Micro-slot channel access for sidelink user equipment (UE)

Abstract

A method for wireless communication at a first sidelink user equipment (UE) includes performing listen before talk (LBT) within a channel occupancy time (COT) in a shared radio frequency spectrum band. The method also includes selecting a full slot sidelink channel waveform hypothesis associated with a first start symbol or a half slot sidelink channel waveform hypothesis associated with a second start symbol according to a timing associated with clearing the LBT. The method also includes transmitting sidelink information to a second sidelink UE during the COT, a transport block size (TBS) associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources for the full slot sidelink channel waveform hypothesis and the half slot sidelink channel waveform hypothesis.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application No. 18 / 448,096, filed on August 10, 2023, entitled “MINI-SLOT CHANNEL ACCESS FOR ASIDELINK USER EQUIPMENT (UE),” which claims the benefit of U.S. Provisional Patent Application No. 63 / 397,314, filed on August 11, 2022, entitled “MINI-SLOTCHANNEL ACCESS FOR A SIDELINK USER EQUIPMENT (UE),” the disclosures of which are expressly incorporated by reference in their entirety. Technical Field

[0003] The present application relates to wireless communication systems, and more particularly to resource reservation for sidelink communications over a shared radio frequency band. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). A wireless multiple-access communication system may include multiple base stations (BSs), each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0005] To meet the growing demand for extended mobile broadband connections, wireless communication technology is evolving from Long Term Evolution (LTE) technology to next-generation New Radio (NR) technology (which may be referred to as the fifth generation (5G)). For example, NR is designed to provide lower latency, higher bandwidth or higher throughput, and higher reliability compared to LTE. NR is designed to operate on a wide array of spectrum bands, for example, from low bands below about 1 gigahertz (GHz) and mid-bands from about 1 GHz to about 6 GHz to high bands such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed spectrum and shared spectrum. Spectrum sharing enables operators to have the opportunity to aggregate spectrum to dynamically support high-bandwidth services. Spectrum sharing can extend the benefits of NR technology to operating entities that may not have access to licensed spectrum.

[0006] In a wireless communication network, a BS can communicate with a UE in both the uplink and downlink directions. Sidelink was introduced in LTE to allow a UE to transmit data to another UE (e.g., from one vehicle to another vehicle) without tunneling through the BS and / or associated core network. LTE sidelink technology has been extended to provide device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, and / or cellular vehicle-to-everything (C-V2X) communication. Similarly, NR can be extended to support sidelink communication, D2D communication, V2X communication, and / or C-V2X on licensed and / or unlicensed bands. Summary of the invention

[0007] In some aspects of the present disclosure, a method for wireless communication by a first sidelink user equipment (UE) includes performing listen-before-talk (LBT) within a channel occupancy time (COT) in a shared radio frequency band. The method also includes selecting a full-slot sidelink channel waveform hypothesis associated with a first start symbol or a half-slot sidelink channel waveform hypothesis associated with a second start symbol based on timing associated with clearing the LBT. The method also includes sending sidelink information to a second sidelink UE during the COT, a transport block size (TBS) associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources used for the full-slot sidelink channel waveform hypothesis and the half-slot sidelink channel waveform hypothesis.

[0008] Another aspect of the present disclosure relates to an apparatus, the apparatus including means for performing LBT within a COT in a shared radio frequency band. The apparatus also includes means for selecting a full-slot sidelink channel waveform hypothesis associated with a first start symbol or a half-slot sidelink channel waveform hypothesis associated with a second start symbol based on timing associated with clearing the LBT. The apparatus also includes means for sending sidelink information to a second sidelink UE during the COT, a TBS associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources used for the full-slot sidelink channel waveform hypothesis and the half-slot sidelink channel waveform hypothesis.

[0009] In other aspects of the present disclosure, a non-transitory computer-readable medium having non-transitory program code recorded thereon is disclosed. The program code is executed by a processor and includes program code for: performing LBT within a COT in a shared radio frequency band. The program code further includes program code for: selecting a full-slot side link channel waveform hypothesis associated with a first start symbol or a half-slot side link channel waveform hypothesis associated with a second start symbol based on timing associated with clearing the LBT. The program code also includes program code for: sending side link information to a second side link UE during the COT, a TBS associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources used for the full-slot side link channel waveform hypothesis and the half-slot side link channel waveform hypothesis.

[0010] Other aspects of the present disclosure relate to a first sidelink user UE, the first sidelink user UE comprising: one or more memories, the one or more memories comprising processor-executable instructions; and one or more processors, the one or more processors being configured to execute the processor-executable instructions and cause the first sidelink UE to perform LBT within a COT in a shared radio frequency band. The one or more processors are also configured to execute the processor-executable instructions and cause the first sidelink UE to select a full-slot sidelink channel waveform hypothesis associated with a first start symbol or a half-slot sidelink channel waveform hypothesis associated with a second start symbol according to a timing associated with clearing the LBT. The one or more processors are further configured to execute the processor-executable instructions and cause the first sidelink UE to send sidelink information to a second sidelink UE during the COT, the TBS associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources used for the full-slot sidelink channel waveform hypothesis and the half-slot sidelink channel waveform hypothesis.

[0011] In some aspects of the present disclosure, a method for wireless communication by a first sidelink UE includes monitoring a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position within each COT time slot of a group of COT time slots, wherein the first PSCCH candidate position appears before the second PSCCH candidate position within each COT time slot of the group of COT time slots. The method also includes receiving a message from a second sidelink UE in a first COT time slot of the group of COT time slots. The method also includes suspending the monitoring of the second PSCCH candidate position in at least the first COT time slot based on the message triggering a suspension condition. The method also includes monitoring the first PSCCH candidate position within each COT time slot of the group of COT time slots after the first COT time slot based on suspending the monitoring of the second PSCCH candidate position.

[0012] Other aspects of the present disclosure relate to an apparatus comprising means for monitoring a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position within each COT time slot of a set of COT time slots, wherein the first PSCCH candidate position occurs before the second PSCCH candidate position within each COT time slot of the set of COT time slots. The apparatus also comprises means for receiving a message from a second sidelink UE in a first COT time slot of the set of COT time slots. The apparatus also comprises means for suspending the monitoring of the second PSCCH candidate position in at least the first COT time slot based on triggering a suspension condition by the message. The apparatus also comprises means for monitoring the first PSCCH candidate position within each COT time slot of the set of COT time slots after the first COT time slot based on suspending the monitoring of the second PSCCH candidate position.

[0013] In other aspects of the present disclosure, a non-transitory computer-readable medium having non-transitory program code recorded thereon is disclosed. The program code is executed by a processor and includes program code for: monitoring a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position within each COT time slot of a group of COT time slots, wherein the first PSCCH candidate position appears before the second PSCCH candidate position within each COT time slot of the group of COT time slots. The program code also includes program code for: receiving a message from a second sidelink UE in a first COT time slot of the group of COT time slots. The program code also includes program code for: suspending the monitoring of the second PSCCH candidate position in at least the first COT time slot based on the message triggering a suspension condition. The program code also includes program code for: monitoring the first PSCCH candidate position in each COT time slot of the group of COT time slots after the first COT time slot based on suspending the monitoring of the second PSCCH candidate position.

[0014] Other aspects of the present disclosure relate to a first sidelink user UE, the first sidelink user UE comprising: one or more memories, the one or more memories comprising processor-executable instructions; and one or more processors, the one or more processors being configured to execute the processor-executable instructions and cause the first sidelink UE to monitor a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position within each COT time slot of a group of COT time slots, wherein the first PSCCH candidate position appears before the second PSCCH candidate position within each COT time slot of the group of COT time slots. The one or more processors are also configured to execute the processor-executable instructions and cause the first sidelink UE to receive a message from the second sidelink UE in the first COT time slot of the group of COT time slots. The one or more processors are further configured to execute the processor-executable instructions and cause the first sidelink UE to suspend the monitoring of at least the second PSCCH candidate position in the first COT time slot based on the message triggering a suspension condition. The apparatus also includes means for monitoring the first PSCCH candidate position within each COT time slot in the set of COT time slots after the first COT time slot based on suspending the monitoring of the second PSCCH candidate position.

[0015] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer readable media, user equipment, base stations, wireless communication devices, and processing systems as substantially described with reference to and as illustrated in the accompanying drawings and description.

[0016] The features and technical advantages of examples according to the present disclosure have been outlined quite broadly above so that the following specific embodiments may be better understood. Additional features and advantages will be described. The disclosed concepts and specific examples may be easily used as a basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the disclosed concepts, both in terms of their organization and method of operation, and the associated advantages will be better understood by considering the following description in conjunction with the accompanying drawings. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description and not as a definition of limitations to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The features, nature and advantages of the present disclosure will become more apparent when the detailed description set forth below is read in conjunction with the accompanying drawings, in which like reference numerals are correspondingly identified throughout.

[0018] Figure 1 A wireless communication network according to various aspects of the present disclosure is illustrated.

[0019] Figure 2A wireless communication network providing sidelink communications according to various aspects of the present disclosure is illustrated.

[0020] Figure 3 Reserving resources for sidelink communications according to various aspects of the present disclosure is illustrated.

[0021] Figure 4 Reserving resources for sidelink communications according to various aspects of the present disclosure is illustrated.

[0022] Figure 5A is a block diagram illustrating an example of a transmitter selecting a half slot based on LBT clearing after a slot boundary according to various aspects of the present disclosure.

[0023] Figure 5B is a block diagram illustrating an example of a transmitter selecting a full slot based on LBT clearing after a slot boundary according to various aspects of the present disclosure.

[0024] Figure 6 is a block diagram illustrating examples of aggregated half-slots and full-slots in accordance with various aspects of the present disclosure.

[0025] Figure 7 is a block diagram illustrating an example in which a receiver such as a sidelink UE monitors two transmission start points per time slot.

[0026] Figure 8 is a flow chart illustrating an example process performed by a sidelink user transmitter in accordance with various aspects of the present disclosure.

[0027] Fig. 9 is a flow chart illustrating an example process performed by a sidelink receiver in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION

[0028] The specific embodiments described below in conjunction with the accompanying drawings are intended as descriptions of various configurations and are not intended to represent the only configurations with which the concepts described herein can be practiced. In order to provide a comprehensive understanding of the various concepts, the specific embodiments include specific details. However, it is apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, in order to avoid obscuring such concepts, well-known structures and components are shown in block diagram form.

[0029] The present disclosure as a whole relates to wireless communication systems, which are also referred to as wireless communication networks. In various embodiments, various techniques and devices can be used for wireless communication networks, such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single carrier FDMA (SC-FDMA) networks, LTE networks, global mobile communication systems (GSM) networks, fifth generation (5G) or new radio (NR) networks, and other communication networks. As described herein, the terms "network" and "system" can be used interchangeably.

[0030] OFDMA networks may implement radio technologies such as Evolved Universal Terrestrial Radio Access (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM, etc. UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents provided by an organization named "3rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These radio technologies and standards are either known or under development. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between a group of telecommunications associations with the goal of defining globally applicable third generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP project aimed at improving the UMTS mobile phone standard. 3GPP may define specifications for next generation mobile networks, mobile systems, and mobile devices. The present disclosure relates to the evolution from LTE, 4G, 5G, NR and beyond wireless technologies, where access to the wireless spectrum is shared between networks using a range of new and different radio access technologies or radio air interfaces.

[0031] Specifically, 5G networks consider various deployments, various spectrums, and various services and devices that can be implemented using a unified air interface based on OFDM. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to scale to (1) ultra-high density (e.g., about 1M nodes / km) 2(1) provide coverage for the massive Internet of Things (IoT) with ultra-low complexity (e.g., on the order of tens of bits / second), ultra-low energy (e.g., on the order of 10+ years battery life), and deep coverage with the ability to reach challenging locations; (2) provide coverage including mission-critical control with strong security to protect sensitive personal, financial, or classified information, ultra-high reliability (e.g., on the order of 99.9999% reliability), ultra-low latency (e.g., on the order of 1 millisecond), and for users with extensive mobility or lack of mobility; and (3) provide coverage with enhanced mobile broadband (including extremely high capacity (e.g., on the order of 10Tbps / km 2 ), very high data rates (e.g., multi-Gbps rates, 100+Mbps user experienced rates), and deep awareness coverage with advanced discovery and optimization.

[0032] The 5G NR communication system can be implemented using an optimized OFDM-based waveform with a scalable parameter set and a transmission time interval (TTI). Additional features may also include a common, flexible framework to efficiently multiplex services and features using a dynamic low-latency time division duplex (TDD) / frequency division duplex (FDD) design; and advanced wireless technologies such as massive multiple-input multiple-output (MIMO), robust millimeter wave (mmWave) transmission, advanced channel decoding, and device-centric mobility. The scalability of the parameter set in 5G NR and the scaling of the subcarrier spacing can efficiently address the operation of various services across different spectrums and different deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD / TDD implementations, the subcarrier spacing may appear at 15kHz on bandwidths (BW) such as 5MHz, 10MHz, 20MHz, etc. For other various outdoor and small cell coverage deployments of TDD greater than 3GHz, the subcarrier spacing may appear at 30kHz on 80MHz / 100MHz BW. For various other indoor broadband implementations, using TDD on the unlicensed portion of the 5 GHz band, subcarrier spacing may occur at 60 kHz over 160 MHz BW. Finally, for various deployments transmitting with the mmWave component at 28 GHz TDD, subcarrier spacing may occur at 120 kHz over 500 MHz BW.

[0033] 5G NR's scalable parameter sets facilitate scalable TTIs for different latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long and short TTIs allows transmission to start on symbol boundaries. 5G NR also envisions a self-contained integrated subframe design with UL / downlink scheduling information, data, and acknowledgment in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL / downlink (which can be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet current business needs).

[0034] The various other aspects and features of the present disclosure are further described below. It should be apparent that the teachings herein can be embodied in various forms, and any specific structure, function, or both disclosed herein are merely representative and not restrictive. Based on the teachings herein, it should be understood by those of ordinary skill in the art that the aspects disclosed herein can be implemented independently of any other aspects, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement a device or practice a method. In addition, such a device can be implemented or such a method can be practiced using other structures, functionality, or structures and functionality other than or different from one or more of the aspects set forth herein. For example, the method can be implemented as a part of a system, device, device, and / or as an instruction stored on a computer-readable medium for execution on a processor or computer. In addition, one aspect can include at least one element of a claim.

[0035] Sidelink communication refers to communication between user equipment devices (UE) without tunneling through a base station (BS) and / or a core network. Sidelink communication may be communicated on a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH). PSCCH and PSSCH are analogous to the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH) in downlink (DL) communication between a BS and a UE. For example, the PSCCH may carry sidelink control information (SCI) and the PSSCH may carry sidelink data (e.g., user data). Each PSCCH is associated with a corresponding PSSCH, where the SCI in the PSCCH may carry reservation and / or scheduling information for sidelink data transmission in the associated PSSCH. Use cases for sidelink communication may include V2X, enhanced mobile broadband (eMBB), industrial IoT (IIoT), and / or NR-lightweight.

[0036] As used herein, the term "sidelink UE" may refer to a user equipment device that performs device-to-device communication or other types of communication with another user equipment independently of any tunneling through a BS (e.g., gNB) and / or associated core network. As used herein, the term "sidelink transmitting UE" may refer to a user equipment device that performs sidelink transmitting operations. As used herein, the term "sidelink receiving UE" may refer to a user equipment device that performs sidelink receiving operations. A sidelink UE may act as a transmitting sidelink UE at one time and as a receiving sidelink UE at another time.

[0037] In some instances, a base station may configure a set of resources for use in sidelink communications between UEs. For example, the base station may configure frame and slot timing that may be used by UEs in sidelink communications. In some cases, the configured resources for sidelink UEs may include shared or unlicensed radio frequency spectrum, wherein a device to access the channel performs a contention-based channel access process that provides fair channel access to the unlicensed or shared radio frequency spectrum. For example, a UE may perform a listen-before-talk (LBT) process (e.g., clear channel assessment (CCA)) and determine whether a signal from another device is detected on a channel or subchannel. In the absence of detecting other signals indicating that another device is using the channel, the UE may determine that the channel is available and send a reservation signal to indicate to other UEs that the channel is reserved for a continuous channel occupancy time (COT).

[0038] As discussed herein, in some cases, a UE may send one or more repetitions of a communication in order to enhance the likelihood of successfully receiving the communication. For example, such techniques may be used in cases where the communication has a high priority, in cases where the communication has a low latency target and / or high reliability, in cases where channel conditions are relatively unfavorable, or in cases of any combination thereof. In a wireless communication network using licensed radio frequency spectrum, based on the scheduling of resources for UE communications, the availability of a channel for sending one or more of such repetitions may be known. Therefore, in such cases, the UE may identify a set of resources for communication and one or more sets of resources for repetitions of communication (e.g., reservation for future resources). The identified resources may then be used to send the communication and the associated resources. However, in cases where unlicensed or shared radio frequency spectrum is used for such communications, the availability of the channel may depend on the successful completion of a contention-based channel access process (e.g., an LBT or CCA process).

[0039] In some examples, resource reservations for one or more repetitions of a communication may be identified relative to a COT and determined based on COT timing. In some cases, a first UE may send a first communication to a second UE during a first COT, and may reserve resources for one or more subsequent COTs for one or more repetitions of the first communication. The first UE may send an indication of a reservation of the reserved resources. In some cases, the reserved resources may be identified based at least in part on a two-stage resource reservation, wherein the reserved resources are identified relative to the timing of the transmission of the reservation indication or the end of the first COT. Such a UE may first determine the timing of the second COT and may then determine the timing of the reserved resources based on the timing of the second COT. In some cases, the reserved resources may be identified based at least in part on one or more offsets from the start time of the second COT. The first UE may use the reserved resources to send one or more additional instances of the first communication.

[0040] In some examples, an indication of the reserved resources may be provided with sidelink control information (SCI) sent by the first UE. In some cases, one or more of the reserved resources may be within a shared COT obtained (competed for and won) by a UE different from the first UE. A UE receiving the SCI indicating the reserved resources may consider the reservation by prohibiting transmission during a period (e.g., 0.5 ms to 2 ms, 1 symbol, or 2 symbols) immediately preceding each reserved resource and during each reserved resource in one or more subsequent COTs. However, if the reserved resources are not used by the reserving UE, other UEs may compete for the reserved resources.

[0041] In some examples, the sidelink transmission is slot-based, such that the sidelink transmission is specified to start on a slot boundary. However, some other communication protocols such as WiFi may transmit immediately after clearing Look Before Talk (LBT) and may block the sidelink transmission. Therefore, for some sidelink transmissions, such as sidelink transmissions in unlicensed spectrum (e.g., SL-U), access to the channel may fail or may be delayed in the presence of WiFi. Some communication systems such as NR-U use mini-slots and slot search space switching to allow the transmitter to transmit within a mini-slot after clearing LBT, rather than waiting until the next slot boundary. In such communication systems, mini-slots introduce new transmission start points.

[0042] However, the increase in the number of transmission start points allows the receiver to monitor more physical sidelink control channel (PSCCH) candidate positions. Therefore, there may be a trade-off between the PSCCH decoding complexity at the receiver and the LBT channel access success rate. In some sidelink networks, two transmission start positions may be implemented across the sidelink (SL) slot. For example, one starting position (e.g., a start symbol) may correspond to a half slot and the other starting position may correspond to a full slot. In some examples, a half-slot structure with an automatic gain control (AGC) symbol and a PSCCH / PSSCH symbol may be specified. A half slot may be half of a full sidelink slot. For example, a sidelink transmitter may be configured with a full slot resource pool and a half slot resource pool, which may overlap in time and frequency. A half slot resource pool may be associated with a 7-symbol half slot that starts at symbol #7 and ends at symbol #13. The combination of the two types of resource pools provides an additional starting symbol to the sidelink UE. The transmitter may select the resource pool with the earliest transmission start point after clearing LBT, and if it selects half-slot RP, it switches to full-slot based RP after the initial half-slot in COT to obtain better spectrum efficiency. From the receiver's point of view, since AGC / PSCCH / PSSCH may start at the first start symbol (such as symbol #0) or the second start symbol (such as symbol #7) based on the LBT result, the receiver may be specified to monitor two PSSCH opportunities in each (full) slot. However, the use of full and half slots may increase the complexity of the transmitter and receiver.

[0043] Various aspects of the present disclosure relate to reducing transmitter and / or receiver complexity. In some examples, based on the initial time slot of the COT being a full time slot or a half time slot transmission, the transmitter complexity can be reduced by avoiding multiple coding assumptions with different transport block (TB) sizes. In some examples, the transmitter can determine the TB size of the initial (full or half) time slot of the COT transmission based on a fixed number of resources (such as resources of a half time slot or resources of a full time slot).

[0044] In some other examples, receiver complexity may be reduced by skipping one or more PSCCH monitoring opportunities. For example, for a given set of resource blocks (RBs), if there is a first transmitter that clears the LBT before the first start symbol (e.g., symbol #0) and starts a full-slot transmission, it is unlikely that a second transmitter will clear the LBT in the middle of a full-slot transmission and start a half-slot transmission starting with symbol #7 unless both transmitters are out of range of the receiver. Based on receiver capabilities, a lower capability receiver may skip PSCCH monitoring at later potential PSCCH candidate positions within the slot if an SCI-1 associated with a full slot or a PSCCH demodulation reference signal (DMRS) associated with a full slot is detected in an earlier candidate position within the same slot and RB set. More specifically, if an SCI-1 is decoded and the reference signal received power (RSRP) associated with the SCI-1 is greater than a preconfigured threshold, the receiver may skip PSCCH monitoring in the remainder of the slot. Alternatively, if the RSRP associated with the PSCCH DMRS is greater than a preconfigured threshold, the receiver may skip PSCCH monitoring in the remainder of the timeslot.

[0045] Various aspects of the subject matter described herein may be implemented to achieve one or more of the following potential advantages. The techniques employed by the described base stations and UEs may provide benefits and enhancements to the operation of a wireless communication system. For example, the operations performed by the UE may provide improvements to reduce the complexity of a transmitter and / or receiver. Reducing complexity may reduce power usage, thereby extending battery life. Reducing transmitter and / or receiver complexity may also increase network bandwidth.

[0046] Figure 1 A wireless communication network 100 according to some aspects of the present disclosure is illustrated. The network 100 may be a 5G network. The network 100 includes several base stations (BSs) 105 (labeled 105a, 105b, 105c, 105d, 105e, and 105f, respectively) and other network entities. The BS 105 may be a station that communicates with the UE 115, and may also be referred to as an evolved Node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to that particular geographic coverage area of ​​the BS 105 and / or a BS subsystem serving that coverage area, depending on the context in which the term is used.

[0047] The BS 105 may provide communication coverage for macro cells or small cells (such as pico cells or femto cells) and / or other types of cells. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with a service subscription with a network provider. A small cell (such as a pico cell) will generally cover a relatively small geographic area and may allow unrestricted access by UEs with a service subscription with a network provider. A small cell (such as a femto cell) will generally also cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS, or a home BS. In Figure 1 In the example shown, BS 105d and 105e may be conventional macro BSs, while BS 105a-105c may be macro BSs with one of three-dimensional (3D), full-dimensional (FD), or massive MIMO capabilities. BS 105a-105c may utilize their higher-dimensional MIMO capabilities to employ 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. BS 105f may be a small cell BS, which may be a home node or a portable access point. BS 105 may support one or more (e.g., two, three, four, etc.) cells.

[0048] Network 100 may support synchronous operation or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

[0049] UEs 115 are scattered throughout the wireless communication network 100, and each UE 115 may be stationary or mobile. UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, etc. UE 115 may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, etc. In one aspect, UE 115 may be a device including a universal integrated circuit card (UICC). In another aspect, UE may be a device that does not include a UICC. In some aspects, UE 115 that does not include a UICC may also be referred to as an IoT device or an Internet of Everything (IoE) device. UE 115a-115d is an example of a mobile smart phone type device that accesses the wireless communication network 100. UE 115 may also be a machine that is specifically configured for connected communications (including machine type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc.). UE 115e-115h are examples of various machines configured for communication to access network 100. UE 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication to access network 100. UE 115 may be able to communicate with any type of BS, whether macro BS, small cell, etc. Figure 1 , a lightning symbol (e.g., a communication link) indicates wireless transmission between a UE 115 and a serving BS 105 (which is a BS designated to provide service to the UE 115 on a downlink (DL) and / or uplink (UL)), desired transmission between BSs 105, backhaul transmission between BSs, or sidelink transmission between UEs 115.

[0050] In operation, BS 105a-105c uses 3D beamforming and cooperative spatial techniques (such as coordinated multi-point (CoMP) or multiple connections) to serve UEs 115a and 115b. Macro BS 105d can perform backhaul communications with BS 105a-105c and small cell BS 105f. Macro BS 105d can also send multicast services that UEs 115c and 115d subscribe to and receive. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

[0051] The BSs 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be examples of gNBs or access node controllers (ANCs)) may interface with the core network via a backhaul link (e.g., NG-C, NG-U, etc.) and may perform radio configuration and scheduling for communications with the UEs 115. In various examples, the BSs 105 may communicate with each other directly or indirectly (e.g., through the core network) via a backhaul link (e.g., X1, X2, etc.), which may be a wired communication link or a wireless communication link.

[0052] The network 100 may also support mission-critical communications using ultra-reliable and redundant links for mission-critical devices, such as UE 115e, which may be a drone. The redundant communication links with UE 115e may include links from macro BSs 105d and 105e, and a link from a small cell BS 105f. Other machine-type devices, such as UE 115f (e.g., a thermometer), UE 115g (e.g., a smart meter), and UE 115h (e.g., a wearable device), may communicate through the network 100 directly with BSs such as small cell BS 105f and macro BS 105e, or through the network in a multi-step configuration by communicating with another user device, such as UE 115f, which communicates temperature measurement information to a smart meter (UE 115g), which then reports to the network through the small cell BS 105f, which relays its information to the network. The network 100 may also provide additional network efficiency through dynamic low latency TDD / FDD communications, such as V2V, V2X, C-V2X communications between UE 115i, 115j, or 115k and other UEs 115 and / or vehicle-to-infrastructure (V2I) communications between UE 115i, 115j, or 115k and BS 105.

[0053] In some implementations, the network 100 utilizes an OFDM-based waveform for communication. An OFDM-based system may divide the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, frequency bins, etc. Each subcarrier may be modulated with data. In some instances, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system BW. The system BW may also be divided into subbands. In other instances, the subcarrier spacing and / or the duration of the TTI may be scalable.

[0054] In some aspects, BS 105 may assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RBs)) for downlink (DL) and uplink (UL) transmissions in network 100. DL refers to the transmission direction from BS 105 to UE 115, and UL refers to the transmission direction from UE 115 to BS 105. The communication may be in the form of a radio frame. A radio frame may be divided into a plurality of subframes or time slots, for example, about 10. Each time slot may also be divided into micro-time slots. In FDD mode, simultaneous UL transmissions and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In TDD mode, UL transmissions and DL transmissions occur in different time periods using the same frequency band. For example, a subset of subframes in a radio frame (e.g., a DL subframe) may be used for DL ​​transmission, and another subset of subframes in a radio frame (e.g., a UL subframe) may be used for UL transmission.

[0055] DL subframes and UL subframes may also be divided into several zones. For example, each DL subframe or UL subframe may have a predefined zone for the transmission of reference signals, control information, and data. Reference signals are predetermined signals that facilitate communication between BS 105 and UE 115. For example, reference signals may have a specific pilot pattern or structure, wherein pilot tones may span an operational BW or frequency band, and each pilot tone is located at a predefined time and a predefined frequency. For example, BS 105 may send a cell-specific reference signal (CRS) and / or a channel state information-reference signal (CSI-RS) to enable UE 115 to estimate a DL channel. Similarly, UE 115 may send a sounding reference signal (SRS) to enable BS 105 to estimate an UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and / or operational data. In some aspects, BS 105 and UE 115 may communicate using self-contained subframes. Self-contained subframes may include a portion for DL ​​communication and a portion for UL communication. A self-contained subframe may be DL-centric or UL-centric. A DL-centric subframe may include a DL communication duration that is longer than a UL communication duration. A UL-centric subframe may include a UL communication duration that is longer than a UL communication duration.

[0056] In some aspects, the network 100 may be an NR network deployed on a licensed spectrum. The BS 105 may transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS)) in the network 100 to facilitate synchronization. The BS 105 may broadcast system information associated with the network 100 (e.g., including a master information block (MIB), remaining system information (RMSI), and other system information (OSI)) to facilitate initial network access. In some cases, the BS 105 may broadcast the PSS, SSS, and / or MIB in the form of a synchronization signal block (SSB) over a physical broadcast channel (PBCH), and may broadcast the RMSI and / or OSI over a physical downlink shared channel (PDSCH).

[0057] In some aspects, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting the PSS from the BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identification value. The UE 115 may then receive the SSS. The SSS may enable radio frame synchronization and may provide a cell identification value that may be combined with the physical layer identification value to identify a cell. The PSS and SSS may be located in the center portion of a carrier or at any suitable frequency within a carrier.

[0058] After receiving the PSS and SSS, the UE 115 may receive the MIB. The MIB may include system information for initial network access and scheduling information for RMSI and / or OSI. After decoding the MIB, the UE 115 may receive the RMSI and / or OSI. The RMSI and / or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource sets (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS.

[0059] After obtaining the MIB, RMSI, and / or OSI, the UE 115 may perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE 115 may send a random access preamble, and the BS 105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, UL grant, temporary cell radio network temporary identifier (C-RNTI), and / or a backoff indicator. Upon receiving the random access response, the UE 115 may send a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response may be referred to as message 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4 (MSG4), respectively. In some examples, the random access process may be a two-step random access procedure, where the UE 115 may send a random access preamble and a connection request in a single transmission, and the BS 105 may respond by sending a random access response and a connection response in a single transmission.

[0060] After establishing the connection, the UE 115 and the BS 105 may enter a normal operation phase in which operational data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL communication and / or DL ​​communication. The BS 105 may send a UL scheduling grant and / or a DL scheduling grant to the UE 115 via the PDCCH. The scheduling grant may be sent in the form of DL control information (DCI). The BS 105 may send a DL communication signal (e.g., carrying data) to the UE 115 via the PDSCH according to the DL scheduling grant. The UE 115 may send a UL communication signal to the BS 105 via the PUSCH and / or the PUCCH according to the UL scheduling grant.

[0061] In some aspects, the network 100 may operate on a system BW or a component carrier (CC) BW. The network 100 may divide the system BW into multiple BWPs (e.g., parts). The BS 105 may dynamically assign the UE 115 to operate on a specific BWP (e.g., a specific part of the system BW). The assigned BWP may be referred to as an active BWP. The UE 115 may monitor the active BWP to find signaling information from the BS 105. The BS 105 may schedule the UE 115 to perform UL or DL ​​communications in the active BWP. In some aspects, the BS 105 may assign a pair of BWPs within the CC to the UE 115 for UL and DL communications. For example, the BWP pair may include one BWP for UL communication and one BWP for DL ​​communication.

[0062] In some aspects, the network 100 may operate on a shared channel, which may include a shared frequency band or an unlicensed frequency band. For example, the network 100 may be an unlicensed NR (NR-U) network operating on an unlicensed frequency band. In such aspects, the BS 105 and the UE 115 may be operated by multiple network operation entities. To avoid conflicts, the BS 105 and the UE 115 may adopt an LBT procedure to monitor transmit opportunities (TXOPs) in the shared channel. The wireless communication device may perform LBT in the shared channel. LBT is a channel access scheme that can be used in an unlicensed spectrum. When the LBT result is that the LBT passes (the wireless communication device wins the competition for the wireless medium), the wireless communication device may access the shared medium to send and / or receive data. For example, a transmitting node (e.g., BS 105 or UE 115) may perform LBT before transmitting in the channel. When the LBT passes, the transmitting node may continue to transmit. When the LBT fails, the transmitting node may prohibit transmitting in the channel. In one example, LBT may be based on energy detection. For example, when the signal energy measured from the channel is below a threshold, the LBT result is a pass. Conversely, when the signal energy measured from the channel exceeds a threshold, the LBT result is a fail. In another example, LBT may be based on signal detection. For example, when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel, the LBT result is a pass. Conversely, when a channel reservation signal is detected in the channel, the LBT result is a fail. TXOP may also be referred to as channel occupancy time (COT).

[0063] In addition, LBT may be in multiple modes. The LBT mode may be, for example, Category 4 (CAT4) LBT or Category 2 (CAT2) LBT. CAT2 LBT refers to LBT without a random backoff period. CAT4 LBT refers to LBT with a random backoff and a variable contention window (CW). The serving BS 105 may perform CAT4 LBT to obtain a COT for communication with the UE. Additionally, the BS 105 may send a COT indication, for example, at the beginning of the COT to indicate the duration of the COT and / or one or more sub-bands in which the COT is located. The serving BS 105 may share the COT with the UE 115. In order to share the COT of the BS 105, the UE may perform CAT2 LBT within the COT of the BS 105. While passing through the CAT2 LBT, the UE may send UL transmissions within the COT of the BS 105. The UE 115 may also obtain a COT outside the COT of the serving BS 105 for UL transmission by performing CAT4 LBT. In some instances, UE 115 may also share the COT of UE 115 with BS 105. In some cases, CAT4 LBT mode may be referred to as Type 1 LBT, and CAT2 LBT mode may be referred to as Type 2 LBT.

[0064] In some aspects, the network 100 may provide sidelink communications to allow a UE 115 to communicate with another UE 115 without tunneling through the BS 105 and / or the core network, such as Figure 2 As shown. As discussed above, sidelink communications may be communicated on the PSCCH and the PSSCH. For example, the PSCCH may carry the SCI, and the PSSCH may carry the SCI and / or sidelink data (e.g., user data). Each PSCCH is associated with a corresponding PSSCH, wherein the SCI in the PSCCH may carry reservation and / or scheduling information for sidelink data transmission in the associated PSSCH. Sidelink communications may also be transmitted via a physical sidelink feedback control channel (PSFCH), which indicates an acknowledgement (ACK)-negative acknowledgement (NACK) for a previously transmitted PSSCH.

[0065] Figure 2 1 illustrates an example of a wireless communication network 200 that provides side link communications according to aspects of the present disclosure. The network 200 may correspond to a portion of the network 100. For the purpose of simplifying the discussion, Figure 2One BS 205 and five UEs 215 (shown as 215a, 215v, 215c, 215d, and 215e) are illustrated, but it will be appreciated that aspects of the present disclosure may be scaled to any suitable number of UEs 215 (e.g., about 2, 3, 4, 5, 7, or more) and / or BSs 205 (e.g., about 2, 3, or more). The BS 205 and the UEs 215 may be similar to the BS 105 and the UEs 115, respectively. The BS 205 and the UEs 215 may share the same radio frequency band for communication. In some cases, the radio frequency band may be a licensed band. In some cases, the radio frequency band may be an unlicensed band (e.g., in the 5 GHz band). In some cases, the radio frequency band may be a frequency range 1 (FR1) band. In some cases, the radio frequency band may be a FR2 band. In general, the radio frequency band may be at any suitable frequency and may have any suitable bandwidth (eg, approximately 5 MHz, approximately 10 MHz, approximately 20 MHz, approximately 80 MHz, approximately 100 MHz, or higher).

[0066] In network 200, some of UE 215 can communicate with each other in peer-to-peer communication. For example, UE 215a can communicate with UE 215b via sidelink 251, UE 215c can communicate with UE 215d via sidelink 252 and / or communicate with UE 215e via sidelink 254, and UE 215d can communicate with UE 215e via sidelink 255. Sidelinks 251, 252, 254, and 255 are unicast bidirectional links. Some of UE 215 can also communicate with BS 205 in UL direction and / or DL ​​direction via communication link 253. For example, UE 215a, 215b, and 215c are within the coverage area 210 of BS 205 and can therefore communicate with BS 205. UE 215d and UE 215e are outside of coverage area 210 and therefore may not communicate directly with BS 205. In some cases, UE 215c may operate as a relay for UE 215d to reach BS 205. In some aspects, some of UEs 215 are associated with vehicles (e.g., similar to UEs 115i to 115k), and communications over side links 251 and / or 252 may be C-V2X communications. C-V2X communications may refer to communications between a vehicle and any other wireless communication device in a cellular network.

[0067] Figure 3The reserved resources (e.g., time and frequency resources) for sidelink communications according to some aspects of the present disclosure are illustrated. In some instances, the method of reserving resources in the COT can implement various aspects of the wireless communication network 100 or 200 as described above. In one example, a first UE can reserve resources in a future COT for sidelink communications with a peer UE.

[0068] For example, the first UE 215a (eg, Figure 1 or Figure 2UE 115 (UE 215) may perform LBT to obtain UE COT 320 in a shared channel for communication with, for example, a peer side link UE. The LBT may be a CAT4 LBT. The LBT may be a pass indicating that the shared channel is idle for transmission. The first UE 215a may share a portion (shown as a first shared COT 322) with other UEs. That is, the first shared COT 322 may be used by other UEs for transmission. After successfully obtaining the first UE COT 320, the first UE 215a may provide a COT indication identifying the first UE COT 320 and the first shared COT 322. The COT indication may include a start time, duration, and / or end time of the first UE COT 320, and / or a start time, duration, and / or end time of the first shared COT 322. Similarly, the second UE 215b may perform LBT to obtain a second UE COT 324 in a shared channel for communication with, for example, a peer side link UE. The LBT may be a CAT4 LBT. The LBT may be a pass indicating that the shared channel is idle for transmission. The second UE 215b may share a portion (shown as the second shared COT 323) with other UEs. That is, the second shared COT 323 may be used by other UEs for transmission. After successfully obtaining the second UE COT 324, the second UE 215b may provide a COT indication identifying the second UE COT 324 and the second shared COT 323. The COT indication may include the start time, duration and / or end time of the second UE COT 324, and / or the start time, duration and / or end time of the second shared COT 323. Similarly, the third UE 215c may perform LBT to obtain the third UE COT 326 in the shared channel for communication with, for example, a peer side link UE. The LBT may be a CAT4 LBT. The LBT may be a pass indicating that the shared channel is idle for transmission. The third UE 215c may share a portion (shown as the third shared COT 325) with other UEs. That is, the third shared COT 325 can be used by other UEs for transmission. After successfully obtaining the third UE COT 326, the third UE 215c can provide a COT indication identifying the third UE COT 326 and the third shared COT 325. The COT indication can include the start time, duration and / or end time of the third UE COT 326, and / or the start time, duration and / or end time of the third shared COT 325.

[0069] In some instances, the first UE 215a may perform LBT before the reserved resources 332 to obtain a COT, so that the reserved resources 332 are within the COT of the first UE 215a. Similarly, the first UE 215a may perform LBT before the reserved resources 334 to obtain a COT, so that the reserved resources 334 are within the COT of the first UE 215a, and so on. Therefore, the reserved resources 332 and the reserved resources 334 are within the future COT of the first UE 215a. In other instances, the reserved resources 332 and 334 may fall within the COT of another UE. For example, another UE 215b may perform LBT to obtain a COT 324, and the reserved resources 332 may be within the shared portion (shown as 323 of the COT 324 of UE215b). For another example, another UE 215c may perform LBT to obtain the COT 326, and the reserved resources 334 may be within the shared portion (shown as 325 of the COT 326 of the UE 215c).

[0070] Figure 4 4 illustrates reserved resources 400 for sidelink communications according to some aspects of the present disclosure. Figure 4 In the figure, the x-axis may represent time in some arbitrary units, and the y-axis may represent frequency in some arbitrary units. The reserved resources 400 may be reserved for a UE (e.g., UE 115, UE 215) to perform sidelink communication in a wireless communication network (e.g., wireless communication network 100 or 200). For example, the resources 400 may be reserved for a retransmission of a first transmission by UE 215a (e.g., a retransmission of a failed first transmission), such as in the reserved resources (RR) 330. In some instances, the UE 215a may transmit one or more transport blocks within the COT 320. The UE 215a may also reserve future resources (e.g., one or more symbols or one or more time slots in time and one or more frequency subcarriers or one frequency subchannel in frequency) for retransmission. In some instances, the UE 215a may reserve future resources within the same COT 320, thereby saving overhead associated with LBT. In other instances, the UE 215a may reserve future resources in a future COT (after the COT 320). exist Figure 4In the illustrated example, UE 215a reserves future resources 400. UE 215a may send an indication of the reservation of future resources 400 in COT 320. Other UEs within the communication range of UE 215a may consider the resource reservation and refrain from competing for the reserved resources 400. In addition, other UEs may not transmit during a time period (e.g., approximately 1 symbol time) immediately before the reserved resources 400, so that UE 215a may perform LBT during the time period and obtain access to the channel for transmitting in the reserved resources 400. The time period to be used by UE 215a for LBT may be referred to as a gap time period. Other UEs receiving the resource reservation may refrain from transmitting during the reserved resources and the gap time period. However, other UEs may compete for resources outside the reserved resources and the gap time period. In some instances, another UE may successfully obtain a COT before the gap time period and may share a portion of the COT, as described above with reference to Figure 3 In some instances, the reserved resources 400 may be within a shared COT of another UE. In such instances, the UE 215a may perform CAT2 LBT (rather than CAT4 LBT) before transmitting in the reserved resources 400.

[0071] The UE 215a may reserve future reserved resources 400 by sending a resource reservation in a channel occupancy time system information (COT SI) (e.g., within SCI-1 and / or SCI-2). The COT SI may be sent within a COT obtained by performing an LBT (e.g., CAT4 LBT) to gain access to the COT 320. In some instances, the COTSI may be sent from the reserved resources 330. The resource reservation may include information related to the reserved resources 400. For example, the resource reservation may include an information element indicating the number of time slots (e.g., consecutive time slots) reserved within the reserved time resources 438. The resource reservation may also include the number of frequency subchannels reserved in the reserved frequency resources 430. In some instances, the reserved frequency resources 430 may include a sidelink subchannel 432 in which the UE 215a may transmit and a frequency guard band 440 on either side (e.g., upper frequency edge and lower frequency edge) of the sidelink subchannel in which the UE 215a may refrain from transmitting. For example, in some aspects, the frequency band can be divided into multiple subchannels similar to the sidelink subchannel 432 and a guard band similar to the guard band 440 between the subchannels. The guard band is inserted between the subchannels to mitigate interference from adjacent subchannels. Thus, for example, when the adjacent subchannel is used for transmission by a different UE, the guard band is not used for transmission.

[0072] In some examples, the resource reservation carried in the COT SI may include information related to the starting time slot 442 of the reserved resources 400. For example, the resource reservation in the COT SI may indicate a timing offset Y 436 that indicates the timing of the starting time slot 442 based on an amount of time from the end of the COT 320 in which the resource reservation carried in the COT SI is sent. In other words, the COTSI may indicate the start time of the resources 400 relative to the end of the COT 320 in which the resource reservation carried in the COT SI is sent. In some examples, the UE 215a may send multiple COT-SIs within the current COT 320, for example, to indicate the end of the current COT 320.

[0073] As another example, the resource reservation in the COT SI may indicate a timing offset X 434 that indicates the timing of the starting time slot 442 based on the amount of time from the transmission of the COT SI. In other words, the COT SI may indicate the start time of the resource 400 relative to the transmission time of the COT SI of the reserved resource 400. For example, the offset X 434 may be the amount of time from the beginning of the time slot in which the COT SI is transmitted. As another example, the offset X 434 may be the amount of time from the end of the time slot in which the COT SI is transmitted.

[0074] Considering the competition for channel access from asynchronous WiFi, sidelink (SL) mini-slot access can be used to improve the channel access success rate. Mini-slots can provide at least two different transmission start points. In some examples, the mini-slot structure integrates automatic gain control (AGC) symbols and can be designated for physical sidelink control channel (PSCCH) or physical sidelink shared channel (PSSCH). In some such examples, PSSCH can be rate matched to close the mini-slot end gap in the channel occupation time (COT) burst.

[0075] In some examples, a half-slot resource pool (RP) may overlap with a corresponding portion of a full-slot. In some such examples, a sidelink transmitter may be configured with a full-slot RP (e.g., symbols #0-#13) and a half-slot RP (e.g., symbols #7-13), which may overlap in time and frequency. A half-slot RP may be associated with a 7-symbol half-slot that starts at symbol #7 and ends at symbol #13. The half-slot RP is not limited to symbols #7-13, and other symbol combinations may be considered. This overlap provides an additional transmission entry point so that once the listen-before-talk (LBT) process clears, the transmitter can initiate transmission instead of waiting for the start of a slot boundary. A half-slot RP may be used when the LBT clears after the slot boundary, while a full-slot RP may be used when the LBT clears at or before the slot boundary. That is, the transmitter selects the RP with the earliest start time based on the LBT clearing.

[0076] Figure 5A 5 is a block diagram illustrating an example 500 in which a transmitter according to various aspects of the present disclosure selects a half-slot 502 based on the clearing of LBT after a slot boundary. As shown in example 500, the LBT is cleared after the slot boundary and before the start point of the half-slot RP 502 (RP#1) within the slot. Therefore, to protect the COT, the transmitter may use a half-slot RP 502 in the first slot and a full-slot RP 504 (RP#0) in the subsequent slot. In some examples, RPs 502 and 504 may be designated for transmission to different receivers (shown as Rxer#0 and Rxer#1). In some examples, the first receiver (Rxer#0) may be a high-capability receiver, while the second receiver (Rxer#1) may be a low-capability receiver.

[0077] Figure 5B 5 is a block diagram illustrating an example 550 of a transmitter selecting a full slot 504 based on the clearing of LBT after a slot boundary in accordance with various aspects of the present disclosure. As shown in example 550, the LBT is cleared at the slot boundary. Therefore, to protect the COT, the transmitter may use a full slot RP 504 (RP#0) for all slots associated with the COT. In some examples, RPs 502 and 504 may be designated for transmission to different receivers (shown as Rxer#0 and Rxer#1).

[0078] In some examples, the capabilities of the UE and the type of broadcast (e.g., broadcast, groupcast, multicast) may determine whether the UE (e.g., receiver) monitors both half-slot RP (e.g., mini-slot) and full-slot RP, or only full-slot RP. For example, groupcast or broadcast transmissions may be limited to full-slot RP. In some examples, the transmitter may schedule transmissions to high-capability UEs at the beginning of a data burst via mini-slot RP or a combination of half-slot RP and full-slot RP. In some examples, conventional hybrid automatic repeat request (HARQ) timelines and physical sidelink feedback channel (PSFCH) mapping rules may be used for half-slot RP and full-slot RP. In the case where the PSFCH instance is aligned with the current slot, the transmitter assigns the last two symbols of the half-slot to the PSFCH.

[0079] As discussed, mini-slot channel access may be used to improve the reliability of transmissions on the sidelink unlicensed band (SL-U) when WiFi or other radio access technologies (RATs) are present. For example, if the link is configured to support mini-slot (e.g., half-slot) channel access, the receiver may monitor the sidelink control information (SCI) at multiple start symbols within a slot. If the number of PSCCH candidates per slot is less than or equal to 44, a UE specific implementation is feasible because the UE may support up to 44 blind PDCCH hypotheses in a cellular link (e.g., Uu link). When half-slots are supported, the number of PSCCH candidates per (full) slot is equal to For example, for SCS 30 KHz, if 5 sub-channels are included per 20 MHz, the receiver can support up to 80 MHz, and for SCS 15 KHz, up to 40 MHz can be supported by 10 sub-channels per 20 MHz.

[0080] However, mini-slot channel access may increase receiver and / or transmitter complexity, which may reduce bandwidth. For example, as discussed, the transmitter may use full-slot RP or half-slot RP for PSSCH based on when the LBT is cleared (at the beginning or midway of the slot). In some examples, the UE timeline may not adapt to re-encoding the PSSCH after the result of the LBT. In some such examples, if the transmitter configures a transport block (TB) that expects a full-slot allocation and the LBT fails, the transmitter may re-encode the data to accommodate a half-slot allocation. Therefore, by encoding multiple hypotheses with different TB sizes, transmitter complexity may increase. In some examples, based on the first slot of the COT being a full-slot or half-slot transmission, transmitter complexity may be reduced by avoiding multiple coding hypotheses with different TB sizes (TBS). In some such examples, the transmitter may determine the TBS of the first (full or half) slot for COT transmission based on the half-slot value of the resource. In some implementations, if half-slot channel access is enabled, the TBS for the first slot (full slot or half slot, depending on the LBT result) of the COT transmission may be selected based only on half-slot resources or full-slot resources. In such examples, transmitter complexity may be reduced by avoiding multiple coding hypotheses with different transport block (TB) sizes.

[0081] In some examples, in order to avoid recoding assumptions of PSCCH and / or PSSCH, the transmitter may configure two separate waveform assumptions for PSCCH and PSSCH. Such waveforms may be stored in a designated buffer. In such examples, the transmitter may store both full-slot and half-slot waveform assumptions. The transmitter may select one of these waveforms based on the result of the LBT. Specifically, the transmitter may select one of these waveforms based on the timing of the LBT clearing within a given slot. Depending on the timing of the LBT clearing, the transmitter may map and rate match the PSCCH and PSSCH to a half-slot or a full-slot. The mapping produces an inverse fast Fourier transform (IFFT) waveform.

[0082] For the initial time slot of the COT, a transport block size (TBS) may be determined based on a predetermined number of resources. In some examples, these resources are half-slot resources. In such examples, the full-slot PSSCH may be rate matched to align with the full-slot resources. In some other examples, the resources are full-slot resources. In such examples, the transmitter may pierce half-slot PSSCH resource elements (REs). That is, the transmitter may omit certain REs from the half-slot PSSCH.

[0083] In some other examples, the transmitter may combine half slots and full slots. Figure 6 600 is a block diagram illustrating an example of aggregated half-slots 602 and full-slots 604 in accordance with various aspects of the present disclosure. Figure 6 In the example of , a transmitter such as a sidelink UE may have two PSCCH / PSSCH waveform assumptions: a full-slot waveform assumption and a half-slot waveform assumption. The transmitter may select one of the waveform assumptions based on the timing of LBT clearing. Figure 6 As shown in the example of , the transmitter may aggregate the half slot 602 and the full slot 604 to generate an aggregated slot 606 based on LBT clearing after the slot boundary and before the start symbol (symbol #7) associated with the half slot. Figure 6 The example of shows time slots for multiple sub-channels. Aspects of the present disclosure are contemplated for one or more sub-channels.

[0084] like Figure 6 As shown in the example of , the PSCCH can be allocated to the second starting symbol (Sym #7) of the half slot 602 and the first starting symbol (eg, Sym #0) of the full slot 604. For ease of explanation, Figure 6Only one PSCCH is marked in the . Each PSCCH may include first side link control information (SCI-1) and second side link control information (SCI-2). SCI-1 may indicate a combination of half slots 602 and full slots 604 (e.g., aggregated slots 606). In some examples, a common demodulation reference signal (DMRS) pattern may be specified regardless of whether the PSCCH starts in a half slot 602 or a full slot 604. SCI-1 may signal a combination of half slots and full slots. Figure 6 In the example of , the transport block size (TBS) is based on resources from one time slot. Depending on the timing of LBT clearing, rate matching and IFFT waveform generation start from the first start symbol (eg, symbol #0) or the second start symbol (eg, symbol #7).

[0085] In some examples, the complexity of a receiver (such as a sidelink UE) may increase because the receiver may monitor multiple PSCCH candidate locations within the COT. Figure 7 is a block diagram illustrating an example in which a receiver such as a sidelink UE monitors two transmission start points per time slot. Figure 7 In the example of , LBT is cleared at the first time slot 702A, and therefore, COT starts at the second time slot 702B. In this example, in both the second time slot 702B and the third time slot 702C, the receiver can monitor for potential PSCCH transmissions at the first starting symbol of the full time slot (e.g., symbol #0) and the second starting symbol of the half time slot (e.g., symbol #7). Figure 7 In the example of , at the fourth time slot 702D, the receiver may switch to monitoring PSCCH transmission at the first starting symbol (e.g., the first transmission start point) after receiving COT system information (SI) including an RP switching indicator. That is, after receiving the RP switching indicator, the receiver may transition to full-slot RP only, so that the receiver monitors one PSCCH per subchannel for each time slot. However, in some cases, the RP switching indicator may be received after the receiver has received several time slots. Therefore, for the initial time slot and one or more time slots after the initial time slot, the receiver may monitor two or more symbols, such as symbol #0 and symbol #7, for possible PSSCH transmissions.

[0086] In some examples, PSCCH candidate search may be reduced at the receiver based on skip rules per time slot and per RB set. In some such examples, a receiver (e.g., a receive side link UE) may skip PSCCH monitoring at later potential PSCCH candidate positions within a time slot if SCI-1 or PSCCH DMRS is detected in an earlier candidate position within the same time slot and RB set. More specifically, if SCI-1 is decoded and / or the reference signal received power (RSRP) of the PSCCH DMRS is greater than a preconfigured threshold at the PSCCH candidate position in the time slot and RB set, the receiver may skip PSCCH monitoring in the remainder of the time slot. Thus, in some implementations, when half-slot access is configured, the receiver may skip PSCCH monitoring at later potential PSCCH candidate positions in a time slot within a RB set if SCI-1 and / or PSCCH DMRS is detected in an earlier candidate position and the RSRP is above a certain preconfigured threshold.

[0087] As discussed, if the receiver detects both SCI-1 and PSCCH DMRS at the first transmission start point associated with a full time slot, it may be unnecessary to monitor PSCCH at the candidate position associated with the half time slot. For example, if SCI-1 is successfully decoded in a given time slot and the RSRP is greater than the RSRP threshold, or if the RSRP of the PSCCH DMRS exceeds the RSRP threshold, the receiver may abandon the PSCCH monitoring at the second starting symbol (e.g., the second transmission point) associated with the half time slot in the given time slot. This process can be repeated for each time slot. If neither condition is met, the receiver can continuously scan the PSCCH candidate positions associated with each half time slot. In some other examples, if the transmitter signals a switch to the full time slot RP via an RP switching indicator included in the COT SI, the receiver stops monitoring the PSCCH candidate positions (e.g., the second starting symbol) associated with each subsequent half time slot.

[0088] In the first starting symbol associated with a full time slot (e.g., symbol #0), a PSCCH / PSSCH transmission from a sidelink transmitter targeting a sidelink receiver inherently represents a full time slot transmission. Therefore, it may be unnecessary to monitor subsequent PSCCH candidate positions in the same time slot and / or subsequent time slots. Therefore, in some other examples, upon decoding the SCI-2 in a given time slot and confirming that the receiver is the designated recipient, the receiver stops monitoring subsequent PSCCH candidate positions within the given time slot, such as PSCCH candidate positions associated with a half time slot. In such examples, the receiver verifies the destination ID included in the SCI-2 to verify that the receiver is the intended recipient. In some such examples, a separate handling may be specified for SCI-2 so that the SCI-2 is decoded prior to the timing of the PSCCH monitoring opportunity associated with the half time slot.

[0089] Figure 8 8 is a flow chart illustrating an example process 800 performed by a UE 215 according to some aspects of the present disclosure. The example process 800 is an example of determining a transport block size based on a fixed number of resources, regardless of whether the initial time slot of the COT is a half time slot or a full time slot. Figure 8 As shown, process 800 begins at block 802 by performing listen-before-talk (LBT) within a channel occupation time (COT) in a shared radio frequency band. At block 804, process 800 selects a full-slot side link channel waveform hypothesis associated with a first start symbol or a half-slot side link channel waveform hypothesis associated with a second start symbol based on timing associated with clearing LBT. In addition, at block 806, process 800 sends side link information to a second side link UE during the COT, and a transport block size (TBS) associated with the COT has a fixed number of resources, which is the same number of resources used for the full-slot side link channel waveform hypothesis and the half-slot side link channel waveform hypothesis. That is, regardless of whether the half-slot side link channel waveform hypothesis or the full-slot side link channel waveform hypothesis is selected, the same fixed number of resources, such as half-slot resources, can be used.

[0090] Fig. 9 900 is a flow chart illustrating an example process 900 performed by a UE 215 according to some aspects of the present disclosure. The example process 900 is an example of skipping one or more PSCCH monitoring opportunities. Fig. 9As shown, the process 900 starts at box 902 by monitoring a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position in each COT time slot in a group of channel occupancy time (COT) time slots. In each COT time slot of the group of COT time slots, the first PSCCH candidate position appears before the second PSCCH candidate position. At box 904, the process 900 receives a message from a second UE in a first COT time slot of the group of COT time slots. At box 906, the process 900 suspends monitoring of the second PSCCH candidate position in at least the first COT time slot after the first COT time slot based on a message triggering a suspension condition. At box 908, the process 900 monitors the first PSCCH candidate position in each COT time slot of the group of COT time slots after the first COT time slot based on suspending the monitoring of the second PSCCH candidate position.

[0091] Specific implementation examples are described in the following numbered clauses:

[0092] Clause 1. In a shared radio frequency band, listen before talk (LBT) is performed within a channel occupancy time (COT); a full-slot side link channel waveform hypothesis associated with a first start symbol or a half-slot side link channel waveform hypothesis associated with a second start symbol is selected based on a timing associated with clearing the LBT; and side link information is sent to a second side link UE during the COT, a transport block size (TBS) associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources used for the full-slot side link channel waveform hypothesis and the half-slot side link channel waveform hypothesis.

[0093] Clause 2. The method according to clause 1 further comprises preparing the half-slot side link channel waveform hypothesis and the full-slot side link channel waveform hypothesis before performing the LBT, wherein each of the half-slot side link channel waveform hypothesis and the full-slot side link channel waveform hypothesis corresponds to a corresponding physical side link control channel (PSCCH) waveform and a corresponding physical side link shared channel (PSSCH) waveform.

[0094] Clause 3. The method of any one of clauses 1 to 2, further comprising selecting the half-slot sidelink channel waveform hypothesis based on the timing being within the initial slot and before the second start symbol of the initial slot.

[0095] Clause 4. The method of clause 3, further comprising mapping and rate matching a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH) to the half-slot sidelink channel waveform hypothesis.

[0096] Clause 5. A method according to any one of clauses 1 to 2, the method further comprising selecting the full-slot side link channel waveform hypothesis based on the timing being within a first slot immediately prior to the initial slot and after symbol six of the first slot.

[0097] Clause 6. The method of clause 5, further comprising mapping and rate matching a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH) to the full-slot sidelink channel waveform assumption.

[0098] Clause 7. A method as described in any of clauses 1 to 6, wherein the fixed number of resources is half-slot resources.

[0099] Clause 8. The method of clause 7, further comprising rate matching a physical sidelink shared channel (PSSCH) to full slot resources in each full slot in the COT.

[0100] Clause 9. The method of clause 7, further comprising sending sidelink control information (SCI) to the second UE indicating that the TBS is based on the half-slot resources.

[0101] Clause 10. The method of any one of clauses 1 to 6, wherein the fixed number of resources is full-slot resources.

[0102] Clause 11. The method of clause 10, further comprising puncturing physical sidelink shared channel (PSSCH) resource elements in each half-slot of the COT.

[0103] Clause 12. A method for performing wireless communications at a first user equipment (UE), the method comprising: monitoring a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position within each COT time slot of a set of channel occupancy time (COT) time slots, wherein the first PSCCH candidate position appears before the second PSCCH candidate position within each COT time slot in the set of COT time slots; receiving a message from a second UE in a first COT time slot of the set of COT time slots; suspending the monitoring of the second PSCCH candidate position in at least the first COT time slot based on a suspension condition triggered by the message; and monitoring the first PSCCH candidate position within each COT time slot in the set of COT time slots after the first COT time slot based on suspending the monitoring of the second PSCCH candidate position.

[0104] Clause 13. A method according to clause 12, wherein: the message is a PSCCH demodulation reference signal (DMRS) associated with a full time slot within the first COT time slot; and the pause condition is triggered based on a reference signal received power (RSRP) associated with the PSCCH DMRS being greater than a threshold.

[0105] Clause 14. A method according to clause 12, wherein: the message is sidelink control information (SCI) 1 associated with the full time slot; and the pause condition is triggered based on decoding the SCI-1 and a reference signal received power (RSRP) associated with the SCI-1 being greater than a threshold.

[0106] Clause 15. The method of clause 12, wherein: the message indicates that the second UE is switching to a full-slot resource pool; and the pause condition is triggered based on the message indicating that the second UE is switching.

[0107] Clause 16. The method of clause 12, wherein: the message is Sidelink Control Information (SCI)-2; and the pause condition is triggered based on decoding the SCI-2 indicating that the first sidelink UE is an intended receiver of the SCI-2.

[0108] Clause 17. The method of clause 12, further comprising monitoring both the first PSCCH candidate position and the second PSCCH candidate position based on the message failing to trigger the suspend condition.

[0109] Clause 17. A UE comprising a processor, a memory coupled to the processor, and instructions stored in the memory and operable when executed by the processor to cause the UE to perform any of clauses 1 to 11.

[0110] Clause 18. An apparatus configured for wireless communication, the apparatus comprising at least one means for performing any of clauses 1 to 11.

[0111] Clause 19. A computer program comprising code for causing an apparatus to perform any of clauses 1 to 11.

[0112] Clause 20. A UE comprising a processor, a memory coupled to the processor, and instructions stored in the memory and operable when executed by the processor to cause the UE to perform any of clauses 12 to 16.

[0113] Clause 21. An apparatus configured for wireless communication, the apparatus comprising at least one means for performing any of clauses 12-16.

[0114] Clause 22. A computer program comprising code for causing an apparatus to perform any of clauses 12 to 16.

[0115] Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0116] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0117] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium, or sent via a computer-readable medium. Other examples and specific implementations are within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. The features that implement the functions may also be physically located at different locations, including being distributed so that the parts of the functions are implemented at different physical locations. In addition, as used herein (including in the claims), "or" used in an item enumeration (e.g., followed by an item enumeration such as "at least one of" or "one or more of") indicates an inclusive enumeration, such that, for example, an enumeration of [at least one of A, B, or C] means: A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0118] As those skilled in the art will understand by now and depending on the specific application at hand, many modifications, substitutions and changes may be made to the materials, devices, configurations and methods of use of the apparatus of the present disclosure without departing from the spirit and scope of the present disclosure. In view of this, the scope of the present disclosure should not be limited to the specific aspects illustrated and described herein (as they are only some examples of the present disclosure), but should be fully equivalent to the attached claims and their functional equivalents.

Claims

1. A method for wireless communication at a first sidelink user equipment (UE), the method comprising: In a shared RF band, listen before talk (LBT) is performed during the channel occupation time (COT); selecting a full-slot side link channel waveform hypothesis associated with a first start symbol or a half-slot side link channel waveform hypothesis associated with a second start symbol based on a timing associated with clearing the LBT; as well as and transmitting sidelink information to a second sidelink UE during the COT, a transport block size (TBS) associated with the COT having a fixed number of resources, the fixed number of resources being the same number of resources for the full-slot sidelink channel waveform hypothesis and the half-slot sidelink channel waveform hypothesis.

2. The method of claim 1 , further comprising preparing the half-slot side link channel waveform hypothesis and the full-slot side link channel waveform hypothesis before performing the LBT, wherein each of the half-slot side link channel waveform hypothesis and the full-slot side link channel waveform hypothesis corresponds to a corresponding physical side link control channel (PSCCH) waveform and a corresponding physical side link shared channel (PSSCH) waveform.

3. The method of claim 1 , further comprising selecting the half-slot sidelink channel waveform hypothesis based on the timing being within the initial time slot and before the second start symbol associated with the initial time slot.

4. The method of claim 3, further comprising mapping and rate matching a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH) to the half-slot sidelink channel waveform assumption.

5. The method of claim 1 , further comprising selecting the full-slot sidelink channel waveform hypothesis based on the timing being within a first slot immediately prior to the initial slot and after symbol six of the first slot.

6. The method of claim 5, further comprising mapping and rate matching a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH) to the full-slot sidelink channel waveform assumption. The method of claim 1 , wherein the fixed number of resources is half-slot resources.

8. The method of claim 7, further comprising rate matching a physical sidelink shared channel (PSSCH) to full-slot resources in each full-slot in the COT.

9. The method of claim 7, further comprising sending sidelink control information (SCI) to the second sidelink UE indicating that the TBS is based on the half-slot resources.

10. The method of claim 1, wherein the fixed number of resources is full-slot resources.

11. The method of claim 10, further comprising puncturing a physical sidelink shared channel (PSSCH) resource element in each half-slot of the COT.

12. A first sidelink user equipment (UE), the first sidelink user equipment (UE) comprising: one or more memories including processor-executable instructions; and One or more processors, the one or more processors being configured to execute the processor-executable instructions and cause the first sidelink UE to perform the method according to any one of claims 1 to 11.

13. A method for wireless communication at a first sidelink user equipment (UE), the method comprising: Monitoring a first physical sidelink control channel (PSCCH) candidate position and a second PSCCH candidate position in each COT time slot of a set of channel occupancy time (COT) time slots, wherein the first PSCCH candidate position occurs before the second PSCCH candidate position in each COT time slot of the set of COT time slots; receiving a message from a second sidelink UE in a first COT time slot of the set of COT time slots; suspending the monitoring of the second PSCCH candidate position in at least the first COT time slot based on the message triggered suspension condition; as well as Based on suspending the monitoring of the second PSCCH candidate position, monitoring the first PSCCH candidate position within each COT time slot in the group of COT time slots after the first COT time slot.

14. The method according to claim 13, wherein: The message is a PSCCH demodulation reference signal (DMRS) associated with a full slot within the first COT slot; and The pause condition is triggered based on a reference signal received power (RSRP) associated with the PSCCH DMRS being greater than a threshold.

15. The method of claim 13, wherein: The message is Sidelink Control Information (SCI)-1 associated with the full slot; and The pause condition is triggered based on decoding the SCI-1 and a reference signal received power (RSRP) associated with the SCI-1 being greater than a threshold.

16. The method of claim 13, wherein: The message indicates that the second sidelink UE is switching to a full-slot resource pool; and The pause condition is triggered based on the message indicating that the second sidelink UE is switching.

17. The method of claim 13, wherein: The message is Sidelink Control Information (SCI) 2; and The pause condition is triggered based on decoding the SCI-2 indicating that the first sidelink UE is an intended receiver of the SCI-2.

18. The method of claim 13, further comprising monitoring both the first PSCCH candidate position and the second PSCCH candidate position based on the message failing to trigger the suspend condition.

19. A first sidelink user equipment (UE), the first sidelink user equipment (UE) comprising: one or more memories including processor-executable instructions; and One or more processors configured to execute the processor-executable instructions and cause the first sidelink UE to perform the method according to any one of claims 13 to 18.

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