WO2021226906A1 - Sélection d'une heure de début correspondant à la détection de canal - Google Patents

Sélection d'une heure de début correspondant à la détection de canal Download PDF

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Publication number
WO2021226906A1
WO2021226906A1 PCT/CN2020/090140 CN2020090140W WO2021226906A1 WO 2021226906 A1 WO2021226906 A1 WO 2021226906A1 CN 2020090140 W CN2020090140 W CN 2020090140W WO 2021226906 A1 WO2021226906 A1 WO 2021226906A1
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WIPO (PCT)
Prior art keywords
channel
wireless communication
sensing
time
determining
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PCT/CN2020/090140
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English (en)
Inventor
Changlong Xu
Jing Sun
Xiaoxia Zhang
Tao Luo
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Qualcomm Incorporated
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Priority to PCT/CN2020/090140 priority Critical patent/WO2021226906A1/fr
Publication of WO2021226906A1 publication Critical patent/WO2021226906A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W74/00—Wireless channel access
    • H04W74/08—Non-scheduled access, e.g. ALOHA
    • H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
    • H04W74/0816—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA] with collision avoidance

Definitions

  • the technology discussed below relates generally to wireless communication and, more particularly, to selecting a start time for channel sensing for sidelink communication during a channel occupancy time (COT) .
  • COT channel occupancy time
  • a cellular network is implemented by enabling wireless user equipment to communicate with one another through signaling with a nearby base station or cell. As a user equipment moves across a service area, handovers take place such that each user equipment maintains communication with one another via its respective cell.
  • P2P peer to peer
  • a wireless user equipment may signal one another directly, rather than via an intermediary base station or cell.
  • P2P peer to peer
  • Somewhat in between these schemes is a system configured for sidelink signaling.
  • sidelink signaling a wireless user equipment communicates in a cellular system, generally under the control of a base station.
  • the wireless user equipment is further configured for sidelink signaling directly between user equipment without transmissions passing through the base station.
  • V2X communication involves the exchange of information not only between vehicles themselves, but also between vehicles and external systems, such as streetlights, buildings, pedestrians, and wireless communication networks.
  • V2X systems enable vehicles to obtain information related to the weather, nearby accidents, road conditions, activities of nearby vehicles and pedestrians, objects nearby the vehicle, and other pertinent information that may be utilized to improve the vehicle driving experience, increase vehicle safety, and support autonomous vehicles.
  • a first sidelink device may select a start time for channel sensing for a transmission during a channel occupancy time (COT) , in a scenario where the COT was reserved on a channel by a second sidelink device.
  • COT channel occupancy time
  • the first sidelink device selects one of a plurality of start times associated with the COT.
  • the first sidelink device selects a slot of the COT and then selects one of a set of start times associated with that slot.
  • the first sidelink device may commence an LBT procedure (e.g., at the start time) to determine whether the channel is available during the COT for a transmission by the first sidelink device.
  • a method of wireless communication at a first wireless communication device may include receiving an indication that a second wireless communication device has reserved a channel for a period of time comprising a plurality of slots, determining a start time for sensing the channel prior to a particular slot of the plurality of slots, commencing sensing of the channel based on the start time, and selectively transmitting on the channel during the period of time based on the sensing of the channel.
  • a first wireless communication device may include a transceiver, a memory, and a processor communicatively coupled to the transceiver and the memory.
  • the processor and the memory may be configured to receive an indication that a second wireless communication device has reserved a channel for a period of time comprising a plurality of slots, determine a start time for sensing the channel prior to a particular slot of the plurality of slots, commence sensing of the channel based on the start time, and selectively transmit on the channel during the period of time based on the sensing of the channel.
  • a first wireless communication device may include means for receiving an indication that a second wireless communication device has reserved a channel for a period of time comprising a plurality of slots, means for determining a start time for sensing the channel prior to a particular slot of the plurality of slots, means for commencing sensing of the channel based on the start time, and means for selectively transmitting on the channel during the period of time based on the sensing of the channel.
  • an article of manufacture for use by a first wireless communication device may include a computer-readable medium having stored therein instructions executable by one or more processors of the wireless communication device to receive an indication that a second wireless communication device has reserved a channel for a period of time comprising a plurality of slots, determine a start time for sensing the channel prior to a particular slot of the plurality of slots, commence sensing of the channel based on the start time, and selectively transmit on the channel during the period of time based on the sensing of the channel.
  • FIG. 1 is a conceptual illustration of an example of a wireless radio access network according to some aspects.
  • FIG. 2 is a conceptual illustration of an example of a vehicle-to-everything (V2X) wireless communication network according to some aspects.
  • V2X vehicle-to-everything
  • FIG. 3 is a schematic diagram illustrating organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM) according to some aspects.
  • OFDM orthogonal frequency divisional multiplexing
  • FIG. 4 is a conceptual illustration of an example of a channel occupancy time according to some aspects.
  • FIG. 5 is a conceptual illustration of an example of frequency division multiplexing over different interlaces according to some aspects.
  • FIG. 6 is a conceptual illustration of an example of a collision during a shared COT according to some aspects.
  • FIG. 7 is a conceptual illustration of a first example of selecting a start time according to some aspects.
  • FIG. 8 is a conceptual illustration of a second example of selecting a start time according to some aspects.
  • FIG. 9 is a block diagram illustrating an example of a hardware implementation for a wireless communication device employing a processing system according to some aspects.
  • FIG. 10 is a flow chart illustrating an example of a method for selecting a start time according to some aspects.
  • Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations.
  • devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments.
  • transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, RF-chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) .
  • innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. of varying sizes, shapes and constitution.
  • the various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards.
  • the RAN 100 may implement any suitable wireless communication technology or technologies to provide radio access.
  • the RAN 100 may operate according to 3 rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G.
  • 3GPP 3 rd Generation Partnership Project
  • NR New Radio
  • the RAN 100 may operate under a hybrid of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards, often referred to as LTE.
  • the 3GPP refers to this hybrid RAN as a next-generation RAN, or NG-RAN.
  • NG-RAN next-generation RAN
  • the geographic region covered by the radio access network 100 may be divided into a number of cellular regions (cells) that can be uniquely identified by a user equipment (UE) based on an identification broadcasted over a geographical area from one access point or base station.
  • FIG. 1 illustrates macrocells 102, 104, and 106, and a small cell 108, each of which may include one or more sectors (not shown) .
  • a sector is a sub-area of a cell. All sectors within one cell are served by the same base station.
  • a radio link within a sector can be identified by a single logical identification belonging to that sector.
  • the multiple sectors within a cell can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell.
  • a respective base station serves each cell.
  • a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE.
  • a BS may also be referred to by those skilled in the art as a base transceiver station (BTS) , a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , an access point (AP) , a Node B (NB) , an eNode B (eNB) , a gNode B (gNB) or some other suitable terminology.
  • BTS base transceiver station
  • ESS extended service set
  • AP access point
  • NB Node B
  • eNB eNode B
  • gNB gNode B
  • two base stations 110 and 112 are shown in cells 102 and 104; and a third base station 114 is shown controlling a remote radio head (RRH) 116 in cell 106. That is, a base station can have an integrated antenna or can be connected to an antenna or RRH by feeder cables.
  • the cells 102, 104, and 106 may be referred to as macrocells, as the base stations 110, 112, and 114 support cells having a relatively large size.
  • a base station 118 is shown in the small cell 108 (e.g., a microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc. ) which may overlap with one or more macrocells.
  • the cell 108 may be referred to as a small cell, as the base station 118 supports a cell having a relatively small size.
  • Cell sizing can be done according to system design as well as component constraints.
  • the radio access network 100 may include any number of wireless base stations and cells.
  • a relay node may be deployed to extend the size or coverage area of a given cell.
  • the base stations 110, 112, 114, 118 provide wireless access points to a core network for any number of mobile apparatuses.
  • FIG. 1 further includes mobile base station 120 (e.g., a quadcopter or a drone configured to function as a base station) . That is, in some examples, a cell might not necessarily be stationary, and the geographic area of the cell may move according to the location of the mobile base station 120 (e.g., the quadcopter or drone) .
  • mobile base station 120 e.g., a quadcopter or a drone configured to function as a base station
  • a cell might not necessarily be stationary, and the geographic area of the cell may move according to the location of the mobile base station 120 (e.g., the quadcopter or drone) .
  • base stations may include a backhaul interface for communication with a backhaul portion (not shown) of the network.
  • the backhaul may provide a link between a base station and a core network (not shown) , and in some examples, the backhaul may provide interconnection between the respective base stations.
  • the core network may be a part of a wireless communication system and may be independent of the radio access technology used in the radio access network.
  • Various types of backhaul interfaces may be employed, such as a direct physical connection, a virtual network, or the like using any suitable transport network.
  • the RAN 100 is illustrated supporting wireless communication for multiple mobile apparatuses.
  • a mobile apparatus is commonly referred to as user equipment (UE) in standards and specifications promulgated by the 3rd Generation Partnership Project (3GPP) , but may also be referred to by those skilled in the art as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology.
  • UE may be an apparatus that provides a user with access to network services.
  • a “mobile” apparatus need not necessarily have a capability to move, and may be stationary.
  • the term mobile apparatus or mobile device broadly refers to a diverse array of devices and technologies.
  • some non-limiting examples of a mobile apparatus include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal computer (PC) , a notebook, a netbook, a smartbook, a tablet, a personal digital assistant (PDA) , and a broad array of embedded systems, e.g., corresponding to an “Internet of things” (IoT) .
  • IoT Internet of things
  • a mobile apparatus may additionally be an automotive or other transportation vehicle, a remote sensor or actuator, a robot or robotics device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-copter, a quad-copter, a remote control device, a consumer and/or wearable device, such as eyewear, a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player) , a camera, a game console, etc.
  • GPS global positioning system
  • a mobile apparatus may additionally be a digital home or smart home device such as a home audio, video, and/or multimedia device, an appliance, a vending machine, intelligent lighting, a home security system, a smart meter, etc.
  • a mobile apparatus may additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device controlling electric power (e.g., a smart grid) , lighting, water, etc.; an industrial automation and enterprise device; a logistics controller; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weaponry, etc.
  • a mobile apparatus may provide for connected medicine or telemedicine support, i.e., health care at a distance.
  • Telehealth devices may include telehealth monitoring devices and telehealth administration devices, whose communication may be given preferential treatment or prioritized access over other types of information, e.g., in terms of prioritized access for transport of critical service data, and/or relevant QoS for transport of critical service data.
  • the cells may include UEs that may be in communication with one or more sectors of each cell.
  • UEs 122 and 124 may be in communication with base station 110; UEs 126 and 128 may be in communication with base station 112; UEs 130 and 132 may be in communication with base station 114 by way of RRH 116; UE 134 may be in communication with base station 118; and UE 136 may be in communication with the mobile base station 120.
  • each base station 110, 112, 114, 118, and 120 may be configured to provide an access point to a core network (not shown) for all the UEs in the respective cells.
  • a mobile network node e.g., the mobile base station 120
  • the mobile base station 120 may operate within cell 102 by communicating with the base station 110.
  • Wireless communication between a RAN 100 and a UE may be described as utilizing an air interface.
  • Transmissions over the air interface from a base station (e.g., base station 110) to one or more UEs (e.g., UE 122 and 124) may be referred to as downlink (DL) transmission.
  • DL downlink
  • the term downlink may refer to a point-to-multipoint transmission originating at a scheduling entity (described further below; e.g., base station 110) .
  • Another way to describe this scheme may be to use the term broadcast channel multiplexing.
  • Uplink Transmissions from a UE (e.g., UE 122) to a base station (e.g., base station 110) may be referred to as uplink (UL) transmissions.
  • UL uplink
  • the term uplink may refer to a point-to-point transmission originating at a scheduled entity (described further below; e.g., UE 122) .
  • DL transmissions may include unicast or broadcast transmissions of control information and/or traffic information (e.g., user data traffic) from a base station (e.g., base station 110) to one or more UEs (e.g., UEs 122 and 124)
  • UL transmissions may include transmissions of control information and/or traffic information originating at a UE (e.g., UE 122)
  • the uplink and/or downlink control information and/or traffic information may be time-divided into frames, subframes, slots, and/or symbols.
  • a symbol may refer to a unit of time that, in an orthogonal frequency division multiplexed (OFDM) waveform, carries one resource element (RE) per sub-carrier.
  • a slot may carry 7 or 14 OFDM symbols.
  • a subframe may refer to a duration of 1ms. Multiple subframes or slots may be grouped together to form a single frame or radio frame.
  • the air interface in the RAN 100 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices.
  • 5G NR specifications provide multiple access for UL or reverse link transmissions from UEs 122 and 124 to base station 110, and for multiplexing DL or forward link transmissions from the base station 110 to UEs 122 and 124 utilizing orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) .
  • OFDM orthogonal frequency division multiplexing
  • CP cyclic prefix
  • 5G NR specifications provide support for discrete Fourier transform-spread-OFDM (DFT-s-OFDM) with a CP (also referred to as single-carrier FDMA (SC-FDMA) ) .
  • DFT-s-OFDM discrete Fourier transform-spread-OFDM
  • SC-FDMA single-carrier FDMA
  • multiplexing and multiple access are not limited to the above schemes, and may be provided utilizing time division multiple access (TDMA) , code division multiple access (CDMA) , frequency division multiple access (FDMA) , sparse code multiple access (SCMA) , resource spread multiple access (RSMA) , or other suitable multiple access schemes.
  • multiplexing DL transmissions from the base station 110 to UEs 122 and 124 may be provided utilizing time division multiplexing (TDM) , code division multiplexing (CDM) , frequency division multiplexing (FDM) , orthogonal frequency division multiplexing (OFDM) , sparse code multiplexing (SCM) , or other suitable multiplexing schemes.
  • the air interface in the RAN 100 may utilize one or more duplexing algorithms.
  • Duplex refers to a point-to-point communication link where both endpoints can communicate with one another in both directions.
  • Full duplex means both endpoints can simultaneously communicate with one another.
  • Half duplex means only one endpoint can send information to the other at a time.
  • a full duplex channel generally relies on physical isolation of a transmitter and receiver, and suitable interference cancellation technologies.
  • Full duplex emulation is frequently implemented for wireless links by utilizing frequency division duplex (FDD) or time division duplex (TDD) .
  • FDD frequency division duplex
  • TDD time division duplex
  • transmissions in different directions operate at different carrier frequencies.
  • TDD transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at some times the channel is dedicated for transmissions in one direction, while at other times the channel is dedicated for transmissions in the other direction, where the direction may change very rapidly, e.g., several times
  • a RAN 100 In the RAN 100, the ability for a UE to communicate while moving, independent of their location, is referred to as mobility.
  • the various physical channels between the UE and the RAN are generally set up, maintained, and released under the control of an access and mobility management function (AMF) , which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality and a security anchor function (SEAF) that performs authentication.
  • AMF access and mobility management function
  • SCMF security context management function
  • SEAF security anchor function
  • a RAN 100 may utilize DL-based mobility or UL-based mobility to enable mobility and handovers (i.e., the transfer of a UE’s connection from one radio channel to another) .
  • a UE may monitor various parameters of the signal from its serving cell as well as various parameters of neighboring cells. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if signal quality from a neighboring cell exceeds that from the serving cell for a given amount of time, the UE may undertake a handoff or handover from the serving cell to the neighboring (target) cell. For example, the UE 124 may move from the geographic area corresponding to its serving cell 102 to the geographic area corresponding to a neighbor cell 106.
  • the UE 124 may transmit a reporting message to its serving base station 110 indicating this condition. In response, the UE 124 may receive a handover command, and the UE may undergo a handover to the cell 106.
  • UL reference signals from each UE may be utilized by the network to select a serving cell for each UE.
  • the base stations 110, 112, and 114/116 may broadcast synchronization signals (e.g., Primary Synchronization Signals (PSSs) , Secondary Synchronization Signals (SSSs) and Physical Broadcast Channels (PBCH) ) .
  • PSSs Primary Synchronization Signals
  • SSSs Secondary Synchronization Signals
  • PBCH Physical Broadcast Channels
  • the UEs 122, 124, 126, 128, 130, and 132 may receive the synchronization signals, derive the carrier frequency and radio frame timing from the synchronization signals, and in response to deriving timing, transmit an uplink pilot or reference signal.
  • the uplink pilot signal transmitted by a UE may be concurrently received by two or more cells (e.g., base stations 110 and 114/116) within the RAN 100.
  • Each of the cells may measure a strength of the pilot signal, and the RAN (e.g., one or more of the base stations 110 and 114/116 and/or a central node within the core network) may determine a serving cell for the UE 124.
  • the network may continue to monitor the uplink pilot signal transmitted by the UE 124.
  • the RAN 100 may handover the UE 124 from the serving cell to the neighboring cell, with or without informing the UE 124.
  • the synchronization signal transmitted by the base stations 110, 112, and 114/116 may be unified in some examples, the synchronization signal might not identify a particular cell, but rather may identify a zone of multiple cells operating on the same frequency and/or with the same timing.
  • the use of zones in 5G networks or other next generation communication networks enables the uplink-based mobility framework and improves the efficiency of both the UE and the network, since the number of mobility messages that need to be exchanged between the UE and the network may be reduced.
  • the air interface in the RAN 100 may utilize licensed spectrum, unlicensed spectrum, or shared spectrum.
  • Licensed spectrum provides for exclusive use of a portion of the spectrum, generally by virtue of a mobile network operator purchasing a license from a government regulatory body.
  • Unlicensed spectrum provides for shared use of a portion of the spectrum without need for a government-granted license. While compliance with some technical rules is generally still required to access unlicensed spectrum, generally, any operator or device may gain access.
  • Shared spectrum may fall between licensed and unlicensed spectrum, wherein technical rules or limitations may be required to access the spectrum, but the spectrum may still be shared by multiple operators and/or multiple RATs.
  • the holder of a license for a portion of licensed spectrum may provide licensed shared access (LSA) to share that spectrum with other parties, e.g., with suitable licensee-determined conditions to gain access.
  • LSA licensed shared access
  • a scheduling entity e.g., a base station
  • resources e.g., time–frequency resources
  • the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UEs or scheduled entities utilize resources allocated by the scheduling entity.
  • Base stations are not the only entities that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs) . In other examples, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station.
  • the UE 138 is illustrated communicating with UEs 140 and 142. In some examples, the UE 138 is functioning as a scheduling entity or a primary sidelink device, and the UEs 140 and 142 may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device.
  • the UE 138 may function as a scheduling entity in a device-to-device (D2D) , peer-to-peer (P2P) , vehicle-to-everything (V2X) , and/or in a mesh network.
  • D2D device-to-device
  • P2P peer-to-peer
  • V2X vehicle-to-everything
  • the UEs 140 and 142 may optionally communicate directly with one another in addition to communicating with a scheduling entity (e.g., the UE 138) .
  • two or more UEs within the coverage area of a serving base station 112 may communicate with each other using sidelink signals 127 without relaying that communication through the base station 112.
  • one or both of the UEs 126 and 128 may function as scheduling entities to schedule sidelink communication therebetween.
  • the UEs 126 and 128 may communicate sidelink signals 127 within a V2X network.
  • V2X networks Two primary technologies that may be used by V2X networks include dedicated short range communication (DSRC) based on IEEE 802.11p standards and cellular V2X based on LTE and/or 5G (New Radio) standards.
  • DSRC dedicated short range communication
  • cellular V2X based on LTE and/or 5G (New Radio) standards.
  • NR New Radio
  • FIG. 2 illustrates an example of a vehicle-to-everything (V2X) wireless communication network 200.
  • a V2X network can connect vehicles 202a –202d to each other (vehicle-to-vehicle (V2V) ) , to roadway infrastructure 205 (vehicle-to-infrastructure (V2I) ) , to mobile devices 206 of pedestrians/cyclists (vehicle-to- pedestrian (V2P) (e.g., mobile devices, such as user equipment (UE) and/or wearables of pedestrians/cyclists) ) , and/or to the network 208 (vehicle-to-network (V2N) ) .
  • V2X vehicle-to-everything
  • a V2I transmission may be between a vehicle (e.g., vehicle 202a) and a roadside unit (RSU) 204, which may be coupled to various infrastructure 205, such as a traffic light, building, streetlight, traffic camera, tollbooth, or other stationary object.
  • RSU 204 may act as a base station enabling communication between vehicles 202a –202d, between vehicles 202a –202d and the RSU 204 and between vehicles 202a –202d and mobile devices 206 of pedestrians/cyclists.
  • the RSU 204 may further exchange V2X data gathered from the surrounding environment, such as a connected traffic camera or traffic light controller, V2X connected vehicles 202a–202d, and mobile devices 206 of pedestrians/cyclists, with other RSUs 204 and distribute that V2X data to V2X connected vehicles 202a –202d and mobile devices 206 of pedestrians/cyclists.
  • V2X data may include status information (e.g., position, speed, acceleration, trajectory, etc. ) or event information (e.g., traffic jam, icy road, fog, pedestrian crossing the road, collision, etc. ) , and may also include video data captured by a camera on a vehicle or coupled to an RSU 204.
  • V2X data may enable autonomous driving and improve road safety and traffic efficiency.
  • the exchanged V2X data may be utilized by a V2X connected vehicle 202a –202d to provide in-vehicle collision warnings, road hazard warnings, approaching emergency vehicle warnings, pre-/post-crash warnings and information, emergency brake warnings, traffic jam ahead warnings, lane change warnings, intelligent navigation services, and other similar information.
  • V2X data received by a V2X connected to a mobile device 206 of a pedestrian/cyclist may be utilized to trigger a warning sound, vibration, flashing light, etc., in case of imminent danger.
  • V2N communication may utilize traditional cellular links to provide cloud services to a V2X device (e.g., within a vehicle 202a –202d or RSU 204, or carried by a pedestrian/cyclist) for latency-tolerant use cases.
  • V2N may enable a V2X network server to broadcast messages (e.g., weather, traffic, or other information) to V2X devices over a wide area network and may enable V2X devices to send unicast messages to the V2X network server.
  • V2N communication may provide backhaul services for RSUs 204.
  • FIG. 3 an expanded view of an exemplary subframe 302A is illustrated, showing an OFDM resource grid.
  • time is in the horizontal direction with units of OFDM symbols; and frequency is in the vertical direction with units of subcarriers.
  • the resource grid 304 may be used to schematically represent time–frequency resources for a given antenna port. That is, in a multiple-input-multiple-output (MIMO) implementation with multiple antenna ports available, a corresponding multiple number of resource grids 304 may be available for communication.
  • the resource grid 304 is divided into multiple resource elements (REs) 306.
  • An RE which is 1 subcarrier ⁇ 1 symbol, is the smallest discrete part of the time–frequency grid, and contains a single complex value representing data from a physical channel or signal.
  • each RE may represent one or more bits of information.
  • a block of REs may be referred to as a physical resource block (PRB) or more simply a resource block (RB) 308, which contains any suitable number of consecutive subcarriers in the frequency domain.
  • an RB may include 12 subcarriers, a number independent of the numerology used.
  • an RB may include any suitable number of consecutive OFDM symbols in the time domain.
  • Scheduling of UEs or V2X devices for downlink, uplink, or sidelink transmissions typically involves scheduling one or more resource elements 306 within one or more sub-bands.
  • a UE or V2X device generally utilizes only a subset of the resource grid 304.
  • an RB may be the smallest unit of resources that can be allocated to a UE/V2X device.
  • the RBs may be scheduled by a base station (e.g., gNB, eNB, RSU, etc. ) or may be self-scheduled by a UE implementing D2D sidelink communication.
  • the RB 308 is shown as occupying less than the entire bandwidth of the subframe 302A, with some subcarriers illustrated above and below the RB 308.
  • the subframe 302A may have a bandwidth corresponding to any number of one or more RBs 308.
  • the RB 308 is shown as occupying less than the entire duration of the subframe 302A, although this is merely one possible example.
  • Each 1 millisecond (ms) subframe 302A may consist of one or multiple adjacent slots.
  • one subframe 302B includes four slots 310, as an illustrative example.
  • a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length.
  • CP cyclic prefix
  • a slot may include 7 or 14 OFDM symbols with a nominal CP.
  • Additional examples may include mini-slots having a shorter duration (e.g., one to three OFDM symbols) . These mini-slots may in some cases be transmitted occupying resources scheduled for ongoing slot transmissions for the same or for different UEs. Any number of resource blocks may be utilized within a subframe or slot.
  • An expanded view of one of the slots 310 illustrates the slot 310 including a control region 312 and a data region 314.
  • the control region 312 may carry control channels
  • the data region 314 may carry data channels.
  • a slot may contain all DL, all UL, or at least one DL portion and at least one UL portion.
  • the structure illustrated in FIG. 3 is merely exemplary in nature, and different slot structures may be utilized, and may include one or more of each of the control region (s) and data region (s) .
  • the various REs 306 within a RB 308 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc.
  • Other REs 306 within the RB 308 may also carry pilots or reference signals, including but not limited to a demodulation reference signal (DMRS) a control reference signal (CRS) , or a sounding reference signal (SRS) .
  • DMRS demodulation reference signal
  • CRS control reference signal
  • SRS sounding reference signal
  • pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB 308.
  • the slot 310 may be utilized for broadcast or unicast communication.
  • a broadcast communication may refer to a point-to-multipoint transmission by a one device (e.g., a vehicle, base station (e.g., RSU, gNB, eNB, etc. ) , UE, or other similar device) to other devices.
  • a unicast communication may refer to a point-to-point transmission by a one device to a single other device.
  • the control region 312 of the slot 310 may include a physical downlink control channel (PDCCH) including downlink control information (DCI) transmitted by a base station (e.g., gNB, eNB, RSU, etc. ) towards one or more of a set of UEs, which may include one or more sidelink devices (e.g., V2X/D2D devices) .
  • the DCI may include scheduling information indicating one or more resource blocks within the control region 312 and/or data region 314 allocated to sidelink devices for sidelink communication.
  • control region 312 of the slot may further include control information transmitted by sidelink devices over the sidelink channel, while the data region 314 of the slot 310 may include data transmitted by sidelink devices over the sidelink channel.
  • control information may be transmitted within a physical sidelink control channel (PSCCH)
  • data may be transmitted within a physical sidelink shared channel (PSSCH) .
  • PSCCH physical sidelink control channel
  • PSSCH physical sidelink shared channel
  • Transport channels carry blocks of information called transport blocks (TB) .
  • TBS transport block size
  • MCS modulation and coding scheme
  • the channels or carriers illustrated in FIG. 3 are not necessarily all of the channels or carriers that may be utilized between devices, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.
  • wireless communication may be conducted over unlicensed radio frequency (RF) spectrum (e.g., an unlicensed RF band) in some scenarios.
  • RF radio frequency
  • a network operator may deploy cells that are configured to communicate on an unlicensed RF spectrum (e.g., in addition to cells operating on a licensed RF spectrum) to extend the coverage of the network or to provide additional services (e.g., higher throughput) to UEs operating within the network.
  • a UE may be configured to communicate with another device (e.g., a BS or another UE) on an unlicensed RF spectrum.
  • devices that transmit over an unlicensed RF spectrum may use a collision avoidance scheme to reduce the likelihood that multiple devices will transmit on the same RF spectrum at the same time.
  • a collision avoidance scheme is a listen-before-talk (LBT) procedure.
  • LBT listen-before-talk
  • the first device may listen for any transmissions by any other devices on that RF spectrum. If the RF spectrum is currently being used, the first device may back-off for a period of time and then re-attempt transmission (e.g., by listening for other transmissions again) .
  • Carrier sense multiple access (CSMA) is one example of an LBT procedure. Other types of LBT procedures may be used as well.
  • NR-U NR operation in the unlicensed RF spectrum
  • some transmissions may be subject to LBT.
  • a wireless device such as a UE or a gNB, may perform a clear channel assessment (CCA) , such as LBT, prior to gaining control of a wireless channel in an unlicensed RF spectrum.
  • CCA clear channel assessment
  • a gNB may transmit, subject to LBT, a synchronization signal block (SSB) that carries synchronization signals and reference signals (e.g., discovery reference signals (DRSs) ) for a UE to discover and synchronize with the gNB.
  • SSB synchronization signal block
  • DRSs discovery reference signals
  • a gNB may schedule uplink transmissions for UEs, specifying which time-domain and frequency-domain resources each UE is to use for its respective uplink transmission.
  • interlaced-based scheduling may be used in the frequency domain.
  • a PRB interlaced waveform may be used in the UL to satisfy occupied channel bandwidth (OCB) goals and/or to boost UL transmit power for a given power spectral density (PSD) limitation.
  • OCB occupied channel bandwidth
  • PSD power spectral density
  • a device may schedule a UE to transmit according to one of more of the interlaces. For example, a BS may schedule a first UE to transmit on interlace 0 and schedule a second UE to transmit on interlace 1. As another example, a BS may schedule a first UE to transmit on interlace 0 and interlace 1. Other examples are possible.
  • a device may reserve the channel for a period of time. This period of time may be referred to as a channel occupancy time (COT) .
  • COT channel occupancy time
  • a device may share the COT it reserved with at least one other device.
  • a gNB can acquire a COT with an extended CCA (eCCA) and share the COT with multiple UEs thereby enabling the UEs to transmit UL signals during the COT.
  • eCCA extended CCA
  • a gNB may transmit during a first portion (e.g., one or more DL slots) of the COT and, following a gap period, one or more UEs may transmit during a remaining portion (e.g., one or more UL slots) of the COT.
  • COT sharing between a gNB and UE in NR-U may provide improved medium access within the COT.
  • LBT procedures may be defined according to different categories. For example, Category 1 (Cat. 1) LBT specifies that LBT is not used. Cat. 2 LBT specifies the use of BTW without random back-off. Cat. 3 LBT specifies the use of LBT with random back-off with a fixed size contention window. Cat. 4 LBT specifies the use of LBT with random back-off with a variable sized contention window.
  • Category 1 (Cat. 1) LBT specifies that LBT is not used.
  • Cat. 2 LBT specifies the use of BTW without random back-off.
  • Cat. 3 LBT specifies the use of LBT with random back-off with a fixed size contention window.
  • Cat. 4 LBT specifies the use of LBT with random back-off with a variable sized contention window.
  • a device may perform different types of LBT procedures in different scenarios. For example, for an UL transmission within a gNB COT, a UE may perform a one-shot LBT procedure in some cases. Alternatively, a UE might not perform an LBT procedure in other cases (e.g. CAT. 1 LBT) .
  • Cat. 2 LBT may be used for DL to UL gaps of 16 microseconds (us) to 25 us.
  • a Cat. 1 LBT may be used when the DL to UL gap duration is less than or equal to 16 us in some examples.
  • a device may support UL to DL COT sharing. For example, sharing of a UE-initiated channel occupancy (e.g., either a configured grant -PUSCH (CG-PUSCH) or a scheduled UL) with a gNB may be supported.
  • the gNB is allowed to transmit (e.g., control signals, control channels, broadcast signals, broadcast channels, etc. ) during the COT to any UEs as long as the transmission contains a transmission for the UE that initiated the COT.
  • the gNB is allowed to transmit DL signals and/or channels (e.g., PDSCH, PDCCH, reference signals, etc. ) meant for the UE that initiated the COT.
  • a UE may use an energy detect (ED) threshold when initiating a channel occupancy. For example, if the energy detected on a channel during the LBT procedure is less than or equal to the ED threshold, the UE may reserve the channel for a COT.
  • ED energy detect
  • the energy detect (ED) threshold that the UE applies when initiating a channel occupancy to be shared with the gNB may be configured by the gNB (e.g., via radio resource control (RRC) signaling) . If the ED threshold that the UE applies when initiating a channel occupancy to be shared with the gNB is not configured, the transmission of the gNB in UE initiated COT may be restricted to include only control and/or broadcast transmissions of up to 2, 4, or 8 OFDM symbols in duration for a 15, 30, or 60 kHz sub-carrier spacing (SCS) , respectively.
  • RRC radio resource control
  • the ED threshold that the gNB configures to the UE to apply when initiating the channel occupancy may be determined based on the maximum gNB transmit (TX) power.
  • a device may perform different types of LBT procedures in different UL to DL COT sharing scenarios.
  • Cat. 2 LBT may be used for DL to UL gaps of 16 microseconds (us) to 25 us.
  • a Cat. 1 LBT may be used when the DL to UL gap duration is less than or equal to 16 us in some examples.
  • COT sharing may be used in NR-U sidelink (SL) .
  • one sidelink UE may be an initiating device and at least one other sidelink UE may be a responding device.
  • FIG. 4 illustrates an example of COT sharing 400 in the time domain (e.g., TDM COT sharing) .
  • an initiating sidelink UE has reserved a COT 402 with a duration of X ms.
  • the initiating sidelink UE transmits information 404 during a first period of time 406 with a duration of Y ms.
  • the initiating sidelink UE allows other UEs to transmit during a shared COT 408.
  • a first responding sidelink UE transmits information 410 during a first portion (e.g., one or more slots) of the shared COT 408 and a second responding sidelink UE (UE2) transmits information 412 during a second portion (e.g., one or more slots) of the shared COT 408.
  • the initiating sidelink UE may send sidelink control information (SCI) that carries information indicating when the UE’s transmission will end (e.g., the end of the first period of time 406) and the length of the remaining COT (e.g., the shared COT 408) .
  • SCI sidelink control information
  • FIG. 5 illustrates an example of COT sharing 500 in the frequency domain (e.g., FDM COT sharing) .
  • an initiating sidelink UE has reserved a COT 502.
  • the initiating sidelink UE transmits information during a first period of time 508.
  • the initiating sidelink UE may transmit control information (e.g., PSCCH) during the shaded boxes (e.g., control information 504) .
  • the initiating sidelink UE may transmit data (e.g., PSSCH) during the unshaded boxes (e.g., data 506) .
  • control information e.g., PSCCH
  • data e.g., PSSCH
  • the initiating sidelink UE allows other UEs to transmit during a shared COT 510.
  • a first responding sidelink UE may transmit information 512 via a first frequency band during the shared COT 510 and a second responding may transmit information 514 via a second frequency band during the shared COT 510.
  • interlace-based COT sharing may be supported between sidelink UEs in some examples.
  • FIG. 5 illustrates an example where two interlaces (interlace 0 and interlace 1) are defined in the frequency domain.
  • the first responding sidelink UE may be allowed to transmit on interlace 0 (e.g., as indicated by the unshaded boxes during the shared COT 510) and the second responding sidelink UE may be allowed to transmit on interlace 1 (e.g., as indicated by the hatched boxes during the shared COT 510) .
  • short transmission gaps may be introduced when multiple UEs are allowed to transmit on different interlaces.
  • the initiating sidelink UE may send SCI that carries information for supporting interlace-based COT sharing.
  • a gap 602 may be defined between a transmission 604 by the initiating sidelink UE and a shared COT 606.
  • LBT e.g., Cat. 2 LBT
  • the transmission starting time during the shared COT 606 may be limited (e.g., to a single point in time or to a specific set of points in time) .
  • a first responding sidelink UE may attempt to transmit information 608 during the shared COT 606 and a second responding sidelink UE may attempt to transmit information 610 during the shared COT 606.
  • the first responding sidelink UE and the second responding sidelink UE may end up transmitting at the same time.
  • a gNB controls which UEs can share a COT at a particular time (e.g., by dynamically scheduling a UE for an UL transmission, or RRC configuring a limited set of UEs for UL transmissions) .
  • sidelink COT sharing e.g., for both FDM and TDM COT sharing
  • a responding sidelink UE’s attempts to share a COT initiation might not be controlled.
  • the transmission by a responding sidelink UE transmission might not be controlled by a gNB.
  • the likelihood of a collision in NR-U sidelink COT sharing may depend on how many sidelink UEs that have traffic to send are in the neighborhood of the initiating sidelink UE.
  • the disclosure relates in some aspects to a COT sharing congestion control mechanism for responding sidelink UEs.
  • multiple sidelink UEs may use the same start point (e.g., start time) or the same limited set of start points defined for a slot of a shared COT. Consequently, there may be collisions since COT sharing sidelink UEs that start at the same time might not detect each other.
  • each of the sidelink UEs may use a one-shot LBT procedure and each of these one-shot LBT procedures may be aligned in time immediately before the selected start point.
  • the disclosure relates in some aspects to a back-off mechanism for mitigating the impact of such a potential collision.
  • a back-off mechanism may be used by each responding sidelink UE that attempts to use the shared COT. That is, responding sidelink UEs may use this back-off mechanism for congestion control on future instances of a COT. Two examples of such a back-off mechanism follow.
  • FIG. 7 illustrates a first example 700 (Option 1) of a back-off mechanism.
  • Option 1 may be referred to as a two-level scheme since it involves selection of a slot and a start point for that slot.
  • a transmission 702 by an initiating sidelink UE precedes a shared COT 704 reserved by the initiating sidelink UE.
  • Several slots (slot N, slot N+1, slot N+2, and slot N+3) are defined within the shared COT 704.
  • several start points are defined for each slot. For example, a first set of start points 706A is defined for the slot N, a second set of start points 706B is defined for the slot N+1, a third set of start points 706C is defined for the slot N+2, and a fourth set of start points 706D is defined for the slot N+3.
  • a sidelink UE determines which slot to use for an LBT procedure for a transmission during the shared COT 704. In some examples, this determination may be based on a first back-off value.
  • the first back-off value may be updated based on the LBT results.
  • the sidelink UE may determine which start point of the set of start points designated for that slot to use for the LBT procedure for the transmission. In some examples, this determination may be based on a second back-off value.
  • a start point e.g., a start point 3 of the second set of start points 706B
  • the second back-off value may be updated based on the LBT results.
  • FIG. 8 illustrates a second example 700 (Option 2) of a back-off mechanism.
  • Option 2 may be referred to as a unified (or one-level) scheme since it involves direct selection of start point from a set of start points for a shared COT.
  • a set of start points may be defined to include all of the start points for the different slots in the shared COT.
  • Several slots (slot N, slot N+1, slot N+2, and slot N+3) are defined within the shared COT 804.
  • a set of start points 806 is defined for all of the slots.
  • the index of the start points may be in increasing order from the first start point for the first slot of the COT to the last start point for the last slot of the COT.
  • start points 0 -3 are defined for the slot N
  • start points 4 -7 are defined for the slot N+1
  • start points 8 -11 are defined for the slot N+2
  • start points 12 -15 are defined for the slot N+3.
  • a sidelink UE determines from this set of start points which start point to use for an LBT procedure for a transmission during the shared COT 804. In some examples, this determination may be based on a back-off value.
  • the back-off value can be updated based on the LBT results.
  • the disclosure relates in some aspects to specifying a back-off value.
  • a back-off value For example, one or more of the back-off values described above may be specified (e.g., defined or updated) based on one or more factors. Several examples follow.
  • a back-off value may depend on the success of a sidelink data transmission in at least one previous shared COT.
  • a back-off value may be increased (e.g., thereby delaying the start of the LBT procedure in a subsequent shared COT) if a transmission is unsuccessful or decreased (e.g., thereby advancing the start of the LBT procedure in a subsequent shared COT) if a transmission is successful.
  • the back-off value may be increased if there is collision (e.g., represented by decoding failure) .
  • a sidelink UE may randomly determine the back-off value for a current shared COT as discussed above and then increase that value upon determining that a receiver (e.g., at a sidelink device) did not successfully receive the transmission for a previous shared COT (e.g., as indicated by a NACK from the receiver) .
  • the back-off value may be increased if an LBT procedure failed.
  • a sidelink UE may randomly determine the back-off value for a current shared COT as discussed above and then increase that value upon determining that the LBT procedure indicated that the channel was busy.
  • the back-off value may be decreased (or the back-off window reset) if there is no collision (e.g., represented by no decoding failure) .
  • a sidelink UE may randomly determine the back-off value for a current shared COT as discussed above and then decrease that value upon determining that a receiver (e.g., at a sidelink device) successfully received the transmission for a previous shared COT (e.g., as indicated by an ACK from the receiver) .
  • a back-off value may depend on a priority (e.g., a data priority and/or a device priority) .
  • a priority e.g., a data priority and/or a device priority
  • different back-off values may be specified for different priority data or different priority sidelink UEs.
  • a lower back-off value may be defined for higher priority data and a higher back-off value may be defined for lower priority data.
  • a lower back-off value may be defined for a higher priority user and a higher back-off value may be defined for a lower priority user.
  • the sidelink UE may use the value specified for the corresponding priority.
  • the sidelink UE may adjust a randomly determined back-off value by an adjustment value specified for the corresponding priority.
  • Multiple priorities and corresponding multiple back-off values or back-off adjustment values may be used in some implementations.
  • a back-off value may depend on the distance between sidelink UEs (e.g., the distance to the sidelink UE that initiated the shared COT) . For example, a lower back-off value may be used if the current UE is relatively close (e.g., related to a threshold) to the COT initiating sharing sidelink UE. In some aspects, this scheme may facilitate localized sharing. In some examples, when a sidelink UE determines the back-off value for a current shared COT, the sidelink UE may use a value that is specified for scenarios where the distance is less than or equal to a threshold.
  • the sidelink UE may adjust a randomly determined back-off value by an adjustment value that is specified for scenarios where the distance is less than or equal to a threshold.
  • Multiple thresholds and corresponding multiple back-off values or back-off adjustment values may be used in some implementations.
  • FIG. 9 is a diagram illustrating an example of a hardware implementation for a wireless communication device 900 (e.g., a sidelink device) employing a processing system 914.
  • the wireless communication device 900 may be a UE or a V2X device as discussed in any one or more of FIGs. 1 -8.
  • an element, or any portion of an element, or any combination of elements may be implemented with a processing system 914 that includes one or more processors 904.
  • the wireless communication device 900 may correspond to one or more of the UE 122, 124, 126, 128, 130, 132, 134, 138, 140, or 142 of FIG. 1 or the V2X devices of FIG. 2.
  • the wireless communication device 900 may be implemented with a processing system 914 that includes one or more processors 904.
  • processors 904 include microprocessors, microcontrollers, digital signal processors (DSPs) , field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure.
  • DSPs digital signal processors
  • FPGAs field programmable gate arrays
  • PLDs programmable logic devices
  • state machines gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure.
  • the wireless communication device 900 may be configured to perform any one or more of the functions described herein. That is, the processor 904, as utilized in a wireless communication device 900, may be used to implement any one or more of the processes and procedures described below.
  • the processing system 914 may be implemented with a bus architecture, represented generally by the bus 902.
  • the bus 902 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 914 and the overall design constraints.
  • the bus 902 communicatively couples together various circuits including one or more processors (represented generally by the processor 904) , a memory 905, and computer-readable media (represented generally by the computer-readable medium 906) .
  • the bus 902 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.
  • a bus interface 908 provides an interface between the bus 902 and a transceiver 910 and between the bus 902 and an interface 930.
  • the transceiver 910 provides a communication interface or means for communicating with various other apparatus over a wireless transmission medium.
  • the wireless communication device may include two or more transceivers 910, each configured to communicate with a respective network type (e.g., terrestrial or non-terrestrial) .
  • the interface 930 provides a communication interface or means of communicating with various other apparatuses and devices (e.g., other devices housed within the same apparatus as the wireless communication device or other external apparatuses) over an internal bus or external transmission medium, such as an Ethernet cable.
  • the interface 930 may include a user interface (e.g., keypad, display, speaker, microphone, joystick) .
  • a user interface is optional, and may be omitted in some examples, such as an IoT device.
  • the processor 904 is responsible for managing the bus 902 and general processing, including the execution of software stored on the computer-readable medium 906.
  • the software when executed by the processor 904, causes the processing system 914 to perform the various functions described below for any particular apparatus.
  • the computer-readable medium 906 and the memory 905 may also be used for storing data that is manipulated by the processor 904 when executing software.
  • One or more processors 904 in the processing system may execute software.
  • Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
  • the software may reside on a computer-readable medium 906.
  • the computer-readable medium 906 may be a non-transitory computer-readable medium.
  • a non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip) , an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD) ) , a smart card, a flash memory device (e.g., a card, a stick, or a key drive) , a random access memory (RAM) , a read only memory (ROM) , a programmable ROM (PROM) , an erasable PROM (EPROM) , an electrically erasable PROM (EEPROM) , a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer.
  • a magnetic storage device e.g., hard disk, floppy disk, magnetic strip
  • an optical disk e.g.
  • the computer-readable medium 906 may reside in the processing system 914, external to the processing system 914, or distributed across multiple entities including the processing system 914.
  • the computer-readable medium 906 may be embodied in a computer program product.
  • a computer program product may include a computer-readable medium in packaging materials.
  • the wireless communication device 900 may be configured to perform any one or more of the operations described herein (e.g., as described above in conjunction with FIGs. 1 -8 and as described below in conjunction with FIG. 10) .
  • the processor 904 as utilized in the wireless communication device 900, may include circuitry configured for various functions.
  • the processor 904 may include communication and processing circuitry 941 configured to communicate over a sidelink carrier to exchange sidelink control information and sidelink data with other sidelink devices.
  • the communication and processing circuitry 941 may be configured to transmit a PSCCH, which may include a sidelink synchronization signal block (S-SSB) , other control information, and/or pilot signals, and/or a PSSCH, which may include sidelink data, within a radio frame based on sidelink transmission timing.
  • the sidelink transmission timing may be determined based on synchronization to a synchronization source (e.g., gNB, eNB, GNSS, etc.
  • a synchronization source e.g., gNB, eNB, GNSS, etc.
  • the communication and processing circuitry 941 may further be configured to execute communication and processing software 951 stored on the computer-readable medium 906 to implement one or more functions described herein.
  • the communication and processing circuitry 941 may obtain information from a component of the wireless communication device 900 (e.g., from the transceiver 910 that receives the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium) , process (e.g., decode) the information, and output the processed information.
  • the communication and processing circuitry 941 may output the information to another component of the processor 904, to the memory 905, or to the bus interface 908.
  • the communication and processing circuitry 941 may receive one or more of signals, messages, other information, or any combination thereof.
  • the communication and processing circuitry 941 may receive information via one or more channels.
  • the communication and processing circuitry 941 may include functionality for a means for receiving.
  • the communication and processing circuitry 941 may obtain information (e.g., from another component of the processor 904, the memory 905, or the bus interface 908) , process (e.g., encode) the information, and output the processed information.
  • the communication and processing circuitry 941 may output the information to the transceiver 910 (e.g., that transmits the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium) .
  • the communication and processing circuitry 941 may send one or more of signals, messages, other information, or any combination thereof.
  • the communication and processing circuitry 941 may send information via one or more channels.
  • the communication and processing circuitry 941 may include functionality for a means for sending (e.g., a means for transmitting) .
  • the processor 904 may include timing control circuitry 942 configured to perform timing control-related operations as discussed herein.
  • the timing control circuitry 942 may include functionality for a means for determining a start time (e.g., based on Option 1 or Option 2) .
  • the timing control circuitry 942 may further be configured to execute timing control software 952 included on the computer-readable medium 906 to implement one or more functions described herein.
  • the processor 904 may include access control circuitry 943 configured to perform access control-related operations as discussed herein.
  • the access control circuitry 943 may include functionality for a means for commencing sensing of a channel (e.g., by performing an LBT procedure at a designated start time) .
  • the access control circuitry 943 may include functionality for a means for selectively transmitting on a channel (e.g., transmitting on the channel if an LBT procedure indicated that the channel was available or not transmitting on the channel if an LBT procedure indicated that the channel was busy) .
  • the access control circuitry 943 may further be configured to execute access control software 953 included on the computer-readable medium 906 to implement one or more functions described herein.
  • FIG. 10 is a flow chart 1000 of a method for wireless communication (e.g., over a sidelink carrier) .
  • a method for wireless communication e.g., over a sidelink carrier
  • some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments.
  • the method may be performed by the wireless communication device 900, as described above and illustrated in FIG. 9, by a processor or processing system, or by any suitable means for carrying out the described functions.
  • a wireless communication device may receiving an indication that a second wireless communication device has reserved a channel (e.g., a shared channel such as a channel on an unlicensed RF spectrum) for a period of time comprising a plurality of slots.
  • the period of time may include (e.g., may be) a channel occupancy time.
  • the timing control circuitry 942 in cooperation with the communication and processing circuitry 941 and the transceiver 910, shown and described above in connection with FIG. 13, may receive an SCI from a sidelink device that indicates that the sidelink device reserved a COT (e.g., independently or in cooperation with another device) and has designated at least a portion of the COT as a shared COT.
  • the wireless communication device may determine a start time for sensing the channel prior to a particular slot of the plurality of slots.
  • the timing control circuitry 942 shown and described above in connection with FIG. 13, may perform operations as described herein for Option 1 or Option 2 to determine a start time associated with a COT.
  • determining the start time for sensing the channel may include selecting the start time from a plurality of start times associated with the period of time. In some examples, selecting the start time from the plurality of start times may include randomly selecting the start time from the plurality of start times. In some examples, the plurality of start times may include a first set of start times that precedes a first slot of the plurality of slots and a second set of start times that precedes a second slot of the plurality of slots, where the second slot follows the first slot. In some examples, determining the start time for sensing the channel may include randomly selecting the start time from the first set of start times and the second set of start times.
  • determining the start time for sensing the channel may include selecting a slot of the plurality of slots. In some examples, selecting the slot of the plurality of slots may include randomly selecting the slot of the plurality of slots. In some examples, a first set of start times precedes a first slot of the plurality of slots and a second set of start times precedes a second slot of the plurality of slots. In some examples, selecting the slot may include selecting the first slot and determining the start time for sensing the channel may include selecting the start time from the first set of start times after selecting the first slot.
  • the wireless communication device may commence sensing of the channel based on the start time.
  • the access control circuitry 943 shown and described above in connection with FIG. 13, may initiate an LBT procedure at a time that is based on the start time determined at block 1004.
  • the wireless communication device may selectively transmit on the channel during the period of time based on the sensing of the channel.
  • the access control circuitry 943 in cooperation with the communication and processing circuitry 941 and the transceiver 910, shown and described above in connection with FIG. 13, may conduct a transmission during a COT if an LBT procedure (e.g., initiated at block 1006) indicated that the corresponding channel was available.
  • the access control circuitry 943 in cooperation with the communication and processing circuitry 941 and the transceiver 910, shown and described above in connection with FIG. 13, may abstain from transmitting during a COT if an LBT procedure (e.g., initiated at block 1006) indicated that the corresponding channel was busy.
  • selectively transmitting on the channel during the period of time based on the sensing of the channel may include determining that the sensing of the channel indicates that the channel is available and commencing the transmitting on the channel during the period of time after determining that the sensing of the channel indicates that the channel is available.
  • selectively transmitting on the channel during the period of time based on the sensing of the channel may include determining that the sensing of the channel indicates that the channel is busy and refraining from the transmitting on the channel during the period of time after determining that the sensing of the channel indicates that the channel is busy.
  • the process may further include determining that the sensing of the channel indicates that the channel is busy and delaying another start time for another sensing of the channel for another period of time after determining that the sensing of the channel indicates that the channel is busy.
  • selectively transmitting on the channel during the period of time may include transmitting data on the channel.
  • the process may further include determining that the data was not successfully received by a receiver and delaying another start time for another sensing of the channel for another period of time after determining that the data was not successfully received by the receiver.
  • selectively transmitting on the channel during the period of time may include transmitting data on the channel.
  • the process may further include determining that the data was successfully received by a receiver and advancing another start time for another sensing of the channel for another period of time after determining that the data was successfully received by the receiver.
  • the process may further include determining a priority associated with the transmitting on the channel during the period of time. In this case, determining the start time for sensing the channel may include determining the start time based on the priority. In some examples, the priority may be associated with at least one of data to be transmitted during the transmitting on the channel, the first wireless communication device, the second wireless communication device, or any combination thereof. In some examples, determining the start time based on the priority may include determining that the priority is a first priority of a set of priorities and advancing the start time after determining that the priority is the first priority. In some examples, the process may further include determining that the priority is a second priority of a set of priorities and delaying the start time after determining that the priority is the second priority.
  • the process may further include determining a distance between the first wireless communication device and the second wireless communication device.
  • determining the start time for sensing the channel may include determining the start time based on the distance.
  • determining the start time based on the distance may include determining that the distance is less than or equal to a threshold and advancing the start time after determining that the distance is less than or equal to the threshold.
  • various aspects may be implemented within other systems defined by 3GPP, such as Long-Term Evolution (LTE) , the Evolved Packet System (EPS) , the Universal Mobile Telecommunication System (UMTS) , and/or the Global System for Mobile (GSM) .
  • LTE Long-Term Evolution
  • EPS Evolved Packet System
  • UMTS Universal Mobile Telecommunication System
  • GSM Global System for Mobile
  • Various aspects may also be extended to systems defined by the 3rd Generation Partnership Project 2 (3GPP2) , such as CDMA2000 and/or Evolution-Data Optimized (EV-DO) .
  • 3GPP2 3rd Generation Partnership Project 2
  • EV-DO Evolution-Data Optimized
  • Other examples may be implemented within systems employing IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Ultra-Wideband (UWB) , Bluetooth, and/or other suitable systems.
  • Wi-Fi IEEE 802.11
  • WiMAX IEEE 8
  • the word “exemplary” is used to mean “serving as an example, instance, or illustration. ” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term “aspects” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.
  • the term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B, and object B touches object C, then objects A and C may still be considered coupled to one another-even if they do not directly physically touch each other. For instance, a first object may be coupled to a second object even though the first object is never directly physically in contact with the second object.
  • circuit and “circuitry” are used broadly, and intended to include both hardware implementations of electrical devices and conductors that, when connected and configured, enable the performance of the functions described in the present disclosure, without limitation as to the type of electronic circuits, as well as software implementations of information and instructions that, when executed by a processor, enable the performance of the functions described in the present disclosure.
  • FIGs. 1 -10 may be rearranged and/or combined into a single component, step, feature or function or embodied in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from novel features disclosed herein.
  • the apparatus, devices, and/or components illustrated in any of FIGs. 1, 2, or 9 may be configured to perform one or more of the methods, features, or steps described herein.
  • the novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware.
  • “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Des aspects concernent la sélection d'une heure de début correspondant la détection d'un canal de communication sans fil. Par exemple, un premier dispositif de liaison latérale peut sélectionner une heure de début pour une détection de canal pour une transmission pendant un temps d'occupation de canal (COT) réservé sur un canal par un second dispositif de liaison latérale. Dans certains exemples, le premier dispositif de liaison latérale sélectionne une heure d'une pluralité d'heures de début associées au COT. Dans certains exemples, le premier dispositif de liaison latérale sélectionne un intervalle du COT et sélectionne ensuite une heure d'un ensemble d'heures de début associées à cet intervalle. Une fois que le premier dispositif de liaison latérale sélectionne une heure de début, le premier dispositif de liaison latérale peut commencer une procédure LBT (par exemple, à l'heure de début) pour déterminer si le canal est disponible pendant le COT pour une transmission par le premier dispositif de liaison latérale.
PCT/CN2020/090140 2020-05-14 2020-05-14 Sélection d'une heure de début correspondant à la détection de canal WO2021226906A1 (fr)

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WO2023229795A1 (fr) * 2022-05-26 2023-11-30 Qualcomm Incorporated Liaison latérale hors réservation de temps d'occupation de canal
WO2024072828A1 (fr) * 2022-09-30 2024-04-04 Qualcomm Incorporated Partage de temps d'occupation de canal dans un spectre sans licence
WO2024067369A1 (fr) * 2022-09-27 2024-04-04 展讯通信（上海）有限公司 Procédé et appareil de traitement de signal, et dispositif

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Publication number Priority date Publication date Assignee Title
WO2023229795A1 (fr) * 2022-05-26 2023-11-30 Qualcomm Incorporated Liaison latérale hors réservation de temps d'occupation de canal
WO2024067369A1 (fr) * 2022-09-27 2024-04-04 展讯通信（上海）有限公司 Procédé et appareil de traitement de signal, et dispositif
WO2024072828A1 (fr) * 2022-09-30 2024-04-04 Qualcomm Incorporated Partage de temps d'occupation de canal dans un spectre sans licence

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