WO2022213355A1

WO2022213355A1 - Multi-beam listen-before-talk (lbt) signaling

Info

Publication number: WO2022213355A1
Application number: PCT/CN2021/086130
Authority: WO
Inventors: Giovanni Chisci; Arumugam Chendamarai Kannan; Siyi Chen; Vinay Chande; Jing Sun; Xiaoxia Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2021-04-09
Filing date: 2021-04-09
Publication date: 2022-10-13

Abstract

Wireless communications systems and methods related to multi-beam listen-before-talk (LBT) signaling are provided. A first wireless communication device communicates, with a second wireless communication device, a plurality of channel access configurations. The first wireless communication device communicates, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, where the scheduling grant includes an indication of a first channel access configuration of the plurality of channel access configurations. The first wireless communication device communicates, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.

Description

MULTI-BEAM LISTEN-BEFORE-TALK (LBT) SIGNALING

TECHNICAL FIELD

This application relates to wireless communication systems, and more particularly to multi-beam listen-before-talk (LBT) signaling for channel access in a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum) .

INTRODUCTION

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . A wireless multiple-access communications system may include a number of base stations (BSs) , each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE) .

To meet the growing demands for expanded mobile broadband connectivity, wireless communication technologies are advancing from the long term evolution (LTE) technology to a next generation new radio (NR) technology, which may be referred to as 5 ^th Generation (5G) . For example, NR is designed to provide a lower latency, a higher bandwidth or a higher throughput, and a higher reliability than LTE. NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrums to dynamically support high-bandwidth services. Spectrum sharing can extend the benefit of NR technologies to operating entities that may not have access to a licensed spectrum.

One approach to avoiding collisions when communicating in a shared spectrum or an unlicensed spectrum is to use a listen-before-talk (LBT) procedure to ensure that the shared channel is clear before transmitting a signal in the shared channel. In a wireless communication network operating over a high-frequency band, such as a millimeter wave (mmWave) band, a wireless communication device may utilize beamforming to form narrow beams for transmission and/or reception due to the high pathloss or blocking in the high-frequency band. Accordingly, a wireless communication device communicating over a high-frequency band may perform a directional LBT. A directional LBT may refer to a wireless communication device utilizing receive beamforming to perform an LBT in a specific beam direction.

BRIEF SUMMARY OF SOME EXAMPLES

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

In one aspect of the disclosure, a method of wireless communication performed by a first wireless communication device, the method includes communicating, with a second wireless communication device, a plurality of channel access configurations; communicating, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and communicating, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.

In an additional aspect of the disclosure, a first wireless communication device includes a memory; a transceiver; and at least one processor coupled to the memory and the transceiver, where the at least one processor is configured to communicate, with a second wireless communication device via the transceiver, a plurality of channel access configurations; communicate, with the second wireless communication device via the transceiver, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and communicate, with the second wireless communication device in the unlicensed band via the transceiver based on the first channel access configuration, the communication signal.

In an additional aspect of the disclosure, a first wireless communication device includes means for communicating, with a second wireless communication device, a plurality of channel access configurations; means for communicating, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and means for communicating, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.

In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon for wireless communication by a first wireless communication device, the program code including code for causing the first wireless communication device to communicate, with a second wireless communication device, a plurality of channel access configurations; code for causing the first wireless communication device to communicate, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and code for causing the first wireless communication device to communicate, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.

Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary aspects in conjunction with the accompanying figures. While features may be discussed relative to certain aspects and figures below, all aspects can include one or more of the advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various aspects discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method aspects it should be understood that such exemplary aspects can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication network according to some aspects of the present disclosure.

FIG. 2 illustrates a communication scenario according to some aspects of the present disclosure.

FIG. 3 illustrates a multi-beam channel access scheme according to some aspects of the present disclosure.

FIG. 4 is a sequence diagram illustrating a multi-beam channel access method according to some aspects of the present disclosure.

FIG. 5 illustrates a multi-beam channel access signaling scheme according to some aspects of the present disclosure.

FIG. 6 illustrates a beam information configuration for multi-beam channel access according to some aspects of the present disclosure.

FIG. 7 illustrates a block diagram of a base station (BS) according to some aspects of the present disclosure.

FIG. 8 illustrates a block diagram of a user equipment (UE) according to some aspects of the present disclosure.

FIG. 9 is a flow diagram of a wireless communication method according to some aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some aspects, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

This disclosure relates generally to wireless communications systems, also referred to as wireless communications networks. In various aspects, the techniques and apparatus may 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 System for Mobile Communications (GSM) networks, 5 ^th Generation (5G) or new radio (NR) networks, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS) . In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from 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 various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the UMTS mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order to achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with a ULtra-high density (e.g., ～1M nodes/km ²) , ultra-low complexity (e.g., ～10s of bits/sec) , ultra-low energy (e.g., ～10+years of battery life) , and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ～99.9999%reliability) , ultra-low latency (e.g., ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ～ 10 Tbps/km ²) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

A 5G NR communication system may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI) ; having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 5, 10, 20 MHz, and the like bandwidth (BW) . For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz BW. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz BW. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz BW. In certain aspects, frequency bands for 5G NR are separated into multiple different frequency ranges, a frequency range one (FR1) , a frequency range two (FR2) , and FR2x. FR1 bands include frequency bands at 7 GHz or lower (e.g., between about 410 MHz to about 7125 MHz) . FR2 bands include frequency bands in mmWave ranges between about 24.25 GHz and about 52.6 GHz. FR2x bands include frequency bands in mmWave ranges between about 52.6 GHz to about 71 GHz. The mmWave bands may have a shorter range, but a higher bandwidth than the FR1 bands. Additionally, 5G NR may support different sets of subcarrier spacing for different frequency ranges.

The scalable numerology of the 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with UL/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL/downlink that may be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet the current traffic needs.

Various other aspects and features of the disclosure are further described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative and not limiting. Based on the teachings herein one of an ordinary level of skill in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. For example, a method may be implemented as part of a system, device, apparatus, and/or as instructions stored on a computer readable medium for execution on a processor or computer. Furthermore, an aspect may comprise at least one element of a claim.

To enable coexistence among multiple devices in a shared or unlicensed spectrum, a listen-before-talk (LBT) procedure may be used to assess whether a shared channel is clear before transmitting a signal in the channel. During the LBT procedure, a wireless communication device may perform a clear channel assessment (CCA) for a predetermined duration to contend for a channel occupancy time (COT) . During the CCA, the wireless communication device may compare the energy level detected in the channel to a threshold value. If the energy level exceeds the threshold, the wireless communication device may determine that the channel is occupied, refrain from transmitting a signal in the channel, and repeat the CCA after a period of time, or the wireless communication device may reduce its transmit power to avoid interfering with other devices that may be using the channel. If the energy level is below the threshold, the wireless communication device may determine that the channel is unoccupied (indicating the device won the contention) and proceed with transmitting a signal in the COT. The wireless communication device that initiates or contends for the COT may be referred to as an initiating device. In some instances, after winning a COT, an initiating device may share the COT with another device, which may be referred to as a responding device. COT sharing may refer to a responding device utilizing a COT of an initiating device for transmission. For channel access in 60 GHz bands, the CCA check procedure specified by European Telecommunications Standards Institute (ETSI) document EN 302 567 V2.2.0 allows a responding device to transmit in a shared COT without performing any CCA check and there is no specific duration requirement on the gap between transmissions of the initiating device and the responding device. Additionally, the ETSI CCA procedure allows a wireless communication device to transmit control signaling messages up to a total duration of 10 milliseconds (ms) within a 100 ms period without performing a CCA.

Wireless communications at high frequencies, such as mmWave frequency ranges in FR2 and FR2x, may experience a high path-loss compared to lower frequency bands that are commonly used in conventional communication systems. To overcome the high path-loss, BSs and UEs may use beamforming techniques to form directional beams for communications. For instance, a BS and/or a UE may be equipped with one or more antenna panels or antenna arrays with antenna elements that can be configured to focus transmit signal energy and/or receive signal energy in a certain spatial direction and/or within a certain spatial angular sector or width. A beam used for such wireless communications may be referred to as an active beam, a best beam, or a serving beam. The active beam may initially be selected from reference beams and then refined over time.

As used herein, the term “transmission beam” may refer to a transmitter transmitting a beamformed signal in a certain spatial direction or beam direction and/or with a certain beam width covering a certain spatial angular sector. The transmission beam may have characteristics such as a beam direction and a beam width. As used herein, the term “reception beam” may refer to a receiver using beamforming to receive a signal from a certain spatial direction or beam direction and/or within a certain beam width covering a certain spatial angular sector. The reception beam may have characteristics such as the beam direction and the beam width. As used herein, the term “beam sweep” or “beam sweeping” may refer to a wireless communication device using sequentially each beam of a set of predefined beams (directing to a set of predefined spatial directions) for transmissions or receptions over a time period to cover a certain angular sector spatially.

As used herein, the term “transmitting device” may refer to a wireless communication device (which may be a UE or a BS) intending to transmit in a channel, having data ready for transmission, and/or performing a transmission operation. As used herein, the term “receiving device” may refer to a wireless communication device (which may be a UE or a BS) performing a reception operation. A wireless communication device may operate as a transmitting device at one time and operate as a receiving device at another time.

In some aspects, a transmitting device operating over a shared or unlicensed high-frequency band (e.g., a 60 gigahertz (GHz) band or FR2x band) may perform beamformed channel sensing. Beamformed channel sensing may include a directional LBT procedure. For instance, a transmitting device (intending to transmit in the shared channel) may perform an LBT in a specific beam direction where a transmission is to be transmitted. The transmitting device may configure a reception beam in the beam direction and measure channel signal energy using the reception beam. If the measured channel signal energy in that beam direction is below a certain threshold, the transmitting device may proceed to transmit in the beam direction. If, however, the measured channel signal energy in that beam direction is above the threshold, the transmitting device may refrain from transmitting in the channel in that beam direction.

With beamformed channel sensing or directional LBT, hidden node issues and/or exposed node issues may be more severe due to the listening or sensing being in a particular beam direction. The hidden node issues may refer to a transmitting device failing to detect a certain interference experienced by a peer or corresponding receiving device, whereas the exposed node issues may refer to a transmitting device experiencing a certain interference that does not impact a peer or corresponding receiving device. In any case, a transmitting device may not have a full view or accurate information of interference at a peer receiving device. Accordingly, in some instances, a transmitting device may request a peer receiving device to assist in performing channel sensing. To that end, the receiving device may perform an LBT in the beam direction to be used for receiving a communication from the transmitting device. The receiving device may report the LBT result to the transmitting device. For instance, the LBT result may indicate whether the channel (in that beam direction) is clear for transmission or scheduling (when the LBT is successful) or not clear for transmission or scheduling (when the LBT fails) . The transmitting device may determine whether to transmit to the receiving device (in that beam direction) based on the LBT result received from the receiving device. For example, if the receiving device indicated that the channel is clear for scheduling or transmission, the transmitting device may proceed to transmit to the receiving device. If, however, the receiving device indicated that the channel is not clear for scheduling or transmission, the transmitting device may refrain from transmitting to the receiving device. In some instances, the transmitting device may also perform its own channel sensing or LBT and determine whether to transmit to the receiving device based on its own channel sensing result and the channel sensing result received from the receiving device.

In certain aspects, a BS may schedule a UE for a DL communication (e.g., DL data) over an unlicensed band. The BS may request the UE to perform an LBT prior to transmitting the DL communication to the UE. The UE may report the LBT result (an indication of whether the channel is clear for scheduling or transmission) to the BS, and the BS may schedule the UE according to the UE’s reported LBT result. For instance, if the UE reported that the channel is clear, the BS may proceed to transmit the DL communication to the UE. In some instances, the BS may also perform an LBT and transmit the DL communication to the UE when the BS’s LBT is also a pass. In other aspects, a BS may schedule a UE to transmit a UL communication, where the UE may perform an LBT prior to the UL communication. In some instances, after the UE transmitted the UL communication to the BS, the UE may also share the COT with the BS so that the BS may utilize any remaining duration of the UE’s COT for DL communication, for example.

In some aspects, it may be desirable for the BS to control LBT operations at the UE, for example, the types of LBT which governs the channel sensing or measurement time, backoff mechanisms, and/or cyclic prefix (CP) extensions (for creating a certain gap time between transmissions in the channel) . In this way, the BS can have better control over spectrum resource utilization and collision avoidance. In some aspects, the BS may transmit a scheduling grant to schedule a UE for an UL communication or a DL communication and may specify in the grant a channel access type to be used by the UE for channel sensing. The channel access type may be indicated by a 2-bit message field specifying whether the UE may access the channel without channel sensing, with channel sensing over a 16 microsecond (μs) duration, or with channel sensing over a 25 μs duration and a corresponding CP extension.

While including a channel access type in a scheduling grant can allow a BS to control LBT operations at a UE, the current channel access type indication is based on a fixed table or a fixed configuration (e.g., the 2-bit message field providing a maximum of four options) . However, there is no consideration for beam direction (s) and/or energy detection thresholds for channel sensing. Additionally, the scheduling grant is a dynamic scheduling grant that is transmitted by the BS per transmission. Accordingly, it may be undesirable for the BS to include an LBT configuration or channel access configuration with a large payload in a dynamic scheduling grant as the bandwidth or resource overhead may increase for each transmission. As used herein, the terms “channel sensing” and “LBT” may be used interchangeably.

The present disclosure describes mechanisms for providing multi-beam LBT signaling for channel access in a high-frequency band (e.g., in FR2x) . For example, a BS may configure a UE with a plurality of channel access configurations including various channel access parameters (e.g., beam directions, LBT energy detection thresholds, LBT random counters, LBT report configurations, etc. ) for perform channel sensing in the shared channel. The BS may subsequently schedule the UE for communicating a communication signal (which may be a UL communication or a DL communication) in the channel. The BS may transmit, to the UE, a scheduling grant indicating which of the channel access configurations the UE may use for performing an LBT prior to the scheduled communication. For instance, the scheduling grant may indicate a first channel access configuration of the plurality of channel access configurations. The UE may perform channel sensing according to the first channel access configuration. Subsequently, the UE and the BS may communicate the communication signal in the channel based on the channel sensing (performed by the UE) indicating the channel is clear for transmission. In some aspects, the UE may also report the channel sensing result to the BS.

In some aspects, the BS may signal the plurality of channel access configurations via a radio resource control (RRC) configuration, and may signal the scheduling grant via downlink control information (DCI) over a physical downlink control channel (PDCCH) . The DCI may be of any suitable DCI formats (e.g., DCI format 0_0, DCI format 0_1, DCI format 1_0, DCI format 1_1) and may include a message field referencing the first channel access configuration of the plurality of channel access configurations. For instance, the plurality of channel access configurations may be in the form of an RRC table, and the message field in the DCI may include an index or identifier (ID) that references the first channel access configuration of the plurality of channel access configurations. In other words, the DCI may activate the first channel access configuration for the scheduled communication.

In some aspects, the BS may indicate a plurality of beam directions (e.g., a set of beam directions) in the plurality of channel access configurations. Each channel access configuration of the plurality of channel access configuration may indicate one or more of the plurality of beam directions. In some aspects, the BS may indicate the plurality of beam directions by indicating the BS’s transmission beams (e.g., DL beams) . For instance, the BS may indicate the plurality of beam directions in the plurality of channel access configuration using transmission configuration indications (TCIs) . In 5G or NR, a TCI is used to establish a quasi-co-location (QCL) relationship (e.g., a spatial relation) between two reference signals. In an aspect, the BS may transmit a certain reference signal (e.g., a synchronization signal block (SSB) ) in a certain beam direction and may associate a certain TCI value with the signal transmitted in the certain beam direction. In this way, if the UE determines that a certain receive beam direction provides the best receive signal strength for the certain signal, the UE may utilize that receive beam direction whenever the BS indicates the certain TCI value for a DL communication.

In some aspects, the BS may indicate the plurality of beam directions by indicating the UE’s transmission beams (e.g., UL beams) . For instance, the BS may indicate the plurality of beam directions in the plurality of channel access configuration using sounding reference signal resource indicator (SRIs) . In 5G or NR, the BS may configure SRS resources for the UE to transmit SRSs. The UE may transmit an SRS using a different beam direction in each SRS resource. The BS may assign an SRI for each SRS resource. In this way, if the BS indicates a certain SRI for a UL communication or a DL communication, the UE may utilize the same beam or same beam direction that was used to transmit in the SRS resource identified by the SRI.

In some aspects, the BS may indicate a plurality of beam groups (e.g., a set of beam groups) in the plurality of channel access configurations. Each beam group of the plurality of beam groups may include a subset of one or more of the plurality of beam directions, and each channel access configuration of the plurality of channel access configurations may indicate at least one beam group of the plurality of beam groups. That is, some channel access configurations may each include one beam group, while other channel access configurations may each include two or more beam groups. Additionally, some beam groups may each include one beam direction, while other beam groups may each include two or more beam directions. In some aspects, the first channel access configuration may include one or more beam groups of the plurality of beam groups. The indication of the first channel access configuration in the scheduling grant may activate channel sensing in each beam group of the one or more beam groups.

In some aspects, when the UE receives the scheduling grant indicating the first channel access configuration including a first beam group and a second beam group of the plurality of beam groups, the UE may perform first channel sensing (e.g., a first directional LBT) in the first beam group and second channel sensing (e.g., a second directional LBT independent of the first directional LBT) in the second beam group. In some instances, the UE may perform the first channel sensing in a combined beam direction of a subset of two or more beam directions of the plurality of beam directions associated with the first beam group. In this regard, the UE may form a wide beam covering all beam directions in the first beam group, receive a signal from the channel using the wide beam, determine a receive signal measurement (e.g., a receive signal power or receive signal strength capturing interference from all sources and/or background noise) for the received signal, and determine whether the received signal measurement satisfies an LBT energy detection threshold. If the received signal measurement is below the threshold, the channel is clear for transmission or scheduling in the beam direction of the first beam group. If, however, the received signal measurement is above the threshold, the channel is not clear for transmission or scheduling in the beam direction of the first beam group.

In some aspects, the BS may indicate one or more LBT energy detection thresholds for each beam group in each channel access configuration. The energy detection thresholds may be used by the UE to determine whether the channel is occupied or free in a certain beam direction. In some instances, it may be desirable for the BS to configure multiple different LBT energy detection thresholds (e.g., a set of energy detection threshold) for a beam group. The different energy detection thresholds may be related to different interference tolerance levels and the BS can determine different transmission parameters (e.g., a transmit power) for the scheduled transmission according to channel statuses for the different LBT energy detection thresholds. The UE may determine a channel sensing result for each LBT energy detection threshold. In this regard, the UE may utilize receive beamforming to receive a signal from the channel in a beam direction of a beam group, determine a receiving signal measurement for the received signal, and determine whether the received signal measurement satisfies each threshold. In this way, the BS and/or the UE can determine whether to proceed with the scheduled communication or cancel the scheduled communication based on the different channel sensing results obtained using the different LBT energy detection thresholds. If the BS and/or the UE determine to proceed with the scheduled communication, the BS may configure its own transmit power (e.g., at a reduced level from a BS nominal or reference transmit power level for DL communication) or configure the UE’s transmit power (e.g., at a reduced level from a UE nominal or reference transmit power level for UL communication) based on the channel sensing results obtained from the different LBT energy detection thresholds.

In some aspects, the BS may indicate one or more random counters for each beam group in each channel access configuration. The random counters may be used by the UE to configure a counter for random backoff for channel sensing. For instance, the UE may draw a random number from a range of numbers specified by a random counter. The UE may backoff for a duration corresponding to the drawn number before performing channel sensing. In some instances, it may be desirable for the BS to configure multiple random counters (e.g., a set of random counters) for a beam group. The different random backoff durations may be associated with different channel access priorities. For instance, the BS may assign a higher channel access priority for traffic with a higher traffic priority (e.g., time critical traffic with a low-latency requirement) and may assign a lower channel access priority for traffic with a lower traffic priority. The UE may perform an LBT using a random backoff that corresponds to a priority of the scheduled communication.

In some aspects, the BS may indicate a report type for the UE to report channel sensing results. The report type may indicate an aperiodic report type, a semi-persistent report type, or a periodic report type. For instance, the scheduling grant can include an aperiodic report trigger, and the UE may transmit a channel sensing report to the BS indicating a channel status for each beam group based on the trigger. The channel status may indicate whether the channel is clear for transmission in a beam direction of the beam group. For instance, the channel status may include a clear channel status or a channel occupied status. In some aspects, the UE may indicate a channel status for each energy detection threshold of each beam group indicated by the first channel access configuration. For instance, if the first channel access configuration indicates a first energy detection threshold and a second energy detection threshold for a first beam group of the plurality of beam groups, the UE may report a first channel status for the first beam group based on the first energy detection threshold and a second channel status for the first beam group based on the second energy detection threshold.

Aspects of the present disclosure can provide several benefits. For example, signaling multiple channel access configurations via an RRC configuration and activating one of the channel access configurations at scheduling time via DCI can allow the BS to have the flexibility in configuring various LBT parameters (e.g., beam directions, beam grouping, LBT energy detection thresholds, and LBT random counters) at the UE without impacting per-transmission DCI scheduling overhead. Providing the BS with flexibility to control LBT operations at the UE can improve spectral resource utilization efficiency and/or reduce collisions. Additionally, grouping beams into groups for channel sensing can allow the BS to have a more accurate or complete interference profile of the UE without having the UE to perform many independent LBTs, and thus may maintain a minimal LBT overhead at the UE. Further, configuring the UE with multiple LBT energy detection thresholds may also allow the BS to have a more accurate or complete interference profile of the UE, and thus the BS can be more efficient in scheduling resources for the UE without causing significant interference to other surrounding nodes.

FIG. 1 illustrates a wireless communication network 100 according to some aspects of the present disclosure. The network 100 may be a 5G network. The network 100 includes a number of base stations (BSs) 105 (individually labeled as 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities. A BS 105 may be a station that communicates with UEs 115 (individually labeled as 115a, 115b, 115c, 115d, 115e, 115f, 115g, 115h, and 115k) 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” can refer to this particular geographic coverage area of a BS 105 and/or a BS subsystem serving the coverage area, depending on the context in which the term is used.

A BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . 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 the example shown in FIG. 1, the

BSs

105d and 105e may be regular macro BSs, while the BSs 105a-105c may be macro BSs enabled with one of three dimension (3D) , full dimension (FD) , or massive MIMO. The BSs 105a-105c may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. The BS 105f may be a small cell BS which may be a home node or portable access point. A BS 105 may support one or multiple (e.g., two, three, four, and the like) cells.

The network 100 may support synchronous 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.

The UEs 115 are dispersed throughout the wireless network 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A 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, or the like. In one aspect, a UE 115 may be a device that includes a Universal Integrated Circuit Card (UICC) . In another aspect, a UE may be a device that does not include a UICC. In some aspects, the UEs 115 that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices. The UEs 115a-115d are examples of mobile smart phone-type devices accessing network 100. A UE 115 may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. The UEs 115e-115h are examples of various machines configured for communication that access the network 100. The UEs 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication that access the network 100. A UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In FIG. 1, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink (DL) and/or uplink (UL) , desired transmission between BSs 105, backhaul transmissions between BSs, or sidelink transmissions between UEs 115.

In operation, the BSs 105a-105c may serve the

UEs

115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. The macro BS 105d may perform backhaul communications with the BSs 105a-105c, as well as small cell, the BS 105f. The macro BS 105d may also transmits multicast services which are subscribed to and received by the

UEs

115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

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 an example of a gNB or an access node controller (ANC) ) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115. In various examples, the BSs 105 may communicate, either directly or indirectly (e.g., through core network) , with each other over backhaul links (e.g., X1, X2, etc. ) , which may be wired or wireless communication links.

The network 100 may also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115e, which may be a drone. Redundant communication links with the UE 115e may include links from the

macro BSs

105d and 105e, as well as links from the small cell BS 105f. Other machine type devices, such as the UE 115f (e.g., a thermometer) , the UE 115g (e.g., smart meter) , and UE 115h (e.g., wearable device) may communicate through the network 100 either directly with BSs, such as the small cell BS 105f, and the macro BS 105e, or in multi-action-size configurations by communicating with another user device which relays its information to the network, such as the UE 115f communicating temperature measurement information to the smart meter, the UE 115g, which is then reported to the network through the small cell BS 105f. The network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such asV2V, V2X, C-V2X communications between a

UE

115i, 115j, or 115k and other UEs 115, and/or vehicle-to-infrastructure (V2I) communications between a

UE

115i, 115j, or 115k and a BS 105.

In some implementations, the network 100 utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some aspects, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other aspects, the subcarrier spacing and/or the duration of TTIs may be scalable.

In some aspects, the BSs 105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB) ) for downlink (DL) and uplink (UL) transmissions in the network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes or slots, for example, about 10. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL 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 a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.

The DL subframes and the UL subframes can be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115. For example, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS 105 may transmit cell specific reference signals (CRSs) and/or channel state information –reference signals (CSI-RSs) to enable a UE 115 to estimate a DL channel. Similarly, a UE 115 may transmit sounding reference signals (SRSs) to enable a BS 105 to estimate a UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and/or operational data. In some aspects, the BSs 105 and the UEs 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for UL communication.

In some aspects, the network 100 may be an NR network deployed over a licensed spectrum. The BSs 105 can 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 BSs 105 can 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 aspects, the BSs 105 may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal block (SSBs) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH) . The MIB may be transmitted over a physical broadcast channel (PBCH) .

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

After receiving the PSS and SSS, the UE 115 may receive a 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 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 set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH) , physical UL shared channel (PUSCH) , power control, and SRS.

After obtaining the MIB, the RMSI and/or the OSI, the UE 115 can 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 transmit 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, a UL grant, a temporary cell-radio network temporary identifier (C-RNTI) , and/or a backoff indicator. Upon receiving the random access response, the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate a contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1) , message 2 (MSG2) , message 3 (MSG3) , and message 4 (MSG4) , respectively. In some examples, the random access procedure may be a two-step random access procedure, where the UE 115 may transmit a random access preamble and a connection request in a single transmission and the BS 105 may respond by transmitting a random access response and a connection response in a single transmission.

After establishing a connection, the UE 115 and the BS 105 can enter a normal operation stage, where operational data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL and/or DL communications. The BS 105 may transmit UL and/or DL scheduling grants to the UE 115 via a PDCCH. The scheduling grants may be transmitted in the form of DL control information (DCI) . The BS 105 may transmit a DL communication signal (e.g., carrying data) to the UE 115 via a PDSCH according to a DL scheduling grant. The UE 115 may transmit a UL communication signal to the BS 105 via a PUSCH and/or PUCCH according to a UL scheduling grant. The connection may be referred to as an RRC connection. When the UE 115 is actively exchanging data with the BS 105, the UE 115 is in an RRC connected state.

In an example, after establishing a connection with the BS 105, the UE 115 may initiate an initial network attachment procedure with the network 100. The BS 105 may coordinate with various network entities or fifth generation core (5GC) entities, such as an access and mobility function (AMF) , a serving gateway (SGW) , and/or a packet data network gateway (PGW) , to complete the network attachment procedure. For example, the BS 105 may coordinate with the network entities in the 5GC to identify the UE, authenticate the UE, and/or authorize the UE for sending and/or receiving data in the network 100. In addition, the AMF may assign the UE with a group of tracking areas (TAs) . Once the network attach procedure succeeds, a context is established for the UE 115 in the AMF. After a successful attach to the network, the UE 115 can move around the current TA. For tracking area update (TAU) , the BS 105 may request the UE 115 to update the network 100 with the UE 115’s location periodically. Alternatively, the UE 115 may only report the UE 115’s location to the network 100 when entering a new TA. The TAU allows the network 100 to quickly locate the UE 115 and page the UE 115 upon receiving an incoming data packet or call for the UE 115.

In some aspects, the BS 105 may communicate with a UE 115 using HARQ techniques to improve communication reliability, for example, to provide a URLLC service. The BS 105 may schedule a UE 115 for a PDSCH communication by transmitting a DL grant in a PDCCH. The BS 105 may transmit a DL data packet to the UE 115 according to the schedule in the PDSCH. The DL data packet may be transmitted in the form of a transport block (TB) . If the UE 115 receives the DL data packet successfully, the UE 115 may transmit a HARQ ACK to the BS 105. Conversely, if the UE 115 fails to receive the DL transmission successfully, the UE 115 may transmit a HARQ NACK to the BS 105. Upon receiving a HARQ NACK from the UE 115, the BS 105 may retransmit the DL data packet to the UE 115. The retransmission may include the same coded version of DL data as the initial transmission. Alternatively, the retransmission may include a different coded version of the DL data than the initial transmission. The UE 115 may apply soft combining to combine the encoded data received from the initial transmission and the retransmission for decoding. The BS 105 and the UE 115 may also apply HARQ for UL communications using substantially similar mechanisms as the DL HARQ.

In some aspects, the network 100 may operate over a system BW or a component carrier (CC) BW. The network 100 may partition the system BW into multiple BWPs (e.g., portions) . A BS 105 may dynamically assign a UE 115 to operate over a certain BWP (e.g., a certain portion of the system BW) . The assigned BWP may be referred to as the active BWP. The UE 115 may monitor the active BWP for signaling information from the BS 105. The BS 105 may schedule the UE 115 for UL or DL communications in the active BWP. In some aspects, a BS 105 may assign a pair of BWPs within the CC to a UE 115 for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications.

In some aspects, the network 100 may operate over a shared channel, which may include shared frequency bands and/or unlicensed frequency bands. For example, the network 100 may be an NR-U network operating over an unlicensed frequency band. In such an aspect, the BSs 105 and the UEs 115 may be operated by multiple network operating entities. To avoid collisions, the BSs 105 and the UEs 115 may employ a listen-before-talk (LBT) procedure to monitor for transmission opportunities (TXOPs) in the shared channel. A TXOP may also be referred to as COT. The goal of LBT is to protect reception at a receiver from interference. For example, a transmitting node (e.g., a BS 105 or a UE 115) may perform an LBT prior to transmitting in the channel. When the LBT passes, the transmitting node may proceed with the transmission. When the LBT fails, the transmitting node may refrain from transmitting in the channel.

An LBT can be based on energy detection (ED) or signal detection. For an energy detection-based LBT, the LBT results in a pass when signal energy measured from the channel is below a threshold. Conversely, the LBT results in a failure when signal energy measured from the channel exceeds the threshold. For a signal detection-based LBT, the LBT results in a pass when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel. Additionally, an LBT may be in a variety of modes. An LBT mode may be, for example, a category 4 (CAT4) LBT, a category 2 (CAT2) LBT, or a category 1 (CAT1) LBT. A CAT1 LBT is referred to a no LBT mode, where no LBT is to be performed prior to a transmission. A CAT2 LBT refers to an LBT without a random backoff period. For instance, a transmitting node may determine a channel measurement in a time interval and determine whether the channel is available or not based on a comparison of the channel measurement against a ED threshold. A CAT4 LBT refers to an LBT with a random backoff and a variable contention window (CW) . For instance, a transmitting node may draw a random number and backoff for a duration based on the drawn random number in a certain time unit.

In some aspects, the network 100 may operate over a mmWave band (e.g., at 60 GHz) . Due to the high pathloss in the mmWave band, the BSs 105 and the UEs 115 may utilize directional beams to communicate with each other. For instance, a BS 105 and/or a UE 115 may be equipped with one or more antenna panels or antenna arrays with antenna elements that can be configured to focus transmit signal energy and/or receive signal energy in a certain spatial direction and within a certain spatial angular sector or width. In general, a BS 105 and/or a UE 115 may be capable of generating a transmission beam for transmission or a reception beam for reception in various spatial direction or beam directions.

FIG. 2 illustrates a communication scenario 200 according to aspects of the present disclosure. The communication scenario 200 may correspond to a communication scenario among BSs 105 and or UEs 115 in the network 100. For simplicity, FIG. 2 illustrates two BSs 205 (shown as 205a and 205b) and two UEs 215 (shown as 215a and 215b) , but a greater number of UEs 215 (e.g., about 3, 4, 5, 6, 7, 8, 9, 10, or more) and/or BSs 205 (e.g., the about 3, 4 or more) may be supported. The BS 205 and the UEs 215 may be similar to the BSs 105 and the UEs 115, respectively. In the scenario 200, the BSs 205 and the UEs 215 communicate with each other over a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum) . The BS 205a may serve the UE 215a, and the BS 205b may serve the UE 215b. In some aspects, the BS 205a and the BS 205b may be operated by different network operating entities.

In some aspects, the shared radio frequency band may be a mmWave band, such as a 60 GHz unlicensed band or FR2x band. As explained above, the high mmWave frequencies can have a high pathloss, and a wireless communication device operating over such frequencies may use beamforming for transmission and/or reception to compensate the high signal attenuation. For instance, the BS 205a may be capable of generating a number of directional transmission beams in a number of beam or spatial directions (e.g., about 2, 4, 8, 16, 32, 64 or more) and may select a certain transmission beam or beam direction to communicate with the UE 215a based on the location of the UE 215a in relation to the location of the BS 205a and/or any other environmental factors such as reflectors and/or scatterers in the surrounding. For example, the BS 205s may select a transmission beam that provides a best quality (e.g., with the highest receive signal strength) for transmission to the UE 215a. The BS 205s may also select a reception beam that provides a best quality (e.g., with the highest receive signal strength) for reception from the UE 215a. The selected transmission beam may or may not be in the same beam direction as the selected reception beam, for example, depending on the environment surrounding the BS 205a and the UE 215a. The UE 215a may also be capable of generating a number of directional transmission beams in a number of beam or spatial directions (e.g., about 2, 4, 8 or more) and may select a certain transmission beam and a certain reception beam that may provide the best quality (e.g., with the highest receive signal strength) to communicate with the BS 205a. In some instances, the BS 205a and the UE 115a may perform a beam selection procedure with each other to determine a best UL beam and a best DL beam for communications. In a similar way, each of the BS 205b, the UE 215b, and the UE 215c may be capable of generating a number of directional transmission beams in a number of beam directions or spatial directions and may select a most suitable transmission beam and a most suitable reception beam to communicate with each other.

In the illustrated example of FIG. 2, the BS 205a may generate three

beams

202a, 202b, and 202c. The BS 205a may determine that the beam 202b provides the best quality for transmitting to the UE 215a. The BS 205a may perform an LBT in the beam direction 203. For instance, the BS 205a may configure an antenna panel or antenna elements (e.g., antennas 716 of FIG. 7) at the BS 205a to form a reception beam in the beam direction 203 for the LBT. The BS 205a may measure signal energy in the beam direction 203. If the measured signal energy is below a certain energy detection threshold (indicating the beam direction 203 is clear for transmission) , the BS 205a may transmit a DL communication signal (e.g., a PDCCH and/or a PDSCH signal) to the UE 215a using the beam 202b (as shown by the pattern-filled beam) as shown. If, however, the measured signal energy is above the energy detection threshold (an LBT failure) , the BS 205a may refrain from transmitting in the beam direction 203.

As further illustrated in FIG. 2, the BS 205b may also generate three

beams

204a, 204b, and 204c. The BS 205b may determine that it may utilize the beam 204b or the beam 204c to communicate with the UE 215b, for example, based on a beam discovery or beam selection procedure. The beam 204c is in a beam direction 208 that is along a line-of-sight (LOS) path between the BS 205b and the UE 215b, whereas the beam 204b may reach the UE 215b along a non-LOS path via a reflector 220. The reflector 220 may be any object (e.g., a building or a configurable reflective surface) that reflects a transmission from the beam 204b along a direction 206 towards a direction 207. The BS 205b may perform an LBT independently in each beam direction of the

beams

204b and 204c. For instance, the BS 205b may configure an antenna panel or antenna elements (e.g., antennas 716 of FIG. 7) at the BS 205b to form a reception beam in the beam direction 208 and perform an LBT in the beam direction 208. In a similar way, the BS 205b may utilize receive beamforming to perform an LBT in the beam direction 206. The BS 205b may detect the transmission between the BS 205a and the UE 215a in the beam direction 208, and thus the LBT in the beam direction 208 may fail. For instance, the BS 205b may determine that a measured signal energy in the beam direction 208 exceeds an energy detection threshold. On the other hand, the BS 205b may determine that the LBT in the beam direction 206 passes (indicating that the channel is clear for transmission in the beam direction 206) since there is no other transmission in the beam direction 206. Accordingly, the BS 205b may transmit a communication signal to the UE 215b using the beam 204b (as shown by the pattern-filled beam) .

As can be observed from FIG. 2, a transmitting device (e.g., the BS 205b) utilizing narrow beam transmissions or beamformed transmissions, may reach a receiving device (e.g., the UE 215b) via multiple different beam directions (e.g., the beam directions 205 and the beam direction 206) . Accordingly, beamformed channel sensing may including performing multiple independent LBTs in different beam directions. Further, as explained above, with beamformed channel sensing, a transmitting device may not have a full view of interference at a corresponding receiving device. Accordingly, it may be beneficial for the receiving device to perform channel sensing and provide the transmitting device with the channel sensing results (e.g., indications of which beam direction is clear for transmission) .

As explained above, a BS (e.g., the BS 105 and/or 205) may schedule a UE (e.g., the UEs 115 and/or 215) for a UL communication or a DL communication over a shared channel (e.g., an unlicensed band) . The BS may configure the UE to assist in performing channel sensing and report the channel sensing results to the BS. In some instances, it may be desirable for the BS to control LBT operations at the UE so that the BS may better utilize resources and/or avoid potential collisions or causes interference to other nodes.

According to aspects of the present disclosure, a BS (e.g., the BS 105 and/or 205) may configure a UE (e.g., the UEs 115 and/or 215) with a plurality of channel access configurations (e.g., LBT configurations) and may subsequently indicate to the UE in a scheduling grant (e.g., UL grant or DL grant) which of the channel access configurations to use for performing an LBT prior to the scheduled communication (e.g., UL communication or DL communication) . In some aspects, the BS may signal the plurality of channel access configurations via an RRC configurations, and may signal the scheduling grant via DCI over a PDCCH. The DCI may include an N-bit message field referencing one of the plurality of channel access configurations. For instance, the plurality of channel access configurations may be in the form of an RRC table, and the N-bit message field in the DCI may include an index or identifier (ID) that references a first channel access configuration of the plurality of channel access configurations. In other words, the DCI may activate the first channel access configuration for the scheduled communication. The plurality of channel access configurations may specify various beam directions for LBTs, LBT energy detection thresholds, LBT random counters, and/or any other suitable LBT controls as will be discussed in greater detail below.

FIG. 3 illustrates a multi-beam channel access scheme 300 according to some aspects of the present disclosure. The scheme 300 may be employed by a BS such as the BSs 105 and/or 205 and/or a UE such as the UEs 115 and/or 215. In particular, the BS may configure the UE to perform beamformed channel sensing (directional LBT) as shown in the scheme 300. For simplicity, FIG. 3 illustrates one BS 205 configuring one UE 215 for beamformed channel sensing, but a greater number of BSs 205 and/or UEs 215 may be supported.

In the scheme 300, the BS 205 may generate a set of beams 302 (shown as 302a, 302b, or 302c) for communication over a shared high-frequency band (e.g., a 60 GHz unlicensed band or any suitable frequencies) . The UE 215 may also generate a set of beams 304 (shown as 304a, 304b, or 304c) for communication over the shared high-frequency band. The BS 205 and the UE 215 may communicate with each other using various transmit-receive beam pairs. A transmit-receive beam pair may refer to a pair of BS 205’s transmit beam and UE 215’s receive beam or a pair of BS 205’s receive beam and UE 215’s transmit beam. In some aspects, the BS 205 and the UE 215 may perform a beam discovery or selection procedure to determine the transmit-receive beam pairs. For instance, the BS 205 may sweep through the set of beams 302 while the UE 215 performs receive signal measurements (e.g., reference signal receive power (RSRP) ) using one of the beams 304. In some instances, the BS 205 sweep through the set of beams 302 by transmitting an SSB in each of the beam direction of the set of beams 302. The BS 205 may repeat sweeping through the set of beams 302 so that the UE 215 may also sweep through the set of beams 304 to determine receive signal measurements for various transmit-receive beam pairs. At the end of the beam sweep and measurements, the UE 215 may have obtained receive signal measurements for multiple transmit-receive beam pairs. In some instances, the UE 215 may sweep through the set of beams 304 repeatedly to allow the BS 205 to perform receive signal measurements using different beams 302. The UE 215 and/or the BS 205 may select a transmit-receive beam pair that provide the highest receive signal measurement among the measurements to communicate with each other. In some instances, the UE 215 and/or the BS 205 may select a few transmit-receive beam pairs with the highest receive signal measurements among the measurements, and may select one of the transmit- receive beam pairs for communication at a later time based on channel sensing as will be discussed more fully below.

In the illustrated example of FIG. 3, the BS 205 and the UE 215 may be connected through three transmit-receive beam pairs. For instance, the BS 205 and the UE 215 may utilize a first transmit-receive beam pair including the BS 205’s beam 302b and the UE 215’s beam 304b (shown by the diagonal-striped beams) along a LOS path between the BS 205 and the UE 215. That is, when the BS 205 utilizes the beam 302b to transmit a DL transmission to the UE 215, the UE 215 may utilize the beam 304b to receive the DL transmission from the BS 205. Alternatively, the BS 205 and the UE 215 may utilize a second transmit-receive beam pair including the BS 205’s beam 302a and the UE 215’s beam 304a (shown by the vertical-striped beams) along a non-LOS path via the reflector 310. That is, when the BS 205 utilizes the beam 302a to transmit a DL transmission to the UE 215, the reflector 310 may reflect the DL transmission in the direction of the UE 215’s beam 304a, and thus the UE 215 may utilize the beam 304a to receive the DL transmission from the BS 205. Yet alternatively, the BS 205 and the UE 215 may utilize a third transmit-receive beam pair including the BS 205’s beam 302c and the UE 215’s beam 304c (shown by the empty-filled beams) along another non-LOS path via the reflector 312. That is, when the BS 205 utilizes the beam 302c to transmit a DL transmission to the UE 215, the reflector 312 may reflect the DL transmission in the direction of the UE 215’s beam 304c, and thus the UE 215 may utilize the beam 304c to receive the DL transmission from the BS 205. The

reflectors

310 and 312 may be substantially similar to the reflector 210. In some instances, the UE 215 and/or the BS 205 may utilize the same transmit-receive beam pair for UL communications and DL communications. That is, when the UE 215 utilizes the beam 304a to transmit an UL transmission to the BS 205, the BS 205 may utilize the beam 302a to receive the UL transmission. Similarly, when the UE 215 utilizes the beam 304b to transmit an UL transmission to the BS 205, the BS 205 may utilize the beam 302b to receive the UL transmission, and so on.

At a later time, the BS 205 may schedule the UE 215 for a DL communication or a UL communication. The BS 205 may request the UE 215 to perform beamformed channel sensing in the beam direction of the UE 215’s beam 304a, for example, for a communication between the BS 205 and the UE 215 using the first transmit-receive beam. Additionally or alternatively, the BS 205 may request the UE 215 to perform beamformed channel sensing in the beam direction of the UE 215’s beam 304b, for example, for a communication between the BS 205 and the UE 215 using the second transmit-receive beam. Additionally or alternatively, the BS 205 may request the UE 215 to perform beamformed channel sensing in the beam direction of the UE 215’s beam 304c, for example, for a communication between the BS 205 and the UE 215 using the second transmit-receive beam.

Accordingly, the UE 215 may perform an independent LBT in each beam direction as requested by the BS 205. Each LBT may be based on a certain energy detection threshold. That is, the UE 215 may configure a reception beam (e.g., the

beam

304a, 304b, or 304c) in a requested beam direction and measure channel signal energy using the reception beam. If the measured channel signal energy is below a certain threshold, the LBT is a pass indicating the beam direction is clear for scheduling. If, however, the measured channel signal energy is above the threshold, the LBT fails indicating the beam direction is not clear for scheduling. The BS 205 may also configure or request the UE 215 to report LBT result. Accordingly, the UE 215 may report to the BS 205 the LBT result for each beam direction, for example, indicating whether the beam direction is clear for scheduling or not. The BS 205 may determine whether to schedule the UE 215 and/or in which beam direction (or which transmit-receive beam pair to use) to schedule the UE 215 based on the received LBT report. In some instances, the BS 205 may also perform an independent LBT in each beam direction of the

beams

302a, 302b, and 302c, and determine whether to schedule the UE 215 and/or in which beam direction (or which transmit-receive beam pair to use) to schedule the UE 215 further based on the BS 205’s LBT results.

In some aspects, the BS 205 may group the transmit-receive beam pairs into multiple beam groups and may request the UE 215 to perform channel sensing for one or more beam groups. In the illustrated example of FIG. 3, the BS 205 may configure the UE 215 with three beam groups, shown as a beam group A 322, a beam group B 324, and a beam group C 326. The beam group A 322 includes the first and second transmit beam pairs, the beam group B 324 includes the third transmit-receive beam pair, and the beam group C 326 includes the first, second, and third transmit-receive beam pairs. In some aspects, the BS 205 may request the UE 215 to perform channel sensing for a beam group by indicating a BS 205’s beam 302 and/or a UE 215’s beam 304. For instance, to indicate the beam group A 322, the BS 205 may indicate the BS 205’s

beam

302a and 302b. The UE 215 may have information related to the association or transmit-receive beam pairing of the BS 205’s beam 302a with the UE 215’s beam 304a and the transmit-receive beam pairing of the BS 205’s beam 302b with the UE 215’s beam 304b. Accordingly, the UE 215 may perform channel sensing using a wide beam including the beam 304a and the beam 304b. That is, the UE 215 may perform channel sensing in a combined beam direction including a beam direction of the beam 304a and a beam direction of the beam 304b. Alternatively, the BS 205 may indicate the beam group A 322 by indicating the UE 215’s

beam

304a and 304b. In a similar way, the BS 205 may indicate the beam group B 324 by indicating the BS 205’s beam 302b or the UE 215’s beam 304b, and may the beam group C 326 by indicating the BS 205’s

beam

302a, 302b, and 302c or the UE 215’s

beam

304a, 304b, and 304c.

In some aspects, the BS 205 may indicate a beam 302 of the BS 205 using a TCI. For instance, in 5G or NR, a TCI is used to establish a QCL relationship (e.g., a spatial relation) between two reference signals. In an aspect, the BS 205 may transmit a certain signal (e.g., an SSB or a certain reference signal) in a certain beam direction and may associate a certain TCI value with the signal transmitted in the certain beam direction. In this way, if the UE 215 determines that a certain receive beam direction provides the best receive signal strength for the certain signal, the UE 215 may utilize that receive beam direction whenever the BS 205 indicates the certain TCI value for a DL communication. As an example, the BS 205 may associate a first TCI value with an SSB or a reference signal transmitted using the beam 302a, associate a second TCI value with an SSB or a reference signal transmitted using the beam 302b, and associate a third TCI value with an SSB or reference signal transmitted using the beam 302c. Accordingly, the BS 205 may indicate the beam group A 322 by indicating the first TCI value (the beam 302a) and the second TCI value (the beam 302b) , indicate the beam group B 324 by indicating the third TCI value ( (the beam 302c) , and indicate the beam group C 326 by indicating the first TCI value (the beam 302a) , the second TCI value (the beam 302c) , and the third TCI value (the beam 302c) .

In some aspects, the BS 205 may indicate a beam 304 of the UE 214 using an SRI. For instance, the BS 205 may configure SRS resources for the UE 215 to transmit SRSs so that the BS 205 may perform UL signal measurements. The BS 205 may associate each SRS resource with a UE 215’s beam direction. In 5G or NR, each SRS resource is assigned with an SRI value, and thus each SRI value may be associated with a UE 215’s beam direction. In this way, if the BS 205 indicates a certain SRI value for a UL communication or a DL communication, the UE 215 may utilize the same beam that was used to in the SRS resource identified by the SRI value. As an example, the BS 205 may assign a first SRI to a first SRS resource configured for the UE 215 to use the beam 304a for transmitting an SRS in the first SRS resource. Similarly, the BS 205 may assign a second SRI to a second SRS resource configured for the UE 215 to use the beam 304b for transmitting an SRS in the second SRS resource. The BS 205 may assign a third SRI to a third SRS resource configured for the UE 215 to use the beam 304c for transmitting an SRS in the third SRS resource. Accordingly, the BS 205 may indicate the beam group A 322 by indicating the first SRI value (the beam 304a) and the second SRI value (the beam 304b) , indicate the beam group B 324 by indicating the third SRI value (the beam 304c) , and indicate the beam group C 326 by indicating the first SRI value (the beam 304a) , the second SRI value (the beam 304c) , and the third SRI value (the beam 304c) .

FIG. 4 is discussed in relation to FIGS. 5 and 6 to illustrate multi-beam channel access. FIG. 4 is a sequence diagram illustrating a multi-beam channel access method 400 according to some aspects of the present disclosure. The method 400 may be implemented between a BS 205 and a UE 215 communicating over a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum) . The method 400 may utilize similar mechanisms as discussed above with respect to FIGS. 2-3. In some aspects, the BS 205 may correspond to the BS 700 of FIG. 7 and may utilize one or more components, such as the processor 702, the memory 704, the multi-beam channel access module 708, the transceiver 710, the modem 712, and the one or more antennas 716 with reference to FIG. 7, to execute the actions of the method 400. In some aspects, the UE 215 may correspond to the UE 800 of FIG. 8 and may utilize one or more components, such as the processor 802, the memory 804, the multi-beam channel access module 808, the transceiver 810, the modem 812, and the one or more antennas 816 with reference to FIG. 8, to execute the actions of the method 400. As illustrated, the method 400 includes a number of enumerated actions, but aspects of the method 400 may include additional action (s) before, after, and in between the enumerated action. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

At action 410, the BS 205 transmits, and the UE 215 receives, a plurality of channel access configurations. In some aspects, the BS 205 may transmit the plurality of channel access configurations via RRC signaling. For instance, the BS 205 may configure the UE 215 with an RRC configuration. The RRC configuration may be in the form of an RRC table, where each table entry may correspond to one of the channel access configuration. Additionally, each RRC table entry may be referenced by a table index or a channel access configuration ID. The plurality of channel access configuration may indicate various parameters for performing channel sensing in an unlicensed band (e.g., a 60 GHz band or FR2x band) .

In some aspects, the plurality of channel access configurations may include an indication of a plurality of beam directions. For instance, the BS 205 and the UE 215 may perform beam discovery and/or beam selection to identify the plurality of beam directions. The beam discovery may include the BS 205 sweeping through a set of beams (e.g., the beams 302) of the BS 205 repeatedly and the UE 215 perform receive signal measurements for each beam of the BS 205. The UE 215 may also sweep through a set of beams (e.g., the beams 304) of the UE 215 to determine receive signal measurements for various transmit-receive beam pairs. In some instances, the UE 215 may sweep through the set of beams 304 repeatedly to allow the BS 215 to perform receive signal measurements using different beams 302. The BS 205 and/or the UE 215 may select a few transmit-receive beam pairs with the highest receive signal measurements among the measurements, for example, as discussed above with reference to FIG. 3. The plurality of beam directions may correspond to the BS’s 205 beams or the UE 215’s beams selected from the transmit-receive pairs.

In some aspects, the plurality of channel access configurations may indicate the plurality of beam directions by indicating beam directions from the perspective of the BS 205. That is, the BS 205 may indicate the plurality of beam directions by indicating the BS 205’s beams (e.g., the

beams

302a, 302b, 302c) . As explained above, the BS 205 may transmit a certain signal (e.g., an SSB or a certain reference signal) in a certain beam direction and may associate a certain TCI value with the signal transmitted in the certain beam direction. In this way, if the UE 215 determines that a certain receive beam direction provides the best receive signal strength for the certain signal, the UE 215 may utilize that receive beam direction whenever the BS 205 indicates the certain TCI value for a DL communication. Accordingly, the BS 205 may indicate the plurality of beam directions (e.g., the BS 205’s beams) by indicating TCI values corresponding to the plurality of beam directions.

In some aspects, the plurality of channel access configurations may indicate the plurality of beam directions by indicating beam direction from the perspective of the UE 215. That is, the BS 205 may indicate the plurality of beam directions by indicating the UE 215’s beams (e.g., the

beams

304a, 304b, 304c) . As explained above, the BS 205 may configure SRS resources for the UE 215 to transmit SRSs. The UE 215 may transmit an SRS using a different beam direction in each SRS resource. The BS 205 may assign an SRI for each SRS resource. In this way, if the BS 205 indicates a certain SRI for a UL communication or a DL communication, the UE 215 may utilize the same beam that was used to transmit in the SRS resource identified by the SRI. Accordingly, the BS 205 may indicate the plurality of beam directions (e.g., the UE 215’s beams) by indicating SRI values corresponding to the plurality of beam directions.

In some aspects, the plurality of channel access configurations may include an indication of a plurality of beam groups. Each beam group of the plurality of beam groups may include a subset of the plurality of beam directions. For instance, the beam groups may be similar to the beam group A 322, the beam group B 324, and/or the beam group C 326. Each beam group may include one or more of the plurality of beam directions. In some instances, one beam group of the plurality of beam groups may include a subset of one beam direction of the plurality of beam directions, and another beam group of the plurality of beam groups may include a subset of two or more beam directions of the plurality of beam directions. In general, each beam group may include any suitable number of beams. Additionally, some beam groups may include a same beam direction. For instance, a first subset of beams for a first beam group may include at least one beam direction that is in a second subset of beams for a second beam group. Referring to the example shown in FIG. 3, the beam 302a is in the beam group A 322 and in the beam group C 326.

Each channel access configuration of the plurality of channel access configurations may indicate at least one beam group of the plurality of beam groups. In some instances, one channel access configuration of the plurality of channel access configurations may indicate one beam group, and another channel access configuration of the plurality of channel access configurations may indicate two or more beam groups. In general, each channel access configuration may indicate any suitable number of beam groups (e.g., 1, 2, 3, 4 or more) . Furthermore, some channel access configurations may include the same beam group. For instance, referring to the example shown in FIG. 3, one of the channel access configurations may include the beam group A 322 and another one of the channel access configuration may include the beam group A 322 and the beam group B 324.

Further, in some aspects, each channel access configuration may also include a set of energy detection thresholds, a set of random counters, and/or a channel access report type for each beam group. The energy detection thresholds may be used by the UE 215 during channel sensing to determine whether the channel is occupied or free. Different energy detection thresholds may correspond to different interference tolerance levels or different channel sensing ranges. The random counters may be used by the UE 215 during channel sensing for random backoff. Different random counters may be associated with different traffic priorities. The channel access report type may indicate one of an aperiodic report type, a semi-persistent report type, or a periodic report type.

At action 420, the BS 205 transmits, and the UE 215 receives, a DL scheduling grant scheduling a DL communication signal in the unlicensed band. The DL scheduling grant may include an indication of a first channel access configuration of the plurality of channel access configurations. In some aspects, the BS 205 may transmit the DL scheduling grant via DCI signaling over a PDCCH. The DCI may indicate a resource allocation (e.g., time-frequency resource allocation) for the DL communication signal, transmission parameter (s) (e.g., modulation coding scheme (MCS) ) for transmitting the DL communication signal, and a reference pointer to the first channel access configuration. For instance, the plurality of channel access configurations may be configured in an RRC configuration as discussed above, and the DCI may include an index referencing an RRC table entry corresponding to the first channel access configuration or a channel access configuration ID that identifies the first channel access configuration. The indication of the first channel access configuration operates as an activation for performing channel sensing using the first channel access configuration.

At action 430, in response to receiving the DL scheduling grant, the UE 215 performs channel sensing in accordance with the first channel access configuration. The UE 215 may perform channel sensing for each beam group indicated by the first channel access configuration. For instance, for each beam group, indicated by the first channel access configuration, the UE 215 may utilize receive beamforming to form a reception beam for receiving a signal from the channel in a beam direction of the beam group and determine a receive signal energy for the receive signal. If a beam group includes more than one beam directions, the UE 215 may utilize receive beamforming to form a wide reception beam for receiving a signal from the channel in all beam directions within the beam group and determine a receive signal energy for the receive signal. That is, the UE 215 may perform channel sensing in a combined beam direction including all beam directions included in the beam group.

As an example, the first channel access configuration may indicate a first beam group and a second beam group. Accordingly, the first UE 215 may perform first channel sensing for the beam group and second channel sensing for the second beam group. Referring to FIG. 3 as an example, if the first beam group corresponds to the beam group A 322, the UE 215 may utilize receive beamforming to form a wide reception beam covering the

beam

304a and 304b for receiving a signal from the channel and determine a receive signal energy for the received signal. Further, if the second beam group corresponds to the beam group B 324, the UE 215 may utilize receive beamforming to form a narrow reception beam (the beam 304c) for receiving a signal from the channel and determine a receive signal energy for the received signal.

For each beam group, the UE 215 may determine a channel status in the beam direction of the beam group is clear or busy. In this regard, the UE 215 may compare a receive signal energy measured from the channel in the beam direction to an energy detection threshold. If the measured channel signal energy is below the energy detection threshold, the UE 215 may determine that the channel is clear for the beam group. That is, the BS 205 and/or the UE 215 may transmit in any beam direction within the beam group. If, however, the measured channel signal energy is above the energy detection threshold, the UE 215 may determine that the channel is not clear for the beam group. That is, the BS 205 and/or the UE 215 may not transmit in any beam direction within the beam group.

As discussed above, the BS 205 may include a plurality of energy detection thresholds for each beam group. Accordingly, for each beam group, the UE 215 may determine whether the channel is clear for communication in a beam direction of the beam group based on each of the plurality of energy detection thresholds. That is, the UE 215 may determine a channel status for the beam group by comparing the measured channel signal energy against each energy detection thresholds. For instance, if the first channel access configuration includes two energy detection thresholds (e.g., a first energy detection threshold and a second energy detection threshold) for a first beam group in the first channel access configuration, the UE 215 may compare the measured channel signal energy against the first energy detection threshold and against the second energy detection threshold. The UE 215 may generate a first channel status based on the comparison against the first energy detection threshold and generate a second channel status based on the comparison against the second energy detection threshold. For instance, if the measured channel signal energy is below the first energy detection threshold, the first channel status may indicate a clear channel status. If, however, the measured channel signal energy is above the first energy detection threshold, the first channel status may indicate a busy channel status. Similarly, if the measured channel signal energy is below the second energy detection threshold, the second channel status may indicate a clear channel status. If, however, the measured channel signal energy is above the second energy detection threshold, the second channel status may indicate a busy channel status. Since the first energy detection threshold and second energy detection threshold are different, the first channel status can be different from the second channel status. For example, the first energy detection threshold may be higher than the second energy detection threshold. As such, the UE 215 may determine that the first channel status based on the first energy detection threshold is clear, but the second channel status based on the second energy detection threshold is busy.

In some aspects, an energy detection threshold be represented by the following relationship:

where EDT represents the energy detection threshold, -80 decibel-milliwatt (dBm) represents a channel sensing range, the operating channel bandwidth represents a frequency bandwidth of the unlicensed band used for the DL communication, Pout represents the radio frequency (RF) output power (e.g., effective isotropic radiated power (EIRP) ) of the UE 215’s RF frontend (e.g., the RF unit 814 of FIG. 8) , and Pmax represents the RF output power limit of the UE 215’s RF frontend.

Further, as discussed above, the BS 205 may include one or more random counters for each beam group. Accordingly, for each beam group, the UE 215 may determine whether the channel is clear for communication in a beam direction of the beam group based on each of the plurality of random counters. The random counters may indicate a range (e.g., a starting number and an ending number) to be used for random backoff. For instance, the UE 215 may draw a random number from the range indicated by a first random counter of the one or more random counters and backoff for a duration corresponding to the drawn number before performing channel sensing. As explained above, the different random counters (random backoff durations) may be associated with different channel access priorities. Accordingly, the UE 215 may select the first random counter based on a traffic priority associated with the scheduled DL communication signal. In some aspects, the UE 215 may have multiple LBT engines or may implement multiple LBTs to perform multiple LBTs each using one of the random counters.

At action 440, the UE 215 transmits, and the BS 205 receives, a channel sensing report. The channel sensing report may indicate a channel status for each beam group indicated by the first channel access configuration. If the first channel access configuration indicates multiple beam groups, the UE 215 may indicate a channel status for each beam group of the one or more beam groups. Further, if the first channel access configuration indicates multiple energy detection thresholds, for example, for a first beam group of the one or more beam groups, the UE 215 may indicate a channel status for the first beam group based on each energy detection threshold. For example, the UE 215 may include in the channel sensing report a first channel status and a second channel status for the first beam group, where the first channel status is determined based on a comparison of the measured channel signal energy against the first energy detection threshold and the second channel status is determined based on a comparison of the measured channel signal energy against the second energy detection threshold as discussed above at action 430. In some aspects, the channel access report type for the first channel access configuration may indicate an aperiodic report type. Accordingly, the UE 215 may transmit the channel sensing report based on an aperiodic trigger, for example, indicating by the DL scheduling grant.

At action 450, in response to receiving the channel sensing report, the BS 205 transmits, and the UE 215 receives, the DL communication signal in a resource and/or using transmit parameter as indicated by the DL scheduling grant. For instance, the channel sensing report at action 440 may indicate that the channel is clear in the beam direction of the first beam group. As such, the BS 205 may transmit the DL communication in a beam direction within the first beam group. The BS 205 may refrain from transmitting the DL communication signal in a beam direction that is not cleared for transmission. In some aspects, the BS 205 may determine a transmit power for transmitting the DL communication signal based on the channel sensing report. For instance, if the UE 215 indicates that the channel is free for a first energy detection threshold, but busy for a second, lower energy detection threshold, the BS 205 may reduce the transmit power such that the transmission of the DL communication signal may not interfere or at least with a minimal interference to a device located at a certain range from the BS 205 205, where the certain range may be associated with the second energy detection threshold.

In some aspects, the BS 205 may transmit the DL communication signal based on the channel sensing report received from the UE 215 without performing channel sensing. That is, the BS 205 may transmit the DL communication signal by sharing a COT acquired by the UE 215 based on the channel sensing at action 430. In other aspects, the BS 205 may also perform channel sensing (a CAT4 LBT or a CAT2 LBT) to acquire a COT and transmit the DL communication signal in its own COT.

The BS 205 may also schedule the UE 215 for UL communication and activate a certain channel access configuration of the plurality of channel access configurations for the UL communication. For instance, at action 460, the BS 205 transmits, and the UE 215 receives, a UL scheduling grant a UL scheduling grant scheduling a UL communication signal in the unlicensed band. The UL scheduling grant may include an indication of a second channel access configuration of the plurality of channel access configurations. In some aspects, the second channel access configuration may be different from the first channel access configuration. In other aspects, the second channel access configuration and the first channel access configuration may correspond to the same channel access configuration. In some aspects, the BS 205 may transmit the UL scheduling grant via DCI signaling over a PDCCH. The DCI may indicate a resource allocation (e.g., time-frequency resource allocation) for the UL communication signal, transmission parameter (s) (e.g., MCS) for transmitting the UL communication signal, and a reference pointer to the second channel access configuration. The indication of the second channel access configuration operates as an activation of the second channel access configuration for channel sensing or performing an LBT.

At action 460, in response to receiving the UL scheduling grant, the UE 215 performs channel sensing in accordance with the second channel access configuration using substantially similar mechanisms as discussed above at action 430. For instance, the UE 215 may perform channel sensing for each beam group indicated by the second channel sensing configuration. If a beam group indicated by the second channel access configuration includes multiple beam directions, the UE 215 may perform channel sensing in a combined beam direction including all the beams in the beam group. Further, if second channel access configuration indicates one or more energy detection thresholds for a beam group, the UE 215 may determine a channel status (an indication of whether the channel is clear for transmission in the beam group) for each energy detection threshold. Further, if the second channel access configuration indicates one or more random counters for a beam group, the UE 215 may select a random counter (a number range) from the one or more random counters (e.g., based on a priority of the scheduled UL communication) , draw a random number from the range indicated by the selected random counter of the one or more random counters and backoff for a duration corresponding to the drawn number before performing channel sensing in a beam direction of the beam group. As an example, the UE 215 may determine (from the channel sensing) that a certain beam group indicated by the second channel access configuration is free.

At action 470, the UE 215 transmits, and the BS 205 receives, the UL communication signal in a resource and/or using transmit parameter as indicated by the UL scheduling grant. The UE 215 may transmit the UL communication signal in a beam direction within the certain beam group (that is cleared for transmission from the channel sensing) .

FIG. 5 illustrates a multi-beam channel access signaling scheme 500 according to some aspects of the present disclosure. The scheme 500 may be employed by a BS such as the BSs 105 and 205 and a UE such as the UEs 115 and 215. In particular, a BS 205 may configure a UE 215 with multiple channel access configurations for performing channel sensing or LBT (s) and may activate one of the channel access configurations at a scheduling time as shown in the scheme 500. For instance, the BS 205 may configure the UE 215 with a plurality of channel access configurations 520 at action 410. The plurality of channel access configurations 520 are shown as channel access configuration 1, channel access configuration 2, …, channel access configuration k, …, channel access configuration L. Each channel access configuration 520 may include various parameters associated with channel sensing. For instance, each channel access configuration may include at least one of beam information 522, one or more energy detection thresholds 524, one or more random counters 526, and a channel sensing report type 528 as shown by the expanded view 502 for the channel access configuration 1.

In some aspects, each channel access configuration 520 may include one or more beam groups in the beam information 522 as shown in FIG. 6.

FIG. 6 illustrates a beam information configuration 600 for multi-beam channel access according to some aspects of the present disclosure. For instance, the beam information 522 for a channel access configuration 520 may be configured as shown in the configuration 600. For instance, the beam information 522 may indicate a plurality of beam groups 610 shown as beam group 1, beam group 2, …beam group K. In some aspects, the beam groups 610 may be similar to the beam group A 322, the beam group B 324, and/or the beam group C 326 discussed above with reference to FIG. 3. In some aspects, the beam information 522 may indicate each of the beam groups 610 by a corresponding beam group ID. For instance, the beam group 1, beam group 2, …, beam group K may be identified by beam group ID 1, beam group ID 2, …, beam group ID K. Each beam group 610 may include a subset of a plurality of beams that can be used for communication between the BS 205 and the UE 215. For simplicity of illustration and discussion, FIG. 6 provides an expanded view for beam group 1, which includes M beams 612 shown as beam 1, beam 2, …, beam M. The beam 1, beam 2, and beam M are shown by corresponding solid-filled beam in the set of beams 602. In general, each beam group 610 may include any suitable number of beams 612. Additionally, some beam groups 610 may include a same beam direction. For instance, a first subset of beams for a first beam group 610 (e.g., the beam group 1) may include at least one beam 612 (e.g., the beam 2) that in a second subset of beams for a second beam group 610 (e.g., the beam group 2) .

In some aspects, the beams 612 may correspond to beams (e.g., the beams 302) of the BS’s 205. For instance, the beams 612 may be indicated by correspond TCI values. As explained above, the BS 205 may transmit a certain signal (e.g., an SSB or a certain reference signal) in a certain beam direction and may associate a certain TCI value with the signal transmitted in the certain beam direction. In this way, if the UE 215 determines that a certain receive beam direction provides the best receive signal strength for the certain signal, the UE 215 may utilize that receive beam direction whenever the BS 205 indicates the certain TCI value for a DL communication.

In other aspects, the beams 612 may correspond to beams (e.g., the beams 304) of the UE’s 215. For instance, the beams 612 may be indicated by corresponding SRI values. As explained above, the BS 205 may configure SRS resources for the UE 215 to transmit SRSs. The UE 215 may transmit an SRS using a different beam direction in each SRS resource. The BS 205 may assign an SRI for each SRS resource. In this way, if the BS 205 indicates a certain SRI for a UL communication or a DL communication, the UE 215 may utilize the same beam that was used to transmit in the SRS resource identified by the SRI.

Returning to FIG. 5, in some aspects, each channel access configuration 520 may include a set of energy detection thresholds 524 per-beam group 610. The energy detection thresholds 524 may be used by the UE 215 during channel sensing to determine whether the channel is occupied or free in a certain beam direction of the beam group 610 as discussed above at action 430. For instance, the channel access configuration 1 may include multiple energy detection threshold 524 for at least one beam group 610. In some aspects, each energy detection threshold 524 may be associated with a certain interference tolerance level or for detection of a device within a certain range.

In some aspects, each channel access configuration 520 may include a set of random counters 526 per-beam group 610. The random counters 526 may be used by the UE 215 during channel sensing to configure a counter for random backoff as discussed above at action 430. For instance, the channel access configuration 1 may include multiple random counters 526 for at least one beam group 610.

In some aspects, each channel access configuration 520 may include a report type 528. The report type may indicate an aperiodic report type, a semi-persistent report type, or a periodic report type. For the aperiodic report type, the UE 215 may provide the BS 205 with a channel sensing report based on a trigger (e.g., include an UL scheduling or a DL scheduling grant) . In some instances, the aperiodic report type may be suitable for load based equipment (LBE) -based LBT. For LBE-based LBT, channel sensing is performed at any time instant and random back-off is used if the channel is found busy. In some aspects, the aperiodic report type may be a default channel sensing report for LBE-based LBT.

For semi-persistent report type, the BS 205 may configure the UE 215 to report channel sensing results at certain time periods or reporting occasions. The BS 205 may also specify in which beam direction (s) or beam group (s) the UE 215 may report channel sensing results. The semi-persistent report type can improve robustness of LBT report reception at the BS 205. For instance, in some instances, the UE 215 may not be successful in gaining access to the channel to transmit a channel sensing report during a certain reporting occasion, but may be successful in gaining access to the channel to transmit a channel sensing report during another reporting occasion. In some other instances, the BS 205 may fail to receive and/or decode a channel sensing report during a certain reporting occasion, but may be successful in decoding a channel sensing report in another reporting occasion.

For periodic report type, the BS 205 may configure the UE 215 to report channel sensing results periodically. In some instances, the periodic report type may be suitable for frame based equipment (FBE) -based LBT. In FBE-based LBT, channel sensing is performed at predetermined time instants (e.g., associated with fixed frame periods (FFPs) ) . For instance, if the channel is busy, the UE 215 may back off for a predetermined time period and sense the channel again after this period. Accordingly, the UE 215 perform LBT periodically according to the FFPs and provide the BS 205 with channel sensing report periodically.

In some aspects, the plurality of the channel access configuration 520 may be a semi-static configuration. For instance, the BS 205 may configure the UE 215 with an RRC configuration including the channel access configurations 520. At a later time, the BS 205 may schedule the UE 215 for a DL communication. The BS 205 may transmit a scheduling grant 510 to the UE 215 indicating a resource allocation (e.g., time-frequency resource allocation) for transmitting the DL communication signal and/or transmission parameter (s) (e.g., MCS) to be used for transmitting the DL communication signal. The scheduling grant 510 includes an N-bit message field 512 including an indication of a first channel access configuration 520 of the plurality of channel access configurations 520. In the illustrated example of FIG. 5, the N-bit message field 512 includes an indication to the channel access configuration L as show by the arrow. In some aspects, the N-bit message field 512 may include a channel access configuration ID identifying the channel access configuration L. In some aspects, the plurality of channel access configurations 520 may be stored in an RRC table, and the N-bit message field 512 may include an index that points an entry in the RRC table that contains the channel access configuration L. In general, the message field 512 may utilize N=log2 (L) bits to indicate an entry in the RRC table with L number of channel access configurations 520.

FIG. 7 is a block diagram of an exemplary BS 700 according to some aspects of the present disclosure. The BS 700 may be a BS 105 as discussed in FIG. 1 or a BS 205 as discussed in FIGS. 1-6. As shown, the BS 700 may include a processor 702, a memory 704, a multi-beam channel access module 708, a transceiver 710 including a modem subsystem 712 and a RF unit 714, and one or more antennas 716. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for example via one or more buses.

The processor 702 may have various features as a specific-type processor. For example, these may include a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 702 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.

The memory 704 may include a cache memory (e.g., a cache memory of the processor 702) , RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory 704 may include a non-transitory computer-readable medium. The memory 704 may store instructions 706. The instructions 706 may include instructions that, when executed by the processor 702, cause the processor 702 to perform operations described herein, for example, aspects of FIGS. 1-6 and 9. Instructions 706 may also be referred to as program code. The program code may be for causing a wireless communication device to perform these operations, for example by causing one or more processors (such as processor 702) to control or command the wireless communication device to do so. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement (s) . For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

The multi-beam channel access module 708 may be implemented via hardware, software, or combinations thereof. For example, the multi-beam channel access module 708 may be implemented as a processor, circuit, and/or instructions 706 stored in the memory 704 and executed by the processor 702. In some examples, the multi-beam channel access module 708 can be integrated within the modem subsystem 712. For example, the multi-beam channel access module 708 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 712. The multi-beam channel access module 708 may communicate with one or more components of BS 700 to implement various aspects of the present disclosure, for example, aspects of FIGS. 1-6 and 9.

In some aspects, the multi-beam channel access module 708 is configured to transmit a plurality of channel access configurations to a UE (e.g., the UEs 115, 215, and/or 800) , for example, via RRC signaling. The plurality of channel access configurations may include various channel sensing parameters for performing channel sensing (e.g., beamformed channel sensing or directional LBT) . In some aspects, the plurality of channel access configurations may include an indication of a plurality of beam directions (e.g., the beam directions 302, 304, 602, 612) . In some aspects, the indication of the plurality of beam directions may be indicated by TCIs (indicative of DL beams of the BS 700) . In some aspects, the indication of the plurality of beam directions may be indicated by SRIs (indicative of UL beams of the UE) . In some aspects, the plurality of channel access configurations may include an indication of a plurality of beam groups (e.g., the

beam groups

322, 324, 326, and/or 610) . Each beam group of the plurality of beam groups may include a subset of one or more of the plurality of beam directions. Each channel access configuration of the plurality of channel access configurations may indicate at least one beam group of the plurality of beam groups. In some aspects, each channel access configuration may include a set of LBT energy detection thresholds (e.g., the energy detection thresholds 524) per beam-group. In some aspects, each channel access configuration may include a set of LBT random counters (e.g., the random counters 526) per beam-group.

In some aspects, the multi-beam channel access module 708 is further configured to transmit, to the UE, a scheduling grant (e.g., the scheduling grant 510) for communicating a communication signal with the UE in an unlicensed band. The scheduling grant may be a PDCCH DCI including an indication of a first channel access configuration of the plurality of channel access configurations. The multi-beam channel access module 708 is further configured to communicate, the communication signal with the UE in the unlicensed band based on the first channel access configuration. In some instances, the scheduling grant is a UL scheduling grant, and as part of communicating the communication signal, the multi-beam channel access module 708 is configured to receive a UL communication signal (e.g., PUCCH UCI and/or PUSCH data) from the UE. In other instances, the scheduling grant is a DL scheduling grant, and as part of communicating the communication signal, the multi-beam channel access module 708 is configured to transmit a DL communication signal (e.g., PDSCH data) to the UE.

In some aspects, the first channel access configuration may include a channel sensing report configuration (e.g., the report type 528) , and the multi-beam channel access module 708 is further configured to receive, from the UE, a channel sensing report based on the first channel access configuration. The channel sensing report may indicate a channel status (e.g. busy or free for transmission) for each beam group indicated by the first channel access configuration. In some instances, if the first channel access configuration indicates multiple energy detection thresholds for each beam group, the channel sensing report may include, for each beam group, a channel status for each energy detection threshold.

As shown, the transceiver 710 may include the modem subsystem 712 and the RF unit 714. The transceiver 710 can be configured to communicate bi-directionally with other devices, such as the UEs 115 and/or BS 700 and/or another core network element. The modem subsystem 712 may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 714 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data (e.g., RRC table (s) for channel access configurations, scheduling grants, channel access configuration activation, RRC configurations, PDSCH data, PDCCH DCI, etc. ) from the modem subsystem 712 (on outbound transmissions) or of transmissions originating from another source such as a UE 115, 215, and/or UE 800. The RF unit 714 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 710, the modem subsystem 712 and/or the RF unit 714 may be separate devices that are coupled together at the BS 700 to enable the BS 700 to communicate with other devices.

The RF unit 714 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 716 for transmission to one or more other devices. The antennas 716 may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver 710. The transceiver 710 may provide the demodulated and decoded data (e.g., channel sensing reports, PUCCH UCI, PUSCH data, etc. ) to the multi-beam channel access module 708 for processing. The antennas 716 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an aspect, the BS 700 can include multiple transceivers 710 implementing different RATs (e.g., NR and LTE) . In an aspect, the BS 700 can include a single transceiver 710 implementing multiple RATs (e.g., NR and LTE) . In an aspect, the transceiver 710 can include various components, where different combinations of components can implement different RATs.

Further, in some aspects, the processor 702 is coupled to the memory 704 and the transceiver 710. The processor 702 is configured to communicate, with a second wireless communication device via the transceiver 710, a plurality of channel access configurations. The processor 702 is further configured to communicate, with the second wireless communication device via the transceiver 710, a scheduling grant for communicating a communication signal in an unlicensed band, where the scheduling grant includes an indication of a first channel access configuration of the plurality of channel access configurations. The processor 702 is further configured to communicate, with the second wireless communication device in the unlicensed band via the transceiver 710 based on the first channel access configuration, the communication signal.

FIG. 8 is a block diagram of an exemplary UE 800 according to some aspects of the present disclosure. The UE 800 may be a UE 115 as discussed in FIG. 1 or a UE 215 as discussed in FIGS. 2-6. As shown, the UE 800 may include a processor 802, a memory 804, a multi-beam channel access module 808, a transceiver 810 including a modem subsystem 812 and a radio frequency (RF) unit 814, and one or more antennas 816. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for example via one or more buses.

The processor 802 may include a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 802 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.

The memory 804 may include a cache memory (e.g., a cache memory of the processor 802) , random access memory (RAM) , magnetoresistive RAM (MRAM) , read-only memory (ROM) , programmable read-only memory (PROM) , erasable programmable read only memory (EPROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an aspect, the memory 804 includes a non-transitory computer-readable medium. The memory 804 may store, or have recorded thereon, instructions 806. The instructions 806 may include instructions that, when executed by the processor 802, cause the processor 802 to perform the operations described herein with reference to a UE 115 or an anchor in connection with aspects of the present disclosure, for example, aspects of FIGS. 1-6 and 9. Instructions 806 may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement (s) as discussed above with respect to FIG. 7.

The multi-beam channel access module 808 may be implemented via hardware, software, or combinations thereof. For example, the multi-beam channel access module 808 may be implemented as a processor, circuit, and/or instructions 806 stored in the memory 804 and executed by the processor 802. In some aspects, the multi-beam channel access module 808 can be integrated within the modem subsystem 812. For example, the multi-beam channel access module 808 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the modem subsystem 812. The multi-beam channel access module 808 may communicate with one or more components of UE 800 to implement various aspects of the present disclosure, for example, aspects of FIGS. 1-6 and 9.

In some aspects, the multi-beam channel access module 808 is configured to receive a plurality of channel access configurations from a BS (e.g., the BSs 105, 205 and/or 700) , for example, via RRC signaling. The plurality of channel access configurations may include various channel sensing parameters for performing channel sensing (e.g., beamformed channel sensing or directional LBT) . In some aspects, the plurality of channel access configurations may include an indication of a plurality of beam directions (e.g., the beam directions 302, 304, 602, 612) . In some aspects, the indication of the plurality of beam directions may be indicated by TCIs (indicative of DL beams of the BS) . In some aspects, the indication of the plurality of beam directions may be indicated by SRIs (indicative of UL beams of the UE 800) . In some aspects, the plurality of channel access configurations may include an indication of a plurality of beam groups (e.g., the

beam groups

In some aspects, the multi-beam channel access module 808 is further configured to receive, from the BS, a scheduling grant (e.g., the scheduling grant 510) for communicating a communication signal with the UE in an unlicensed band. The scheduling grant may be a PDCCH DCI including an indication of a first channel access configuration of the plurality of channel access configurations. The multi-beam channel access module 808 is further configured to communicate, the communication signal with the BS in the unlicensed band based on the first channel access configuration. In some instances, the scheduling grant is a UL scheduling grant, and as part of communicating the communication signal, the multi-beam channel access module 808 is configured to transmit a UL communication signal (e.g., PUCCH UCI and/or PUSCH data) to the BS. In other instances, the scheduling grant is a DL scheduling grant, and as part of communicating the communication signal, the multi-beam channel access module 808 is configured to receive a DL communication signal (e.g., PDSCH data) from the BS.

In some aspects, the multi-beam channel access module 708 is further configured to perform channel sensing (an independent LBT) for each beam group indicated by the first channel access configuration. For instance, for each beam group, indicated by the first channel access configuration, the multi-beam channel access module 808 is further configured to configure the antennas 816 for receive beamforming to form a reception beam for receiving a signal from the channel in a beam direction of the beam group and determine a receive signal energy for the receive signal. If a beam group includes more than one beam directions, the multi-beam channel access module 708 is further configured to configure the antennas 816 to form a wide reception beam for receiving a signal from the channel in all beam directions within the beam group and determine a receive signal energy for the receive signal. In some aspects, if a beam group of the first channel access configuration includes multiple energy detection thresholds, the multi-beam channel access module 808 is further configured to determine a channel status based on each energy detection threshold, for example, by comparing the receive signal energy against each energy detection threshold as discussed above with reference to FIG. 4. In some aspects, if a beam group of the first channel access configuration includes multiple random counters, the multi-beam channel access module 808 is further configured to select a random counter (a number range) from the one or more random counters (e.g., based on a priority of the scheduled UL communication) , draw a random number from the range indicated by the selected random counter of the one or more random counters and backoff for a duration corresponding to the drawn number before performing channel sensing in a beam direction of the beam group.

In some aspects, the first channel access configuration may include a channel sensing report configuration (e.g., the report type 528) , and the multi-beam channel access module 808 is further configured to transmit, to the BS, a channel sensing report based on the first channel access configuration. The channel sensing report may indicate a channel status (e.g. busy or free for transmission) for each beam group indicated by the first channel access configuration. In some instances, if the first channel access configuration indicates multiple energy detection thresholds, the channel sensing report may include, for each beam group, a channel status for each energy detection threshold.

As shown, the transceiver 810 may include the modem subsystem 812 and the RF unit 814. The transceiver 810 can be configured to communicate bi-directionally with other devices, such as the BSs 105 and 700. The modem subsystem 812 may be configured to modulate and/or encode the data from the memory 804 and/or the multi-beam channel access module 808 according to a modulation and coding scheme (MCS) , e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 814 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data (e.g., channel sensing reports, PUCCH UCI, PUSCH data, etc. ) or of transmissions originating from another source such as a UE 115, a BS 105, or an anchor. The RF unit 814 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 810, the modem subsystem 812 and the RF unit 814 may be separate devices that are coupled together at the UE 800 to enable the UE 800 to communicate with other devices.

The RF unit 814 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 816 for transmission to one or more other devices. The antennas 816 may further receive data messages transmitted from other devices. The antennas 816 may provide the received data messages for processing and/or demodulation at the transceiver 810. The transceiver 810 may provide the demodulated and decoded data (e.g., RRC table (s) for channel access configurations, scheduling grants, channel access configuration activation, RRC configurations, PDSCH data, PDCCH DCI, etc. ) to the multi-beam channel access module 808 for processing. The antennas 816 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an aspect, the UE 800 can include multiple transceivers 810 implementing different RATs (e.g., NR and LTE) . In an aspect, the UE 800 can include a single transceiver 810 implementing multiple RATs (e.g., NR and LTE) . In an aspect, the transceiver 810 can include various components, where different combinations of components can implement different RATs.

Further, in some aspects, the processor 802 is coupled to the memory 804 and the transceiver 810. The processor 802 is configured to communicate, with a second wireless communication device via the transceiver 810, a plurality of channel access configurations. The processor 802 is further configured to communicate, with the second wireless communication device via the transceiver 810, a scheduling grant for communicating a communication signal in an unlicensed band, where the scheduling grant includes an indication of a first channel access configuration of the plurality of channel access configurations. The processor 802 is further configured to communicate, with the second wireless communication device in the unlicensed band via the transceiver 810 based on the first channel access configuration, the communication signal.

FIG. 9 is a flow diagram illustrating a wireless communication method 900 according to some aspects of the present disclosure Aspects of the method 900 can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the blocks. In one aspect, a wireless communication device, such as a UE 115, 215, or 800, may utilize one or more components, such as the processor 802, the memory 804, the multi-beam channel access module 808, the transceiver 810, the modem 812, the RF unit 814, and the one or more antennas 816, to execute the blocks of method 900. In another aspect, a wireless communication device, such as a

BS

105, 205, or 700, may utilize one or more components, such as the processor 702, the memory 704, the multi-beam channel access module 708, the transceiver 710, the modem 712, the RF unit 714, and the one or more antennas 716, to execute the blocks of method 900. The method 900 may employ similar mechanisms as described in FIGS. 1-6. As illustrated, the method 900 includes a number of enumerated blocks, but aspects of the method 900 may include additional blocks before, after, and in between the enumerated blocks. In some aspects, one or more of the enumerated blocks may be omitted or performed in a different order.

At block 910, a first wireless communication device communicates, with a second wireless communication device, a plurality of channel access configurations (e.g., the channel access configuration 520) . In some aspects, the first wireless communication device may correspond to a BS similar to the BSs 105 and/or 205, and the second wireless communication device may correspond to a UE similar to the UEs 115 and/or 215. The communicating the plurality of channel access configurations may include the BS transmitting an RRC configuration including the plurality of channel access configurations to the UE. In other aspects, the first wireless communication device may correspond to a UE similar to the UEs 115 and/or 215, and the second wireless communication device may correspond to a BS similar to the BSs 105 and/or 205. The communicating the plurality of channel access configurations may include the UE receiving an RRC configuration including the plurality of channel access configurations from the BS. In some aspects, means for performing the functionality of block 910 can, but not necessarily, include, for example, multi-beam channel access module 708, transceiver 710, antennas 716, processor 702, and/or memory 704 with reference to FIG. 7, or multi-beam channel access module 808, transceiver 810, antennas 816, processor 802, and/or memory 804 with reference to FIG. 8.

The plurality of channel access configurations may include various channel sensing parameters for performing channel sensing (e.g., beamformed channel sensing or directional LBT) . In some aspects, as part of communicating the plurality of channel access configurations, the first wireless communication device may communicate, with the second wireless communication device, an indication of a plurality of beam directions (e.g., the beams 302, 304, 602, 612) , where each channel access configuration may indicate one or more of the plurality of beam directions.

In some aspects, as part of communicating the indication of the plurality of beam directions, the first wireless communication device may communicate, with the second wireless communication device, a plurality of transmission configuration indications (TCIs) . A TCI is used to establish a quasi-co-location (QCL) relationship (e.g., a spatial relation) between two reference signals transmitted by a BS. Each TCI may indirectly indicate a beam direction of a BS. For instance, as explained above, a BS 205 may transmit a certain signal (e.g., an SSB or a certain reference signal) in a certain beam direction and may associate a certain TCI with the signal transmitted in the certain beam direction. Accordingly, a TCI may be indicative of a certain beam direction (e.g., of a BS 205’s transmission beam) .

In some aspects, as part of communicating the indication of the plurality of beam directions, the first wireless communication device may communicate, with the second wireless communication device, a plurality of sounding reference signal resource indicators (SRIs) . An SRI may identify a certain SRS resource. For instance, as explained above, a BS 205 may configure SRS resources, where each SRS resource is configured for a UE 215 to transmit an SRS in a certain beam direction. Accordingly, an SRI may be indicative of a certain beam direction (e.g., of a UE 215’s transmission beam) .

In some aspects, as part of communicating the plurality of channel access configurations, the first wireless communication device may communicate, with the second wireless communication device, an indication of a plurality of beam groups (e.g., the

beam groups

322, 324, 326, and/or 610) . Each beam group of the plurality of beam groups may include a subset of the plurality of beam directions. Each channel access configuration of the plurality of channel access configurations may indicate at least one beam group of the plurality of beam groups. In some instances, a channel access configuration of the plurality of channel access configurations may include more than one beam groups. In some instances, a beam group of the plurality of beam groups may include more than one beam directions. In some instances, there can be overlap (s) between beams directions in the plurality of beam groups. For instance, a same beam direction can be included in two different beam groups of the plurality of beam groups. In some instances, different beam groups of the plurality of beam groups may include a different subset of the plurality of beam directions.

In some aspects, as part of communicating the plurality of channel access configurations, the first wireless communication device may communicate, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and one or more energy detection thresholds (e.g., the energy detection thresholds 524) associated with the first beam group. The energy detection thresholds may be used for channel sensing, for example, to determine whether a channel is occupied or free in a certain beam direction. In some instances, the first channel access configuration may include multiple energy detection thresholds per beam group. Each energy detection thresholds may correspond to a certain interference tolerance level.

In some aspects, as part of communicating the plurality of channel access configurations, the wireless communication device may communicate, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and one or more random counters (e.g., the random counters 526) associated with the first beam group. The random counters 526 may be used by the UE 215 during channel sensing to configure a counter for random backoff. In some instances, the first wireless communication device may indicate multiple random counters per beam group. Each random counter may be associated with a certain traffic type.

At block 920, the first wireless communication device communicates, with the second wireless communication device, a scheduling grant (e.g., the scheduling grant 510) for communicating a communication signal in an unlicensed band. The scheduling grant may be a UL scheduling grant or a DL scheduling grant. The scheduling grant includes an indication of a first channel access configuration of the plurality of channel access configurations. In some aspects, as part of communicating the scheduling grant, the first wireless communication device may communicate DCI including a message field (e.g., the message field 512) referencing the first channel access configuration. In some aspects, means for performing the functionality of block 920 can, but not necessarily, include, for example, multi-beam channel access module 708, transceiver 710, antennas 716, processor 702, and/or memory 704 with reference to FIG. 7, or multi-beam channel access module 808, transceiver 810, antennas 816, processor 802, and/or memory 804 with reference to FIG. 8.

At block 930, the first wireless communication device communicates, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal. In some aspects, the first wireless communication device may correspond to a BS, the second wireless communication device may correspond to a UE, and the communicating the communication signal may include the BS transmitting a DL communication signal (e.g., PDSCH data) to the UE. In some aspects, the first wireless communication device may correspond to a BS, the second wireless communication device may correspond to a UE, and the communicating the communication signal may include the BS receiving a UL communication signal (e.g., PUSCH data) from the UE. In some aspects, the first wireless communication device may correspond to a UE, the second wireless communication device may correspond to a BS, and the communicating the communication signal may include the UE receiving a DL communication signal (e.g., PDSCH data) from the BS. In some aspects, the first wireless communication device may correspond to a UE, the second wireless communication device may correspond to a BS, and the communicating the communication signal may include the UE transmitting a UL communication signal (e.g., PUSCH data) to the BS. In some aspects, means for performing the functionality of block 930 can, but not necessarily, include, for example, multi-beam channel access module 708, transceiver 710, antennas 716, processor 702, and/or memory 704 with reference to FIG. 7, or multi-beam channel access module 808, transceiver 810, antennas 816, processor 802, and/or memory 804 with reference to FIG. 8.

In some aspects, the first channel access configuration may indicate one or more beam groups of the plurality of beam groups, and the scheduling grant communicated at block 920 may activate channel sensing in each beam group of the one or more beam groups. For instance, the first wireless communication device may be a UE, and the first wireless communication device may further perform, based on the scheduling grant, first channel sensing (e.g., a first LBT) in a first beam group of the one or more beam groups. For instance, the first wireless communication device may utilize receive beamforming to receive a signal from the channel in a beam direction of the first beam group, calculate a receive signal measurement for the received signal, and compare the calculated received signal measurement to an energy detection threshold. In some instances, the energy detection threshold may be indicated by the first channel access configuration for the first beam group. Further, the first wireless communication device may perform, based on the scheduling grant, second channel sensing (e.g., a second LBT independent of the first LBT) in a second beam group of the one or more beam groups using similar mechanisms as the first channel sensing. In some aspects, as part of performing the first channel sensing, the first wireless communication device may perform, based on the first channel access configuration, the first channel sensing in a combined beam direction of a subset of two more beam directions of the plurality of beam directions associated with the first beam group. In other words, the first wireless communication device may utilize receive beamforming to generate a wide beam covering all beam directions in the subset when performing the first channel sensing.

In some aspects, as part of communicating the plurality of channel access configuration at block 910, the first wireless communication device may communicate, with the second wireless communication device, the first channel access configuration including a channel sensing report configuration. In some aspects, the first wireless communication device may further communicate, with the second wireless communication device based on the channel sensing report configuration, a channel sensing report, and the communicating the communication signal is further based on the channel sensing report. In some aspects, the first channel access configuration may indicate one or more beam groups, where each beam group includes one or more beam directions. Further, as part of communicating the channel sensing report, the first wireless communication device may communicate, with the second wireless communication device, an indication of a channel status for each beam group. The channel status may indicate whether the channel is clear for a transmission or occupied (busy) in a beam direction. In some aspects, the first channel access configuration indicates a first energy detection threshold and a second energy detection threshold for a first beam group of the one or more beam groups. Further, as part of communicating the indication of the channel status, the first wireless communication device may communicate, with the second wireless communication device, an indication of a first channel status for the first beam group based on the first energy detection threshold and an indication of a second channel status for the first beam group based on the second energy detection threshold. For instance, the first channel status may indicate whether the channel is clear in the beam direction of the first beam group based on whether a receive signal measurement in the beam direction satisfies the first energy detection threshold or not. Similarly, the second channel status may indicate whether the channel is clear in the beam direction of the first beam group based on whether the receive signal measurement in the beam direction satisfies the second energy detection threshold or not. In some aspects, the channel sensing report configuration may indicate one of an aperiodic report type, a semi-persistent report type, or a periodic report type. An aperiodic channel sensing report may be triggered by a request (e.g., PDCCH DCI) . A semi-persistent channel sensing report may be transmitted in report occasions configured by a configuration (e.g., an RRC configuration) . A periodic channel sensing report may be transmitted periodically in periodic report occasions configured by a configuration (e.g., an RRC configuration) .

Further aspects of the present disclosure include the following:

1. A method of wireless communication performed by a first wireless communication device, the method comprising:

communicating, with a second wireless communication device, a plurality of channel access configurations;

communicating, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and

communicating, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.

2. The method of aspect 1, wherein:

the communicating the plurality of channel access configurations comprises:

communicating a radio resource control (RRC) configuration including the plurality of channel access configurations; and

the communicating the scheduling grant comprises:

communicating downlink control information (DCI) including a message field referencing the first channel access configuration.

3. The method of any of aspects 1-2, wherein the communicating the plurality of channel access configurations comprises:

communicating, with the second wireless communication device, an indication of a plurality of beam directions, wherein each channel access configuration indicates one or more of the plurality of beam directions.

4. The method of any of aspects 1-3, wherein the communicating the indication of the plurality of beam directions comprises:

communicating, with the second wireless communication device, a plurality of transmission configuration indications (TCIs) .

5. The method of any of aspects 1-3, wherein the communicating the indication of the plurality of beam directions comprises:

communicating, with the second wireless communication device, a plurality of sounding reference signal resource indicators (SRIs) .

6. The method of any of aspects 1-5, wherein the communicating the plurality of channel access configurations further comprises:

communicating, with the second wireless communication device, an indication of a plurality of beam groups, each beam group of the plurality of beam groups including a subset of the plurality of beam directions, wherein each channel access configuration of the plurality of channel access configurations indicates at least one beam group of the plurality of beam groups.

7. The method of any of aspects 1-6, wherein:

the first channel access configuration indicating one or more beam groups of the plurality of beam groups; and

the communicating the scheduling grant comprises:

communicating, with the second wireless communication device, the scheduling grant activating channel sensing in each beam group of the one or more beam groups.

8. The method of any of aspects 1-7 further comprising:

performing, based on the scheduling grant, first channel sensing in a first beam group of the one or more beam groups; and

performing, based on the scheduling grant, second channel sensing in a second beam group of the one or more beam groups.

9. The method of any of aspects 1-8, wherein the performing the first channel sensing comprises:

performing, based on the first channel access configuration, the first channel sensing in a combined beam direction of a subset of two more beam directions of the plurality of beam directions associated with the first beam group.

10. The method of any of aspects 1-9, wherein the communicating the plurality of channel access configurations further comprises:

communicating, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and one or more energy detection thresholds associated with the first beam group.

11. The method of any of aspects 1-10, wherein the communicating the plurality of channel access configurations further comprises: communicating, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and one or more random counters associated with the first beam group.

12. The method of any of aspects 1-11, wherein the communicating the plurality of channel access configurations comprises:

communicating, with the second wireless communication device, the first channel access configuration including a channel sensing report configuration.

13. The method of any of aspects 1-12, further comprising:

communicating, with the second wireless communication device based on the channel sensing report configuration, a channel sensing report, wherein the communicating the communication signal is further based on the channel sensing report.

14. The method of any of aspects 1-13, wherein the first channel access configuration indicates one or more beam groups, wherein each beam group includes one or more beam directions, and wherein the communicating the channel sensing report comprises:

communicating, with the second wireless communication device, an indication of a channel status for each beam group.

15. The method of any of aspects 1-14, wherein the first channel access configuration indicates a first energy detection threshold and a second energy detection threshold for a first beam group of the one or more beam groups, and wherein the communicating the indication of the channel status comprises:

communicating, with the second wireless communication device, an indication of a first channel status for the first beam group based on the first energy detection threshold and an indication of a second channel status for the first beam group based on the second energy detection threshold.

16. The method of any of aspects 1-15, wherein the channel sensing report configuration indicates one of an aperiodic report type, a semi-persistent report type, or a periodic report type.

17. An apparatus comprising a processor coupled to a transceiver, wherein the processor and transceiver are configured to perform the method of any one of aspects 1-16.

18. An apparatus comprising means for performing the method of any one of aspects 1-16.

19. A non-transitory computer readable medium including program code, which when executed by one or more processors, causes a wireless communication device to perform the method of any one of aspects 1-16.

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 referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list 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) .

As those of some skill in this art will by now appreciate and depending on the particular application at hand, many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to that of the particular aspects illustrated and described herein, as they are merely by way of some examples thereof, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.

Claims

A method of wireless communication performed by a first wireless communication device, the method comprising:

communicating, with a second wireless communication device, a plurality of channel access configurations;

communicating, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and

communicating, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.
The method of claim 1, wherein:

the communicating the plurality of channel access configurations comprises:

communicating a radio resource control (RRC) configuration including the plurality of channel access configurations; and

the communicating the scheduling grant comprises:

communicating downlink control information (DCI) including a message field referencing the first channel access configuration.
The method of claim 1, wherein the communicating the plurality of channel access configurations comprises:

communicating, with the second wireless communication device, an indication of a plurality of beam directions, wherein each channel access configuration indicates one or more of the plurality of beam directions.
The method of claim 3, wherein the communicating the indication of the plurality of beam directions comprises:

communicating, with the second wireless communication device, a plurality of transmission configuration indications (TCIs) .
The method of claim 3, wherein the communicating the indication of the plurality of beam directions comprises:

communicating, with the second wireless communication device, a plurality of sounding reference signal resource indicators (SRIs) .
The method of claim 3, wherein the communicating the plurality of channel access configurations further comprises:

communicating, with the second wireless communication device, an indication of a plurality of beam groups, each beam group of the plurality of beam groups including a subset of the plurality of beam directions, wherein each channel access configuration of the plurality of channel access configurations indicates at least one beam group of the plurality of beam groups.
The method of claim 6, wherein:

the first channel access configuration indicating one or more beam groups of the plurality of beam groups; and

the communicating the scheduling grant comprises:

communicating, with the second wireless communication device, the scheduling grant activating channel sensing in each beam group of the one or more beam groups.
The method of claim 7, further comprising:

performing, based on the scheduling grant, first channel sensing in a first beam group of the one or more beam groups; and

performing, based on the scheduling grant, second channel sensing in a second beam group of the one or more beam groups.
The method of claim 8, wherein the performing the first channel sensing comprises:

performing, based on the first channel access configuration, the first channel sensing in a combined beam direction of a subset of two more beam directions of the plurality of beam directions associated with the first beam group.
The method of claim 6, wherein the communicating the plurality of channel access configurations further comprises:

communicating, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and one or more energy detection thresholds associated with the first beam group.
The method of claim 6, wherein the communicating the plurality of channel access configurations further comprises:

communicating, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and one or more random counters associated with the first beam group.
The method of claim 1, wherein the communicating the plurality of channel access configurations comprises:

communicating, with the second wireless communication device, the first channel access configuration including a channel sensing report configuration.
The method of claim 12, further comprising:

communicating, with the second wireless communication device based on the channel sensing report configuration, a channel sensing report,

wherein the communicating the communication signal is further based on the channel sensing report.
The method of claim 13, wherein the first channel access configuration indicates one or more beam groups, wherein each beam group includes one or more beam directions, and wherein the communicating the channel sensing report comprises:

communicating, with the second wireless communication device, an indication of a channel status for each beam group.
The method of claim 14, wherein the first channel access configuration indicates a first energy detection threshold and a second energy detection threshold for a first beam group of the one or more beam groups, and wherein the communicating the indication of the channel status comprises:

communicating, with the second wireless communication device, an indication of a first channel status for the first beam group based on the first energy detection threshold and an indication of a second channel status for the first beam group based on the second energy detection threshold.
The method of claim 13, wherein the channel sensing report configuration indicates one of an aperiodic report type, a semi-persistent report type, or a periodic report type.
A first wireless communication device comprising:

a memory;

a transceiver; and

at least one processor coupled to the memory and the transceiver, wherein the at least one processor is configured to:

communicate, with a second wireless communication device via the transceiver, a plurality of channel access configurations;

communicate, with the second wireless communication device via the transceiver, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and

communicate, with the second wireless communication device in the unlicensed band via the transceiver based on the first channel access configuration, the communication signal.
The first wireless communication device of claim 17, wherein:

the at least one processor configured to communicate the plurality of channel access configurations is configured to:

communicate a radio resource control (RRC) configuration including the plurality of channel access configurations; and

the at least one processor configured to communicate the scheduling grant is configured to:

communicate downlink control information (DCI) including a message field referencing the first channel access configuration.
The first wireless communication device of claim 17, wherein the at least one processor configured to communicate the plurality of channel access configurations is configured to:

communicate, with the second wireless communication device, an indication of a plurality of beam directions, wherein each channel access configuration indicates one or more of the plurality of beam directions.
The first wireless communication device of claim 19, wherein the at least one processor configured to communicate the plurality of channel access configurations is configured to:

communicate, with the second wireless communication device, an indication of a plurality of beam groups, each beam group of the plurality of beam groups including a subset of the plurality of beam directions, wherein each channel access configuration of the plurality of channel access configurations indicates at least one beam group of the plurality of beam groups.
The first wireless communication device of claim 20, wherein the at least one processor configured to communicate the plurality of channel access configurations is configured to:

communicate, with the second wireless communication device, the first channel access configuration indicating a first beam group of the plurality of beam groups and at least one or more energy detection thresholds or one or more random counters associated with the first beam group.
The first wireless communication device of claim 17, wherein the at least one processor configured to communicate the plurality of channel access configurations is configured to:

communicate, with the second wireless communication device, the first channel access configuration including a channel sensing report configuration.
The first wireless communication device of claim 22, wherein the at least one processor is further configured to:

communicate, with the second wireless communication device via the transceiver based on the channel sensing report configuration, a channel sensing report,

wherein the at least one processor configured to communicating the communication signal is configured to:

communicate, with the second wireless communication device, the communication signal further based on the channel sensing report.
The first wireless communication device of claim 23, wherein the first channel access configuration indicates one or more beam groups, wherein each beam group includes one or more beam directions, and wherein the at least one processor configured to communicate the channel sensing report is configured to:

communicate, with the second wireless communication device, an indication of a channel status for each beam group.
The first wireless communication device of claim 24, wherein the first channel access configuration indicates a first energy detection threshold and a second energy detection threshold for a first beam group of the one or more beam groups, and wherein the at least one processor configured to communicate the indication of the channel status is configured to:

communicate, with the second wireless communication device, an indication of a first channel status for the first beam group based on the first energy detection threshold and an indication of a second channel status for the first beam group based on the second energy detection threshold.
The first wireless communication device of claim 23, wherein the channel sensing report configuration indicates one of an aperiodic report type, a semi-persistent report type, or a periodic report type.
A first wireless communication device comprising:

means for communicating, with a second wireless communication device, a plurality of channel access configurations;

means for communicating, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and

means for communicating, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.
The first wireless communication device of claim 27, wherein the means for communicating the plurality of channel access configurations is configured to:

communicate, with the second wireless communication device, an indication of a plurality of beam directions, wherein each channel access configuration indicates one or more of the plurality of beam directions.
The first wireless communication device of claim 28, wherein the means for communicating the plurality of channel access configurations is further configured to:

communicate, with the second wireless communication device, an indication of a plurality of beam groups, each beam group of the plurality of beam groups including a subset of the plurality of beam directions, wherein each channel access configuration of the plurality of channel access configurations indicates at least one beam group of the plurality of beam groups.
A non-transitory computer-readable medium having program code recorded thereon for wireless communication by a first wireless communication device, the program code comprising:

code for causing the first wireless communication device to communicate, with a second wireless communication device, a plurality of channel access configurations;

code for causing the first wireless communication device to communicate, with the second wireless communication device, a scheduling grant for communicating a communication signal in an unlicensed band, the scheduling grant including an indication of a first channel access configuration of the plurality of channel access configurations; and

code for causing the first wireless communication device to communicate, with the second wireless communication device in the unlicensed band based on the first channel access configuration, the communication signal.