Method and apparatus for sharing channel occupancy time

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a first user equipment (UE) may determine one or more contention slot start times based at least in part on a pre-talk duration and an automatic gain control duration during a channel occupancy time shared with a second UE. The first UE may send a sidelink communication to the second UE at a start time selected from one or more of the one or more contention slot start times. Many other aspects are provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is the 371st national phase of Patent Cooperation Treaty (PCT) application No. PCT / CN2020 / 084849, entitled “TECHNIQUES FOR UE-TO-UE CHANNELOCCUPANCY TIME SHARING IN UNLICENSED SPECTRUM”, filed on April 15, 2020, which is expressly incorporated herein by reference. Technical Field

[0003] Aspects of the present disclosure relate generally to wireless communications, and more particularly to techniques and apparatuses for user equipment (UE) to UE channel occupancy time sharing in unlicensed spectrum. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE) systems. LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard released by the Third Generation Partnership Project (3GPP).

[0005] A wireless communication network may include several base stations (BS) that may support communications for several user equipments (UEs). User equipments (UEs) may communicate with base stations (BSs) via downlinks and uplinks. A downlink (or forward link) refers to a communication link from a BS to a UE, and an uplink (or reverse link) refers to a communication link from a UE to a BS. As will be described in detail herein, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0006] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user devices to communicate at municipal, national, regional and even global levels. New Radio (NR) (also referred to as 5G) is a set of enhancements to the LTE mobile standard released by the Third Generation Partnership Project (3GPP). NR is designed to better support mobile broadband Internet access by: improving spectrum efficiency; reducing costs; improving services; utilizing new spectrum; and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL), using CP-OFDM and / or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple input multiple output (MIMO) antenna technology and carrier aggregation to better integrate with other open standards. However, as the demand for mobile broadband access continues to increase, there is a need for further improvements in LTE technology and NR technology. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that adopt these technologies. Summary of the invention

[0007] In some aspects, a method of wireless communication performed by a first user equipment (UE) may include: determining one or more contention slot start times based at least in part on a listen-before-talk (LBT) duration and an automatic gain control (AGC) duration during a channel occupancy time shared with a second UE; and sending a sidelink communication to the second UE at a start time selected from one or more of the one or more contention slot start times.

[0008] In some aspects, a first UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to: determine one or more contention slot start times based at least in part on an LBT duration and an AGC duration during a channel occupancy time shared with a second UE; and send a sidelink communication to the second UE at a start time selected from one or more of the one or more contention slot start times.

[0009] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. When executed by one or more processors of a first UE, the one or more instructions may cause the one or more processors to perform the following operations: determine one or more contention slot start times based at least in part on the LBT duration and the AGC duration during a channel occupancy time shared with a second UE; and send a sidelink communication to the second UE at a start time selected from one or more of the one or more contention slot start times.

[0010] In some aspects, an apparatus for wireless communication may include: a unit for determining one or more contention slot start times within a channel occupancy time shared with a UE based at least in part on an LBT duration and an AGC duration; and a unit for sending a sidelink communication to the UE at a start time selected from one or more of the one or more contention slot start times.

[0011] In some aspects, the one or more contention slot start times occur in one or more of a last symbol in a current slot or a first symbol in a next slot.

[0012] In some aspects, the LBT duration begins at the beginning of a last symbol in a current slot and the AGC duration includes at least a portion of a first symbol in a next slot.

[0013] In some aspects, the one or more contention slot start times occur in a window between an end time of the LBT duration and a start time of the AGC duration.

[0014] In some aspects, the portion of the first symbol in the next time slot that corresponds to the AGC duration is based at least in part on a subcarrier spacing.

[0015] In some aspects, the number of the one or more contention slot start times is based at least in part on a contention slot duration.

[0016] In some aspects, the number of the one or more contention slot start times is based at least in part on a subcarrier spacing.

[0017] In some aspects, the LBT duration has a length that depends on the location in which the first symbol of the sidelink communication is transmitted.

[0018] In some aspects, the one or more contention slot start times are identified relative to an end time of the LBT duration.

[0019] In some aspects, the one or more contention slot start times are identified relative to a start time of the AGC duration.

[0020] In some aspects, the start time for sending the sidelink communication is randomly selected from one or more of the one or more contention slot start times.

[0021] As substantially described herein with reference to and as illustrated by the accompanying figures and description, aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and / or processing systems.

[0022] The features and technical advantages of the examples according to the present disclosure have been outlined quite extensively above so that the subsequent detailed description may be better understood. Other features and advantages will be described below. The disclosed concepts and specific examples may be easily used as a basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent structures do not depart from the scope of the appended claims. The features of the concepts disclosed herein (their organization and method of operation) and the associated advantages will be better understood from the following description when considered in conjunction with the accompanying drawings. Each of the accompanying drawings is provided for the purpose of illustration and description and not as a definition of the limitations of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to be able to understand the above-mentioned features of the present disclosure in detail, a more specific description briefly summarized above can be obtained by reference to various aspects, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope thereof, because the description may allow for other equivalent aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0024] Figure 1 is a diagram illustrating an example of a wireless communication network in accordance with various aspects of the present disclosure.

[0025] Figure 2 is a diagram illustrating an example of a base station communicating with a UE in a wireless communication network according to various aspects of the present disclosure.

[0026] Figure 3 is a diagram illustrating an example of sidelink communications according to various aspects of the present disclosure.

[0027] Figure 4A is a diagram illustrating examples of sidelink communications and access link communications according to various aspects of the present disclosure.

[0028] Figure 4B is a diagram illustrating an example of channel occupancy time sharing between sidelink UEs according to various aspects of the present disclosure.

[0029] Figure 5A-5G is a diagram illustrating one or more examples of UE-to-UE channel occupancy time sharing in an unlicensed spectrum in accordance with various aspects of the present disclosure.

[0030] Figure 6 is a diagram illustrating an example process performed, for example, by a UE according to various aspects of the present disclosure.

[0031] Figure 7 is a conceptual data flow diagram illustrating the flow of data between different components in an example apparatus according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0032] Various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be implemented in many different forms and should not be interpreted as being limited to any specific structure or function given throughout the present disclosure. Instead, these aspects are provided so that the present disclosure is thorough and complete, and the scope of the present disclosure is fully conveyed to those skilled in the art. Based on the teachings of this article, a person skilled in the art should understand that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently or implemented in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions other than the various aspects of the present disclosure set forth herein or not set forth herein. It should be understood that any aspect of the present disclosure disclosed herein can be embodied by one or more elements of the claims.

[0033] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0034] It should be noted that although various aspects may be described herein using terminology generally associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applied to communication systems based on other generations, such as 5G and higher, including NR technology.

[0035] Figure 1 1 is a diagram showing a wireless network 100 in which various aspects of the present disclosure may be implemented. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. The wireless network 100 may include several base stations 110 (shown as BS110a, BS110b, BS110c, and BS110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS and / or a BS subsystem serving the coverage area, depending on the context in which the term is used.

[0036] A BS may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access to UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access to UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown in , BS110a can be a macro BS of macro cell 102a, BS110b can be a pico BS of pico cell 102b, and BS110c can be a femto BS of femto cell 102c. The BS can support one or more (e.g., three) cells. The terms "eNB", "base station", "NR BS", "gNB", "TRP", "AP", "Node B", "5G NB" and "cell" may be used interchangeably herein.

[0037] In some aspects, the cells may not necessarily be stationary, and the geographic area of ​​the cells may move according to the location of the mobile BS. In some aspects, the BSs may be interconnected to each other and / or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as direct physical connections, virtual networks, etc. using any suitable transport network.

[0038] The wireless network 100 may also include a relay station. A relay station is an entity that receives transmissions of data from an upstream station (e.g., a BS or a UE) and sends transmissions of data to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that relays transmissions for other UEs. Figure 1 In the example shown in , a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, or the like.

[0039] The wireless network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0040] A network controller 130 may be coupled to a set of BSs and provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other, for example, directly or indirectly via a wireless or wired backhaul.

[0041] UE 120 (e.g., 120a, 120b, 120c) can be dispersed throughout the wireless network 100, and each UE can be fixed or mobile. UE can also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. UE can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or medical apparatus, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music device or video device, or a satellite radio unit), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing device, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0042] Some UEs may be considered as machine type communication (MTC) UEs, or evolved or enhanced machine type communication (eMTC) UEs. MTC UEs and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide connectivity for or to a network (e.g., a wide area network such as the Internet or a cellular network), for example, via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered as user premises equipment (CPE). UE 120 may be included in a housing that houses components of UE 120, such as a processor component, a memory component, and the like.

[0043] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific RAT and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, frequency channel, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0044] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly (e.g., without using base station 110 as an intermediary for communicating with each other) using one or more sidelink channels. For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocol (e.g., which may include vehicle-to-vehicle (V2V) protocol, vehicle-to-infrastructure (V2I) protocol, vehicle-to-pedestrian (V2P) protocol, vehicle-to-network (V2N) protocol, etc.), mesh network, etc. In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations as performed by base station 110 described elsewhere herein.

[0045] As mentioned above, Figure 1 This is provided as an example only. Other examples may be related to Figure 1 The examples described are different.

[0046] Figure 2 A block diagram shows a design 200 of a base station 110 and a UE 120, which may be Figure 1 Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≥1 and R≥1.

[0047] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for the UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.) and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)) and reference signals (e.g., cell-specific reference signals (CRS)). If applicable, the transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, and can provide T output symbol streams to T modulators (MOD) 232a to 232t. Each modulator 232 can process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be sent via T antennas 234a to 234t, respectively. According to various aspects described in detail below, synchronization signals can be generated with position coding to transmit additional information.

[0048] At UE 120, antennas 252a to 252r may receive downlink signals from base station 110 and / or other base stations, and may provide received signals to demodulators (DEMODs) 254a to 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) received signals to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols when applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0049] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 if applicable, and further processed by the receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide decoded data to a data sink 239 and decoded control information to a controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0050] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2Any other components of the base station 110 may perform one or more techniques associated with UE-to-UE channel occupancy time sharing in an unlicensed spectrum, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component may perform or direct e.g. Figure 6 The operations of the process 600 and / or other processes as described herein. The memories 242 and 282 may store data and program codes for the base station 110 and the UE 120, respectively. In some aspects, the memory 242 and / or the memory 282 may include a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, when executed by one or more processors of the base station 110 and / or the UE 120, the one or more instructions may perform or direct, for example, Figure 6 The scheduler 246 may schedule UEs for data transmission on the downlink and / or uplink.

[0051] In some aspects, the UE 120 may include: means for determining one or more contention slot start times based at least in part on a listen before talk (LBT) duration and an automatic gain control (AGC) duration during a channel occupancy time shared with another UE 120, means for sending a sidelink communication to the other UE 120 at one or more selected start times of the one or more contention slot start times, and so on. In some aspects, such means may include combining Figure 2 One or more components of UE 120 are depicted, such as controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and the like.

[0052] As mentioned above, providing Figure 2 As an example. Other examples may differ from Figure 2 An example of description.

[0053] Figure 3 is a diagram illustrating an example 300 of sidelink communications in accordance with various aspects of the present disclosure.

[0054] As in Figure 3As shown, the first UE 305-1 can communicate with the second UE 305-2 (and one or more other UEs 305) via one or more sidelink channels 310. The UEs 305-1 and 305-2 can communicate using one or more sidelink channels 310 for P2P communication, D2D communication, V2X communication (e.g., which can include V2V communication, V2I communication, V2P communication, V2N communication, etc.), mesh networking, etc. In some aspects, the UEs 305 (e.g., UE 305-1 and / or UE 305-2) can correspond to one or more other UEs described elsewhere herein, such as UE 120. In some aspects, the one or more sidelink channels 310 can use a PC5 interface and / or can operate in a high frequency band (e.g., a 5.9 GHz band). For example, in a first mode (sometimes referred to as mode 1, etc.), a base station (e.g., base station 110) may allocate resources for one or more sidelink channels 310, may provide dynamic grants or activate configured sidelink grants for sidelink communications, may receive sidelink feedback reported by a transmitting UE, etc. Additionally or alternatively, in a second mode (sometimes referred to as mode 2, etc.), UEs 305-1 and 305-2 may autonomously select sidelink resources for one or more sidelink channels 310, and sidelink communications may be scheduled using sidelink control information (SCI). Additionally or alternatively, in some cases, UE 305 may use global navigation satellite system (GNSS) timing to synchronize the timing of transmission time intervals (TTIs) (e.g., frames, subframes, time slots, symbols, etc.).

[0055] As in Figure 3As further shown, the one or more sidelink channels 310 may include a physical sidelink control channel (PSCCH) 315, a physical sidelink shared channel (PSSCH) 320, a physical sidelink feedback channel (PSFCH) 325, and the like. The PSCCH 315 may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and / or a physical uplink control channel (PUCCH) used for cellular communication with the base station 110 via an access link or access channel. The PSSCH 320 may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and / or a physical uplink shared channel (PUSCH) used for cellular communication with the base station 110 via an access link or access channel. For example, the PSCCH 315 may carry an SCI 330, which may indicate various control information for sidelink communication, such as one or more resources (e.g., time resources, frequency resources, space resources, etc.), wherein a transport block (TB) 335 may be carried on the PSSCH 320. The TB 335 may include data. The PSFCH 325 may be used to communicate sidelink feedback 340, such as hybrid automatic repeat request (HARQ) feedback (eg, acknowledgement or negative acknowledgement (ACK / NACK) information), transmit power control (TPC), scheduling request (SR), and the like.

[0056] In some aspects, one or more sidelink channels 310 may use a resource pool. For example, a scheduling assignment (e.g., included in SCI 330) may be transmitted in a subchannel using specific resource blocks (RBs) across time. In some aspects, a data transmission associated with a scheduling assignment (e.g., on PSSCH 320) may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing). In some aspects, the scheduling assignment and the associated data transmission are not transmitted on adjacent RBs.

[0057] In some aspects, the UE 305 may operate using a transmission mode in which resource selection and / or scheduling is performed by the UE 305 (e.g., rather than the base station 110). In some aspects, the UE 305 may perform resource selection and / or scheduling by sensing channel availability for transmission. For example, the UE 305 may measure a received signal strength indicator (RSSI) parameter associated with each sidelink channel (e.g., a sidelink RSSI (S-RSSI) parameter), may measure a reference signal received power (RSRP) parameter associated with each sidelink channel (e.g., a PSSCH-RSRP parameter), may measure a reference signal received quality (RSRQ) parameter associated with each sidelink channel (e.g., a PSSCH-RSRQ parameter), etc., and may select a channel for transmission of sidelink communications based at least in part on the measurement.

[0058] Additionally or alternatively, the UE 305 may perform resource selection and / or scheduling using the SCI 330 received in the PSCCH 315, which may indicate occupied resources, channel parameters, etc. Additionally or alternatively, the UE 305 may perform resource selection and / or scheduling by determining a channel busy rate (CBR) associated with each sidelink channel, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that the UE 305 may use for a particular set of subframes).

[0059] In a transmission mode in which resource selection and / or scheduling is performed by the UE 305, the UE 305 may generate a sidelink grant and may send the grant in the SCI 330. The sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks to be used for an upcoming sidelink transmission on the PSSCH 320 (e.g., for TB 335), one or more subframes to be used for an upcoming sidelink transmission, a modulation and coding scheme (MCS) to be used for an upcoming sidelink transmission, and the like. In some aspects, the UE 305 may generate a sidelink grant indicating one or more parameters for semi-persistent scheduling (SPS), such as the periodicity of the sidelink transmission. Additionally or alternatively, the UE 305 may generate a sidelink grant for event-driven scheduling, such as for an on-demand sidelink message.

[0060] As mentioned above, providing Figure 3 As an example. Other examples may differ from Figure 3 Examples described.

[0061] Figure 4Ais a diagram illustrating an example 400 of sidelink and access link communications in accordance with various aspects of the present disclosure.

[0062] As in Figure 4A As shown above, Figure 3 As described, the transmitter (Tx) UE 405 and the receiver (Rx) UE 410 can communicate with each other via a side link. As further shown, in some side link modes, the base station 110 can communicate with the Tx UE 405 via a first access link. Additionally or alternatively, in some side link modes, the base station 110 can communicate with the Rx UE 410 via a second access link. The Tx UE 405 and / or the Rx UE 410 can correspond to one or more UEs described elsewhere herein, such as, Figure 1 UE 120. Thus, as described herein, a sidelink may refer to a direct link between UE 120, and an access link may refer to a direct link between base station 110 and UE 120. Sidelink communications may be sent via a sidelink, and access link communications may be sent via an access link. Access link communications may be downlink communications (from base station 110 to UE 120) or uplink communications (from UE 120 to base station 110). Furthermore, in some aspects, sidelink communications may be sent via a sidelink, and / or access link communications may be sent via an access link, in a licensed radio frequency (RF) spectrum, an unlicensed RF spectrum, and / or any suitable combination thereof.

[0063] For example, in order to adapt to the growing business needs, various efforts have been made to improve the spectrum efficiency in wireless networks and thereby increase network capacity (e.g., via the use of high-order modulation, advanced MIMO antenna technology, multi-cell coordination technology, etc.). Another possible way to improve network capacity is to expand system bandwidth. However, the available spectrum in the low frequency bands that are traditionally licensed or otherwise allocated to mobile network operators has become very scarce. Accordingly, various technologies have been developed to enable cellular radio access technologies (RATs) to operate in unlicensed or other shared spectrum. For example, licensed assisted access (LAA) uses carrier aggregation on the downlink to combine LTE in licensed bands and LTE in unlicensed bands (e.g., 2.4 GHz and / or 5 GHz bands that have been filled by wireless local area networks (WLANs) or "Wi-Fi" devices). In other examples, enhanced LAA (eLAA) and further enhanced LAA (feLAA) technologies enable uplink and downlink LTE operation in unlicensed spectrum, MulteFire is an LTE-based technology that operates in both unlicensed and shared spectrum in standalone mode, NR-U enables NR operation in unlicensed spectrum, etc. In general, when operating a cellular RAT (e.g., using LAA, eLAA, feLAA, MulteFire, NR-U, etc.) in unlicensed spectrum, one challenge that arises is the need to ensure fair coexistence with incumbent (e.g., WLAN) systems that may be operating in the unlicensed spectrum.

[0064] For example, before obtaining access to an unlicensed channel and / or transmitting through an unlicensed channel, a transmitting device (e.g., base station 110, UE 405, UE 410, etc.) may need to perform a listen-before-talk (LBT) process to contend for access to the unlicensed channel. The LBT process may generally include a clear channel assessment (CCA) process, which is performed to determine whether the unlicensed channel is available (e.g., not occupied by other transmitters). Specifically, the CCA process may include detecting an energy level on an unlicensed channel and determining whether the energy level meets (e.g., is less than or equal to) a threshold, which is sometimes referred to as an energy detection threshold, etc. When the energy level meets (e.g., is not equal to or exceeds) the threshold, the CCA process is considered successful, and the transmitting device may obtain access to the unlicensed channel for a duration referred to as a channel occupancy time (COT), during which the transmitting device may perform transmission without performing additional LBT operations. When the energy level does not meet the threshold, the CCA process is unsuccessful, and the contention for access to the unlicensed channel may be considered unsuccessful.

[0065] When the CCA process results in a determination that the unlicensed channel band is unavailable (e.g., because the energy level detected on the unlicensed channel indicates that another device is already using the channel), the CCA process may be performed again at a later time. In environments where the transmitting device may lack access to the unlicensed channel (e.g., due to WLAN activity or transmissions from other devices), an extended CCA (eCCA) process may be employed to increase the likelihood that the transmitting device will successfully gain access to the unlicensed channel. For example, a transmitting device performing an eCCA process may perform a random number of CCA processes (from 1 to q) based on an eCCA counter. If and / or when the transmitting device senses that the channel has become idle, the transmitting device may begin a random wait period based on the eCCA counter, and if the channel remains idle within the random wait period, the transmitting device may begin transmitting.

[0066] Accordingly, although wireless networks may be configured to use unlicensed spectrum to achieve faster data rates, provide a more responsive user experience, offload traffic from licensed spectrum, etc., the need to ensure fair coexistence with incumbent systems (e.g., WLAN devices) may hinder efficient use of unlicensed spectrum. For example, even in the absence of interference, the LBT process used to ensure that no other device is already using the channel introduces delays before transmission can begin, which may reduce the user experience, result in unacceptable performance for latency-sensitive or delay-sensitive applications, etc. In addition, these problems may be exacerbated when the initial CCA process is unsuccessful because the transmitting device may only transmit on the channel after performing an additional number of CCA processes and determining that the channel has become idle and remains idle during a random waiting period. In addition, in some cases, the channel occupancy time obtained by the transmitting device may have a duration that is longer than the duration necessary for the transmitting device to perform the desired transmission, which may result in inefficient use of the unlicensed channel.

[0067] Accordingly, in some cases, the wireless network may enable the channel occupancy time obtained by the transmitting device to be shared with other nodes in order to improve access, efficiency, etc. to unlicensed channels. For example, when sharing the downlink-to-uplink channel occupancy time through the access link, the base station 110 may use eCCA to obtain the channel occupancy time, and the channel occupancy time may be shared with one or more UEs (e.g., UE 405, UE 410, etc.), which may then transmit uplink signals within the channel occupancy time obtained by the base station 110. In this case, a UE attempting to initiate an uplink transmission within the channel occupancy time shared with the base station 110 may perform the uplink transmission without having to perform an LBT process, or the UE may perform the uplink transmission after performing a single-slot CCA using a shorter LBT process (e.g., a category 2 LBT process when the downlink-to-uplink gap duration is between 16 and 25 μs, a category 1 LBT process when the downlink-to-uplink gap duration is less than or equal to 16 μs, etc.). Additionally or alternatively, the wireless network may support uplink to downlink channel occupancy time sharing over the access link. In this case, the time of UE-initiated channel occupancy (e.g., for a configured grant PUSCH or scheduled uplink transmission) may be shared with base station 110. Thus, base station 110 may be allowed to transmit control and / or broadcast signals and / or channels for any UE served by base station 110, provided that the transmission includes downlink signals, channels, and / or other transmissions (e.g., PDSCH, PDCCH, reference signals, etc.) that are intended to be received by the UE that initiated the channel occupancy.

[0068] Additionally or alternatively, the wireless network may support UE-to-UE channel occupancy time sharing via a sidelink. Figure 4B As shown by reference numeral 415, the channel occupancy time acquired by the initiating UE can be shared in a frequency division multiplexing (FDM) mode by dividing the channel occupancy time into a plurality of interlaces (e.g., time periods during which one or more UEs can perform transmission operations). Figure 4B , the initiating UE may use one or more sidelink resources (e.g., time and frequency resources) to transmit in a first interlace after obtaining the channel occupancy time, and the responding UE (e.g., UE 410, etc.) may use sidelink frequency resources that do not overlap with the sidelink frequency resources used by the initiating UE to perform transmission operations in subsequent interlaces. Accordingly, as in Figure 4BIt is shown that FDM or interlace-based channel occupancy time sharing can introduce short transmission gaps between each interlace to allow other UEs to perform transmission operations in subsequent interlaces during the shared channel occupancy time, and the sidelink control information sent by the initiating UE can carry information for supporting interlace-based channel occupancy time sharing.

[0069] Additionally or alternatively, UE-to-UE channel occupancy time sharing may be enabled in a time division multiplexing (TDM) mode, as indicated by reference numeral 420. In this case, the total channel occupancy time may be divided into an initial time period during which the initiating UE may perform a transmission that may include one or more sidelink control information transmissions indicating when the initial transmission will end, the remaining duration of the channel occupancy time available for sharing, and the like. Accordingly, one or more responding UEs may monitor the sidelink control information sent by other UEs (e.g., the initiating UE) to recover the channel occupancy time sharing information that may be used to perform transmissions during a time period corresponding to the shared channel occupancy time.

[0070] Accordingly, as described above, UE-to-UE channel occupation time sharing can enable better access to unlicensed spectrum, more efficient use of unlicensed spectrum, etc. by enabling multiple UEs to perform transmissions during the channel occupation time obtained by an initiating UE (e.g., a UE that successfully performed an LBT process to obtain access to an unlicensed channel). However, in some cases, it may be challenging to implement UE-to-UE channel occupation time sharing because sidelink communications typically have an unchanging time slot structure that provides limited opportunities (e.g., contention slots) in which another UE can perform an LBT process before transmitting. Some aspects described herein relate to techniques and apparatus that enable the following operations: UE-to-UE channel occupation time sharing in an unlicensed spectrum by defining one or more contention slot start times based at least in part on the LBT duration and the automatic gain control (AGC) duration in the channel occupation time shared by the initiating UE. In this way, a responding UE attempting to initiate a sidelink transmission during the channel occupation time shared by the initiating UE can select an appropriate contention slot that leaves enough time between the contention slots to perform the LBT operation during the LBT duration to ensure that the unlicensed channel is available before transmitting. In addition, since sidelink signal characteristics can vary depending on the UEs participating in sidelink communications in a given area at a given time, the AGC duration can ensure that: responding UEs performing transmissions during the shared channel occupancy time and initiating UEs that may be receiving the transmissions can perform AGC training to tune or otherwise configure the RF front end and / or other receiving components to match the received signal power, to prevent the receiving components from becoming saturated, to maintain a stable signal level at the output stage regardless of changes in the signal level at the input stage, and so on.

[0071] As mentioned above, Figure 4A-4B is provided as one or more examples. Other examples may be related to Figure 4A-4B The examples described are different.

[0072] Figure 5A-5G is a diagram illustrating one or more examples 500 of UE-to-UE channel occupancy time sharing in an unlicensed spectrum in accordance with various aspects of the present disclosure. Figure 5A As shown, example 500 includes: an initiating UE 120i that has acquired a channel occupancy time during which the UE 120i is allowed to transmit on an unlicensed channel; and a responding UE 120r that communicates with the UE 120i on a sidelink via the unlicensed channel. Figure 5B-5GAs shown, UE 120r may determine one or more contention slot start times during which UE 120r may send sidelink communications in order to share the channel occupancy time acquired by UE 120i.

[0073] As in Figure 5A , and by reference numeral 510, UE 120i may successfully perform an LBT process to obtain a channel occupancy time during which UE 120i is allowed to transmit on an unlicensed channel. For example, before obtaining access to an unlicensed channel and transmitting on the unlicensed channel, UE 120i may perform an LBT process to contend for access to the unlicensed channel. In some aspects, the LBT process may include a clear channel assessment (CCA) process performed by UE 120i to determine whether the unlicensed channel is available (e.g., not occupied by other transmitters). Specifically, UE 120i may detect an energy level on the unlicensed channel, and if the energy level on the unlicensed channel satisfies (e.g., is less than or equal to) a threshold, the CCA process may be deemed successful. In this case, UE 120i may obtain access to an unlicensed channel to obtain a channel occupancy time during which UE 120i may perform transmissions without performing additional LBT operations. Additionally or alternatively, in the event that the energy level detected on the unlicensed channel fails to meet (e.g., is greater than or equal to) the threshold, the UE 120i may perform the CCA procedure again and obtain the channel occupation time at a later time. Additionally or alternatively, the UE 120i may obtain the channel occupation time by performing an extended CCA (eCCA) procedure, etc.

[0074] As in Figure 5A As further shown, and indicated by reference numeral 512, UE 120i may send, and UE 120r may receive, sidelink control information to enable sharing of channel occupancy time acquired by UE 120i. For example, in some aspects, the sidelink control information may carry information to enable interlace-based sharing of channel occupancy time in FDM mode, information indicating when transmission of UE 120i will end, and / or remaining length of channel occupancy time available for sharing in TDM mode, and the like.

[0075] As in Figure 5AAs further shown, and by reference numeral 514, UE 120r may determine one or more candidate contention slot start times, wherein UE 120r may attempt to perform an LBT procedure based at least in part on a sidelink slot structure for sidelink communications between UEs 120i, 120r. For example, as shown by reference numeral 516-1, a sidelink slot structure without a physical sidelink feedback channel (PSFCH) may include a total of fourteen (14) symbols, of which thirteen (13) symbols are indexed from zero (0) to twelve (12) and may be used for physical sidelink control channel (PSCCH) and / or physical sidelink shared channel (PSSCH) transmissions, and the last symbol in the slot (index thirteen (13)) is reserved as a gap during which no transmission is performed. Additionally, as shown in Figure 5A As shown, the first symbol can be used for AGC training, whereby the second symbol (symbol 1) is a repetition of the first symbol (symbol 0) to increase reliability for PSCCH and / or PSSCH transmission (e.g., because the receiving UE may not be able to correctly receive and / or decode the first symbol before performing AGC training). Alternatively, as shown in reference numeral 516-2, the sidelink time slot structure with PSFCH may include a total of fourteen (14) symbols, of which ten (10) symbols are indexed from zero (0) to nine (9) and can be used for PSCCH and / or PSSCH transmission, two symbols indexed eleven (11) and twelve (12) are used for repetition of PSFCH symbols, and two symbols indexed ten (10) and thirteen (13) are reserved as gaps during which no transmission is performed.

[0076] Thus, in some aspects, UE 120r can determine one or more candidate contention slot start times, which can represent possible times when UE 120r can begin transmissions in the channel occupancy time shared by UE 120i, within a joint period that includes the last symbol (symbol 13) in a current slot (e.g., the slot before the transmission) and the first symbol (symbol 0) in a next slot (e.g., the slot in which UE 120r will perform the transmission). For example, regardless of whether the sidelink slot structure includes PSFCH symbols, the last symbol in the slot is a gap symbol and the first symbol in the slot is a repetition of the second symbol. Accordingly, the last symbol in the current slot and the first symbol in the next slot can provide a joint mechanism of two symbols during which one or more candidate contention slot start times can be determined. In some aspects, the two-symbol period can include an initial period T minGap, which corresponds to an LBT duration during which the UE 120r may perform an LBT procedure before transmitting. For example, in some aspects, the LBT duration may be a 16 μs period or a 25 μs period, depending on the position of the first symbol in which the UE 120r is to transmit. For example, the LBT duration may be 25 μs in the case where the UE 120i sharing the channel occupancy time has not yet performed a transmission to allow for the full 25 μs LBT duration, or the LBT duration may be 16 μs in the case where the UE 120r is attempting to transmit in the first time slot after the UE 120i completes the transmission.

[0077] Moreover, in some aspects, the two symbol periods may include an AGC period T AGC , which may be reserved for AGC training between UE 120r and another UE (e.g., UE 120i) that is expected to be the recipient of the sidelink transmission from UE 120r. For example, as described above, AGC training is typically used to enable the receiving UE to tune or otherwise configure the RF front end and / or other receiving components to match the received signal power, to prevent the receiving components from becoming saturated, to maintain a stable signal level at the output stage regardless of changes in the signal level at the input stage, etc. Therefore, the AGC period T AGC It may correspond to a half symbol (e.g., the second half of symbol 0). Alternatively, in the case of 15kHz subcarrier spacing (which generally has a longer symbol duration than 30kHz or 60kHz subcarrier spacing), the AGC period T AGC Full symbols (eg, all of symbol 0) may be included to achieve better AGC performance.

[0078] Accordingly, in some aspects, the candidate contention slot start time may be as follows: minGap The start time of AGC duration T AGC The duration T between is determined by:

[0079] T=2*T symbol –T minGap -T AGC

[0080] Among them, T symbol is the duration of a symbol, which can vary depending on the subcarrier spacing. For example, for 15kHz subcarrier spacing, T symbol It can be about 66.7μs. For 30kHz subcarrier spacing, T symbol It can be about 33.4μs. For 60kHz subcarrier spacing, T symbolIt may be about 16.7 μs, and / or the like. Accordingly, given a duration of about 9 μs for a contention slot in which an LBT process is attempted, the number K of possible candidate contention slot start times may be determined as follows:

[0081]

[0082] Accordingly, since the duration T depends on the duration of one symbol, the number K of possible candidate contention slot start times may similarly depend on the duration of one symbol, as described below with reference to Figure 5B-5G Further described. In addition, in some aspects, the candidate contention time slot start time can be relative to the end point T of the LBT duration. minGap Or relative to the start time T of the AGC duration AGC For example, in some aspects, the end time of the LBT duration can be represented as t 0 , and the K candidate contention slot start times can be determined as t for k=0, ..., K-1 0 +9×k. Or, relative to the AGC duration T AGC In the case where the start time of the candidate contention slot is defined as the start time of the candidate contention slot, the start time of the AGC duration can be expressed as t 0 , and the K candidate contention slot start times can be determined as t for k=0, ..., K-1 0 -9 x k. In either case, as indicated by reference numeral 418, UE 120r may randomly select one of the candidate contention slot start times and send a sidelink communication to UE 120i during the channel occupancy time shared by UE 120i.

[0083] For example, as in Figure 5B As shown and referenced by numeral 520, the UE 120r may randomly select a set of candidate contention slot start times for a 15 kHz subcarrier spacing, where t is defined relative to the end time of the LBT duration. 0 In this case, at 15 kHz subcarrier spacing with 66.7 μs symbol duration, the total span of two symbol periods including the gap symbol (symbol 13) and the repeated symbol for AGC training (symbol 0) is 133.4 μs. Accordingly, assuming the LBT duration T minGap The second half of symbol 0 is reserved for AGC training, and the duration T in which the contention slot start time can occur includes 1.5 symbols - T minGap , which is about 75 μs. Given a duration of about 9 μs for each contention slot, the LBT duration T minGapThe end of AGC duration T AGC The time period T between the start of 0 +9×k(e.g., t 0 ,t 0 +9μs,…,t 0 +81μs) for up to 10 candidate contention slot start times. Or, as in Figure 5C As shown and referenced by numeral 522, UE 120r may randomly select a set of candidate contention slot start times for 15 kHz subcarrier spacing, where t is defined relative to the start time of the AGC duration. 0 , so that the candidate contention slot start time is at time t for k=0, ..., K-1 0 -9×k (for example, t 0 ,t 0 -9μs,…,t 0 -81μs). In addition, in the case where UE 120r selects a candidate contention slot start time before the slot boundary between slot n and slot n+1, the signal sent before the slot boundary can be considered as a cyclic prefix extension of symbol 0 in slot n+1. Alternatively, in the case where UE 120r selects a candidate contention slot start time after the slot boundary between slot n and slot n+1, the gap after the slot boundary can be obtained by puncturing symbol 0 in slot n+1. In this case, since there are multiple candidate contention slot start times available before the slot boundary, the AGC duration can be extended to full symbols (e.g., all of symbol 0) to improve AGC performance. In addition, in the case of using a shorter LBT duration of 16μs, the time period T can have an additional candidate contention slot start time. Accordingly, in some cases, the AGC duration can have a length that depends on the UE function (e.g., how much time is required to perform AGC training), the length of the LBT duration, etc.

[0084] In another example, as in Figure 5D As shown and referenced by numeral 530, UE 120r may randomly select a set of candidate contention slot start times for 30 kHz subcarrier spacing, where t 0 is defined relative to the end time of the LBT duration. In this case, at 30 kHz subcarrier spacing with a 33.4 μs symbol duration, the total span of two symbol periods containing the gap symbol (symbol 13) and the repeated symbol for AGC training (symbol 0) is approximately 66.7 μs. Accordingly, assuming the LBT duration T minGapThe second half of symbol 0 is reserved for AGC training, in which the contention time slot start time duration T includes 1.5 symbols - T minGap , or about 41.7 μs. In this case, the time period T may be included in the time t for k=0, ..., K-1. 0 +9×k(e.g., t 0 ,t 0 +9μs,…,t 0 +27μs) for up to 4 candidate contention slot start times. Or, as in Figure 5E As shown, and by reference numeral 532, t may be defined relative to the start time of the AGC duration. 0 , so that the candidate contention slot start time is at time t for k=0, ..., K-1 0 -9×k (for example, t 0 ,t 0 -9μs,…,t 0 -27μs). In addition, in the case where UE 120r selects a candidate contention slot start time before the slot boundary between slot n and slot n+1, the signal sent before the slot boundary can be considered as a cyclic prefix extension of symbol 0 in slot n+1. Alternatively, in the case where UE 120r selects a candidate contention slot start time after the slot boundary between slot n and slot n+1, the gap after the slot boundary can be obtained by puncturing symbol 0 in slot n+1. In this case, because only two candidate contention slot start times before the slot boundary are available, the AGC duration can be limited to half a symbol to provide more candidate contention slot start times. In addition, in the case of using a shorter LBT duration of 16μs, the time period T can have an additional candidate contention slot start time.

[0085] In another example, as in Fig. 5F As shown and referenced by numeral 540, UE 120r may randomly select a set of candidate contention slot start times for the 60 kHz subcarriers, where t 0 is defined relative to the end time of the LBT duration. In this case, at 60 kHz subcarrier spacing with a 16.7 μs symbol duration, the total span of two symbol periods containing the gap symbol (symbol 13) and the repeated symbol for AGC training (symbol 0) is approximately 33.4 μs. Accordingly, assuming the LBT duration T minGap The second half of the symbol in symbol 0 is reserved for AGC training, in which the duration T of the contention slot start time includes 1.5 symbols - T minGap, or about 8.4 μs. In this case, the time period T may only include the time t 0 One (1) candidate contention slot start time at . Figure 5G As shown in FIG. 5 and by reference numeral 542, t may be defined relative to the start time of the AGC duration. 0 , so that the candidate contention slot start time appears at time t 0 At (e.g., at the start time of the AGC duration). Furthermore, in this case, there may be no candidate contention slot start times before the slot boundary between slot n and slot n+1, so a gap after the slot boundary may be obtained by puncturing symbol 0 in slot n+1. In this case, because there are no candidate contention slot start times available before the slot boundary, the AGC duration may be limited to half a symbol to ensure that there is at least one candidate contention slot start time to choose from (although the time period T may have one additional candidate contention slot start time when a shorter LBT duration of 16 μs is used, as described above).

[0086] As mentioned above, Figure 5A-5G are provided as one or more examples. Other examples may be related to Figure 5A-5G The examples described are different.

[0087] Figure 6 6 is a diagram illustrating an example process 600 performed, for example, by a first UE in accordance with various aspects of the present disclosure. Example process 600 is an example in which a first UE (e.g., UE 120, UE 305-1, UE 305-2, UE 405, UE 410, UE 120i, UE 120r, etc.) performs operations associated with UE-to-UE channel occupancy time sharing in an unlicensed spectrum.

[0088] As in Figure 6 6. As shown, in some aspects, process 600 may include determining one or more contention slot start times based at least in part on the LBT duration and the AGC duration during a channel occupancy time shared with a second UE (block 610). For example, as described above, a first UE may determine (e.g., using controller / processor 280, memory 282, etc.) one or more contention slot start times based at least in part on the LBT duration and the AGC duration during a channel occupancy time shared with a second UE.

[0089] As in Figure 6As further shown, in some aspects, process 600 may include sending a sidelink communication to a second UE at a start time selected from one or more of the one or more contention slot start times (block 620). For example, as described above, a first UE may (e.g., using controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, memory 282, etc.) send a sidelink communication to a second UE at a start time selected from one or more of the one or more contention slot start times.

[0090] Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0091] In a first aspect, one or more contention slot start times occur in one or more of a last symbol in a current slot or a first symbol in a next slot.

[0092] In a second aspect, alone or in combination with the first aspect, the LBT duration starts from the beginning of the last symbol in the current slot, and the AGC duration includes at least a portion of the first symbol in the next slot.

[0093] In a third aspect, alone or in combination with one or more of the first and second aspects, one or more contention slot start times occur in a window between an end time of the LBT duration and a start time of the AGC duration.

[0094] In a fourth aspect, alone or in combination with one or more of the first to third aspects, a portion of a first symbol in a next time slot corresponding to an AGC duration is based at least in part on a subcarrier spacing.

[0095] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the amount of one or more contention slot start times is based at least in part on a contention slot duration.

[0096] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the amount of one or more contention slot start times is based at least in part on a subcarrier spacing.

[0097] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the LBT duration has a length that depends on a position in which a first symbol of the sidelink communication is transmitted.

[0098] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, one or more contention slot start times are identified relative to an end time of an LBT duration.

[0099] In a ninth aspect, alone or in combination with one or more of the first to eighth aspects, one or more contention slot start times are identified relative to a start time of an AGC duration.

[0100] In a tenth aspect, either alone or in combination with one or more of the first to ninth aspects, a start time for transmitting a sidelink communication is randomly selected from one or more of the one or more contention slot start times.

[0101] although Figure 6 Example blocks of process 600 are shown, but in some aspects process 600 may include Figure 6 Additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in the process 600. Additionally or alternatively, two or more blocks of process 600 can be performed in parallel.

[0102] Figure 7 700 is a conceptual data flow diagram illustrating data flow between different components in an example apparatus 702. The apparatus 702 may be a UE (e.g., UE 120, UE 305-1, UE 305-2, UE 405, UE 410, UE 120i, UE 120r, etc.). In some aspects, the apparatus 702 includes a receiving component 704, a determining component 706, and / or a sending component 708. As shown in Figure 7 As shown, device 702 can communicate with another device 750 (eg, another UE) using receiving component 704 and / or sending component 708.

[0103] Receiving component 704 may receive one or more sidelink communications from device 750. For example, receiving component 704 may receive one or more sidelink transmissions from device 750 via an unlicensed channel during a channel occupancy time acquired by device 750. Moreover, in some aspects, receiving component 704 may receive sidelink control information from device 750 that includes information for enabling device 702 to share the channel occupancy time acquired by device 750. In some aspects, receiving component 704 may include an antenna (e.g., antenna 252), a receive processor (e.g., receive processor 258), a controller / processor (e.g., controller / processor 280), a transceiver, a receiver, and the like.

[0104] The determining component 706 may determine one or more contention slot start times based at least in part on the LBT duration and the AGC duration within a channel occupancy time shared with the apparatus 750. In some aspects, the determining component 706 may include a processor (e.g., the transmit processor 264, the receive processor 258, the controller / processor 280, etc.).

[0105] The transmitting component 708 may transmit one or more sidelink communications to the apparatus 750. For example, the transmitting component 708 may transmit the sidelink communication to the apparatus 750 at a start time selected from one or more of the one or more contention slot start times determined by the determining component 706. In some aspects, the transmitting component 708 may include an antenna (e.g., antenna 252), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a transceiver, a transmitter, etc.

[0106] The apparatus may include executing Figure 7 Additional components to each box in the aforementioned process 700 and / or similar processes. Figure 7 Each block in the aforementioned process 700 and / or similar processes may be performed by a component, and the apparatus may include one or more of these components. These components may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for processor implementation, or a combination of the above.

[0107] exist Figure 7 The number and arrangement of components shown in are provided as examples. Figure 7 There may be additional components, fewer components, different components, or components arranged differently than those shown. Figure 7 Two or more components shown may be implemented in a single component or in Figure 7 A single component shown may be implemented as multiple distributed components. Additionally or alternatively, Figure 7 The illustrated set of components (e.g., one or more components) may perform one or more of the operations described in Figure 7 Another set of components are shown to perform functions.

[0108] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of these aspects.

[0109] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0110] As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0111] It will be apparent that the systems and / or methods described herein can be implemented in various forms of hardware, firmware, and / or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit these aspects. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code - it should be understood that software and hardware can be designed to implement the systems and / or methods based at least in part on the description herein.

[0112] Although the specific combination of features is stated in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner not specifically stated in the claims and / or disclosed in the specification. Although each dependent claim listed below can directly rely on only one claim, the disclosure of various aspects includes each dependent claim and each other claim combination in the claim set. The phrase "at least one" in the reference item list refers to any combination of those items, including a single member. As an example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc and any combination with multiple identical elements (for example, aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc or any other ordering of a, b and c).

[0113] Unless explicitly stated, any element, action or instruction used in this article should not be interpreted as critical or essential. In addition, as used in this article, the articles "one" and "an" are intended to include one or more items and can be used interchangeably with "one or more". In addition, as used in this article, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.), and can be used interchangeably with "one or more". In the case of only wanting one item, the term "only one" or similar language is used. In addition, as used in this article, the terms "have", "have", "contain" etc. are intended to be open terms. In addition, unless explicitly stated otherwise, the phrase "based on" is intended to mean "based at least in part on".

Claims

1. A method of wireless communication performed by a first user equipment (UE), comprising: determining one or more contention slot start times within a channel occupancy time shared with a second UE based at least in part on a listen before talk (LBT) duration and an automatic gain control (AGC) duration; and A sidelink communication is sent to the second UE at a start time selected from one or more of the one or more contention slot start times.

2. The method according to claim 1, wherein: The one or more contention slot start times occur in one or more of the last symbol in a current slot or the first symbol in a next slot.

3. The method according to claim 1, wherein: The LBT duration starts from the start of the last symbol in the current slot, and the AGC duration includes at least a portion of the first symbol in the next slot.

4. The method according to claim 3, wherein: The one or more contention slot start times occur in a window between an end time of the LBT duration and a start time of the AGC duration.

5. The method according to claim 3, wherein: The portion of the first symbol in the next time slot corresponding to the AGC duration is based at least in part on a subcarrier spacing.

6. The method according to claim 1, wherein: The number of the one or more contention slot start times is based at least in part on a contention slot duration or a subcarrier spacing.

7. The method according to claim 1, wherein: The LBT duration has a length that depends on the location in which the first symbol of the sidelink communication is transmitted.

8. The method according to claim 1, wherein: The one or more contention slot start times are identified relative to an end time of the LBT duration or relative to a start time of the AGC duration.

9. The method according to claim 1, wherein: The start time for sending the sidelink communication is randomly selected from the one or more of the one or more contention slot start times.

10. A first user equipment (UE) for wireless communication, comprising: Memory; as well as one or more processors operatively coupled to the memory, the memory and the one or more processors being configured to: determining one or more contention slot start times within a channel occupancy time shared with a second UE based at least in part on a listen before talk (LBT) duration and an automatic gain control (AGC) duration; and A sidelink communication is sent to the second UE at a start time selected from one or more of the one or more contention slot start times.

11. The first UE according to claim 10, wherein: The one or more contention slot start times occur in one or more of the last symbol in a current slot or the first symbol in a next slot.

12. The first UE according to claim 10, wherein: The LBT duration starts from the start of the last symbol in the current slot, and the AGC duration includes at least a portion of the first symbol in the next slot.

13. The first UE according to claim 12, wherein: The one or more contention slot start times occur in a window between an end time of the LBT duration and a start time of the AGC duration.

14. The first UE according to claim 12, wherein: The portion of the first symbol in the next time slot corresponding to the AGC duration is based at least in part on a subcarrier spacing.

15. The first UE according to claim 10, wherein: The number of the one or more contention slot start times is based at least in part on a contention slot duration or a subcarrier spacing.

16. The first UE according to claim 10, wherein: The LBT duration has a length that depends on the location in which the first symbol of the sidelink communication is transmitted.

17. The first UE according to claim 10, wherein: The one or more contention slot start times are identified relative to an end time of the LBT duration or relative to a start time of the AGC duration.

18. The first UE according to claim 10, wherein: The start time for sending the sidelink communication is randomly selected from the one or more of the one or more contention slot start times.

19. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: One or more instructions that, when executed by one or more processors of a first user equipment (UE), cause the one or more processors to perform the following operations: determining one or more contention slot start times within a channel occupancy time shared with a second UE based at least in part on a listen before talk (LBT) duration and an automatic gain control (AGC) duration; and A sidelink communication is sent to the second UE at a start time selected from one or more of the one or more contention slot start times.

20. The non-transitory computer readable medium of claim 19, wherein: The one or more contention slot start times occur in one or more of the last symbol in a current slot or the first symbol in a next slot.

21. The non-transitory computer readable medium of claim 19, wherein: The LBT duration starts from the start of the last symbol in the current slot, and the AGC duration includes at least a portion of the first symbol in the next slot.

22. The non-transitory computer readable medium of claim 21, wherein: The one or more contention slot start times occur in a window between an end time of the LBT duration and a start time of the AGC duration.

23. The non-transitory computer readable medium of claim 21, wherein: The portion of the first symbol in the next time slot corresponding to the AGC duration is based at least in part on a subcarrier spacing.

24. The non-transitory computer readable medium of claim 19, wherein: The number of the one or more contention slot start times is based at least in part on a contention slot duration or a subcarrier spacing.

25. The non-transitory computer readable medium of claim 19, wherein: The LBT duration has a length that depends on the location in which the first symbol of the sidelink communication is transmitted.

26. The non-transitory computer readable medium of claim 19, wherein: The one or more contention slot start times are identified relative to an end time of the LBT duration or relative to a start time of the AGC duration.

27. The non-transitory computer readable medium of claim 19, wherein: The start time for sending the sidelink communication is randomly selected from the one or more of the one or more contention slot start times.

28. An apparatus for wireless communication, comprising: means for determining one or more contention slot start times within a channel occupancy time shared with a user equipment (UE) based at least in part on a listen-before-talk (LBT) duration and an automatic gain control (AGC) duration; as well as Means for sending a sidelink communication to the UE at a start time selected from one or more of the one or more contention slot start times.

29. The device according to claim 28, wherein The one or more contention slot start times occur in one or more of the last symbol in the current slot, the first symbol in the next slot, or a window between the end time of the LBT duration and the start time of the AGC duration.

30. The device according to claim 28, wherein The LBT duration starts from the start of the last symbol in the current slot, and the AGC duration includes at least a portion of the first symbol in the next slot.

31. The device according to claim 30, wherein The portion of the first symbol in the next time slot corresponding to the AGC duration is based at least in part on a subcarrier spacing.

32. The apparatus of claim 28, wherein: The number of the one or more contention slot start times is based at least in part on a contention slot duration or a subcarrier spacing.

33. The apparatus of claim 28, wherein: The LBT duration has a length that depends on the location in which the first symbol of the sidelink communication is transmitted.

34. The apparatus of claim 28, wherein: The one or more contention slot start times are identified relative to an end time of the LBT duration or relative to a start time of the AGC duration.

35. The apparatus of claim 28, wherein: The start time for sending the sidelink communication is randomly selected from the one or more of the one or more contention slot start times.

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