WO2021142698A1

WO2021142698A1 - Transmitter resource conflict avoidance in c-v2x

Info

Publication number: WO2021142698A1
Application number: PCT/CN2020/072414
Authority: WO
Inventors: Jintao HOU; Zengyu Hao; Feng Chen; Yi Qin; Chunxia LI; Haizhou LIU; Hongjin GUO; Xiaochen Chen
Original assignee: Qualcomm Incorporated
Priority date: 2020-01-16
Filing date: 2020-01-16
Publication date: 2021-07-22

Abstract

Aspects of the disclosure relate to a vehicle-to-everything (V2X) device that may identify a first set of candidate resources for transmission of a V2X communication and obtain a second set of candidate resources from the first set by removing the candidate resources that have a greater likelihood of collision than the candidate resources remaining in the first set. A first candidate resource may be selected from the second set of candidate resources. The V2X device may reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, and may transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices, and transmit and retransmit the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.

Description

TRANSMITTER RESOURCE CONFLICT AVOIDANCE IN C-V2X

TECHNICAL FIELD

The technology discussed below relates generally to wireless communication networks, and more particularly, to Cellular-Vehicle-to-Everything (C-V2X) wireless communication.

INTRODUCTION

Cellular-Vehicle-to-Everything (C-V2X) communication involves the wireless exchange of information between not only vehicles themselves, but also between vehicles and external systems, such as streetlights, buildings, pedestrians, and wireless communication networks. C-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 and increase vehicle safety.

C-V2X is a technology that may be used by Vehicle-to-Everything (V2X) networks. C-V2X is based on Long Term Evolution (LTE) and/or 5G (New Radio) standards. C-V2X is designed to be compatible with both 4G LTE and emerging New Radio (NR) technologies, enabling C-V2X devices to support both C-V2X connections and LTE and/or NR connections.

Within a V2X network, control information may be communicated between V2X devices through a physical sidelink control channel (PSCCH) , while data may be communicated between V2X devices through a physical sidelink shared channel (PSSCH) . V2X transmissions may be reserved; however, despite reservations of resources, collisions between traffic transmitted by two or more V2X devices using the same time and frequency resources may still occur. As the demand for V2X communication increases, research and development continue to advance V2X technologies not only to meet the growing demand for V2X, but also to advance and enhance the V2X performance capability.

BRIEF SUMMARY OF SOME EXAMPLES

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

Various aspects of the disclosure relate to a method of vehicle-to-everything (V2X) wireless communication, which may be operational at a V2X device. In some examples, the method may include identifying a first set of candidate resources for transmission of a V2X communication and obtaining a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than the candidate resources remaining in the first set. The method may further include selecting a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication and reserving, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively. In addition, the method may further include transmitting a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices and transmitting and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.

In one example, a vehicle-to-everything (V2X) device for V2X wireless communication is disclosed. The V2X device may include a processor, a transceiver communicatively coupled to the processor, and a memory communicatively coupled to the processor. In some examples, the processor and the memory may be configured to identify a first set of candidate resources for transmission of a V2X communication and obtain a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than the candidate resources remaining in the first set. The processor and the memory may further be configured to select a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication. Furthermore, the processor and the memory may also be configured to reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively. According to some aspects, the processor and the memory of the V2X device may also be configured to transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices and transmit and retransmit the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.

According to still another example, a vehicle-to-everything (V2X) device for V2X wireless communication may include means for identifying a first set of candidate resources for transmission of a V2X communication and means for obtaining a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set. The V2X device may also include means for selecting a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication and means for reserving, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively. In some examples, the V2X device may also include means for transmitting a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices as well as means for transmitting and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.

Still other aspects disclosed herein relate to an article of manufacture for use by a vehicle-to-everything (V2X) device for V2X wireless communication. In some examples, the article of manufacture may include a non-transitory computer-readable medium having stored therein instructions executable by one or more processors of the V2X device. The executable instructions may cause the V2X device to identify a first set of candidate resources for transmission of a V2X communication and obtain a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set. The executable instructions may still further cause the V2X device to select a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication and reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively. Still further, the executable instructions may cause the V2X device to transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices and transmit and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.

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

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless radio access network.

FIG. 2 is a diagram illustrating an example of a vehicle-to-everything (V2X) wireless communication network.

FIG. 3 is a schematic diagram illustrating organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM) .

FIG. 4A is a schematic diagram of a resource grid depicting resource allocations for V2X devices that autonomously select radio resources according to some aspects of the present disclosure.

FIG. 4B depicts the resource grid of FIG. 4A and extends the resource grid along the time axis.

FIG. 5 is a block diagram illustrating an example of a hardware implementation for a V2X device employing a processing system according to some aspects of the present disclosure.

FIG. 6 is a flow chart of an exemplary method for V2X wireless communication, operational at V2X device according to some aspects of the present disclosure.

FIG. 7 is a flow chart of another exemplary method for V2X wireless communication, operational at a V2X device according to some aspects of the present disclosure.

DETAILED DESCRIPTION

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

While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described aspects. For example, 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. ) . It is intended that 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. Referring now to FIG. 1, as an illustrative example without limitation, a schematic illustration of a radio access network (RAN) 100 is provided. The RAN 100 may implement any suitable wireless communication technology or technologies to provide radio access. As one example, the RAN 100 may operate according to 3 ^rd Generation Partnership Project (3GPP) New Radio (NR) specifications, often referred to as 5G. As another example, 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. Of course, many other examples may be utilized within the scope of the present disclosure.

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. In a cell that is divided into sectors, 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.

In general, a respective base station (BS) serves each cell. Broadly, 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.

In FIG. 1, 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. In the illustrated example, the

cells

102, 104, and 106 may be referred to as macrocells, as the

base stations

110, 112, and 114 support cells having a large size. Further, 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. In this example, 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. It is to be understood that the radio access network 100 may include any number of wireless base stations and cells. Further, 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 a quadcopter or drone 120, which may be configured to function as a base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile base station such as the quadcopter 120.

In general, 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. A UE may be an apparatus that provides a user with access to network services.

Within the present document, 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. For example, some non-limiting examples of a mobile apparatus include 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) . 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. 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. Still further, 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.

Within the RAN 100, the cells may include UEs that may be in communication with one or more sectors of each cell. For example,

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 mobile base station 120. Here, 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.

In another example, a mobile network node (e.g., quadcopter 120) may be configured to function as a UE. For example, the quadcopter 120 may operate within cell 102 by communicating with base station 110. In some aspects of the present disclosure, two or more UE (e.g., UEs 126 and 128) may communicate with each other using peer to peer (P2P) or sidelink signals 127 without relaying that communication through a base station (e.g., base station 112) .

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) may be referred to as downlink (DL) transmission, while transmissions of control information and/or traffic information originating at a UE (e.g., UE 122) may be referred to as uplink (UL) transmissions. In addition, the uplink and/or downlink control information and/or traffic information may be time-divided into frames, subframes, slots, and/or symbols. As used herein, 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. Of course, these definitions are not required, and any suitable scheme for organizing waveforms may be utilized, and various time divisions of the waveform may have any suitable duration.

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. For example, multiple access for uplink (UL) or reverse link transmissions from

UEs

122 and 124 to base station 110 may be provided utilizing time division multiple access (TDMA) , code division multiple access (CDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , sparse code multiple access (SCMA) , single-carrier frequency division multiple access (SC-FDMA) , resource spread multiple access (RSMA) , or other suitable multiple access schemes. Further, multiplexing downlink (DL) or forward link 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) , single-carrier frequency division multiplexing (SC-FDM) or other suitable multiplexing schemes.

Further, 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. In a wireless link, 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) . In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated from one another using time division multiplexing. That is, at sometimes 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 per subframe.

In various implementations, the air interface in the radio access network 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. For example, 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.

In order for transmissions over the RAN 100 to obtain a low block error rate (BLER) while still achieving very high data rates, channel coding may be used. That is, wireless communication may generally utilize a suitable error correcting block code. In a typical block code, an information message or sequence is split up into code blocks (CBs) , and an encoder (e.g., a CODEC) at the transmitting device then mathematically adds redundancy to the information message. Exploitation of this redundancy in the encoded information message can improve the reliability of the message, enabling correction for any bit errors that may occur due to the noise.

In some examples, access to the air interface may be scheduled, wherein a scheduling entity (e.g., a base station) allocates resources (e.g., time–frequency resources) for communication among some or all devices and equipment within its service area or cell. Within the present disclosure, as discussed further below, 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. For example, 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

UEs

140 and 142 may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE, which may be stationary, may function as a scheduling entity in a device-to-device (D2D) , peer-to-peer (P2P) , or vehicle-to-vehicle (V2V) network, a vehicle-to-everything (V2X) , enhanced V2X (eV2X) , LTE V2X, NR V2X, cellular V2X (C-V2X) , and/or in a mesh network. In a mesh network example,

UEs

140 and 142 may optionally communicate directly with one another in addition to communicating with the scheduling entity 138.

Various aspects of the present disclosure may relate to New Radio (NR) cellular V2X (C-V2X) or other V2X standards, collectively referred to herein as V2X. In some examples, V2X communications may be enabled by sidelink communications scheduled by a roadside unit (RSU) , which may be, for example, a stationary UE operating as a scheduling entity for V2X communication. However, use of an RSU is not mandatory and in many use cases a UE (which may not be categorized as an RSU) may operate as a scheduling entity. It should be understood that the concepts disclosed herein may not be limited to a particular V2X or C-V2X standard.

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 204/205 (vehicle-to-infrastructure (V2I) ) , to pedestrians/cyclists 206 (vehicle-to-pedestrian (V2P) ) , and/or to the network 208 (vehicle-to-network (V2N) ) .

A V2X transmissions may include, for example, unicast transmissions, groupcast transmissions, and broadcast transmissions. Unicast describes a transmission, for example, from a vehicle (e.g., vehicle 202a) to one other vehicle (e.g., vehicle 202b) . Groupcast arises when a group of UEs (e.g., vehicles 202a–202d) form a cluster. Data may be groupcasted within the cluster. Broadcast describes a transmission from, for example, a UE (e.g., vehicle 202a) to surrounding receivers (e.g., vehicle 202b-202d, RSU 204, mobile devices 206 of pedestrians/cyclists, the network 208, or any combination thereof) in proximity to the transmitting UE. The preceding lists were illustrative and non-limiting.

A V2I transmission may be between a vehicle (e.g., vehicle 202a) and an RSU 204, which may be coupled to various infrastructure 205, such as a traffic light, building, streetlight, traffic camera, tollbooth, or other stationary object. The 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 pedestrians 206. Examples of 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.

Such V2X data may enable autonomous driving and improve road safety and traffic efficiency. For example, 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. In addition, V2X data received by a V2X connected 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 on a pedestrian 206) for latency-tolerant use cases. For example, 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. In addition, V2N communication may provide backhaul services for RSUs 204.

Multiple use cases may derive advantages from V2X communications. The use cases include, but are not limited to, vehicle platooning, extended sensors, advanced driving, and remote driving. Vehicles platooning enables vehicles (e.g., vehicles 202a-202d) to dynamically form a group or cluster travelling together. All the vehicles in the platoon may receive periodic data from a leading vehicle, in order to carry on platoon operations. This data allows the distance between vehicles to be reduced to distances that are less than what might be considered as safe separation distances for non-platooned vehicles. Platooning applications may allow the vehicles following the leading vehicle to be autonomously driven.

Extended sensors may enable the exchange of raw or processed data gathered through local sensors (e.g., RSU 204) or live video data among vehicles (e.g., vehicles 202a-202d) , RSUs (e.g., RSU 204) , devices of pedestrians (e.g., pedestrian 206) , and V2X application servers (not shown) . Use of these extended sensors may allow a vehicle to enhance its perception of its local environment, beyond what tis own sensors can detect, to provide a more holistic view of the local environment.

Advanced driving may enable semi-automated or fully-automated driving. Longer inter-vehicle distance may be assumed. Each vehicle (e.g., vehicles 202a-202d) and/or RSU (e.g., RSU 204) shares data obtained from its local sensors with vehicles in proximity, thus allowing vehicles to coordinate their trajectories or maneuvers. In addition, each vehicle may share its driving intention with vehicles in proximity. The benefits of this use case group may include safer traveling, collision avoidance, and improved traffic efficiency.

Remote driving enables a remote driver or a V2X application to operate a remote vehicle for those passengers who cannot drive themselves or a remote vehicle located in dangerous environments, or remote trucking vehicle. For a case where variation is limited and routes are predictable, such as public transportation, driving based on cloud computing may be used. In addition, access to cloud-based back-end service platforms may be considered for this use case group.

A UE may support V2X, non-V2X (e.g., 4G, LTE, LTE Advanced, 5G) , or both types of communications. V2X and non-V2X communications may occur in the same radio bands. Accordingly, radio spectrum may be shared by V2X and non-V2X communication devices and systems. However, without coordination, multiple transmitters may all transmit at the same time and in the same radio channels as one another. To avoid this, and to provide interoperability between devices and systems, a base station (e.g., eNB or gNB) may allocate one or more resource blocks (e.g., predefined segments in the frequency and time domains) during a given transmission time interval (TTI) for V2X communication. This may help to prevent interference between V2X and non-V2X communications, but collisions may still occur when two or more UEs attempt to transmit and/or receive V2X data in the allocated V2X resource blocks. For example, collisions may occur between transmission and/or reception of V2X data of the two or more UEs attempting to use the same V2X resource blocks at the same time and in the same frequencies.

In various aspects of the disclosure, for V2X transmissions from a given device (e.g., a UE, a vehicle, an RSU, etc. ) , in unicast, groupcast, and broadcast type transmissions, the given V2X device may measure at least one of the Received Signal Strength Indicator (RSSI) , the Reference Signal Received Power (RSRP) , or the Reference Signal Received Quality (RSRQ) to detect which allocated V2X resources (e.g., in terms of resource blocks, subchannels, times) are being utilized by other V2X devices. The given V2X device may then avoid using the resources already in use. In this way, resource conflicts may be prevented in many cases. However, in field testing of devices using V2X communications, instances may still occur in which two or more V2X devices select the same resource to transmit data. In these instances, collisions occur and the transmitted data from a first V2X device may not be successfully decoded by an intended recipient (one more other V2X devices) due to the interference caused by the collision.

Various aspects of the present disclosure will be described with reference to an OFDM waveform, schematically illustrated in FIG. 3. It should be understood by those of ordinary skill in the art that the various aspects of the present disclosure may be applied to an SC-FDMA waveform in substantially the same way as described herein below. That is, while some examples of the present disclosure may focus on an OFDM link for clarity, it should be understood that the same principles may be applied as well to SC-FDMA waveforms. Additionally, it should be understood that V2X communication may be implemented using SC-FDMA and/or OFDMA waveforms; however, these types of waveforms are recited for exemplary and non-limiting purposes.

Referring now to FIG. 3, an expanded view of an exemplary subframe 302 is illustrated, showing an OFDM resource grid. However, as those skilled in the art will readily appreciate, the physical (PHY) transmission structure for any particular application may vary from the example described here, depending on any number of factors. Here, 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. Depending on the modulation utilized in a particular implementation, each RE may represent one or more bits of information. In some examples, 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. In one example, an RB may include 12 subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may include any suitable number of consecutive OFDM symbols in the time domain. Within the present disclosure, it is assumed that a single RB such as the RB 308 entirely corresponds to a single direction of communication (either transmission or reception for a given device) .

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. Thus, a UE or V2X device generally utilizes only a subset of the resource grid 304. In some examples, an RB may be the smallest unit of resources that can be allocated to a UE/V2X device. Thus, the more RBs scheduled for a UE/V2X device, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE/V2X device. A resource pool is a set of time-frequency resources that can be used for sidelink transmission and/or reception. From a UE’s point of view, a resource pool may be inside the UE's bandwidth, within a sidelink bandwidth part (SL BWP) and may have a single numerology. Time domain resources in a resource pool may be non-contiguous. Multiple resource pools may be (pre-) configured to a UE in a carrier.

In this illustration, the RB 308 is shown as occupying less than the entire bandwidth of the subframe 302, with some subcarriers illustrated above and below the RB 308. In a given implementation, the subframe 302 may have a bandwidth corresponding to any number of one or more RBs 308. Further, in this illustration, the RB 308 is shown as occupying less than the entire duration of the subframe 302, although this is merely one possible example.

Each 1 ms subframe 302 may consist of one or multiple adjacent slots. In the example shown in FIG. 3, one subframe 302 includes four slots 310, as an illustrative example. In some examples, a slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, 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. In general, the control region 312 may carry control channels, and the data region 314 may carry data channels. Of course, 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) .

Although not illustrated in FIG. 3, the various REs 306 within an 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) . These 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.

In some examples, the slot 310 may be utilized for broadcast, groupcast, or unicast communication. In V2X networks, a broadcast communication may refer to a point-to-multipoint transmission by one V2X device (e.g., a vehicle, roadside unit (RSU) , UE of a pedestrian/cyclist, or other V2X device) to other V2X devices. A groupcast transmission may refer to a point-to-multipoint transmission by one V2X device (e.g., a vehicle) in a cluster of devices (e.g., a cluster of vehicles) . A unicast communication may refer to a point-to-point transmission by one V2X device (e.g., a vehicle, roadside unit (RSU) , UE of a pedestrian/cyclist, or other V2X device) to a single other V2X device. In some examples, the V2X control information may be transmitted within a physical sidelink control channel (PSCCH) , while the V2X data may be transmitted within a physical sidelink shared channel (PSSCH) .

These physical channels described above are generally multiplexed and mapped to transport channels for handling at the medium access control (MAC) layer. Transport channels carry blocks of information called transport blocks (TB) . The transport block size (TBS) , which may correspond to a number of bits of information, may be a controlled parameter, based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission.

The channels or carriers illustrated in FIG. 3 are not necessarily all of the channels or carriers that may be utilized between V2X 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. V2X may be deployed in a carrier dedicated to Intelligent Transport System (ITS) services, or a carrier shared with cellular services. Therefore, resource arrangements where all the symbols in a slot are available for V2X sidelink, or where only a subset of consecutive symbols in a slot (which are not dynamically indicated) may be available for V2X sidelink.

Within a V2X network, such as the V2X network 200 illustrated in FIG. 2, the number of V2X packets that may be received and processed by a V2X device within a subframe 302 or slot 310 is directly related to the number of other nearby V2X devices broadcasting packets in the network. Resource allocation for, for example, a physical sidelink shared channel (PSSCH) may be based on a concept of sub-channels in the frequency domain, and a device (e.g., a UE, a V2X enabled UE, a V2X device) may perform either transmission or reception in a slot on a carrier. With regard to reference signals, according to one aspect, a Demodulation Reference Signal (DMRS) may be associated with a PSSCH and may be transmitted in one of several possible patterns in the time domain. Physical channels may be multiplexed. For example, a PSSCH may be associated to a PSCCH when the PSCCH carries at least the Sidelink Control information (SCI) necessary to decode the PSSCH. Several options may exist for multiplexing of the physical channels. For example, the PSCCH and the associated PSSCH may be transmitted using non-overlapping time resources (where the frequency resources may be the same or different) , the PSCCH and the associated PSSCH may be transmitted using non-overlapping frequency resources (where the time resources used by the two channels may be the same) , or part of the PSCCH and the associated PSSCH maybe transmitted using overlapping time resources in non-overlapping frequency resources, but another part of the associated PSSCH and/or another part of the PSCCH may be transmitted using non-overlapping time resources. For channel measurement purposes, Channel State information (CSI) for V2X transmissions may include, for example, Channel Quality Indicator (CQI) , Precoding Matrix Indicator (PMI) , Rank Indication (RI) , Received Signal Strength Indicator (RSSI) , Reference Signal Received Power (RSRP) , Reference Signal Received Quality (RSRQ) , path gain/path loss, interference condition, vehicle motion. By way of example, a transmitting V2X device may derive a pathloss estimation from a sidelink RSRP reported by a receiving V2X device.

A UE can be configured by higher layers with one or more PSSCH resource configuration (s) . A PSSCH resource configuration may be for reception of PSSCH, or for transmission of PSSCH. An example of a PSSCH related procedure is described below.

A UE may transmit sidelink control information (SCI) on the PSCCH that describes where PSCCH transmissions will occur. Generally, the PSCCH transmissions may occur in a set of time and frequency resources (hereinafter “resources” ) of a radio frame or portions thereof. For example, the PSCCH transmissions may occur in a set of subframes in a PSCCH period and in a set of resource blocks within the set of subframes. According to one aspect, the set of subframes and the set of resource blocks within the set of subframes for PSCCH transmission may be determined using a subframe pool indicated by a PSSCH resource configuration. A UE may follow a given procedure for determining subframes and resource blocks for transmitting PSSCH and for reserving resources for sidelink transmission.

A UE may monitor subframes in a resource pool or in an otherwise predetermined set of time frequency resources allotted to V2X transmission or reception (V2X signaling of control and data information) to determine resource block pool and subframe pool for sidelink transmissions. The UE may decode PSCCH in each monitored subframe and measure S-RSSI in the monitored subframes as well as PSSCH-RSRP. Based on these measurements, the UE may exclude single-subframe resources from a candidate list of single subframe resources for PSSCH transmission.

FIG. 4A is a schematic diagram of a resource grid 402 depicting resource allocations for V2X devices that autonomously select radio resources according to some aspects of the present disclosure. Such a resource allocation may be used by V2X devices for Mode 4 transmissions as defined by the 3GPP standard setting body. As shown in FIG. 4A, the PSCCH and PSSCH channels are separated in the frequency domain. The resource grid is vertically divided in frequency into subcarriers. According to some aspects, the subcarriers may have 15 kHz spacing. The resource grid 402 is horizontally divided in time into subframes. In the illustration of FIG. 4A, each time unit is a subframe long (e.g., 1 ms in duration) . The subframe may be divided in half (not shown) and each half is then referred to as a slot or a time slot. According to some aspects, a slot (from a perspective of a V2X device, and more generally from a perspective of a UE) may be a series of 7 single-carrier frequency division multiple access (SC-FDMA) symbols. A subframe may therefore include 14 SC-FDMA symbols. A resource block may occupy 12 sub-channels (140 kHz) in the frequency domain and 7 symbols (0.5 milliseconds) in the time domain. There may be one pair of resource blocks per subframe. According to the aspects illustrated in FIG. 4A, the lowest sub-channels (lowest frequencies) of resource blocks may be used for PSCCH transmission, the remaining sub-channels may be used for PSSCH transmission. The pattern of PSCCH resource blocks below PSSCH resource block continues vertically, along the frequency axis. It is noted that while the PSCCH and PSSCH are depicted in adjacent resource blocks, according to some aspects the PSCCH and PSSCH may be transmitted on non-adjacent resource blocks.

A V2X device transmits and receives data on the PSSCH channel. Control information on the PSCCH channel that is associated with the a given data transmission on the PSSCH channel is transmitted along with the associated data transmission. Accordingly, sidelink data in N resource blocks is accompanied by sidelink control information (SCI) that may occupy two contiguous resource blocks per time slot, as shown in FIG. 4A. In some examples, a V2X device may transmit sidelink data and the corresponding SCI in the same subframe; however, the data and the SCI may be adjacent or non-adjacent, so long as they are in the same subframe.

FIG. 4A depicts a first set of candidate resources 400 in the resource grid 402. The depicted first set of candidate resources comprise ten subframes, as shown. The first set of candidate resources may be identified in a V2X sidelink grant request sent down to the PHY layer (of the V2X device) from the higher MAC layer. The first set of candidate resources 400 may be referred to as a candidate resource pool. In the illustrated example, the candidate resource pool may be subdivided into PSCCH resource pools and PSSCH resource pools, as shown. In the example, the total resource pool is made up of ten subframes horizontally (e.g., one radio frame) and twenty four resource blocks vertically. These values were picked for illustrative purposes only. While a resource pool may be granted (defined) by a higher level entity, a given V2X device will not typically attempt to reserve the entire resource pool for its own use.

Instead, V2X devices may allocate resources from the resource pool autonomously (e.g., as in Mode 4 transmissions as mentioned above) . One method of autonomous resource allocation (or more precisely resource self-selection) may be divided into three processes: sensing, reservation, and transmission.

During sensing, each V2X device monitors the communications of all other nearby V2X devices and maintains a record of metrics associated with the monitoring. The recorded metrics may be used by the V2X device to determine a set of candidate resources that may be reserved by the V2X device. Because of the autonomous nature of the V2X resource allocation, none of the V2X devices knows which of the candidate resources have been reserved by its V2X neighbors. To avoid collision during transmission (e.g., where two nearby V2X devices transmit at the same time using the same resource) , a V2X device may use the sensing results to identify a subset of the candidate resources that appear to be the least used, or if used, have at least one of very weak signals or poor quality signals therein. It would appear to follow that using the least used candidate resource would present the least likelihood of collision risk. However, collisions may still occur, even when using the sensing method. Nevertheless, the sensing method will be briefly described, and aspects will be disclosed that may be used to improve transmitter resource conflict avoidance.

As stated above, a resource pool (a first set of candidate resources) may be established. All V2X devices monitor (sense) all resources within the resource pool and store metrics related to the monitoring. In one example, a MAC layer of a V2X device may request a sensing report from the lower PHY layer of the V2X device. The PHY layer may extract the recorded metrics to prepare the sensing report from a channel record buffer of the V2X device.

According to one aspect, the PHY layer of the V2X device may conduct an exemption procedure to remove candidate resources with a higher likelihood of causing collisions from the first set of candidate resources 400. The exemption procedure helps to narrow down the sensing report and thereby reduces the set of candidate resources that may be reported to higher layers in the sensing report.

In order to determine which candidate resources should be removed from the first set of candidate resources 400 (e.g., the resource pool) , the V2X device may apply a set of conditions to the first set of candidate resources. For example, if a value of the reference signal received power (RSRP) of the PSSCH of a given subframe is greater than or equal to a predetermined threshold value, then the given subframe may be removed from the first set of candidate resources. Of course, the predetermined threshold may be set too low, in which case the RSRP of the PSSCHs of all of the subframes in the first set of candidate resources would be greater than or equal to the predetermined threshold and the entire resource pool would be excluded from the section set of candidate resources. To prevent this, when measuring resources against a threshold, if the number of candidate resources remaining in the resource pool is less than a predetermined number (where the predetermined number may be given as a percentage of the total starting number of candidate resources in the resource pool) , the predetermined threshold may be raised, and the threshold condition may be checked again. According to one example, the predetermined threshold may be raised by 3 dB in the just described circumstance. According to one aspect, the number of candidate resources to be removed from the first set of candidate resources 400 may be limited such that at least a predetermined percentage of the original total number of candidate resources remains in the second set of candidate resources 404. In one example, the predetermined percentage is twenty percent.

According to another example, a metric, such as a linear average of the sidelink received signal strength indicator (S-RSSI) may be determined for each subframe remaining in the first set of candidate resources. The subframes may be ranked in order according to such a metric and the top twenty percent (for example) of the candidate resources with the lowest metric may be included in the second set of candidate resources.

According to still another example, the metric may be a measure of signal quality such as a reference signal received quality (RSRQ) . In such an example, only those subframes with the worst RSRQ would be added to the second set of candidate resources.

The second set of candidate resources may be sent to a higher layer (e.g., the MAC layer) for additional processing.

FIG. 4B depicts the resource grid 402 of FIG. 4A and extends the resource grid 402 along the time axis. As shown, the V2X device may remove, from the first set of candidate resources 400, those candidate resources (e.g., subframes 0, 2-6, 8, and 9) that, if used for transmission, would have a greater likelihood of collision than the remaining candidate resources (e.g., subframes 1 and 7) . According to some examples described herein, the candidate resources remaining from the first set of candidate resources 400 may be referred to as a second set of candidate resources 404. According to the present example, the second set of candidate resources includes subframes 1 and 7.

According to some aspects, the higher layer of the V2X device (e.g., the MAC layer) may receive the second set of candidate resources from the lower layer of the V2X device (e.g., the PHY layer) and may initiate a selection or re-selection process if a given trigger condition is met. The trigger conditions may include, for example, a sidelink resource reselection counter (SLRRC) reaching zero, the V2X device not transmitting or retransmitting any packets during the last second or other suitable duration of time, the V2X device has missed more reserved transmission opportunities than what is allowed by higher layers, the V2X device could not meet the latency requirement for the a previous transmission, the previously allocated resources are not sufficient for an incoming MAC protocol data unit (PDU) , or a new sidelink grant request is made or received.

Subsequent to detecting a trigger, the V2X device (e.g., the MAC layer of the V2X device) may select one candidate resource from the second set of candidate resources 404 for resource reservation. The selection may be accomplished as a random selection. In the example of FIG. 4B, the second subframe (index=1) is the selected candidate resource 406 from the second set of candidate resources 404. The V2X device (e.g., the MAC layer of the V2X device) may next periodically reserve 408 the selected candidate resource with a given period and a given number of reservations. Higher layers may set the given period and number of reservations. The given number of reservations may be determined by, for example, setting a sidelink resource reselection counter (SLRRC) . The given period may be a predefined value. For example, 20, 50, 100, 200, …, 1000 milliseconds. In FIG. 4B, the given period is depicted as 100 milliseconds, accordingly, the selected candidate resource 406 is thus reserved at subframe 1, as shown, then reserved 100 milliseconds later at subframe 101, then reserved 100 milliseconds later at subframe 201, etc. until, for example, the SLRRC runs down to zero.

The pattern established by the first reservation and following periodic reservations may be recorded or memorialized in a form of a transmission scheduling map. According to aspects described herein, the transmission scheduling map may be transmitted to one or more nearby V2X devices. The transmission may be by way of the PSSCH. According to some aspects, the V2X device may alert one or more nearby V2X devices of a possibility of transmission collision if any of the one or more nearby V2X devices transmits on any of the resources identified in the transmission scheduling map. Furthermore, the V2X device may receive unique transmission scheduling maps from the one or more nearby V2X devices, which alert the V2X device as to the candidate resources being used by the one or more nearby V2X devices for their transmissions. The V2X device may transmit and retransmit a V2X communication to the one or more nearby V2X using the reserved resources according to its transmission scheduling map and may avoid transmitting on any resources identified in the unique transmission scheduling maps of the one or more nearby V2X devices. In this way, collision avoidance during transmissions may be avoided.

FIG. 5 is a block diagram illustrating an example of a hardware implementation for a V2X device 500 employing a processing system 514 according to some aspects of the present disclosure. For example, the V2X device 500 may correspond to a vehicle, a mobile or wearable device of a passenger in the vehicle, a mobile or wearable device of a pedestrian/cyclist, or an RSU, as shown and described above in reference to FIG. 2.

The V2X device 500 may be implemented with a processing system 514 that includes one or more processors (represented generally by the processor 504) . Examples of the processor 504 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. In various examples, the V2X device 500 may be configured to perform any one or more of the functions described herein. That is, the processor 504, as utilized in the V2X device 500, may be used to implement any one or more of the processes and procedures described below.

In this example, the processing system 514 may be implemented with a bus architecture, represented generally by the bus 502. The bus 502 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 514 and the overall design constraints. The bus 502 links together various circuits including one or more processors (represented generally by the processor 504) , a memory 505, and computer-readable medium 506. The bus 502 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 508 provides an interface between the bus 502 and a transceiver 521. The transceiver 521 provides a means for communicating with various other apparatus over a transmission medium (e.g., air interface) . The bus interface 508 further provides an interface between the bus 502 and a user interface 512 (e.g., keypad, display, touch screen, speaker, microphone, control knobs, etc. ) . In addition, the bus interface 508 may provide an interface between the bus 502 and one or more peripherals. For example, peripherals may include a navigation system 522, a global positioning system (GPS) receiver 523, one or more sensors 524, a V2X system 525, and/or a camera 526. In the illustrated example, the V2X system 525 is illustrated external to the processing system 514; however, in another example, the V2X system 525 may be internal to the processing system 514, e.g., operational by the processor 504 utilizing software stored on the computer-readable medium 506.

The V2X system 525 may be configured to obtain V2X data from the navigation system 522, GPS receiver 523, sensors 524, and/or camera 526. In addition, the V2X system 525 may be configured to receive V2X data from one or more nearby V2X devices (e.g., vehicles, mobile devices of pedestrians, RSU’s, etc., within a range of the V2X system 525) or from a V2X server via the transceiver 521. In some examples, such as in which the V2X device 500 is within a vehicle, the V2X data may include one or more of a position (e.g., coordinates) of the vehicle and/or nearby vehicle (s) , a speed of the vehicle and/or nearby vehicle (s) , a trajectory of the vehicle and/or nearby vehicle (s) , a route of the vehicle and/or nearby vehicle (s) , traffic information, weather information, road hazard information, the location of one or more pedestrians or cyclists, etc. In addition, the V2X data may include video data captured from the camera 526 attached to the V2X device or received from another V2X device. The V2X data may be maintained, for example, within memory 505 and may further be transmitted to another V2X device (e.g., one or more nearby V2X devices) via the transceiver 521.

The V2X system 525 may further communicate with the user interface 512 to enable a passenger or user in the vehicle cabin to interact with the V2X system 525. For example, the V2X system 525 may provide alerts or other information obtained from the V2X data to the user via the user interface 512. In some examples, the V2X system 525 may further control one or more components (not shown) of the V2X system to facilitate automated driving and/or assisted driving (e.g., control braking and/or steering for collision-avoidance) .

The navigation system 522 provides a means for mapping or planning a route to one or more destinations for the V2X device 500. In the illustrated example, the navigation system 522 is illustrated external to the processing system 514; however, in another example, the navigation system 522 may be internal to the processing system 514, e.g., operational by the processor 504 utilizing software stored on the computer-readable medium 506. The GPS receiver 523 provides a means for communicating with a plurality of GPS satellites and determining position, speed, and trajectory information of the V2X device 500. The one or more sensors 524 may include any suitable set of one or more sensors, including, for example, sensors for determining whether the V2X device 500 is braking or accelerating. The set of sensors 524 may further include other types of gauges, such as a speedometer. The camera 526 may include a back-up camera or other camera coupled to the V2X device 500.

The processor 504 is responsible for managing the bus 502 and general processing, including the execution of software (computer code, computer instructions) stored on the computer-readable medium 506. The software, when executed by the processor 504, causes the processor 504 (or more generally the processing system 514) to perform the various functions described below for any particular apparatus. The computer-readable medium 506 and the memory 505 may also be used for storing data that is manipulated by the processor 504 when executing software.

One or more processor circuits (generally represented by processor 504) in the processing system 514 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 computer-readable medium 506 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. The computer-readable medium 506 may reside in the processing system 514, external to the processing system 514, or distributed across multiple entities including the processing system 514. The computer-readable medium 506 may be embodied in a computer program product. By way of example, a computer program product may include a non-transient computer-readable medium in packaging materials. In some examples, the computer-readable medium 506 may be part of the memory 505. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

In some aspects of the disclosure, the processor 504 may include circuitry configured for various functions. For example, the processor 504 may include communication and processing circuitry 541 configured to communicate over a V2X channel to exchange V2X control information and V2X data with other nearby V2X devices. The communication and processing circuitry 541 may further be configured to communicate over a 4G (LTE) and/or 5G (NR) channel with a base station (e.g., eNB or gNB) . In some examples, the communication and processing circuitry 541 may be configured to transmit or receive a PSCCH and/or a PSSCH within one or more of the subframes or slots of the V2X channel.

The communication and processing circuitry 541 (in coordination with the V2X system 525 or otherwise) may further be configured to determine whether the V2X device 500 has generated or obtained V2X data to be transmitted to other nearby V2X devices.

The communication and processing circuitry 541 may further be configured to generate control information within a PSCCH to reserve resources for a transmission of V2X communications (data and/or control) (or to reserve resources for an expected future transmission of V2X communications) .

In addition, the communication and processing circuitry 541 may be configured to generate reservation information associated with a plurality of reservations, each associated with respective control information generated and transmitted on the PSCCH. For example, the reservation information may indicate the number of resource blocks reserved across one or more subframes or slots for each transmission. The communication and processing circuitry 541 may further be configured to communicate with a V2X server via a base station (e.g., eNB or gNB) over licensed spectrum allocated to an LTE or NR wireless communication network. For example, the communication and processing circuitry 541 may be configured to receive broadcast V2X data (e.g., weather, traffic, map data, etc. ) from the V2X server and/or generate and transmit a unicast message to the V2X server for latency-tolerant use cases via the transceiver 510. The communication and processing circuitry 541 may further be configured to execute communication and processing software 551 stored on the computer-readable medium 506 to implement one or more functions described herein.

The processor 504 may further include candidate resource identification circuitry 542, which may be configured to identify a first set of candidate resources for transmission of a V2X communication. The candidate resource identification circuitry 542 may further be configured to execute candidate resource identification software 552 stored on the computer-readable medium 506 to implement one or more functions described herein.

The processor 504 may further include candidate resource set modification circuitry 543, which may be configured to obtain a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission by the V2X device 500, have a greater likelihood of collision than candidate resources remaining in the first set. The first set of candidate resources may be modified by removal of certain candidate resources and may be referred to herein as the second set of candidate resources following removal of the certain candidate resources. The candidate resource set modification circuitry 543 may operate in coordination with candidate resource set modification software 553 stored on the computer-readable medium 506 to implement one or more functions described herein.

The processor 504 may further include candidate resource selecting circuitry 544, which may be configured to select a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication. The selection may be accomplished with random selection. The candidate resource selecting circuitry 544 may operate in coordination with candidate resource selecting software 554 stored on the computer-readable medium 506 to implement one or more functions described herein.

The processor 504 may still further include resource reservation circuitry 545, which may be configured to reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources, in which to transmit and periodically retransmit the first V2X communication, respectively. The resource reservation circuitry 545 may operate in coordination with the resource reservation software 555 stored on the computer-readable medium 506 to implement one or more functions described herein.

The processor 504 may still further include scheduling map circuitry 546. The scheduling map circuitry 546 may be configured to generate a first transmission scheduling map, identifying the first set of reserved resources. The scheduling map circuitry 546 may also be configured to receive one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices. The scheduling map circuitry 546 may be also be configured remove the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources. The transmit scheduling map circuitry 546 may operate in coordination with the transmit scheduling map software 556 stored on the computer-readable medium 506 to implement one or more functions described herein.

The candidate resource selecting circuitry 544 may further be configured to select a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication. The selection may be accomplished with random selection. Following which, the resource reservation circuitry 545 may be configured to reserve, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources, in which to transmit and periodically retransmit the second V2X communication, respectively. The scheduling map circuitry 546 may additionally be configured to generate a third transmission scheduling map, identifying the second set of reserved resources.

The processor 504 may make use of the transceiver 521 to transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices, transmit and retransmit the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map, transmit a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices, and transmit and retransmit the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map.

FIG. 6 is a flow chart 600 of an exemplary method for V2X wireless communication, operational at a V2X device, according to some aspects of the present disclosure. As described below, 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. In some examples, the method may be performed by the V2X device 500, as described above, and illustrated in FIG. 5, by a processor or processing system, or by any suitable means for carrying out the described functions.

At block 602, the V2X device may identify a first set of candidate resources for transmission of a V2X communication. In some examples, the V2X device and one or more nearby V2X devices may each use the first set of candidate resources as a resource pool from which to generate unique transmission scheduling maps. According to some aspects, each resource of the first set of candidate resources comprise at least one of one or more subframes or one or more resource blocks. In some examples, the V2X device may receive the first set of candidate resources in a V2X grant (e.g., a sidelink grant) . In some examples, the V2X device may receive the V2X grant as a prelude to executing the method. In other words, receiving the V2X grant may trigger execution of the method. According to some aspects, the candidate resource identification circuitry 542 shown and described above in connection with FIG. 5 may identify the first set of candidate resources.

At block 604, the V2X device may obtain a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set. In some examples, determining the candidate resources that have the greater likelihood of collision may be based on at least one of a measure of received signal power or received signal quality. In other examples, determining the candidate resources that have the greater likelihood of collision may be based on at least one of a determination of a received signal strength indicator (RSSI) or a determination of a reference signal received quality (RSRQ) . In still other examples, determining the candidate resources that have the greater likelihood of collision may be based on at least one of a comparison of a received signal strength indicator (RSSI) to a first predetermined threshold value or a comparison of a reference signal received quality (RSRQ) to a second predetermined threshold value. In the preceding example, the first predetermined threshold value may be different from the second predetermined threshold value. According to some aspects, the candidate resource set modification circuitry 543 shown and described above in connection with FIG. 5 may obtain the second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set.

At block 606, the V2X device may select a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication. According to some aspects, the candidate resource selecting circuitry 544 shown and described above in connection with FIG. 5 may select the first candidate resource from the second set of candidate resources, for transmission of the first V2X communication.

At block 608, the V2X device may reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources, in which to transmit and periodically retransmit the first V2X communication, respectively. According to some aspects, the resource reservation circuitry 545 shown and described above in connection with FIG. 5 may reserve, as the first set of reserved resources, the first candidate resource and the first predetermined number of first additional resources, in which to transmit and periodically retransmit the first V2X communication, respectively.

At block 610, the V2X device may transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices. In some examples, the first transmission scheduling map comprises a bitmap. According to some aspects, the V2X device alerts the one or more nearby V2X devices of a possibility of transmission collision if any one or more of the nearby V2X devices transmits on any of the first set of reserved resources. In some examples, the V2X device may transmit an alert, in other examples, the first transmission scheduling map may be taken as an implicit alert.

According to some aspects, the V2X device may transmit the first transmission scheduling map with a first transmission of the first V2X communication. According to some aspects, the V2X device may transmit at least one of the first transmission scheduling map or the first V2X communication (as an initial transmission or as a retransmission) as data in a physical sidelink shared channel (PSSCH) . According to some aspects, the V2X device may transmit at least one of the first transmission scheduling map or the first V2X communication (as an initial transmission or as a retransmission) as a unicast, a groupcast, or a broadcast over-the-air transmission. According to some aspects, the V2X device may transmit at least one of the first transmission scheduling map or the first V2X communication (as an initial transmission or as a retransmission) without relaying the at least one of the first transmission scheduling map or the first V2X communication through a radio access network of a radio access network provider. According to some aspects, the V2X device may transmit at least one of the first transmission scheduling map or the first V2X communication (as an initial transmission or as a retransmission) via a sidelink interface. According to some aspects, the V2X device may transmit at least one of the first transmission scheduling map or the first V2X communication (as an initial transmission or as a retransmission) via a PC5 reference point. By way of example, the transmit scheduling map circuitry 546, together with the communication and processing circuitry 541 and the transceiver 521 shown and described above in connection with FIG. 5 may transmit the first transmission scheduling map, identifying the first set of reserved resources, to the one or more nearby V2X devices.

At block 612, the V2X device may transmit and retransmit the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map. The first transmission of the first V2X communication may be made with the transmission of the first transmission scheduling map or separately from the transmission of the first transmission scheduling map. In one example, the V2X device may transmit and retransmit the first V2X communication as a unicast, a groupcast, or a broadcast over-the-air transmission. According to some aspects, the V2X device may transmit and retransmit the first V2X communication without relaying the first V2X communication through a radio access network of a radio access network provider. According to some aspects, the V2X device may transmit and retransmit the first V2X communication via a sidelink interface. According to some aspects, the V2X device may transmit and retransmit the first V2X communication via a PC5 reference point. By way of example, the transmit scheduling map circuitry 546, together with the communication and processing circuitry 541 and the transceiver 521 shown and described above in connection with FIG. 5 may transmit and retransmit the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map. According to aspects described herein, transmitting and retransmitting according to the first transmission scheduling map prevents collisions between transmissions over the first candidate resource by the V2X device and the one or more nearby V2X devices.

FIG. 7 is a flow chart 700 of an exemplary method for V2X wireless communication, operational at a V2X device according to some aspects of the present disclosure. As described below, 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. In some examples, the method may be performed by the V2X device 500, as described above, and illustrated in FIG. 5, by a processor or processing system, or by any suitable means for carrying out the described functions.

At block 702, the V2X device may receive one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices. By way of example, the transmit scheduling map circuitry 546, together with the communication and processing circuitry 541 and the transceiver 521 shown and described above in connection with FIG. 5 may receive one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices.

At block 704, the V2X device may remove the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources. According to some aspects, the candidate resource set modification circuitry 543 shown and described above in connection with FIG. 5 may remove the second candidate resource, if present, from the second set of candidate resources, to form the third set of candidate resources.

At block 706, the V2X device may select a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication. According to some aspects, the candidate resource selecting circuitry 544 shown and described above in connection with FIG. 5 may select the third candidate resource from the third set of candidate resources, for transmission of the second V2X communication.

At block 708, the V2X device may reserve, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources, in which to transmit and periodically retransmit the second V2X communication, respectively. According to some aspects, the resource reservation circuitry 545 shown and described above in connection with FIG. 5 may reserve, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources, in which to transmit and periodically retransmit the second V2X communication, respectively.

At block 710, the V2X device may transmit a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices. In some examples, the third transmission scheduling map comprises a bitmap. According to some aspects, the V2X device alerts the one or more nearby V2X devices of a possibility of transmission collision if any one or more of the nearby V2X devices transmits on any of the second set of reserved resources. In some examples, the V2X device may transmit an alert, in other examples, the first transmission scheduling map may be taken as an implicit alert.

According to some aspects, the V2X device may transmit the third transmission scheduling map with a first transmission of the second V2X communication. According to some aspects, the V2X device may transmit at least one of the third transmission scheduling map or the second V2X communication (as an initial transmission or as a retransmission) as data in a physical sidelink shared channel (PSSCH) . According to some aspects, the V2X device may transmit at least one of the third transmission scheduling map or the second V2X communication (as an initial transmission or as a retransmission) as a unicast, a groupcast, or a broadcast over-the-air transmission. According to some aspects, the V2X device may transmit at least one of the third transmission scheduling map or the second V2X communication (as an initial transmission or as a retransmission) without relaying the at least one of the third transmission scheduling map or the second V2X communication through a radio access network of a radio access network provider. According to some aspects, the V2X device may transmit at least one of the third transmission scheduling map or the second V2X communication (as an initial transmission or as a retransmission) via a sidelink interface. According to some aspects, the V2X device may transmit at least one of the third transmission scheduling map or the second V2X communication (as an initial transmission or as a retransmission) via a PC5 reference point. By way of example, the transmit scheduling map circuitry 546, together with the communication and processing circuitry 541 and the transceiver 521 shown and described above in connection with FIG. 5 may transmit the third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices.

At block 712, the V2X device may transmit and retransmit the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map. The first transmission of the second V2X communication may be made with the transmission of the third transmission scheduling map or separately from the transmission of the third transmission scheduling map. In one example, the V2X device may transmit and retransmit the second V2X communication as a unicast, a groupcast, or a broadcast over-the-air transmission. According some aspects, the V2X device may transmit and retransmit the second V2X communication without relaying the second V2X communication through a radio access network of a radio access network provider. According to some aspects, the V2X device may transmit and retransmit the second V2X communication via a sidelink interface. According to some aspects, the V2X device may transmit and retransmit the second V2X communication via a PC5 reference point. By way of example, the transmit scheduling map circuitry 546, together with the communication and processing circuitry 541 and the transceiver 521 shown and described above in connection with FIG. 5 may transmit and retransmit the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map. According to aspects described herein, transmitting and retransmitting according to the third transmission scheduling map prevents collisions between transmissions over the second candidate resource by the V2X device and the one or more nearby V2X devices.

In one example, the first transmission scheduling map may be appended to the third transmission scheduling and the appended map may be transmitted as the third transmission scheduling map (e.g., a composite map) .

According to some aspects, the third transmission scheduling map and the second V2X communication are transmitted to the one or more nearby V2X devices as a unicast, a groupcast, or a broadcast over-the-air transmission. According to another aspect, the third transmission scheduling map and the second V2X communication are transmitted to the one or more nearby V2X devices without being relayed through a radio access network of a radio access network provider. According to still other aspects, the third transmission scheduling map and the second V2X communication are transmitted to the one or more nearby V2X devices via a sidelink interface. According to another aspect, the third transmission scheduling map and the second V2X communication are transmitted to the one or more nearby V2X device via a PC5 reference point.

In one configuration, a vehicle-to-everything (V2X) device for V2X wireless communication may include means for identifying a first set of candidate resources for transmission of a V2X communication, means for obtaining a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set, means for selecting a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication, means for reserving, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources, in which to transmit and periodically retransmit the first V2X communication, respectively, means for transmitting a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices, and means for transmitting and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.

The aforementioned V2X device may also include means for receiving one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices, means for removing the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources, means for selecting a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication, means for reserving, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources, in which to transmit and periodically retransmit the second V2X communication, respectively, means for transmitting a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices, and means for transmitting and retransmitting the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map. According to one aspect, transmitting and retransmitting according to the third transmission scheduling map prevents collisions between transmissions by the V2X device and the one or more nearby V2X devices over the second candidate resource.

Several aspects of a wireless communication network have been presented with reference to an exemplary implementation. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards.

By way of example, 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) . 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) . 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. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

Within the present disclosure, 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. The terms “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.

One or more of the components, steps, features and/or functions illustrated in FIGs. 1–7 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 FIGs. 1-5 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.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “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.

Claims

A method of vehicle-to-everything (V2X) wireless communication, operational at a V2X device, comprising:

identifying a first set of candidate resources for transmission of a V2X communication;

obtaining a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than the candidate resources remaining in the first set;

selecting a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication;

reserving, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively;

transmitting a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices; and

transmitting and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.
The method of claim 1, wherein the V2X device and the one or more nearby V2X devices each use the first set of candidate resources as a resource pool from which to generate unique transmission scheduling maps.
The method of claim 1, wherein each resource of the first set of candidate resources comprise at least one of one or more subframes or one or more resource blocks.
The method of claim 1, wherein the method further comprises: receiving the first set of candidate resources in a V2X grant.
The method of claim 1, wherein the method further comprises: receiving a V2X grant to trigger execution of the method.
The method of claim 1, wherein the method further comprises: determining the candidate resources having the greater likelihood of collision based on at least one of a measure of received signal power or a measure of received signal quality.
The method of claim 1, wherein the method further comprises: determining the candidate resources having the greater likelihood of collision based on a determination of at least one of a received signal strength indicator (RSSI) or a reference signal received quality (RSRQ) .
The method of claim 1, wherein the method further comprises: determining the candidate resources having the greater likelihood of collision based on at least one of a comparison of a received signal strength indicator (RSSI) to a first predetermined threshold value or a comparison of a reference signal received quality (RSRQ) to a second predetermined threshold value.
The method of claim 1, wherein the first transmission scheduling map comprises a bitmap.
The method of claim 1, wherein the method further comprises: alerting the one or more nearby V2X devices of a possibility of transmission collision if any one or more of the nearby V2X devices transmits on any of the first set of reserved resources.
The method of claim 1, wherein the method further comprises: transmitting the first transmission scheduling map with a first transmission of the first V2X communication.
The method of claim 1, wherein the method further comprises: transmitting at least one of the first transmission scheduling map or the first V2X communication as data in a physical sidelink shared channel (PSSCH) .
The method of claim 1, wherein the method further comprises: transmitting at least one of the first transmission scheduling map or the first V2X communication as a unicast, a groupcast, or a broadcast over-the-air transmission.
The method of claim 1, wherein the method further comprises: transmitting at least one of the first transmission scheduling map or the first V2X communication without relaying the at least one of the first transmission scheduling map or the first V2X communication through a radio access network of a radio access network provider.
The method of claim 1, wherein the method further comprises: transmitting at least one of the first transmission scheduling map or the first V2X communication via a sidelink interface.
The method of claim 1, wherein the method further comprises: transmitting at least one of the first transmission scheduling map or the first V2X communication via a PC5 reference point.
The method of claim 1, wherein the method further comprises:

receiving one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices;

removing the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources;

selecting a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication;

reserving, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the second V2X communication, respectively;

transmitting a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices; and

transmitting and retransmitting the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map,

wherein transmitting and retransmitting according to the third transmission scheduling map prevents collisions between transmissions over the second candidate resource.
The method of claim 17, wherein the method further comprises:

appending the first transmission scheduling map to the third transmission scheduling and transmitting the appended map as the third transmission scheduling map.
The method of claim 17, wherein the method further comprises: transmitting the third transmission scheduling map and the second V2X communication as a unicast, a groupcast, or a broadcast over-the-air transmission.
The method of claim 17, wherein the method further comprises: transmitting the third transmission scheduling map and the second V2X communication without relaying the third transmission scheduling map and the second V2X communication through a radio access network of a radio access network provider.
The method of claim 17, wherein the method further comprises: transmitting the third transmission scheduling map and the second V2X communication via a sidelink interface.
The method of claim 17, wherein the method further comprises: transmitting the third transmission scheduling map and the second V2X communication via a PC5 reference point.
A vehicle-to-everything (V2X) device for V2X wireless communication, comprising:

a processor;

a transceiver communicatively coupled to the processor; and

a memory communicatively coupled to the processor, wherein the processor and the memory are configured to:

identify a first set of candidate resources for transmission of a V2X communication;

obtain a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than the candidate resources remaining in the first set;

select a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication;

reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively;

transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices; and

transmit and retransmit the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.
The V2X device of claim 23, wherein the processor and the memory are further configured to:

receive one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices;

remove the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources;

select a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication;

reserve, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the second V2X communication, respectively;

transmit a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices; and

transmit and retransmit the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map,

wherein transmitting and retransmitting according to the third transmission scheduling map prevents collisions between transmissions over the second candidate resource.
A vehicle-to-everything (V2X) device for V2X wireless communication, comprising:

means for identifying a first set of candidate resources for transmission of a V2X communication;

means for obtaining a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set;

means for selecting a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication;

means for reserving, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively;

means for transmitting a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices; and

means for transmitting and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.
The V2X device of claim 25, further comprising:

means for receiving one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices;

means for removing the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources;

means for selecting a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication;

means for reserving, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the second V2X communication, respectively;

means for transmitting a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices; and

means for transmitting and retransmitting the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map,

wherein transmitting and retransmitting according to the third transmission scheduling map prevents collisions between transmissions over the second candidate resource.
An article of manufacture for use by a vehicle-to-everything (V2X) device for V2X wireless communication, the article of manufacture comprising:

a non-transitory computer-readable medium having stored therein instructions executable by one or more processors of the V2X device to:

identify a first set of candidate resources for transmission of a V2X communication;

obtain a second set of candidate resources from the first set by removing the candidate resources from the first set that, if used for transmission, have a greater likelihood of collision than candidate resources remaining in the first set;

select a first candidate resource from the second set of candidate resources, for transmission of a first V2X communication;

reserve, as a first set of reserved resources, the first candidate resource and a first predetermined number of first additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the first V2X communication, respectively;

transmit a first transmission scheduling map, identifying the first set of reserved resources, to one or more nearby V2X devices; and

transmit and retransmitting the first V2X communication to the one or more nearby V2X devices according to the first transmission scheduling map.
The article of manufacture of claim 27, wherein the instructions executable by the one or more processors of the V2X device further include instructions to:

receive one or more second transmission scheduling maps, each identifying at least one candidate resource from the first set of candidate resources as a second candidate resource reserved for use by a respective one of the one or more nearby V2X devices;

remove the second candidate resource, if present, from the second set of candidate resources, to form a third set of candidate resources;

select a third candidate resource from the third set of candidate resources, for transmission of a second V2X communication;

reserve, as a second set of reserved resources, the third candidate resource and a second predetermined number of second additional resources from the second set of candidate resources, in which to transmit and periodically retransmit the second V2X communication, respectively;

transmit a third transmission scheduling map, identifying the second set of reserved resources, to the one or more nearby V2X devices; and

transmit and retransmit the second V2X communication to the one or more nearby V2X devices according to the third transmission scheduling map,

wherein transmitting and retransmitting according to the third transmission scheduling map prevents collisions between transmissions over the second candidate resource.