximum energy detection threshold; (2) an indication of a second type of maximum energy detection threshold; (3) an indication of an offset for the first type of maximum energy detection threshold; (4) an indication of an offset for the second type of maximum energy detection threshold; (5) a condition to use the first and/or the second type of maximum energy detection threshold; (6) calculation of the default maximum energy detection threshold; and (7) channel occupancy sharing for configured sidelink transmission.

In one embodiment, at least one first type of maximum energy detection (ED) threshold can be provided to a UE, with potential condition to apply the first type of maximum energy detection threshold as described in the examples of this disclosure.

In one example, the at least one first type of maximum energy detection threshold can be provided to a UE by a pre-configuration.

In another example, the at least one first type of maximum energy detection threshold can be configured by a gNB using a higher layer parameter (e.g., a RRC parameter). For one instance, the at least one first type of maximum energy detection threshold can be associated with a resource pool configured by the gNB (e.g., per resource pool). In another instance, the at least one first type of maximum energy detection threshold can be associated with a cell of the gNB (e.g., per cell).

In yet another example, the at least one first type of maximum energy detection threshold can be configured by a UE using a higher layer parameter (e.g., a PC5 RRC parameter). For one instance, the at least one first type of maximum energy detection threshold can be associated with a resource pool (e.g., per resource pool). In another instance, the at least one first type of maximum energy detection threshold can be associated with a UE (e.g., per UE).

In one example, the candidate values of the at least one first type of maximum energy detection threshold can be determined based on a sidelink priority (e.g., the transmission priority). For instance, there can be a mapping between the candidate value(s) of the at least one first type of maximum energy detection threshold to a sidelink priority, and when the sidelink priority is higher, the corresponding applicable candidate value(s) of the at least one first type of maximum energy detection threshold is higher.

FIG.16illustrates a flowchart of a method1600for a UE procedure for setting an energy detection threshold using the first type of maximum energy detection threshold according to embodiments of the present disclosure. The embodiment of the method1600illustrated inFIG.16is for illustration only. The method1600as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). One or more of the components illustrated inFIG.16can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions.

An example UE procedure to set the energy detection threshold based on the first type of maximum energy detection threshold is shown inFIG.16. For instance, this example can be applied when the offset for the first type of maximum energy detection threshold is not supported.

The UE determines whether the first type of maximum energy detection threshold is provided (1601).

If the first type of maximum energy detection threshold is provided to the UE, the UE can set the energy detection threshold (e.g., XThresh) to be less than or equal to the first type of maximum energy detection threshold provided to the UE (1604).

If the first type of maximum energy detection threshold is not provided to the UE, the UE can calculate a default maximum energy detection threshold (e.g., X′Thresh_max) (1602) and set the default maximum energy detection threshold as the first type of maximum energy detection threshold (1603), then the UE can set the energy detection threshold (e.g., XThresh) to be less than or equal to the first type of maximum energy detection threshold (1604).

In one embodiment, at least one second type of maximum ED threshold can be provided to a UE, with potential condition to apply the second type of maximum energy detection threshold as described in the examples of this disclosure.

In one example, the at least one second type of maximum energy detection threshold can be provided to a UE by a pre-configuration.

In another example, the at least one second type of maximum energy detection threshold can be configured by a gNB using a higher layer parameter (e.g., a RRC parameter). For one instance, the at least one second type of maximum energy detection threshold can be associated with a resource pool configured by the gNB (e.g., per resource pool). In another instance, the at least one second type of maximum energy detection threshold can be associated with a cell of the gNB (e.g., per cell).

In yet another example, the at least one second type of maximum energy detection threshold can be configured by a UE using a higher layer parameter (e.g., a PC5 RRC parameter). For one instance, the at least one second type of maximum energy detection threshold can be associated with a resource pool (e.g., per resource pool). In another instance, the at least one second type of maximum energy detection threshold can be associated with a UE (e.g., per UE).

In one example, the candidate values of the at least one second type of maximum energy detection threshold can be determined based on a sidelink priority (e.g., the transmission priority). For instance, there can be a mapping between the candidate value(s) of the at least one second type of maximum energy detection threshold to a sidelink priority, and when the sidelink priority is higher, the corresponding applicable candidate value(s) of the at least one second type of maximum energy detection threshold is higher.

An example UE procedure to set the energy detection threshold based on the second type of maximum energy detection threshold is shown inFIG.17. For instance, this example can be applied when the offset for the second type of maximum energy detection threshold is not supported.

FIG.17illustrates a flowchart of a method1700for a UE procedure for setting an energy detection threshold using the second type of maximum energy detection threshold according to embodiments of the present disclosure. The embodiment of the method1700illustrated inFIG.17is for illustration only. The method1700as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). One or more of the components illustrated inFIG.17can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions.

The UE determines whether the second type of maximum energy detection threshold is provided (1701).

If the second type of maximum energy detection threshold is provided to the UE, the UE can set the energy detection threshold (e.g., XThresh) to be less than or equal to the second type of maximum energy detection threshold provided to the UE (1704).

If the second type of maximum energy detection threshold is not provided to the UE, the UE can calculate a default maximum energy detection threshold (e.g., X′Thresh_max) (1702) and set the default maximum energy detection threshold as the second type of maximum energy detection threshold (1703), then the UE can set the energy detection threshold (e.g., XThresh) to be less than or equal to the second type of maximum energy detection threshold (1704).

In one embodiment, an offset for the first type of maximum energy detection threshold can be provided to a UE, with potential condition to apply the first type of maximum energy detection threshold as described in the examples of this disclosure.

In one example, the offset for the first type of maximum energy detection threshold can be provided to a UE by a pre-configuration.

In another example, the offset for the first type of maximum energy detection threshold can be configured by a gNB using a higher layer parameter (e.g., a RRC parameter). For one instance, the offset for the first type of maximum energy detection threshold can be associated with a resource pool configured by the gNB (e.g., per resource pool). In another instance, the offset for the first type of maximum energy detection threshold can be associated with a cell of the gNB (e.g., per cell).

In yet another example, the offset for the first type of maximum energy detection threshold can be configured by a UE using a higher layer parameter (e.g., a PC5 RRC parameter). For one instance, the offset for the first type of maximum energy detection threshold can be associated with a resource pool (e.g., per resource pool). In another instance, the offset for the first type of maximum energy detection threshold can be associated with a UE (e.g., per UE).

In one example, the candidate values of the offset for the first type of maximum energy detection threshold can be determined based on a sidelink priority (e.g., the transmission priority). For instance, there can be a mapping between the candidate value(s) of the offset for the first type of maximum energy detection threshold to a sidelink priority, and when the sidelink priority is higher, the corresponding applicable candidate value(s) of offset for the first type of maximum energy detection threshold is higher.

FIG.18illustrates a flowchart of a method1800for a UE procedure for setting an energy detection threshold using the first type of maximum energy detection threshold and/or the offset for the first type of maximum energy detection threshold according to embodiments of the present disclosure. The embodiment of the method1800illustrated inFIG.18is for illustration only. The method1800as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). One or more of the components illustrated inFIG.18can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions.

An example UE procedure to set the energy detection threshold based on the first type of maximum energy detection threshold and/or the offset for the first type of maximum energy detection threshold is shown inFIG.18. For instance, this example can be applied when the offset for the first type of maximum energy detection threshold is supported.

The UE determines whether the first type of maximum energy detection threshold is provided (1801).

If the first type of maximum energy detection threshold is provided to the UE, the UE can set the energy detection threshold (e.g., XThresh) to be less than or equal to the first type of maximum energy detection threshold provided to the UE (1806).

If the first type of maximum energy detection threshold is not provided to the UE, the UE can calculate a default maximum energy detection threshold (e.g., X′Thresh_max) (1802), according to an example of this disclosure, and further determines whether an offset for the first type of maximum energy detection threshold is provided (1803).

If the offset for the first type of maximum energy detection threshold is provided to the UE, the UE applies the offset for the first type of maximum energy detection threshold to the default maximum energy detection threshold (e.g., X′Thresh_max) to determine the first type of maximum energy detection threshold (1805), and set the energy detection threshold (e.g., XThresh) to be less than or equal to the first type of maximum energy detection threshold (1806).

If the offset for the first type of maximum energy detection threshold is not provided to the UE, the UE sets the first type of maximum energy detection threshold as the default maximum energy detection threshold (e.g., X′Thresh_max) (1804), and set the energy detection threshold (e.g., X Thresh) to be less than or equal to the first type of maximum energy detection threshold (1806).

In one embodiment, an offset for the second type of maximum energy detection threshold can be provided to a UE, with potential condition to apply the second type of maximum energy detection threshold as described in the examples of this disclosure.

In one example, the offset for the second type of maximum energy detection threshold can be provided to a UE by a pre-configuration.

In another example, the offset for the second type of maximum energy detection threshold can be configured by a gNB using a higher layer parameter (e.g., a RRC parameter). For one instance, the offset for the second type of maximum energy detection threshold can be associated with a resource pool configured by the gNB (e.g., per resource pool). In another instance, the offset for the second type of maximum energy detection threshold can be associated with a cell of the gNB (e.g., per cell).

In yet another example, the offset for the second type of maximum energy detection threshold can be configured by a UE using a higher layer parameter (e.g., a PC5 RRC parameter). For one instance, the offset for the second type of maximum energy detection threshold can be associated with a resource pool (e.g., per resource pool). In another instance, the offset for the second type of maximum energy detection threshold can be associated with a UE (e.g., per UE).

In one example, the candidate values of the offset for the second type of maximum energy detection threshold can be determined based on a sidelink priority (e.g., the transmission priority). For instance, there can be a mapping between the candidate value(s) of the offset for the second type of maximum energy detection threshold to a sidelink priority, and when the sidelink priority is higher, the corresponding applicable candidate value(s) of offset for the second type of maximum energy detection threshold is higher.

FIG.19illustrates a flowchart of a method1900for a UE procedure for setting an energy detection threshold using the second type of maximum energy detection threshold and/or the offset for the second type of maximum energy detection threshold according to embodiments of the present disclosure. The embodiment of the method1900illustrated inFIG.19is for illustration only. The method1900as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). One or more of the components illustrated inFIG.19can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions.

An example UE procedure to set the energy detection threshold based on the second type of maximum energy detection threshold and/or the offset for the second type of maximum energy detection threshold is shown inFIG.19. For instance, this example can be applied when the offset for the second type of maximum energy detection threshold is supported.

The UE determines whether the second type of maximum energy detection threshold is provided (1901).

If the second type of maximum energy detection threshold is provided to the UE, the UE can set the energy detection threshold (e.g., XThresh) to be less than or equal to the second type of maximum energy detection threshold provided to the UE (1906).

If the second type of maximum energy detection threshold is not provided to the UE, the UE can calculate a default maximum energy detection threshold (e.g., X′Thresh_max) (1902), according to an example of this disclosure, and further determines whether an offset for the second type of maximum energy detection threshold is provided (1903).

If the offset for the second type of maximum energy detection threshold is provided to the UE, the UE applies the offset for the second type of maximum energy detection threshold to the default maximum energy detection threshold (e.g., X′Thresh_max) to determine the second type of maximum energy detection threshold (1905), and set the energy detection threshold (e.g., XThresh) to be less than or equal to the second type of maximum energy detection threshold (1906).

If the offset for the second type of maximum energy detection threshold is not provided to the UE, the UE sets the second type of maximum energy detection threshold as the default maximum energy detection threshold (e.g., X′Thresh_max) (1904), and set the energy detection threshold (e.g., XThresh) to be less than or equal to the second type of maximum energy detection threshold (1906).

In one embodiment, a UE applies the first type of maximum energy detection threshold (and/or the associated offset) and/or the second type of maximum energy detection threshold (and/or the associated offset) based on an example as described in this disclosure.

In one example, the at least one second type of maximum energy detection threshold (and/or the associated offset) can be applied for the channel access procedure after which the UE initializes a channel occupancy to perform sidelink transmission(s) and shares its channel occupancy to a gNB and/or other UE(s). For this example, whether the at least one second type of maximum energy detection threshold (and/or the associated offset) is provided or not can be used as an indication of whether the corresponding channel occupancy sharing is supported or not, respectively.

In one example, at least one second type of maximum energy detection threshold (and/or the associated offset) can be applied for the channel access procedure after which the UE initializes a channel occupancy to perform sidelink transmission(s) and shares its channel occupancy to other UE(s) for sidelink transmission(s) on the same channel.

In another example, at least one second type of maximum energy detection threshold (and/or the associated offset) can be applied for the channel access procedure after which the UE initializes a channel occupancy to perform sidelink transmission(s) and shares its channel occupancy to other UE(s) for uplink transmission(s) on the same channel.

In yet another example, at least one second type of maximum energy detection threshold (and/or the associated offset) can be applied for the channel access procedure after which the UE initializes a channel occupancy to perform sidelink transmission(s) and shares its channel occupancy to a gNB for downlink transmission(s) on the same channel.

In one example, the transmission from the UE that initializes a channel occupancy can be or include a scheduled sidelink transmission.

In another example, the transmission from the UE that initializes a channel occupancy can be or include a configured sidelink transmission.

In one example, if the at least one second type of maximum energy detection threshold (and/or the associated offset) is not provided, the transmission in the shared channel occupancy may not include any unicast transmissions and/or the transmission duration has an upper bound (e.g., 2 ms, which is 2, 4 or 8 symbols for 15, 30, or 60 kHz SCS respectively).

In another example, if the at least one second type of maximum energy detection threshold (and/or the associated offset) is not provided, the transmission in the shared channel occupancy may not include any groupcast transmissions and/or the transmission duration has an upper bound (e.g., 2 ms, which is 2, 4 or 8 symbols for 15, 30, or 60 kHz SCS respectively).

In one example, if the at least one second type of maximum energy detection threshold (and/or the associated offset) is provided to at least one second UE by a first UE, potentially with a further condition that the at least one second UE is provided an indication that other radio access technology is absent (e.g., by a higher layer parameter from a gNB and/or the first UE), the first UE may use its transmit power to determine the resulting at least one second type of maximum energy detection threshold.

In another example, if the at least one second type of maximum energy detection threshold (and/or the associated offset) is provided to at least one second UE by a first UE, potentially with a further condition that the at least one second UE is provided an indication that other radio access technology is absent (e.g., by a higher layer parameter from a gNB and/or the first UE), the first UE may use PCMAX_H,cto determine the resulting at least one second type of maximum energy detection threshold.

In yet another example, if the at least one second type of maximum energy detection threshold (and/or the associated offset) is provided to at least one second UE by a first UE, potentially with a further condition that the at least one second UE is provided an indication that other radio access technology is absent (e.g., by a higher layer parameter from a gNB and/or the first UE), the first UE may use PCMAXto determine the resulting at least one second type of maximum energy detection threshold.

In another example, the first type of maximum energy detection threshold (and/or the associated offset) can be applied for the channel access procedure after which the UE performs sidelink transmission when the second type of maximum energy detection threshold is not applied. In one instance, the first type of maximum energy detection threshold (and/or the associated offset) can be applied for all the cases of the channel access procedure after which the UE performs sidelink transmission, when the second type of maximum energy detection threshold is not supported.

In yet another example, the case that the first type of maximum energy detection threshold (and/or the associated offset) can be applied is the same as the case that the second type of maximum energy detection threshold (and/or the associated offset) can be applied, and there is no distinguish of the first or second type of maximum energy detection threshold (and/or the associated offset), e.g., the description on the applicability of the second type of maximum energy detection threshold (and/or the associated offset) in this disclosure can be applied to the first type of maximum energy detection threshold (and/or the associated offset) as well, and the description on the applicability of the first type of maximum energy detection threshold (and/or the associated offset) in this disclosure can be applied to the second type of maximum energy detection threshold (and/or the associated offset) as well.

FIG.20illustrates a flowchart of a method2000for a UE procedure for sidelink transmission based on the maximum ED thresholds according to embodiments of the present disclosure. The embodiment of the method2000illustrated inFIG.20is for illustration only. The method2000as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). One or more of the components illustrated inFIG.20can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions.

An example UE procedure for sidelink transmission based on the maximum energy detection thresholds is shown inFIG.20.

The UE determines whether the second type of maximum energy detection threshold (and/or the associated offset) is applicable for the sidelink transmission, based on the examples described in this disclosure (2001).

If the second type of maximum energy detection threshold (and/or the associated offset) is applicable for the sidelink transmission, the UE further determines whether the second type of maximum energy detection threshold (and/or the associated offset) is provided (2002).

If the second type of maximum energy detection threshold (and/or the associated offset) is provided, the UE sets the energy detection threshold based on the provided second type of maximum energy detection threshold (and/or the associated offset) (2003), according to examples described in this disclosure (e.g., as shown inFIG.17orFIG.19).

If the second type of maximum energy detection threshold (and/or the associated offset) is not provided, the UE sets the energy detection threshold based on the first type of maximum energy detection threshold (and/or the associated offset) (2004), according to examples described in this disclosure (e.g., as shown inFIG.16orFIG.18).

If the second type of maximum energy detection threshold (and/or the associated offset) is not applicable for the sidelink transmission, the UE sets the energy detection threshold based on the first type of maximum energy detection threshold (and/or the associated offset) (2004), according to examples described in this disclosure (e.g., as shown inFIG.16orFIG.18).

The UE then performs channel access procedure based on the energy detection threshold (2005).

The UE performs the sidelink transmission if the channel access procedure succeeds (e.g., the sensing of the channel in the channel access procedure is idle) (2006).

FIG.21illustrates a flowchart of a method2100for a UE procedure for sidelink transmission based on the maximum ED thresholds according to embodiments of the present disclosure. The embodiment of the method2100illustrated inFIG.21is for illustration only. The method2100as may be performed by a UE (e.g.,111-116as illustrated inFIG.1). One or more of the components illustrated inFIG.21can be implemented in specialized circuitry configured to perform the noted functions or one or more of the components can be implemented by one or more processors executing instructions to perform the noted functions.

Another example UE procedure for sidelink transmission based on the maximum energy detection thresholds is shown inFIG.21.

The UE determines whether the second type of maximum energy detection threshold (and/or the associated offset) is applicable for the sidelink transmission, based on the examples described in this disclosure (2101).

If the second type of maximum energy detection threshold (and/or the associated offset) is applicable for the sidelink transmission, the UE further determines whether the second type of maximum energy detection threshold (and/or the associated offset) is provided (2102).

If the second type of maximum energy detection threshold (and/or the associated offset) is provided, the UE sets the energy detection threshold based on the provided second type of maximum energy detection threshold (and/or the associated offset) (2103), according to examples described in this disclosure (e.g., as shown inFIG.17orFIG.19).

If the second type of maximum energy detection threshold (and/or the associated offset) is not provided, the UE sets the energy detection threshold based on the default maximum energy detection threshold, which is calculated by the UE, according to example described in this disclosure (2104).

If the second type of maximum energy detection threshold (and/or the associated offset) is not applicable for the sidelink transmission, the UE sets the energy detection threshold based on the first type of maximum energy detection threshold (and/or the associated offset) (2105), according to examples described in this disclosure (e.g., as shown inFIG.16orFIG.18).

The UE then performs channel access procedure based on the energy detection threshold (2106).

The UE performs the sidelink transmission if the channel access procedure succeeds (e.g., the sensing of the channel in the channel access procedure is idle) (2107).

In one embodiment, a default maximum energy detection threshold (e.g., X′Thresh_max) can be calculated by a UE.

In one example, if a UE is provided an indication that other radio access technology is absent (e.g., by a higher layer parameter from a gNB and/or another UE), the default maximum energy detection threshold can be calculated as: X′Thresh_max=min(Tmax+ΔTmax,Xreg) where for one instance, Tmax=10 log10(3.16228·10−8(mW/MHz) BW(MHz)) and Tmaxis in dBm, wherein BW is the channel bandwidth in MHz; for another instance, Xregis the maximum energy detection threshold defined by regulatory requirements in dBm when such requirements are defined, otherwise Xregis same as Tmax+ΔTmaxfor yet another instance, ΔTmaxcan be a value, e.g., fixed as 10 dB, or pre-configured, or provided by higher layer parameter from a gNB and/or a UE.

In another example, if a UE is not provided an indication that other radio access technology is absent (e.g., by a higher layer parameter from a gNB and/or another UE), the default maximum energy detection threshold can be calculated as:

where Tmax=10 log10(3.16228·10−8(mW/MHz) BW(MHz)) and Tmaxis in dBm, wherein BW is the channel bandwidth in MHz, PHis fixed as 23 dBm.

In one example, PTXis set to the value of PCMAX_H,c.

In another example, PTXis set to the value of PCMAX.

In yet another example, PTXis set to the maximum UE output power in dBm for the channel.

In another example, TAis set to a smaller value for transmission with a discovery burst (e.g., 5 dB), and TAis set to a larger value otherwise (e.g., 10 dB). For instance, a discovery burst can be referring to the transmissions allowed to perform quick channel access procedure, e.g., including S-SS/PSBCH block and/or PSFCH transmissions.

In yet another example, TAcan be set to a value based on the priority (e.g., transmission priority) of the associated transmission. For instance, TAcan be set to a smaller value if the priority (e.g., transmission priority) of the associated transmission is higher.

In one embodiment, a message including channel occupancy sharing information can be transmitted by a first UE to at least one second UE on sidelink.

In one example, the message can be included in an SCI format. For one sub-example, the SCI format can be SCI format 1-A. For another sub-example, the SCI format can be SCI format 2-A. For yet another sub-example, the SCI format can be SCI format 2-B. For yet another sub-example, the SCI format can be SCI format 2-C. For yet another sub-example, the SCI format can be a new SCI format other than the sub-examples above.

In another example, the message can be included in a higher layer parameter transmitted from the first UE to the at least one second UE (e.g., PC5 RRC parameter).

In yet another example, the message can be transmitted over a sidelink channel. For one sub-example, the sidelink channel can be PSCCH. For another sub-example, the sidelink channel can be PSSCH. For yet another sub-example, the sidelink channel can be PSFCH.

In one example, if a first UE initializes a channel occupancy and shares the channel occupancy with at least one second UE, wherein the transmission from the first UE is or includes configured sidelink transmission, the at least one second UE may transmit a transmission that follows the configured sidelink transmission by the first UE, according to the message including channel occupancy sharing information can be transmitted by the first UE to at least one second UE.

In one example, the at least one second UE can be configured with a set of channel occupancy sharing information (e.g., using a table), wherein each channel occupancy sharing information includes at least one of a time domain offset value, a time domain duration value, or a channel access priority class (CAPC), or includes that the channel occupancy sharing is not available. The message including channel occupancy sharing information can be determined as one from the set of channel occupancy sharing information (e.g., determines as one row from the table). The bitwidth of the message can be based on the size of the set (e.g., number of rows in the table).

In one example, the second UE can be configured with channel occupancy sharing information including a time domain offset value. The message including channel occupancy sharing information can be determined as whether to use the configured channel occupancy sharing information including a time domain offset value to determine the channel occupancy sharing. The bitwidth of the message can be 1.

In one embodiment, the indication can be whether the second type of maximum energy detection threshold is provided to the second UE, e.g., if the second type of maximum energy detection threshold is provided to the second UE, the first sub-example is used; and if the second type of maximum energy detection threshold is not provided to the second UE, the second sub-example is used.

In another embodiment, when the first UE provides multiple indications of the information on channel occupancy sharing information (e.g., other than channel occupancy sharing information being not available), the information for sidelink transmissions in the shared channel occupancy (e.g., configured SL transmissions) may be consistent from the multiple indications (e.g., consistent starting timing for transmission, and/or consistent transmission duration).

In yet another embodiment, if the at least one second UE is provided with the second type of maximum energy detection threshold, the second UE sets the maximum energy detection threshold as the provided second type of maximum energy detection threshold for the channel access procedure associated with its transmission, if at least one of the following conditions satisfies: the first UE does not provide the message including the channel occupancy sharing information in its sidelink transmission (e.g., the sidelink transmission is a scheduled sidelink transmission), or when the first UE provides the message including the channel occupancy sharing information wherein the information is other than channel occupancy sharing information being not available (e.g., the sidelink transmission is a configured sidelink transmission and the channel occupancy is shared).

In yet another embodiment, if the at least one second UE is provided with the message including channel occupancy sharing information indicating that the channel occupancy sharing is not available, the at least one second UE may assume the channel occupancy initialized by the first UE is not shared for transmission by the at least one second UE.

In yet another embodiment, if the at least one second UE is provided with the message including channel occupancy sharing information indicating at least one of a time domain offset value, a time domain duration value, or a channel access priority class, the at least one second UE may assume the channel occupancy initialized by the first UE can be shared for transmission by the at least one second UE, and the transmission starting from a slot determined based on the indicated time domain offset value, and/or with a transmission duration given by the indicated time domain duration value, and/or with a channel access procedure associated with the indicated channel access priority class. For one instance, the transmission can start from the slot with index n+O, wherein n is index of the slot where the message is received by the at least one second UE, and O is given by the indicated time domain offset value.

In yet another embodiment, if the at least one second UE is provided with the message including channel occupancy sharing information indicating a time domain offset value, the at least one second UE may assume the channel occupancy initialized by the first UE can be shared for transmission by the at least one second UE. For one instance, the transmission can occur in the slot within index n+O, wherein n is index of the slot where the message is received by the at least one second UE, and O is given by the indicated time domain offset value. For another instance, the transmission can occur 14·O symbols from the end of the slot where the message is received by the at least one second UE, and O is given by the indicated time domain offset value.