Visual feature sharing for relative pose

Abstract

Aspects relate to techniques for visual feature sharing between wireless communication devices for relative pose determination. A first wireless communication device may send a request for visual feature sharing to a second wireless communication device and, in response, receive a message from the second wireless communication device that includes a plurality of features (e.g., keypoints) of an image captured by the second wireless communication device. The first wireless communication device may then calculate a relative pose of the first wireless communication device relative to the second wireless communication device based on an association between the feature provided by the second wireless communication device and an additional feature obtained from an additional image captured by the first wireless communication device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to pending U.S. non-provisional application No. 17 / 902,325, filed on September 2, 2022, which is assigned to the assignee of the present application and is hereby expressly incorporated herein by reference as if fully set forth below and for all applicable purposes. Technical Field

[0003] The technology discussed below relates generally to wireless communication networks, and more particularly, to relative pose determination between wireless communication devices. Background Art

[0004] Visual odometry can be used in various applications such as automotive applications. Visual odometry generally involves comparing consecutive image frames (e.g., in a video sequence) to infer the trajectory and pose of an object such as a vehicle. Pose refers to the translation (e.g., the geometric movement of a vehicle in two or three dimensions) and the orientation / rotation (e.g., pitch, yaw, roll) of a vehicle. Visual odometry can be used, for example, in advanced driver assistance system (ADAS) applications to determine vehicle pose for collision avoidance, cooperative driving, and / or other vehicle safety features. Summary of the invention

[0005] An overview of one or more aspects of the present disclosure is presented below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all expected features of the present disclosure, and is neither intended to identify key or important elements of all aspects of the present disclosure, nor is it intended to describe the scope of any or all aspects of the present disclosure. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in a form as a preface to a more detailed description presented later.

[0006] In one example, a first wireless communication device is disclosed. The first wireless communication device includes: a transceiver; a memory; and a processor coupled to the transceiver and the memory. The processor may be configured to send a request for visual feature sharing to a second wireless communication device via the transceiver and receive a message from the second wireless communication device via the transceiver. The message may include a plurality of first features of a first image captured by the second wireless communication device in a first field of view. Each of the plurality of first features includes a corresponding first key point of the first image. The processor may be further configured to obtain a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each of the plurality of second features includes a corresponding second key point of the second image. The processor may be further configured to calculate a relative pose of the first wireless communication device relative to the second wireless communication device based on an association between the plurality of first features and the plurality of second features.

[0007] Another example provides a method capable of operating at a first wireless communication device. The method may include sending a request for visual feature sharing to a second wireless communication device and receiving a message from the second wireless communication device. The message may include a plurality of first features of a first image captured by the second wireless communication device in a first field of view. Each of the plurality of first features includes a corresponding first key point of the first image. The method may also include obtaining a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each of the plurality of second features includes a corresponding second key point of the second image. The method may also include calculating a relative pose of the first wireless communication device relative to the second wireless communication device based on an association between the plurality of first features and the plurality of second features.

[0008] Another example provides a first wireless communication device, which includes a component for sending a request for visual feature sharing to a second wireless communication device and receiving a message from the second wireless communication device. The message may include multiple first features of a first image captured by the second wireless communication device in a first field of view. Each of the multiple first features includes a corresponding first key point of the first image. The first wireless communication device may also include a component for obtaining multiple second features of a second image captured by the first wireless communication device in a second field of view. Each of the multiple second features includes a corresponding second key point of the second image. The first wireless communication device may also include a component for calculating the relative posture of the first wireless communication device relative to the second wireless communication device based on the association between the multiple first features and the multiple second features.

[0009] Another example provides a non-transitory computer-readable medium having stored therein instructions executable by one or more processors of a first wireless communication device to send a request for visual feature sharing to a second wireless communication device and receive a message from the second wireless communication device. The message may include a plurality of first features of a first image captured by the second wireless communication device in a first field of view. Each of the plurality of first features includes a corresponding first key point of the first image. The non-transitory computer-readable medium may also include instructions executable by the one or more processors of the first wireless communication device to obtain a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each of the plurality of second features includes a corresponding second key point of the second image. The non-transitory computer-readable medium may also include instructions executable by the one or more processors of the first wireless communication device to calculate a relative pose of the first wireless communication device relative to the second wireless communication device based on an association between the plurality of first features and the plurality of second features.

[0010] Another example provides a wireless communication device, the wireless communication device comprising: a transceiver; a memory; and a processor coupled to the transceiver and the memory. The processor may be configured to receive a request for visual feature sharing from another wireless communication device via the transceiver and send a message to the other wireless communication device via the transceiver. The message may include a plurality of features in a field of view associated with the wireless communication device. Each of the plurality of features includes a corresponding key point of an image captured by the wireless communication device.

[0011] Another example provides a method operable at a wireless communication device. The method may include receiving a request for visual feature sharing from another communication device and sending a message to the other wireless communication device. The message may include a plurality of features in a field of view associated with the wireless communication device. Each of the plurality of features includes a corresponding key point of an image captured by the wireless communication device.

[0012] Another example provides a wireless communication device that includes a component for receiving a request for visual feature sharing from another communication device and a component for sending a message to the other wireless communication device. The message may include a plurality of features in a field of view associated with the wireless communication device. Each feature of the plurality of features includes a corresponding key point of an image captured by the wireless communication device.

[0013] Another example provides a non-transitory computer-readable medium having stored therein instructions executable by one or more processors of a first wireless communication device to receive a request for visual feature sharing from another communication device and to send a message to the other communication device. The message may include a plurality of features in a field of view associated with the wireless communication device. Each of the plurality of features includes a corresponding key point of an image captured by the wireless communication device.

[0014] These and other aspects will be more fully understood after reading the following specific embodiments. After reading the description of the specific exemplary examples below in conjunction with the drawings, other aspects, features and examples will be obvious to those of ordinary skill in the art. Although each feature may be discussed below with respect to certain examples and drawings, all examples may include one or more of the advantageous features discussed herein. In other words, although one or more examples may be discussed as having certain advantageous features, one or more of such features may also be used according to the various examples discussed herein. In a similar manner, although the exemplary examples may be discussed below as device, system or method examples, such exemplary examples may be implemented in various devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a diagram illustrating an example of a wireless radio access network in accordance with some aspects.

[0016] Figure 2 is a diagram illustrating an example of a frame structure for use in a wireless communication network in accordance with some aspects.

[0017] Figure 3 is a diagram illustrating an example of a wireless communication network employing sidelink communications in accordance with some aspects.

[0018] Figure 4A and Figure 4B is a diagram illustrating an example of a side link slot structure according to some aspects.

[0019] Figure 5 is a diagram illustrating an example of an image including key points according to some aspects.

[0020] Figure 6 is a diagram illustrating an example of relative pose determination between vehicles in accordance with some aspects.

[0021] Figure 7 is a diagram illustrating exemplary signaling between wireless communication devices for relative pose determination in accordance with some aspects.

[0022] Figure 8is a diagram illustrating an example of relative pose determination using keypoints from images captured at different cameras in accordance with some aspects.

[0023] Fig. 9 is a diagram illustrating an example of global pose determination between vehicles in accordance with some aspects.

[0024] Fig.10 is a diagram illustrating an example of a message including visual feature sharing information in accordance with some aspects.

[0025] Fig.11 is a diagram illustrating an example of sidelink ranging operations between wireless communication devices in accordance with some aspects.

[0026] Fig.12 is a block diagram illustrating an example of a hardware implementation for a wireless communication device employing a processing system in accordance with some aspects.

[0027] Fig.13 is a flow chart of an exemplary process for relative pose determination according to some aspects.

[0028] Fig.14 is a flow chart of another exemplary process for relative pose determination in accordance with some aspects.

[0029] Fig.15 is a flow chart of another exemplary process for relative pose determination in accordance with some aspects.

[0030] Fig.16 is a flow chart of another exemplary process for relative pose determination in accordance with some aspects.

[0031] Fig.17 is a flow chart of an exemplary process for visual feature sharing according to some aspects. DETAILED DESCRIPTION

[0032] The specific embodiments described below in conjunction with the accompanying drawings are intended as descriptions of various configurations and are not intended to represent the only configurations with which the concepts described herein can be practiced. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, it is apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid blurring these concepts.

[0033] A mobile device equipped with a camera may be able to determine the two-dimensional or three-dimensional displacement of the camera over time. For example, in automotive applications, visual odometry can be used to estimate the trajectory and pose of a vehicle. For some applications, such as advanced driver assistance systems (ADAS), high accuracy in relative vehicle pose determination (e.g., relative to another vehicle or object) can improve reaction time to lane changes, collision avoidance, and / or cooperative driving. Without highly accurate relative pose determination, ADAS systems may bias vehicles to go straight in their lanes, which increases the reaction time of the ADAS system to react to lane changes. Due to the delay between image capture and field of view limitations, using only onboard cameras to determine relative vehicle pose may not meet the high accuracy requirements of ADAS systems.

[0034] In order to reduce the time for obtaining relative vehicle pose and improve the accuracy of relative vehicle pose calculation, various aspects of the present invention relate to a mechanism for sharing visual features between wireless communication devices to enable determination of relative pose between wireless communication devices. A first wireless communication device may send a request for visual feature sharing to a second wireless communication device, and in response, receive a message from the second wireless communication device including multiple features (e.g., first features) within a field of view (e.g., a first field of view) associated with the second wireless communication device. Each first feature may include a corresponding first key point of a first image captured by the second wireless communication device.

[0035] The first wireless communication device may then obtain a plurality of second features in a second field of view associated with the first wireless communication device. Each second feature may also include a corresponding second key point of a second image captured by the first wireless communication device. The first wireless communication device may calculate a relative pose of the first wireless communication device relative to the second wireless communication device based on an association between the plurality of first features and the plurality of second features.

[0036] In some examples, each feature (first feature and second feature) may also include a feature descriptor corresponding to the respective feature. The first wireless communication device may then calculate a relative pose by associating the first plurality of features with the second plurality of features based on the first / second key points and the corresponding first / second feature descriptors.

[0037] In some examples, the first wireless communication device may also calculate a global pose in a coordinate system (e.g., a global coordinate system) based on the relative pose. For example, the second wireless communication device may also provide its global pose to the first wireless communication device, and the first wireless communication device may calculate the global pose of the first wireless communication device based on the global pose of the second wireless communication device and the calculated relative pose.

[0038] In some examples, the message includes a timestamp indicating a first time at which the plurality of first features were obtained at the second wireless communication device. The wireless communication device may also determine mobility information (e.g., using an inertial measurement unit (IMU)) between the first time and a second time at which the plurality of second features were obtained at the first wireless communication device, and further calculate the relative pose based on the mobility information.

[0039] In some examples, the first wireless communication device and the second wireless communication device may perform a sidelink ranging operation. In this example, the first wireless communication device may send a request for visual feature sharing during the sidelink ranging operation. In addition, the second wireless communication device may send a message within a sidelink ranging measurement report.

[0040] Although various aspects and examples are described in this application by illustrating some examples, it will be understood by those skilled in the art that additional specific implementations and use cases may be generated in many different arrangements and scenarios. The innovations described herein may be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, various aspects and / or uses may be generated via integrated chip examples and other devices based on non-module components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / shopping devices, medical devices, AI-enabled devices, etc.). Although some examples may or may not specifically point to use cases or applications, the applicability of a wide range of described innovations may occur. Specific implementations may range from chip-level or modular components to non-modular, non-chip-level specific implementations, and further to aggregated, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some actual settings, the devices incorporating the described aspects and features may also necessarily include additional components and features for the implementation and implementation of the claimed and described examples. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The innovations described herein are intended to be practiced in a variety of devices of different sizes, shapes, and configurations, chip-level components, systems, distributed arrangements, disaggregated arrangements (e.g., base stations and UEs), end-user devices, etc.

[0041] The various concepts presented throughout this disclosure may be implemented across a wide variety of telecommunication systems, network architectures, and communication standards. Figure 1, a schematic diagram of a radio access network 100 is provided as an illustrative example and not limiting. The RAN 100 may implement any one or more suitable wireless communication technologies to provide radio access. As an example, the RAN 100 may operate in accordance with the 3rd Generation Partnership Project (3GPP) New Radio (NR) specifications (commonly referred to as 5G). As another example, the RAN 100 may operate in accordance with a mix of 5G NR and Evolved Universal Terrestrial Radio Access Network (eUTRAN) standards (commonly referred to as LTE). 3GPP refers to such a hybrid RAN as the Next Generation RAN or NG-RAN. Of course, many other examples may be utilized within the scope of the present disclosure.

[0042] The geographic area covered by the radio access network 100 may be divided into a plurality of cellular areas (cells) that may be uniquely identified by user equipment (UE) based on an identity broadcast from an access point or base station over the geographic area. Figure 1 Cells 102, 104, 106 and cell 108 are illustrated, each of which may include one or more sectors (not shown). A sector is a sub-area of ​​a cell. All sectors within a cell are served by the same base station. A radio link within a sector may be identified by a single logical identifier belonging to the sector. In a cell divided into sectors, multiple sectors within a cell may be formed by multiple groups of antennas, each of which is responsible for communicating with a UE in a portion of the cell.

[0043] Typically, a corresponding base station (BS) serves each cell. In a broad sense, a base station is a network element in a radio access network that is responsible for radio transmission and reception to or from a UE in one or more cells. Those skilled in the art may also refer to a BS 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 eNodeB (eNB), a gNodeB (gNB), a transmit receive point (TRP), or some other appropriate term. In some examples, a base station may include two or more TRPs that may be co-located or non-co-located. Each TRP may communicate on the same or different carrier frequencies in the same or different frequency bands. In an example in which RAN 100 operates according to both the LTE standard and the 5G NR standard, one of the base stations may be an LTE base station, and the other base station may be a 5G NR base station.

[0044] Various base station arrangements can be used. Figure 1, two base stations 110 and 112 are shown in cells 102 and 104; and a third base station 114 is shown as controlling a remote radio head (RRH) 116 in cell 106. That is, the base station may have an integrated antenna, or may be connected to an antenna or RRH by a feeder cable. In the illustrated example, cells 102, 104, and 106 may be referred to as macro cells because base stations 110, 112, and 114 support cells with large sizes. In addition, base station 118 is shown in cell 108, which may overlap with one or more macro cells. In this example, cell 108 may be referred to as a small cell (e.g., a micro cell, a pico cell, a femto cell, a home base station, a home Node B, a home eNode B, etc.) because base station 118 supports a cell with a relatively small size. Cell size settings may be performed according to system design and component constraints.

[0045] It should be understood that the radio access network 100 may include any number of wireless base stations and cells. In addition, relay nodes 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 the core network for any number of mobile devices.

[0046] Figure 1 Also included is an unmanned aerial vehicle (UAV) 120, which may be a drone or a quadcopter. UAV 120 may be configured to act as a base station, or more specifically, a mobile base station. That is, in some examples, the cell may not necessarily be stationary, and the geographic area of ​​the cell may move depending on the location of a mobile base station (such as UAV 120).

[0047] Typically, a base station may include a backhaul interface for communicating with a backhaul portion of a network (not shown). The backhaul may provide a link between the base station and a core network (not shown), and in some examples, the backhaul may provide interconnection between respective base stations. The core network may be 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 using any suitable transport network, a virtual network, or the like.

[0048] RAN 100 is illustrated as supporting wireless communications for multiple mobile devices. Mobile devices are generally referred to as user equipment (UE) in standards and specifications promulgated by the Third Generation Partnership Project (3GPP), but may also be referred to as mobile stations (MS), subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals (AT), mobile terminals, wireless terminals, remote terminals, handsets, terminals, user agents, mobile clients, clients, or some other suitable terminology by those skilled in the art. UE may be a device that provides access to network services to a user.

[0049] In this document, a "mobile" device does not necessarily need to have the ability to move, and it can be stationary. The term mobile device or mobile device refers to a wide variety of devices and technologies. For example, some non-limiting examples of mobile devices include mobile stations, cellular (cell) phones, smart phones, session initiation protocol (SIP) phones, laptops, personal computers (PCs), notebooks, netbooks, smartbooks, tablet devices, personal digital assistants (PDAs) and a wide range of embedded systems, for example, corresponding to the "Internet of Things" (IoT). The mobile device can additionally be a car or other transportation vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a global positioning system (GPS) device, an object tracking device, a drone, a multi-axis aircraft, a quadcopter, a remote control device, a consumer and / or wearable device (such as glasses, wearable cameras, virtual reality devices, smart watches, health or fitness trackers, digital audio players (e.g., MP3 players), cameras, game consoles, etc. The mobile device can additionally be a digital home or smart home device (such as home audio, video and / or multimedia devices), an appliance, a vending machine, a smart lighting device, a home security system, a smart meter Table, etc. The mobile device can additionally be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device that controls electrical power (e.g., a smart grid), lighting, water supply, etc., an industrial automation and enterprise device, a logistics controller and / or agricultural equipment, etc. In addition, the mobile device can provide connected medical or telemedicine support, such as health care at a distance. Telemedicine devices can include telemedicine monitoring devices and telemedicine management devices, whose communications can be given priority or priority access over other types of information, for example, in terms of priority access for the transmission of critical service data and / or related QoS for the transmission of critical service data.

[0050] Within the RAN 100, the cells may include UEs that may communicate with one or more sectors of each cell. For example, UEs 122 and 124 may communicate with base station 110; UEs 126 and 128 may communicate with base station 112; UEs 130 and 132 may communicate with base station 114 via RRH 116; UE 134 may communicate with base station 118; and UE 136 may communicate 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 UEs in the corresponding cell. In some examples, UAV 120 (e.g., a quadcopter) may be a mobile network node and may be configured to act as a UE. For example, UAV 120 may operate within cell 102 by communicating with base station 110.

[0051] Wireless communication between RAN 100 and a UE (e.g., UE 122 or 124) may be described as utilizing an air interface. Transmissions from a base station (e.g., base station 110) to one or more UEs (e.g., UEs 122 and 124) over an air interface may be referred to as downlink (DL) transmissions. According to certain aspects of the present disclosure, the term "downlink" may refer to point-to-multipoint transmissions originating at a scheduling entity (described further below; e.g., base station 110). Another way to describe this scheme may be to use the term "broadcast channel multiplexing". Transmissions from a UE (e.g., UE 122) to a base station (e.g., base station 110) may be referred to as uplink (UL) transmissions. According to further aspects of the present disclosure, the term "uplink" may refer to point-to-point transmissions originating at a scheduled entity (described further below; e.g., UE 122).

[0052] For example, DL transmission may include unicast or broadcast transmission 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), while UL transmission may include transmission of control information and / or traffic information originated at a UE (e.g., UE 122). In addition, uplink and / or downlink control information and / or traffic information may be time-divided into frames, subframes, time slots, and / or symbols. As used herein, a symbol may refer to a time unit in which one resource element (RE) is carried per subcarrier in an orthogonal frequency division multiplexing (OFDM) waveform. A time slot may carry 7 or 14 OFDM symbols. A subframe may refer to a duration of 1 ms. Multiple subframes or time slots may be grouped together to form a single frame or radio frame. In the present disclosure, a frame may refer to a predetermined duration (e.g., 10 ms) for wireless transmission, wherein each frame is composed of, for example, 10 subframes each of 1 ms. Of course, these definitions are not required, and any suitable scheme for organizing a waveform may be utilized, and the various time divisions of the waveform may have any suitable duration.

[0053] In some examples, access to the air interface may be scheduled, where a scheduling entity (e.g., a base station) allocates resources (e.g., time-frequency resources) for communication between some or all devices and equipment within its service area or cell. Within the present disclosure, as further discussed below, a scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communications, a UE or scheduled entity utilizes resources allocated by the scheduling entity.

[0054] The base station is not the only entity that acts as a scheduling entity. That is, in some examples, the UE can act as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs). For example, two or more UEs (e.g., UEs 138, 140, and 142) can communicate with each other using side link signals 137 without relaying the communication through a base station. In some examples, UEs 138, 140, and 142 can each act as a scheduling entity or a sender side link device and / or a scheduled entity or a receiver side link device to schedule resources and communicate side link signals 137 between the two without relying on scheduling or control information from the base station. In other examples, two or more UEs (e.g., UEs 126 and 128) within the coverage area of ​​a base station (e.g., base station 112) can also communicate side link signals 127 via a direct link (side link) without transmitting the communication through base station 112. In this example, base station 112 can allocate resources to UEs 126 and 128 for side link communication. In either case, such sidelink signaling 127 and 137 may be implemented in a peer-to-peer (P2P) network, a device-to-device (D2D) network, a vehicle-to-vehicle (V2V) network, a vehicle-to-everything (V2X) network, a mesh network, or other suitable direct link network.

[0055] In some examples, a D2D relay framework may be included within a cellular network to facilitate relaying of communications to / from base station 112 via a D2D link (e.g., side link 127 or 137). For example, one or more UEs (e.g., UE 128) within the coverage area of ​​base station 112 may operate as relay UEs to expand the coverage of base station 112, improve transmission reliability to one or more UEs (e.g., UE 126), and / or allow the base station to recover from a failed UE link due to, for example, blocking or fading.

[0056] The two main technologies that can be used by V2X networks include dedicated short-range communications (DSRC) based on the IEEE 802.11p standard and cellular V2X based on LTE and / or 5G (New Radio) standards. For simplicity, various aspects of the present disclosure may refer to New Radio (NR) cellular V2X networks, referred to herein as V2X networks. However, it should be understood that the concepts disclosed herein may not be limited to a specific V2X standard, or may refer to sidelink networks other than V2X networks.

[0057] In order to obtain a low block error rate (BLER) for transmissions over the air interface while still achieving very high data rates, channel coding may be used. That is, wireless communications may typically utilize a suitable error-correcting block code. In a typical block code, an information message or sequence is split into code blocks (CBs), and an encoder (e.g., a codec) at the sender device then mathematically adds redundancy to the information message. Utilizing this redundancy in the encoded information message may improve the reliability of the message, enabling correction of any bit errors that may occur due to noise.

[0058] Data decoding can be implemented in a variety of ways. In early 5G NR specifications, user data is decoded using quasi-cyclic low-density parity check (LDPC) with two different basemaps: one basemap is used for large code blocks and / or high code rates, and the other basemap is used for other cases. Control information and physical broadcast channel (PBCH) are decoded based on nested sequences using polar decoding. For these channels, puncturing, shortening, and repetition are used for rate matching.

[0059] Aspects of the present disclosure may be implemented using any suitable channel code. Various implementations of base stations and UEs may include appropriate hardware and capabilities (eg, encoders, decoders, and / or codecs) to utilize one or more of these channel codes for wireless communications.

[0060] In the RAN 100, the ability of a UE to communicate while moving (independent of its location) is called mobility. The various physical channels between the UE and the RAN are generally set up, maintained, and released under the control of an access and mobility management function (AMF). In some scenarios, the AMF may include: a security context management function (SCMF) and a security anchor function (SEAF) that performs authentication. The SCMF may manage security contexts for both control plane functionality and user plane functionality in whole or in part.

[0061] In some examples, the RAN 100 may implement mobility and handover (i.e., the transfer of a UE's connection from one radio channel to another). For example, during a call with a scheduling entity, or at any other time, the UE may monitor various parameters of the signal from its serving cell and various parameters of neighboring cells. Based on the quality of these parameters, the UE may maintain communication with one or more neighboring cells. During this time, if the UE moves from one cell to another, or if the signal quality from a neighboring cell exceeds the signal quality from the serving cell for a given amount of time, the UE may perform a handover or handover from the serving cell to a neighboring (target) cell. For example, a UE 124 may move from a geographic area corresponding to its serving cell 102 to a geographic area corresponding to a neighboring cell 106. When the signal strength or quality from a neighboring cell 106 exceeds the signal strength and quality of its serving cell 102 for a given amount of time, the UE 124 may send a report message to its serving base station 110 indicating this. In response, the UE 124 may receive a handover command, and the UE may perform a handover to the cell 106.

[0062] In various specific implementations, the air interface in the RAN 100 may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum typically provides exclusive use of a portion of the spectrum with the help of a mobile network operator purchasing a license from a government regulator. Unlicensed spectrum provides shared use of a portion of the spectrum without the need for a government-granted license. Although it is still generally necessary to comply with some technical rules to access the unlicensed spectrum, access is generally available to any operator or device. Shared spectrum may fall between licensed spectrum and unlicensed spectrum, where some technical rules or restrictions may be required to access the spectrum, but the spectrum can still be shared by multiple operators and / or multiple RATs. For example, a license holder of a portion of licensed spectrum may provide licensed shared access (LSA) to share the spectrum with other parties (e.g., with appropriate licensee-determined conditions to obtain access).

[0063] The air interface in the RAN 100 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of various devices. For example, the 5G NR specification provides multiple access for UL or reverse link transmissions from UEs 122 and 124 to base station 110, and multiplexing of DL or forward link transmissions from base station 110 to UEs 122 and 124 using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP). In addition, for UL transmissions, the 5G NR specification provides support for discrete Fourier transform spread OFDM (DFT-s-OFDM) with CP (also known as single carrier FDMA (SC-FDMA)). However, within the scope of the present disclosure, multiplexing and multiple access are not limited to the above schemes, and may be provided using time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource extension multiple access (RSMA), or other suitable multiple access schemes. In addition, multiplexing of DL transmissions from base station 110 to UEs 122 and 124 may be provided using time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

[0064] In addition, the air interface in the RAN 100 may utilize one or more duplex algorithms. Duplex refers to a point-to-point communication link in which two endpoints can communicate with each other in two directions. Full-duplex means that two endpoints can communicate with each other at the same time. Half-duplex means that only one endpoint can transmit information to the other endpoint at a time. Half-duplex emulation is often implemented for wireless links using time division duplex (TDD). In TDD, transmissions in different directions on a given channel are separated from each other using time division multiplexing. That is, at certain times, the channel is dedicated to transmission in one direction, and at other times, the channel is dedicated to transmission in another direction, where the direction can change very quickly, for example, several times per time slot. In wireless links, full-duplex channels generally rely on physical isolation of transmitters and receivers and suitable interference cancellation techniques. Full-duplex emulation is often implemented for wireless links by utilizing frequency division duplex (FDD) or space division duplex (SDD). In FDD, transmissions in different directions can operate at different carrier frequencies (e.g., within a paired spectrum). In SDD, transmissions in different directions on a given channel are separated from each other using spatial division multiplexing (SDM). In other examples, full-duplex communication may be implemented within an unpaired spectrum (e.g., within a single carrier bandwidth), where transmissions in different directions occur within different sub-bands of the carrier bandwidth. This type of full-duplex communication may be referred to herein as sub-band full-duplex (SBFD), also known as flexible duplex.

[0065] Reference Figure 2Various aspects of the present disclosure are described using OFDM waveforms schematically illustrated in . It should be understood by those skilled in the art that various aspects of the present disclosure can be applied to SC-FDMA waveforms in substantially the same manner as described herein below. That is, while some examples of the present disclosure may focus on OFDM links for clarity, it should be understood that the same principles can also be applied to SC-FDMA waveforms.

[0066] Reference now Figure 2 , illustrates an expanded view of an exemplary subframe 202 showing an OFDM resource grid. However, as will be readily apparent to one skilled in the art, the PHY transmit structure for any particular application may differ from the example described herein, depending on any number of factors. Here, time is in units of OFDM symbols in the horizontal direction; and frequency is in units of subcarriers of a carrier in the vertical direction.

[0067] Resource grid 204 may be used to schematically represent the time-frequency resources for a given antenna port. That is, in a multiple-input multiple-output (MIMO) implementation with multiple available antenna ports, a corresponding plurality of resource grids 204 may be available for communication. Resource grid 204 is divided into a plurality of resource elements (REs) 206. RE (which is 1 subcarrier x 1 symbol) is the smallest discrete portion 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) 208, which includes any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include 12 subcarriers (a number independent of the parameter set used). In some examples, depending on the parameter set, 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 RB 208) corresponds entirely to communication in a single direction (transmission or reception for a given device).

[0068] A collection of contiguous or discontinuous resource blocks may be referred to herein as a resource block group (RBG), a subband, or a bandwidth part (BWP). A collection of subbands or BWPs may span the entire bandwidth. Scheduling a UE or sidelink device (hereinafter collectively referred to as a UE) for downlink, uplink, or sidelink transmission typically involves scheduling one or more resource elements 206 within one or more subbands or bandwidth parts (BWPs). Therefore, a UE typically utilizes only a subset of a resource grid 204. In some examples, an RB may be the smallest resource unit that may be allocated to a UE. Therefore, the more RBs scheduled for a UE, and the higher the modulation scheme selected for the air interface, the higher the data rate for the UE. The RBs may be scheduled by a base station (e.g., a gNB, eNB, etc.), or may be self-scheduled by a UE / sidelink device implementing D2D sidelink communication.

[0069] In this illustration, RB 208 is shown as occupying less than the entire bandwidth of subframe 202, with some subcarriers illustrated above and below RB 208. In a given implementation, subframe 202 may have a bandwidth corresponding to any number of one or more RBs 208. Furthermore, in this illustration, RB 208 is shown as occupying less than the entire duration of subframe 202, although this is only one possible example.

[0070] Each 1 ms subframe 202 may be composed of one or more adjacent time slots. Figure 2 In the example shown, as an illustrative example, a subframe 202 includes four time slots 210. In some examples, a time slot may be defined according to a specified number of OFDM symbols with a given cyclic prefix (CP) length. For example, a time slot may include 7 or 12 OFDM symbols with a nominal CP. Additional examples may include micro-slots (sometimes referred to as shortened transmission time intervals (TTIs)) with shorter durations (e.g., one to three OFDM symbols). These micro-slots or shortened transmission time intervals (TTIs) may be transmitted in some cases by occupying resources that are scheduled for ongoing time slot transmissions for the same UE or different UEs. Any number of resource blocks may be utilized within a subframe or time slot.

[0071] An expanded view of one of the time slots 210 illustrates that the time slot 210 includes a control region 212 and a data region 214. In general, the control region 212 may carry control channels, and the data region 214 may carry data channels. Of course, a time slot may contain full DL, full UL, or at least one DL portion and at least one UL portion. Figure 2 The illustrated structure is merely exemplary in nature and different slot structures may be utilized and may include one or more regions in each of the control region and the data region.

[0072] Although in Figure 2 Although not illustrated in the figure, each RE 206 within the RB 208 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs 206 within the RB 208 may also carry pilot or reference signals. These pilot signals or reference signals may be provided to a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation / detection of control channels and / or data channels within the RB 208.

[0073] In some examples, time slot 210 may be utilized for broadcast, multicast, groupcast, or unicast communications. For example, broadcast, multicast, or groupcast communications may refer to point-to-multipoint transmissions from one device (e.g., a base station, UE, or other similar device) to other devices. Here, broadcast communications are delivered to all devices, while multicast or groupcast communications are delivered to multiple intended receiving devices. Unicast communications may refer to point-to-point transmissions from one device to a single other device.

[0074] In an example of cellular communication over a cellular carrier via a Uu interface, for DL ​​transmissions, a scheduling entity (e.g., a base station) may allocate one or more REs 206 (e.g., within a control region 212) to one or more scheduled entities (e.g., UEs) to carry DL control information including one or more DL control channels, such as a physical downlink control channel (PDCCH). The PDCCH carries downlink control information (DCI), including, but not limited to, power control commands (e.g., one or more open-loop power control parameters and / or one or more closed-loop power control parameters), scheduling information, grants, and / or assignments of REs for DL ​​transmissions and UL transmissions. The PDCCH may also carry HARQ feedback transmissions, such as acknowledgements (ACKs) or negative acknowledgements (NACKs). HARQ is a technique well known to those of ordinary skill in the art, in which the integrity of packet transmissions may be checked for accuracy at the receiving side, for example, using any appropriate integrity check mechanism, such as a checksum or a cyclic redundancy check (CRC). If the integrity of the transmission is confirmed, an ACK may be sent, and if it is not confirmed, a NACK may be sent. In response to the NACK, the sending device may transmit a HARQ retransmission, which may implement trace combining, incremental redundancy, and the like.

[0075] The base station may also allocate one or more REs 206 (e.g., in the control region 212 or the data region 214) to carry other DL signals, such as a demodulation reference signal (DMRS); a phase tracking reference signal (PT-RS); a channel state information (CSI) reference signal (CSI-RS); and a synchronization signal block (SSB). The SSBs may be broadcast at regular intervals based on a periodicity (e.g., 5ms, 10ms, 20ms, 20ms, 80ms, or 120ms). The SSBs include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast control channel (PBCH). The UE may utilize the PSS and SSS to achieve radio frame, subframe, time slot, and symbol synchronization in the time domain, to identify the center of the channel (system) bandwidth in the frequency domain, and to identify the physical cell identity (PCI) of the cell.

[0076] The PBCH in the SSB may also include a master information block (MIB) containing various system information and parameters for decoding a system information block (SIB). The SIB may be, for example, SystemInformationType 1 (SIB1), which may include various additional system information. The MIB and SIB1 together provide minimum system information (SI) for initial access. Examples of system information sent in the MIB may include, but are not limited to, subcarrier spacing (e.g., a default downlink parameter set), a system frame number, a configuration of a PDCCH control resource set (CORESET) (e.g., PDCCH CORESET0), a cell barring indicator, a cell reselection indicator, a grid offset, and a search space for SIB1. Examples of remaining minimum system information (RMSI) sent in SIB1 may include, but are not limited to, a random access search space, a paging search space, downlink configuration information, and uplink configuration information.

[0077] In an UL transmission, a scheduled entity (e.g., a UE) may utilize one or more REs 206 to a scheduling entity to carry UL control information (UCI) including one or more UL control channels, such as a physical uplink control channel (PUCCH). The UCI may include various packet types and categories, including pilots, reference signals, and information configured to enable or assist in decoding uplink data transmissions. Examples of uplink reference signals may include a sounding reference signal (SRS) and an uplink DMRS. In some examples, the UCI may include a scheduling request (SR), i.e., a request to the scheduling entity to schedule the uplink transmission. In this document, in response to the SR sent on the UCI, the scheduling entity may send downlink control information (DCI), which may schedule resources for uplink packet transmissions. The UCI may also include HARQ feedback, channel state feedback (CSF) (such as a CSI report), or any other appropriate UCI.

[0078] In addition to control information, one or more REs 206 (e.g., within the data region 214) may also be allocated for data traffic. Such data traffic may be carried on one or more traffic channels, such as a physical downlink shared channel (PDSCH) for DL ​​transmissions or a physical uplink shared channel (PUSCH) for UL transmissions. In some examples, one or more REs 206 within the data region 214 may be configured to carry other signals, such as one or more SIBs and DMRS.

[0079] In an example of sidelink communication over a sidelink carrier via a PC5 interface, a control region 212 of a time slot 210 may include a physical sidelink control channel (PSCCH) including sidelink control information (SCI) sent by an initiating (transmitting) sidelink device (e.g., a TxV2X device or other Tx UE) to a set of one or more other receiving sidelink devices (e.g., an Rx V2X device or other Rx UE). A data region 214 of the time slot 210 may include a physical sidelink shared channel (PSSCH) including sidelink data traffic sent by an initiating (transmitting) sidelink device in resources reserved by the transmitting sidelink device on the sidelink carrier via the SCI. Other information may also be sent via various REs 206 within the time slot 210. For example, HARQ feedback information may be sent from a receiving sidelink device to a transmitting sidelink device in a physical sidelink feedback channel (PSFCH) within the time slot 210. Additionally, one or more reference signals, such as a sidelink SSB, a sidelink CSI-RS, a sidelink SRS, a sidelink DMRS, and / or a sidelink positioning reference signal (PRS), may be sent within time slot 210 .

[0080] These physical channels described above are typically multiplexed and mapped to transport channels for processing at the medium access control (MAC) layer. The transport channels carry information blocks called transport blocks (TBs). Based on the modulation and coding scheme (MCS) and the number of RBs in a given transmission, the transport block size (TBS), which may correspond to the number of information bits, may be a controlled parameter.

[0081] Figure 2 The channels or carriers illustrated are not necessarily all channels or carriers that may be utilized between devices, and one 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 channels, control channels, and feedback channels.

[0082] Figure 3An example of a wireless communication network 300 configured to support sidelink communication is illustrated. In some examples, the sidelink communication may include D2D or V2X communication. V2X communication involves not only the direct wireless exchange of information between the vehicles (e.g., vehicles 302 and 304) themselves, but also the direct wireless exchange of information between the vehicles 302 / 304 and infrastructure (e.g., roadside units (RSUs) 306) (such as street lights, buildings, traffic cameras, toll booths or other stationary objects), vehicles 302 / 304 and pedestrians 308, and vehicles 302 / 304 and wireless communication networks (e.g., base stations 310). In some examples, V2X communication can be implemented according to the new radio (NR) cellular V2X standard defined by 3GPP (Release 16) or other suitable standards.

[0083] V2X communication enables vehicles 302 and 304 to obtain information related to weather, nearby accidents, road conditions, activities of nearby vehicles and pedestrians, objects near the vehicle, and other relevant information that can be used to improve the vehicle driving experience and improve vehicle safety. For example, such V2X data can enable autonomous driving and improve road safety and traffic efficiency. For example, V2X-connected vehicles 302 and 304 can use the exchanged V2X data to provide vehicle collision warnings, road hazard warnings, approaching emergency vehicle warnings, pre-impact / post-impact warnings and information, emergency braking warnings, forward traffic jam warnings, lane change warnings, smart navigation services, and other similar information. In addition, V2X data received by the V2X-connected mobile device of the pedestrian / cyclist 308 can be used to trigger warning sounds, vibrations, flashing lights, etc. in the event of an impending danger.

[0084] Sidelink communications between vehicle UEs (V-UEs) 302 and 304, or between V-UEs 302 or 304 and RSUs 306 or pedestrian UEs (P-UEs) 308 may occur over a sidelink 312 utilizing a proximity services (ProSe) PC5 interface. In various aspects of the present disclosure, the PC5 interface may be further utilized to support D2D sidelink 312 communications in other proximity use cases (e.g., in addition to V2X). Examples of other proximity use cases may include smart wearable devices, public safety, or business-based (e.g., entertainment, education, office, medical, and / or interactive) proximity services. Figure 3 In the example shown, ProSe communication may also occur between UEs 314 and 316 .

[0085] ProSe communication may support different operation scenarios, such as in-coverage, out-of-coverage, and partial coverage. Out-of-coverage refers to a scenario where UEs (e.g., UEs 314 and 316) are outside the coverage area of ​​a base station (e.g., base station 310), but each UE is still configured for ProSe communication. Partial coverage refers to a scenario where some UEs (e.g., V-UE 304) are outside the coverage area of ​​the base station 310, while other UEs (e.g., V-UE 302 and P-UE 308) are in communication with the base station 310. In-coverage refers to a scenario where UEs (e.g., V-UE 302 and P-UE 308) are in communication with the base station 310 (e.g., gNB) via a Uu (e.g., cellular interface) connection to receive ProSe service authorization and provisioning information to support ProSe operation.

[0086] To facilitate D2D side link communications, such as between UEs 314 and 316, over side link 312, UEs 314 and 316 may transmit discovery signals between them. In some examples, each discovery signal may include a synchronization signal, such as a primary synchronization signal (PSS) and / or a secondary synchronization signal (SSS), that facilitates device discovery and synchronization of communications on side link 312. For example, the discovery signal may be used by UE 316 to measure signal strength and channel status of a potential side link (e.g., side link 312) with another UE (e.g., UE 314). UE 316 may utilize these measurements to select a UE (e.g., UE 314) for side link communications or relay communications.

[0087] In a 5G NR sidelink, sidelink communications may utilize a transmit or receive resource pool. For example, the minimum resource allocation unit in frequency may be a subchannel (e.g., which may include, for example, 10, 15, 20, 25, 50, 75, or 100 consecutive RBs), and the minimum resource allocation unit in time may be a time slot. The number of subchannels in a resource pool may include between one and twenty-seven. The configuration of a resource pool (RP) between two sidelink devices for communication therebetween may be pre-configured (e.g., a factory setting on a UE, such as determined by a sidelink standard or specification) or provided by a base station (e.g., base station 310).

[0088] In addition, sidelink (e.g., PC5) communications may have two main resource allocation operation modes. In the first mode (mode 1), the base station (e.g., gNB) 310 may allocate resources to a sidelink device (e.g., a V2X device or other sidelink device) for sidelink communications between the sidelink devices in various ways. For example, the base station 310 may dynamically allocate sidelink resources (e.g., dynamic grants) to the sidelink device in response to a request for sidelink resources from the sidelink device. For example, the base station 310 may schedule sidelink communications via DCI 3_0. In some examples, the base station 310 may schedule PSCCH / PSSCH within the uplink resources indicated in DCI 3_0. The base station 310 may also activate a pre-configured sidelink grant (e.g., a configured grant) for sidelink communications between sidelink devices. In some examples, the base station 310 may activate a configured grant (CG) via RRC signaling. In mode 1, the sidelink feedback may be reported back to the base station 310 by the transmitting sidelink device.

[0089] In the second mode (Mode 2), the sidelink devices may autonomously select sidelink resources for sidelink communications between them. In some examples, the transmitting sidelink device may perform resource / channel sensing to select unoccupied resources (e.g., subchannels) on the sidelink channel. The signaling on the sidelink is the same between the two modes. Therefore, from the receiver's perspective, there is no difference between these modes.

[0090] In some examples, sidelink (e.g., PC5) communications may be scheduled using sidelink control information (SCI). SCI may include two SCI phases. The sidelink control information of phase 1 (first phase SCI) may be referred to herein as SCI-1. The sidelink control information of phase 2 (second phase SCI) may be referred to herein as SCI-2.

[0091] SCI-1 may be sent on a physical sidelink control channel (PSCCH). SCI-1 may include resource allocation for sidelink resources and information for decoding the sidelink control information (i.e., SCI-2) of the second phase. For example, SCI-1 may include physical sidelink shared channel (PSSCH) resource assignment and resource reservation period (if enabled). SCI-1 may also identify the priority level (e.g., quality of service (QoS)) of PSSCH. For example, an ultra-reliable low-latency communication (URLLC) service may have a higher priority than a short message service (e.g., a short message service (SMS) service). Additionally, SCI-1 may include a PSSCH demodulation reference signal (DMRS) pattern (if more than one pattern is configured). DMRS may be used by a receiver for radio channel estimation for demodulating associated physical channels. As indicated, SCI-1 may also include information about SCI-2, for example, SCI-1 may disclose the format of SCI-2. Here, the format indicates the resource size of SCI-2 (e.g., the number of REs allocated for SCI-2), the number of PSSCH DMRS ports, and the modulation and coding scheme (MCS) index. In some examples, SCI-1 can use two bits to indicate the SCI-2 format. Therefore, in this example, four different SCI-2 formats can be supported. SCI-1 may include other information useful for establishing and decoding PSSCH resources.

[0092] SCI-2 may be sent on the PSSCH and may include information for decoding the PSSCH. According to some aspects, SCI-2 includes a 16-bit layer 1 (L1) destination identifier (ID), an 8-bit L1 source ID, a hybrid automatic repeat request (HARQ) process ID, a new data indicator (NDI), and a redundancy version (RV). For unicast communications, SCI-2 may also include a CSI report trigger. For multicast communications, SCI-2 may also include a zone identifier and a maximum communication range for NACK. SCI-2 may include other information useful for establishing and decoding PSSCH resources.

[0093] In some examples, the SCI (e.g., SCI-1 and / or SCI-2) may also include resource assignments for one or more retransmissions of sidelink transmissions (e.g., sidelink traffic / data) or for resources reserved for one or more additional (new) sidelink transmissions. Thus, the SCI may include corresponding PSSCH resource reservations and assignments for one or more PSSCH transmissions. For example, the SCI may include a reservation message indicating a PSSCH resource reservation for an initial sidelink transmission (initial PSSCH) and one or more additional PSSCH resource reservations for one or more retransmissions of the PSSCH.

[0094] Figure 4A and Figure 4B is a diagram illustrating an example of a side link time slot structure according to some aspects. For example, the side link time slot structure can be utilized in a V2X or other D2D network that implements a side link. Figure 4A and Figure 4B In the example shown, time is in the horizontal direction, in units of symbols 402 (e.g., OFDM symbols); and frequency is in the vertical direction. Here, a carrier bandwidth 404 allocated for sidelink wireless communication is illustrated along the frequency axis. The carrier bandwidth 404 may include multiple subchannels, where each subchannel may include a configurable number of PRBs (e.g., 10, 15, 20, 25, 50, 75, or 100 PRBs).

[0095] Figure 4A and Figure 4B An example of a corresponding time slot 400a or 400b is illustrated, respectively, which includes fourteen symbols 402 that can be used for sidelink communication. However, it should be understood that the sidelink communication can be configured to occupy less than fourteen symbols in the time slot 400a or 400b, and the present disclosure is not limited to any particular number of symbols 402. Each sidelink time slot 400a and 400b includes a physical sidelink control channel (PSCCH) 406 that occupies the control region 418 of the time slots 400a and 400b and a physical sidelink shared channel (PSSCH) 408 that occupies the data region 420 of the time slots 400a and 400b. The PSCCH 406 and the PSSCH 408 are each transmitted on one or more symbols 402 of the time slot 400a. The PSCCH 406 includes, for example, an SCI-1 (e.g., SCI format 1-A) that schedules the transmission of data services (e.g., packets) on the time-frequency resources of the corresponding PSSCH 408. As shown Figure 4A and Figure 4B As shown, PSCCH 406 and corresponding PSSCH 408 are transmitted in the same time slots 400a and 400b. In some examples, PSCCH 406 may schedule PSSCH in a subsequent time slot.

[0096] In some examples, the PSCCH 406 duration is configured as two or three symbols. In addition, the PSCCH 406 can be configured to span a configurable number of PRBs, limited to a single subchannel. For a resource pool, the PSCCH resource size can be fixed (e.g., 10% to 100% of a subchannel in the first two or three symbols). For example, the PSCCH 406 can occupy 10, 12, 15, 20, or 25 RBs of a single subchannel. Figure 4A and Figure 4BIn each of the examples shown, the starting symbol of the PSCCH 406 is the second symbol of the corresponding slot 400a or 400b, and the PSCCH 406 spans three symbols 402. The PSCCH 406 may also include a DMRS.

[0097] PSSCH 408 may be time division multiplexed (TDM) with PSCCH 406 and / or frequency division multiplexed (FDM) with PSCCH 406. Figure 4A In the example shown, the PSSCH 408 includes a first portion 408a that is TDM-ed with the PSCCH 406, and a second portion 408b that is FDM-ed with the PSCCH 406. Figure 4B In the example shown, PSSCH 408 is TDMed with PSCCH 406 .

[0098] One layer transmission and two layer transmission of PSSCH 408 can be supported by various modulation orders (e.g., QPSK, 16-QAM, 64-QAM, and 256-QAM). In addition, PSSCH 408 may include DMRS 414 configured with two, three, or four symbol DMRS patterns. For example, Figure 4A The illustrated time slot 400a illustrates a two symbol DMRS pattern, while Figure 4B The illustrated time slot 400b illustrates a three symbol DMRS pattern. In some examples, the transmitting UE may select a DMRS pattern based on channel conditions and indicate the selected DMRS pattern in SCI-1. The DMRS pattern may be selected, for example, based on the number of PSSCH 408 symbols in time slot 400a or 400b. In some examples, DMRS 414 may be based on a King sequence, and configuration type 1 may be used for a frequency domain pattern of PSSCH DMRS 414. In addition, in each time slot 400a and 400b, there is a gap symbol 416 after PSSCH 408.

[0099] Each time slot 400a and 400b also includes SCI-2 412, which is mapped to consecutive RBs in PSSCH 408 starting from the first symbol containing the PSSCH DMRS. Figure 4A In the example shown, the first symbol containing the PSSCH DMRS is the fifth symbol that occurs immediately after the last symbol carrying the PSCCH 406. Therefore, the SCI-2 412 is mapped to the RB within the fifth symbol. Figure 4BIn the example shown, the first symbol containing the PSSCH DMRS is the second symbol, which also includes the PSCCH 406. In addition, the SCI-2 / PSSCH DMRS 412 is shown as spanning symbols two through five. Thus, the SCI-2 / PSSCH DMRS 412 may be FDMed with the PSCCH 406 in symbols two through four and TDMed with the PSCCH 406 in symbol five.

[0100] SCI-2 can be scrambled separately from the sidelink shared channel. In addition, SCI-2 can utilize QPSK. When PSSCH transmission spans two layers, SCI-2 modulation symbols can be replicated on two layers (e.g., repeated on these two layers). SCI-1 in PSCCH 406 can be blind decoded at the receiving wireless communication device. However, since the format, starting position and number of REs of SCI-2 412 can be derived from SCI-1, blind decoding of SCI-2 is not required at the receiver (receiving UE).

[0101] exist Figure 4A and Figure 4B In each of the time slots 400a and 400b, the second symbol of each time slot 400a and 400b is copied to (repeated on) its first symbol 410 for automatic gain control (AGC) stabilization. Figure 4A In , the second symbol including the PSCCH 406 FDMed with the PSSCH 408b may be sent on both the first symbol and the second symbol. Figure 4B In the example shown, the second symbol containing the PSCCH 406 FDMed with the SCI-2 / PSSCH DMRS 412 may be sent on both the first symbol and the second symbol.

[0102] Visual odometry can be used in sidelink (e.g., V2X) applications to estimate the trajectory and pose of a wireless communication device (e.g., a V2X device, such as a vehicle). Pose refers to the translation of the vehicle (e.g., the geometric change in the position of the vehicle in two or three dimensions) and the orientation / rotation of the vehicle (e.g., pitch, yaw, roll). Visual odometry involves comparing consecutive image frames (e.g., in a video sequence) to infer the trajectory of the vehicle. For example, the two-dimensional displacement of five or more stationary key points detected and tracked across two camera images is sufficient to restore the three-dimensional displacement of the camera to at most a global scale factor. In some examples, the vehicle may include auxiliary sensors, such as an inertial measurement unit (IMU), to determine the displacement on a global scale.

[0103] Figure 5is a diagram illustrating an example of an image 500 including keypoints 502 in accordance with some aspects. As used herein, the term keypoints 502 refers to groups of pixels 504 in the image 500 that can be tracked between image frames, such as corner points on an object. Figure 5 An example of a corner detection method shown is a feature from the accelerated segment test (FAST) (Machine Learning for High-Speed ​​Corner Detection, Edward Rosten & Tom Drummond, ECCV 2006: Computer Vision Vision–ECCV 2006 pages 430 to 443, Part of the Lecture Notes in Computer Science book series (LNIP, Volume 3951)). In the FAST method, a tested pixel 504p with intensity Ip can be identified as a point of interest. A circle of sixteen pixels (pixels 1 to 16) surrounding the tested pixel (e.g., a Bresenham circle with a radius of 3) can then be identified. Pixel p can be considered a corner if there is a set of n adjacent pixels in the circle of sixteen pixels that are all brighter than Ip+t or all darker than Ip-t, where t is a threshold and n is configurable. In this example, n can be twelve. For example, the intensities of pixels 1, 5, 9, and 13 of the circle can be compared to Ip. If at least three of the four pixels do not meet the threshold criteria, the pixel p is not considered to be an interest point. Figure 5 As is clear from the figure, at least three of the four pixels meet the threshold criteria. Therefore, all sixteen pixels can be compared with pixel p to determine whether twelve consecutive pixels meet the threshold criteria. This process can be repeated for each pixel 504 in the image 500 to identify the corner point corresponding to the key point 502 in the image 500.

[0104] although Figure 5 The FAST key point identification method is illustrated, but it should be understood that the present disclosure is applicable to any key point identification method. Examples of key point identification methods may include (but are not limited to) SIFT (Scale Invariant Feature Transform), ORB (Orientation FAST (Features from Acceleration Segment Test) and Rotation BRIEF (Binary Robust Independent Elementary Features)), BRIEF and Harris Corner.

[0105] As indicated above, key points 502 represent features of image 500 that can be tracked. For example, various cross-correlation or optical flow methods can track features (key points) across image frames. In some examples, each feature may also include a feature descriptor that assists the tracking process. The feature descriptor can summarize one or more characteristics of the key point 502 in a (e.g., constant length) vector format. For example, a feature descriptor may correspond to the intensity of the key point 502. In general, the feature descriptor is independent of the key point 502 position, is robust to image transformations, and scales independently. Therefore, key points with feature descriptors can be re-detected independently in each image frame and then subjected to a key point matching / tracking procedure. For example, key points in two different images that have matching descriptors and have the smallest distance between them can be considered matching key points.

[0106] The pose of the camera can then be calculated based on the two-dimensional displacement of multiple keypoints in consecutive images. For example, the pose can be determined by forming and factoring the essential matrix using eight keypoints 502 or using the Nister method with five keypoints 502. As another example, a perspective n-point (PnP) algorithm with three keypoints 502 can be used to determine the pose while also tracking the depth of the keypoints.

[0107] In some aspects, the relative pose between the cameras can be determined using images captured by different cameras that contain a minimum number of identical features (eg, based on a pose determination method). Figure 6 602 and 604 according to some aspects. In some examples, each of the vehicles 602 and 604 can be a wireless communication device, such as a V2X device including a sensor (e.g., a camera) for capturing images. In addition, the vehicles 602 and 604 can each be an ego vehicle within an intelligent transportation system. The vehicles 602 and 604 are shown in a two-dimensional coordinate system represented by an X-axis and a Y-axis. Therefore, the pose of each vehicle 602 and 604 can be determined in the X, Y coordinate system.

[0108] In addition, the relative pose between vehicles 602 and 604 can also be determined based on a rotating coordinate system centered on one of the vehicles represented by the X_v axis and the Y_v axis (e.g., vehicle 602). In some examples, the rotating coordinate system can be centered on the camera of vehicle 602. The relative pose of vehicle 604 relative to vehicle 602 may include the relative pose of vehicle 604 in the X_v and Y_v directions corresponding to ΔX v and ΔY v In addition, the relative position of vehicle 604 relative to vehicle 602 may include the relative position of vehicle 604 corresponding to the angle Δθ vThe relative orientation 608.

[0109] To facilitate relative pose determination, various aspects of the present disclosure provide mechanisms for sharing visual features between wireless communication devices (e.g., vehicles 602 and 604). For example, vehicle 604 may capture an image within the field of view of an onboard camera of vehicle 604 and use FAST, ORB, BRIEF, SIFT, Harris corners, or another keypoint detection algorithm to identify multiple keypoints in the image. Vehicle 604 may then send the identified features (keypoints) to vehicle 602. Vehicle 602 may use the received keypoints from vehicle 604 and matching keypoints obtained from images in the same or similar (e.g., common) field of view captured by the onboard camera of vehicle 602 to perform relative pose determination between vehicle 602 and vehicle 604.

[0110] Figure 7 704) for relative pose determination according to some aspects. Each of WCD-1 702 and WCD-2 704 may be, for example, a vehicle (e.g., an ego vehicle), a UE, a V2X device, or a sidelink device. WCD-1 702 and WCD-2 704 are in proximity to each other. In some examples, WCD-1 702 and WCD-2 704 may have established a sidelink between them (e.g., via a discovery signal).

[0111] At 706, WCD-1 702 may send a request for visual feature sharing to WCD-2 704. For example, WCD-1 702 may not know its pose and may request WCD-2 704 to provide keypoints to WCD-1 702. In some examples, WCD-1 702 may send a request to provide keypoints from multiple images acquired by WCD-2 704 over time (e.g., at different times). In some examples, the request may indicate specific times (e.g., t1, t2, ..., t3) at which the images should be captured. N ). In other examples, WCD-1 702 may send multiple requests at different times, each requesting WCD-2 704 to provide key points from one or more images.

[0112] In some examples, the request may include an indication of a field of view in which a key point is requested. For example, the field of view of WCD-2 704 may be adjustable, or WCD-1 702 may send a request to multiple second WCDs, and a second WCD (e.g., WCD-2 704) with a requested field of view may respond to the request. In some examples, the indication may also include a coordinate system for the field of view. For example, the coordinate system may be a global coordinate system or other preconfigured coordinate system. Examples of global coordinate systems may include, but are not limited to, LLA (longitude, latitude, altitude) and ECEF (Earth Centered Earth Fixed), also known as a geocentric coordinate system. Thus, the request may request features within a field of view defined using a particular coordinate system. In other examples, the indication includes a differential value (e.g., + / -X degrees) of a field of view relative to a previous set of features (e.g., key points) received from WCD-2 704.

[0113] In some examples, the request may be sent via one or more of a unicast sidelink message, a multicast (or groupcast) sidelink message, or a broadcast sidelink message. In other examples, the request may be sent via a network entity (e.g., a base station or gNB in ​​a converged base station architecture, or a central unit (CU), a distributed unit (DU), a radio unit (RU), a near real-time (near RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC in a decomposed base station architecture) that wirelessly communicates with WCD-1 702 and WCD-2 704. For example, the request may be sent to the network entity via a Uu link between WCD-1 702 and the network entity, and the network entity may send the request to WCD-2 704 via a Uu link between the network entity and WCD-2 704.

[0114] At 708, WCD-2 704 may obtain a plurality of first features of a first image captured by WCD-2 704 in a first field of view. The first field of view may be indicated in the request, or may be based on the position of a sensor (e.g., a camera) on WCD-2 704 of the captured image. WCD-2 704 may use FAST, BRIEF, ORB, SIFT, Harris corners, or another keypoint detection algorithm to identify the plurality of first features in the first image. WCD-2 704 may also determine (e.g., calculate) a feature descriptor for each feature. In one example, WCD-2 704 may use its camera to obtain an image at a first time instant 1. WCD-2 704 may then use a keypoint detection algorithm to determine that the M keypoint locations of image I will be A=[(u1,v1),(u2,v2),…(u M ,v M )] and the corresponding features F = [F1, F2, ... F M ].

[0115] At 710, WCD-2 704 may send a message including a plurality of first features to WCD-1 702. In some examples, each of the first features may include a corresponding first key point. In other examples, each of the first features may include a corresponding first key point and a corresponding first feature descriptor. The first feature descriptor may be a SIFT, ORB, HOG (Gradient Orientation Histogram), GLOH (Gradient Location and Orientation Histogram), and / or SURF (Speeded Up Robust Features) feature descriptor. In one example, the message may include features of an image {} and corresponding pixel locations {} for each of the features. In some examples, the message may also include a timestamp indicating a first time (time t1) at which the plurality of first features were obtained.

[0116] In some examples, the message may be sent via one or more of a unicast sidelink message, a multicast (or groupcast) sidelink message, or a broadcast sidelink message. In other examples, the message may be sent via a network entity (e.g., a base station or gNB in ​​a converged base station architecture, or a central unit (CU), a distributed unit (DU), a radio unit (RU), a near real-time (near RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC in a decomposed base station architecture) that wirelessly communicates with WCD-1 702 and WCD-2 704. For example, the message may be sent to the network entity via a Uu link between WCD-2 704 and the network entity, and the network entity may send the request to WCD-1 702 via a Uu link between the network entity and WCD-1 702.

[0117] At 712, WCD-1 702 may obtain a plurality of second features of a second image captured by WCD-1 702 in a second field of view. The second field of view and the first field of view may include a common field of view. WCD-1 702 may use FAST, BRIEF, ORB, SIFT, Harris corner point, or another key point detection algorithm to identify the plurality of second features in the second image. WCD-1 702 may also determine (e.g., calculate) a second feature descriptor for each feature. The second feature descriptor may be a SIFT, ORB, HOG, GLOH, and / or SURF feature descriptor.

[0118] In one example, WCD-1 702 may use its camera to obtain image L at a second time (e.g., second time instant 2). Second time instant 2 may be close in time to first time instant 1. For example, second time instant 2 may be within a preconfigured duration (or threshold duration) from time instant 1. In examples where second time instant 2 is outside the preconfigured duration (e.g., the time difference between 2 and 1 exceeds the threshold duration), WCD-1 702 may not use the plurality of first features and may send a new request for visual feature sharing to WCD-2 704, or WCD-1 702 may use a subsequent set of features transmitted by WCD-2 704 based on the original request sent at 706.

[0119] At 714, WCD-1 702 may calculate a relative pose of WCD-1 702 relative to WCD-2 704 based on the association between the plurality of first features and the plurality of second features. In one example, WCD-1 702 may use an image obtained from its camera at time 2, and match the plurality of first features obtained from WCD-2 704 with the plurality of second features obtained from image L to associate the first features with the second features. For example, various cross-correlation or optical flow methods and / or feature descriptors may be used to match the first features with the second features. For example, the pixel positions of the matches of the N features obtained by WCD-1 702 may be represented as = [(_1,_1), (_2,_2), ... (_N,_N)]. WCD-1 702 may then determine the relative pose using an essential matrix, Nister's method, or a PnP algorithm.

[0120] In some examples, WCD-1 702 may obtain inertial sensor information (e.g., from an IMU on WCD-1 702) and determine mobility information of WCD-1 702 between a first time when a plurality of first features are obtained at WCD-2 704 and a second time when a plurality of second features are obtained by WCD-1 702. WCD-1 702 may also use the mobility information to calculate a relative pose of WCD-1 702.

[0121] Figure 8 is a diagram illustrating an example of relative pose determination using key points from images captured at different cameras C1 and C2 in accordance with some aspects. Figure 8In the example shown, each of the cameras C1 and C2 may be positioned on a different wireless communication device such as a vehicle. A real point M in a three-dimensional space (x, y, z) may be projected onto corresponding image planes I1 and I2 of each of the vehicle cameras C1 and C2 to generate features (key points) m1 and m2. By correlating or associating (e.g., matching) multiple sets of features (e.g., corresponding to multiple real points), epipolar constraints on relative vehicle poses (e.g., line l1 between m1 and e1 and line l2 between m2 and e2) may be extracted. Therefore, based on the key points of the multiple real points and the epipolar constraints, the first wireless communication device associated with the camera C1 may determine the relative pose (rotation (R), translation (T)) of the first wireless communication device relative to the second wireless communication device associated with the camera C2.

[0122] Fig. 9 is a diagram illustrating an example of global pose determination between vehicles 902 and 904 according to some aspects. In some examples, each of vehicles 902 and 904 can be a wireless communication device, such as a V2X device. In addition, vehicles 902 and 904 can each be an ego vehicle within an intelligent transportation system. Each of vehicles 902 and 904 can also include sensors (e.g., cameras) 906 and 908, respectively, for capturing images in their respective fields of view 910 and 912.

[0123] In some examples, the vehicle 902 may not know its global pose in the global coordinate system. For example, the vehicle 902 may have just been started and has not yet obtained its global positioning system (GPS) coordinates. In this example, the vehicle 902 may send a request 914 for visual feature sharing to a nearby vehicle (e.g., vehicle 904). The request 914 may also include a request for the global pose of the vehicle 904. In response to receiving the request 914, the vehicle 904 may capture an image (e.g., a first image) within the field of view 912 of the onboard camera 908 of the vehicle 904 and use FAST, ORB, BRIEF, SIFT, Harris corner point or another key point detection algorithm to identify multiple key points in the image. In addition, the vehicle 904 may obtain (e.g., retrieve from memory) the global pose of the vehicle 904 in a global coordinate system (e.g., LLA or ECEF) or other preconfigured or specified coordinate systems. For example, vehicle 904 may include a navigation system (eg, a Global Navigation Satellite System (GNSS) receiver) or a GPS receiver that may be configured to determine a global position of vehicle 904 within a global coordinate system.

[0124] The vehicle 904 may then send a message 916 to the vehicle 902 including the identified features (key points) and the global pose of the vehicle 904 (e.g., a first global pose). The vehicle 902 may then capture an image (e.g., a second image) within the field of view 910 of the onboard camera 906 of the vehicle 902 and identify a plurality of key points in the image using FAST, ORB, BRIEF, SIFT, Harris corners, or another key point detection algorithm. The fields of view 910 and 912 of the respective cameras 906 and 908 include a common region 918 within which common features may be identified by the vehicles 902 and 904. Thus, the vehicle 902 may calculate the relative pose of the vehicle 902 relative to the vehicle 904 based on the association between the common features. For example, the vehicle 902 may calculate the relative pose using an essential matrix, a Nister method, or a PnP algorithm.

[0125] The vehicle 902 may also calculate a global pose (e.g., a second global pose) of the vehicle 902 based on the relative pose between the vehicles 902 and 904 and the first global pose of the vehicle 904. In an example where the first global pose of the vehicle 904 is based on a vehicle reference system (e.g., a central axis or other portion of a vehicle body frame) rather than a camera reference system, the vehicle 904 may also calculate an additional relative pose of the camera 908 relative to a reference system associated with the vehicle 904. For example, the reference system may correspond to a vehicle body frame of the vehicle 904 on which the camera 908 is mounted. The message 916 may also include an additional relative pose, and the vehicle 902 may further calculate a second global pose (e.g., a global pose of the vehicle 902) based on the additional relative pose.

[0126] Fig.10 is a diagram illustrating an example of a message 1000 including visual feature sharing information according to some aspects. Fig.10In the example shown, the message 1000 includes a plurality of features 1002 within an image captured by the wireless communication device transmitting the message 1000. For each feature 1002, the message 1000 may include a keypoint 1004 (e.g., an identification of the keypoint), and in some examples, may also include a feature descriptor 1006. The message 1000 may also include a corresponding position (e.g., a pixel position) 1008 of each of the features 1002 in the image. In some examples, the message 1000 may also include a timestamp 1010 when the feature 1002 was obtained. In addition, the message 1000 may optionally include a global pose 1012 of the wireless communication device transmitting the message 1000. In examples where the global pose 1012 is associated with a reference frame different from the camera, the message 1000 may also include a relative pose 1014 of the camera relative to the reference frame of the wireless communication device transmitting the message 1000.

[0127] In some examples, message 1000 may be sent during a sidelink ranging operation. Within a sidelink communication network (e.g., a V2X network), positioning of a UE may enhance or support various features, such as navigation, autonomous driving, and cooperative safety. Positioning of a UE may be achieved, for example, using a global navigation satellite system (GNSS) receiver within the UE and / or via sidelink-based ranging between UEs. For example, the UEs may exchange positioning reference signals (PRS) on a sidelink to determine relative distances between UEs and / or absolute locations (e.g., geographic coordinates) of the UEs. Sidelink ranging operations may enhance the range and position accuracy of GNSS-based positioning, or may be utilized in situations where GNSS is degraded or unavailable.

[0128] Fig.11 1 is a diagram illustrating an example of sidelink ranging operations between wireless communication devices (WCD-1 1102 and WCD-2 1104) according to some aspects. Each of WCD-1 1102 and WCD-2 1104 can be, for example, a vehicle (e.g., an ego vehicle), a UE, a V2X device, or a sidelink device. WCD-1 1102 and WCD-2 1104 are in proximity to each other. In some examples, WCD-1 1102 and WCD-2 1104 may have established a sidelink between them (e.g., via a discovery signal).

[0129] At 1106, a sidelink ranging session may be established using a three-way messaging handshake technique. For example, at 1108, WCD-1 1102 may send a sidelink ranging session establishment message to one or more target WCDs (e.g., WCD-2 1104) in the vicinity of WCD-1 1102. In one example, the request may be signaled at the application layer, thereby implementing a radio access technology (RAT) independent technique for session establishment. In other examples, the request may be signaled at the physical layer (e.g., within SCI-2) or at the medium access control (MAC) layer.

[0130] In response to receiving the sidelink ranging session setup message, WCD-2 1104 may send a sidelink ranging session response message to WCD-1 1102 to join the sidelink ranging session at 1110. Then, at 1112, WCD-1 1102 may send a sidelink ranging session confirm message to WCD-2 1104 to confirm the establishment of the sidelink ranging session.

[0131] In some examples, WCD-1 1102 may also include a request for visual feature sharing within the sidelink ranging setup message at 1106 and / or within the sidelink ranging session configuration message at 1112. In other examples, WCD-1 1102 may send the request for visual feature sharing after the handshake messaging at 1106.

[0132] At 1114, each of WCD-1 1102 and WCD-2 1104 may transmit a respective PRS. For example, at 1114a, WCD-1 1102 may transmit a PRS (PRS1), and at 1114b, WCD-2 1104 may transmit a PRS (PRS2). For example, the PRS may be transmitted according to the PRS resource indicated in the sidelink ranging session setup message. In some examples, the PRS may be a wideband PRS transmitted across a specific frequency band or subband.

[0133] At 1116, each of the WCDs may exchange ranging measurement reports obtained based on the PRS. For example, at 1118a, WCD-1 1102 may send a ranging measurement report (RMR1) obtained by WCD-1 1102 based on a received PRS from WCD-2 1104. Similarly, at 1118b, WCD-2 1104 may send a ranging measurement report (RMR2) to WCD-1 1102. In some examples, the RMRs may be sent within a corresponding SCI-2, within a corresponding sidelink MAC-CE, or via other unicast or broadcast sidelink messages.

[0134] Each of the RMRs may include a round trip time (RTT) between the respective WCDs calculated based on the PRS. For example, WCD-1 1102 may calculate the RTT between WCD-1 1102 and WCD-2 1104 based on the transmit time and receive time of PRS2. Similarly, WCD-2 1104 may calculate the RTT between WCD-2 1104 and WCD-1 1102 based on the transmit time and receive time of PRS1. The RMRs may also include the location (e.g., geographic coordinates) of the respective WCDs, if known. Based on the RMRs received from WCD-2 1104, WCD-1 1102 may discern its relative location or absolute location (e.g., geographic coordinates).

[0135] In some examples, RMR 1118b transmitted from WCD-2 1104 to WCD-1 1102 may also include a plurality of features (e.g., key points and corresponding feature descriptors, if available) of the image captured by WCD-2 1104. WCD-1 1102 may also calculate a relative pose of WCD-1 1102 with respect to WCD-2 1104 using the features included in RMR 1118b.

[0136] Fig.12 12 is a block diagram illustrating an example of a hardware implementation of a wireless communication device 1200 employing a processing system 1214. For example, the wireless communication 1200 may correspond to the above referenced Figure 1 , Figure 3 , Figure 6 , Figure 7 and / or Fig. 9 A sidelink device, such as a vehicle or other V2X device, is shown and described.

[0137] The wireless communication device 1200 may be implemented using a processing system 1214 including one or more processors 1204. Examples of the processor 1204 include a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gated logic, a discrete hardware circuit, and other suitable hardware configured to perform various functionalities described throughout the present disclosure. In various examples, the wireless communication device 1200 may be configured to perform any one or more of the functions described herein. That is, the processor 1204 as utilized in the wireless communication device 1200 may be used to implement any one or more of the processes and procedures described below.

[0138] In some examples, the processor 1204 may be implemented via a baseband or modem chip, and in other implementations, the processor 1204 may include multiple devices distinct and other than a baseband or modem chip (e.g., in scenarios such as those that may work together to implement the examples discussed herein). And as mentioned above, various hardware arrangements and components outside of a baseband modem processor may be used in implementations, including RF chains, power amplifiers, modulators, buffers, interleavers, adders / summers, etc.

[0139] In this example, the processing system 1214 may be implemented using a bus architecture, which is generally represented by bus 1202. The bus 1202 may include any number of interconnecting buses and bridges, depending on the specific application and overall design constraints of the processing system 1214. The bus 1202 links together various circuits including one or more processors, which are generally represented by processor 1204, memory 1205, and computer-readable media, which are generally represented by computer-readable media 1206. The bus 1202 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 further.

[0140] The bus interface 1208 provides an interface between the bus 1202 and the transceiver 1210. The transceiver 1210 provides a communication interface or component for communicating with various other devices through a transmission medium (e.g., an air interface). Depending on the nature of the device, a user interface 1212 (e.g., a keypad, a display, a touch screen, a speaker, a microphone, a control knob, etc.) may also be provided. Of course, such a user interface 1212 is optional and may be omitted in some examples. In addition, the bus interface 1208 may also provide an interface between the bus 1202 and a sensor 1230 such as a camera.

[0141] The processor 1204 is responsible for managing the bus 1202 and general processing, including executing software stored on a computer-readable medium 1206. The software, when executed by the processor 1204, causes the processing system 1214 to perform various functions described below for any particular device. The computer-readable medium 1206 and the memory 1205 can also be used to store data manipulated by the processor 1204 when executing the software. For example, the memory 1205 can store one or more of a request 1216 for visual feature sharing, a message 1218 including multiple features of an image, one or more global poses 1220, one or more relative poses 1222, and / or a timestamp 1224, which can be used by the processor 1204 in a visual feature sharing application.

[0142] One or more processors 1204 in the processing system may execute software. Software should be construed broadly to mean instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, processes, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer readable medium 1206.

[0143] Computer readable medium 1206 may be a non-transitory computer readable medium. Non-transitory computer readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical disks (e.g., compact disks (CDs) or digital versatile disks (DVDs)), smart cards, flash memory devices (e.g., card, stick, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer. Computer readable medium 1206 may reside in processing system 1214, be external to processing system 1214, or be distributed across multiple entities including processing system 1214. Computer readable medium 1206 may be embodied in a computer program product. For example, a computer program product may include a computer readable medium in a packaging material. In some examples, computer readable medium 1206 may be part of memory 1205. Those skilled in the art will recognize how to best implement the described functionality presented throughout this disclosure, depending on the specific application and the overall design constraints imposed on the overall system. In some examples, computer-readable medium 1206 may be implemented on an article of manufacture, which may also include one or more other elements or circuits, such as processor 1204 and / or memory 1205.

[0144] In some aspects of the present disclosure, the processor 1204 may include circuits configured for various functions. For example, the processor 1204 may include a communication and processing circuit 1242 that is configured to communicate with one or more side link devices (e.g., other wireless communication devices) via a corresponding side link (e.g., a PC5 interface). In addition, the communication and processing circuit 1242 may be configured to communicate with a network entity (e.g., a base station such as a gNB or eNB) via a Uu link. In some examples, the communication and processing circuit 1242 may include one or more hardware components that provide a physical structure that performs processes related to wireless communication (e.g., signal reception and / or signal transmission) and signal processing (e.g., processing received signals and / or processing signals for transmission). For example, the communication and processing circuit 1242 may include one or more transmit / receive chains.

[0145] In some implementations where communication involves receiving information, the communication and processing circuitry 1242 may obtain information from a component of the wireless communication device 1200 (e.g., from a transceiver 1210 that receives information via radio frequency signaling or some other type of signaling suitable for an applicable communication medium), process (e.g., decode) the information, and output the processed information. For example, the communication and processing circuitry 1242 may output the information to another component of the processor 1204, to the memory 1205, or to the bus interface 1208. In some examples, the communication and processing circuitry 1242 may receive one or more of a signal, a message, other information, or any combination thereof. In some examples, the communication and processing circuitry 1242 may receive information via one or more channels. In some examples, the communication and processing circuitry 1242 may include functionality for components for receiving. In some examples, the communication and processing circuitry 1242 may include functionality for components for processing, including components for demodulating, components for decoding, and the like.

[0146] In some implementations where communication involves transmitting (e.g., sending) information, the communication and processing circuitry 1242 may obtain information (e.g., from another component of the processor 1204, the memory 1205, or the bus interface 1208), process the information (e.g., modulate, encode, etc. the information), and output the processed information. For example, the communication and processing circuitry 1242 may output the information to the transceiver 1210 (e.g., which transmits the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium). In some examples, the communication and processing circuitry 1242 may transmit one or more of a signal, a message, other information, or any combination thereof. In some examples, the communication and processing circuitry 1242 may transmit information via one or more channels. In some examples, the communication and processing circuitry 1242 may include functionality for components for transmitting (e.g., components for sending). In some examples, the communication and processing circuitry 1242 may include functionality for components for generating, including components for modulating, components for encoding, and the like.

[0147] In some examples, the communication and processing circuitry 1242 may be configured to send a request 1216 for visual feature sharing to another wireless communication device via the transceiver 1210. In other examples, the communication and processing circuitry 1242 may be configured to receive a request 1216 for visual feature sharing from another wireless communication device. In some examples, the request 1216 may be at least one of a unicast side link message, a multicast side link message, or a broadcast side link message. In other examples, the communication and processing circuitry 1242 may be configured to send or receive the request 1216 via a network entity that wirelessly communicates with the wireless communication device 1200 and the other wireless communication device.

[0148] The communication and processing circuit 1242 may be further configured to receive a message 1218 including a plurality of features of an image captured by the other wireless communication device via the transceiver 1210 from another wireless communication device. In other examples, the communication and processing circuit 1242 may be configured to send a message 1218 including a plurality of features of an image captured by the camera 1230 of the wireless communication device 1200 to another wireless communication device. In some examples, each feature may include a key point and may optionally also include a corresponding feature descriptor corresponding to the key point. In some examples, the message 1218 may be at least one of a unicast side link message, a multicast side link message, or a broadcast side link message. In other examples, the communication and processing circuit 1242 may be configured to send or receive the message 1218 via a network entity that wirelessly communicates with the wireless communication device 1200 and the other wireless communication device. The communication and processing circuit 1242 may be further configured to execute the communication and processing instructions (software) 1252 stored in the computer-readable medium 1206 to implement one or more of the functions described herein.

[0149] The processor 1204 may also include a visual feature sharing circuit 1244 configured to generate and / or process a request for visual feature sharing 1216. The visual feature sharing circuit 1244 may also be configured to generate and / or process a message 1218 including a plurality of features.

[0150] In some examples, the visual feature sharing circuit 1244 may generate a request 1216 including an indication of a field of view to be used by another wireless communication device when capturing an image. In some examples, the indication includes a coordinate system of the field of view. In other examples, the indication includes a differential value relative to a previous set of features received from another wireless communication device. In some examples, the visual feature sharing circuit 1244 may operate with the communication and processing circuit 1242 to perform a side link ranging operation between the wireless communication device 1200 and another wireless communication device. In this example, the visual feature sharing circuit 1244 may be configured to generate and send a request 1216 for visual feature sharing during a side link ranging operation.

[0151] In some examples, the visual feature sharing circuit 1244 may generate a message 1218 in response to receiving the request 1216. In this example, the visual feature sharing circuit 1244 may be configured to obtain a plurality of features of an image captured by a sensor (e.g., a camera) 1230, and include the plurality of features in the message 1218. In some examples, each of the plurality of features includes a corresponding key point of the image. In some examples, each of the plurality of features also includes a corresponding feature descriptor corresponding to the corresponding key point. In some examples, the visual feature sharing circuit 1244 may be further configured to obtain a corresponding set of features for each of the plurality of images captured by the sensor 1230 and include each corresponding set of features in the message 1218. In some examples, the visual feature sharing circuit 1244 may be configured to obtain a timestamp 1224 indicating the time at which the plurality of features were obtained, and include the timestamp 1224 in the message 1218.

[0152] The visual feature sharing circuit 1244 may be further configured to determine a global pose 1220 or retrieve the global pose 1220 from the memory 1205, and include the global pose 1220 in the message 1218. In examples where the reference frame of the global pose 1220 is different from the sensor (e.g., camera) 1230, the visual feature sharing circuit 1244 may be further configured to calculate a relative pose (e.g., relative pose 1222) of the sensor 1230 relative to a reference frame associated with the wireless communication device 1200. In some examples, the reference frame corresponds to a vehicle body frame of a vehicle (e.g., wireless communication device 1200) on which the sensor 1230 is mounted.

[0153] In the example where the request 1216 is received during the sidelink ranging operation, the visual feature sharing circuit 1244 may also send a message 1218 within the sidelink ranging measurement report. The visual feature sharing circuit 1244 may be further configured to execute visual feature sharing instructions (software) 1254 stored in the computer-readable medium 1206 to implement one or more of the functions described herein.

[0154] The processor 1204 may also include a pose calculation circuit 1246 configured to calculate a relative pose (e.g., relative pose 1222) between the wireless communication device and another wireless communication device. In some examples, the visual feature sharing circuit 1244 may be configured to receive a plurality of first features in a first field of view from another (e.g., second) wireless communication device within a message 1218. In this example, the pose calculation circuit 1246 may be configured to obtain a plurality of second features in a second field of view associated with the wireless communication device 1200. Each of the plurality of second features may include a corresponding second key point of an image captured by the sensor 1230 of the wireless communication device 1200. The pose calculation circuit 1246 may then calculate a relative pose 1222 of the wireless communication device 1200 relative to the other wireless communication device based on an association between the plurality of first features and the plurality of second features.

[0155] In some examples, each of the first features may include a corresponding first feature descriptor corresponding to a corresponding first key point, and each of the second features may include a corresponding second feature descriptor corresponding to a corresponding second key point. In this example, the pose calculation circuit 1246 may be further configured to associate the plurality of first features with the plurality of second features based on the first key point, the second key point, the first feature descriptor, and the second feature descriptor.

[0156] In some examples, the message 1218 may also include a first global pose 1220 of the other wireless communication device in the coordinate system. In this example, the pose calculation circuit 1246 may be further configured to calculate a second global pose 1220 of the wireless communication device 1200 in the coordinate system based on the first global pose 1220 and the relative pose 1222 of the wireless communication device 1200 relative to the other wireless communication device. In examples where the message 1218 also includes an additional relative pose 1222 of a sensor (e.g., a camera) on the other wireless communication device relative to a reference system (e.g., a vehicle body frame) associated with the other wireless communication device, the pose calculation circuit 1246 may be further configured to calculate the second global pose 1220 based further on the additional relative pose 1222.

[0157] In some examples, the message 1218 may also include a timestamp 1224 indicating a first time at which the plurality of first features were obtained at the other wireless communication device. In this example, the pose calculation circuit 1246 may be further configured to determine mobility information of the wireless communication device 1200 between the first time and a second time at which the plurality of second features were obtained at the wireless communication device 1200. The pose calculation circuit 1246 may be further configured to calculate a relative pose 1222 of the wireless communication device 1200 relative to the other wireless communication device further based on the mobility information. The pose calculation circuit 1246 may also be configured to execute pose calculation instructions (software) 1256 stored in the computer-readable medium 1206 to implement one or more of the functions described herein.

[0158] Fig.13 is a flow chart of an exemplary process 1300 for relative pose determination according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for all example implementations. In some examples, the method may be as described above and in Fig.12 The wireless communication device 1200 illustrated in the example is executed by a processor or a processing system or by any suitable means for performing the described functions.

[0159] At block 1302, a wireless communication device (e.g., a first wireless communication device) may send a request for visual feature sharing to a second wireless communication device. In some examples, the request may include an indication of a first field of view. In some examples, the indication may include a coordinate system of the first field of view. In other examples, the indication may include a differential value relative to a previous set of features received from the second wireless communication device. For example, the above in conjunction with Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for sending the request.

[0160] At block 1304, the first wireless communication device may receive a message from the second wireless communication device. The message may include a plurality of first features of a first image captured by the second wireless communication device in a first field of view. Each of the plurality of first features may include a corresponding first key point of the first image. In some examples, the message includes at least one of a unicast side link message, a multicast side link message, or a broadcast side link message. In some examples, the first wireless communication device may receive the message from the second wireless communication device via a network entity that wirelessly communicates with the first wireless communication device and the second wireless communication device. Fig.12The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for receiving messages.

[0161] At block 1306, the first wireless communication device may obtain a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each second feature in the plurality of second features may include a corresponding second key point of the second image. Fig.12 The pose calculation circuit 1246 shown and described, together with the sensor 1230, can provide a component for obtaining a plurality of second features.

[0162] At box 1308, the first wireless communication device may calculate the relative posture of the first wireless communication device with respect to the second wireless communication device based on the association between the multiple first features and the multiple second features. In some examples, each of the multiple first features also includes a corresponding first feature descriptor corresponding to the corresponding first key point, and each of the multiple second features also includes a corresponding second feature descriptor corresponding to the corresponding second key point. In this example, the first wireless communication device may associate the multiple first features with the multiple second features based on the first key point, the second key point, the first feature descriptor, and the second feature descriptor. The above is combined with Fig.12 The pose calculation circuit 1246 shown and described may provide components for calculating relative pose.

[0163] Fig.14 is a flow chart of another exemplary process 1400 for relative pose determination according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for all exemplary implementations. In some examples, the method may be as described above and in Fig.12 The wireless communication device 1200 illustrated in the example is executed by a processor or a processing system or by any suitable means for performing the described functions.

[0164] At block 1402, a wireless communication device (e.g., a first wireless communication device) may send a request for visual feature sharing to a second wireless communication device. In some examples, the request may include an indication of a first field of view. In some examples, the indication may include a coordinate system of the first field of view. In other examples, the indication may include a differential value relative to a previous set of features received from the second wireless communication device. For example, the above in conjunction with Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for sending the request.

[0165] At box 1404, the first wireless communication device may receive a message from the second wireless communication device. The message may include a first global pose of the second wireless communication device and a plurality of first features of a first image captured by the second wireless communication device in a first field of view. Each of the plurality of first features may include a corresponding first key point of the first image. In some examples, the message includes at least one of a unicast side link message, a multicast side link message, or a broadcast side link message. In some examples, the first wireless communication device may receive the message from the second wireless communication device via a network entity that wirelessly communicates with the first wireless communication device and the second wireless communication device. The above is combined with Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for receiving messages.

[0166] At block 1406, the first wireless communication device may obtain a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each second feature in the plurality of second features may include a corresponding second key point of the second image. Fig.12 The pose calculation circuit 1246 shown and described, together with the sensor 1230, can provide a component for obtaining a plurality of second features.

[0167] At box 1408, the first wireless communication device may calculate the relative posture of the first wireless communication device with respect to the second wireless communication device based on the association between the multiple first features and the multiple second features. In some examples, each of the multiple first features also includes a corresponding first feature descriptor corresponding to the corresponding first key point, and each of the multiple second features also includes a corresponding second feature descriptor corresponding to the corresponding second key point. In this example, the first wireless communication device may associate the multiple first features with the multiple second features based on the first key point, the second key point, the first feature descriptor, and the second feature descriptor. The above is combined with Fig.12 The pose calculation circuit 1246 shown and described may provide components for calculating relative pose.

[0168] At 1410, the first wireless communication device may calculate a second global pose of the first wireless communication device in a coordinate system based on the first global pose and the relative pose. In some examples, the message may also include an additional relative pose of a sensor on the second wireless communication device relative to a reference system associated with the second wireless communication device. For example, the reference system may correspond to a vehicle body frame associated with the second wireless communication device. In this example, the first wireless communication device may further calculate a second global pose based on the additional relative pose. Fig.12 The pose calculation circuit 1246 shown and described may provide components for calculating a second global pose.

[0169] Fig.15 is a flow chart of another exemplary process 1500 for relative pose determination according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for all exemplary implementations. In some examples, the method may be as described above and in Fig.12 The wireless communication device 1200 illustrated in the example is executed by a processor or a processing system or by any suitable means for performing the described functions.

[0170] At block 1502, a wireless communication device (e.g., a first wireless communication device) may send a request for visual feature sharing to a second wireless communication device. In some examples, the request may include an indication of a first field of view. In some examples, the indication may include a coordinate system of the first field of view. In other examples, the indication may include a differential value relative to a previous set of features received from the second wireless communication device. For example, the above in conjunction with Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for sending the request.

[0171] At box 1504, the first wireless communication device may receive a message from the second wireless communication device. The message may include multiple first features of a first image captured by the second wireless communication device in a first field of view and a timestamp indicating a first time when the multiple first features were obtained at the second wireless communication device. Each of the multiple first features may include a corresponding first key point of the first image. In some examples, the message includes at least one of a unicast side link message, a multicast side link message, or a broadcast side link message. In some examples, the first wireless communication device may receive the message from the second wireless communication device via a network entity that wirelessly communicates with the first wireless communication device and the second wireless communication device. The above is combined with Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for receiving messages.

[0172] At block 1506, the first wireless communication device may obtain a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each second feature in the plurality of second features may include a corresponding second key point of the second image. Fig.12 The pose calculation circuit 1246 shown and described, together with the sensor 1230, can provide a component for obtaining a plurality of second features.

[0173] At block 1508, the first wireless communication device may determine mobility information of the first wireless communication device between a first time and a second time at which a plurality of second features are obtained at the first wireless communication device. Fig.12 The pose calculation circuit 1246 shown and described may determine mobility information.

[0174] At box 1510, the first wireless communication device may calculate the relative posture of the first wireless communication device with respect to the second wireless communication device based on the association between the multiple first features and the multiple second features and the mobility information. In some examples, each of the multiple first features also includes a corresponding first feature descriptor corresponding to the corresponding first key point, and each of the multiple second features also includes a corresponding second feature descriptor corresponding to the corresponding second key point. In this example, the first wireless communication device may associate the multiple first features with the multiple second features based on the first key point, the second key point, the first feature descriptor, and the second feature descriptor. The above is combined with Fig.12 The pose calculation circuit 1246 shown and described may provide components for calculating relative pose.

[0175] Fig.16 is a flow chart of another exemplary process 1600 for relative pose determination according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for all exemplary implementations. In some examples, the method may be as described above and in Fig.12 The wireless communication device 1200 illustrated in the example is executed by a processor or a processing system or by any suitable means for performing the described functions.

[0176] At block 1602, a wireless communication device (e.g., a first wireless communication device) may perform a sidelink ranging operation between the first wireless communication device and a second wireless communication device. Fig.12 The communication and processing circuitry 1242 shown and described, together with the visual feature sharing circuitry 1244 and the transceiver 1210, may provide means for performing sidelink ranging operations.

[0177] At block 1604, the first wireless communication device may send a request for visual feature sharing to the second wireless communication device during a sidelink ranging operation. In some examples, the request may include an indication of the first field of view. In some examples, the indication may include a coordinate system of the first field of view. In other examples, the indication may include a differential value relative to a previous set of features received from the second wireless communication device. For example, the above in conjunction with Fig.12The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for sending the request.

[0178] At block 1606, the first wireless communication device may receive a message from the second wireless communication device within a sidelink ranging measurement report. The message may include a plurality of first features of a first image captured by the second wireless communication device in the first field of view. Each of the plurality of first features may include a corresponding first key point of the first image. Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for receiving messages.

[0179] At block 1608, the first wireless communication device may obtain a plurality of second features of a second image captured by the first wireless communication device in a second field of view. Each second feature of the plurality of second features may include a corresponding second key point of the second image. Fig.12 The pose calculation circuit 1246 shown and described, together with the sensor 1230, can provide a component for obtaining a plurality of second features.

[0180] At box 1610, the first wireless communication device may calculate the relative posture of the first wireless communication device with respect to the second wireless communication device based on the association between the multiple first features and the multiple second features. In some examples, each of the multiple first features also includes a corresponding first feature descriptor corresponding to the corresponding first key point, and each of the multiple second features also includes a corresponding second feature descriptor corresponding to the corresponding second key point. In this example, the first wireless communication device may associate the multiple first features with the multiple second features based on the first key point, the second key point, the first feature descriptor, and the second feature descriptor. The above is combined with Fig.12 The pose calculation circuit 1246 shown and described may provide components for calculating relative pose.

[0181] In one configuration, the wireless communication device 1200 includes a component for sending a request for visual feature sharing to a second wireless communication device and a component for receiving a message from the second wireless communication device, wherein the message includes multiple first features of a first image captured by the second wireless communication device in a first field of view, and each of the multiple first features includes a corresponding first key point of the first image. The wireless communication device also includes: a component for obtaining multiple second features of a second image captured by the first wireless communication device in a second field of view, wherein each of the multiple second features includes a corresponding second key point of the second image; and a component for calculating the relative posture of the first wireless communication device with respect to the second wireless communication device based on the association between the multiple first features and the multiple second features. In one aspect, the aforementioned components may be Fig.12 The processor 1204 is shown configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

[0182] Of course, in the above examples, the circuits included in the processor 1204 are provided only as examples, and other components for performing the functions described may be included in various aspects of the present disclosure, including but not limited to those stored in the computer-readable storage medium 1206 or Figure 1 , Figure 3 , Figure 7 and / or Fig.11 Any other suitable device or component described in any of the above and using, for example, Figures 13 to 16 Instructions of the described processes and / or algorithms.

[0183] Fig.17 is a flow chart of an exemplary process 1700 for visual feature sharing according to some aspects. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of the present disclosure, and some of the illustrated features may not be required for all example implementations. In some examples, the method may be as described above and in Fig.12 The wireless communication device 1200 illustrated in the example is executed by a processor or a processing system or by any suitable means for performing the described functions.

[0184] At block 1702, a wireless communication device (e.g., a second wireless communication device) may receive a request for visual feature sharing from a first wireless communication device. Fig.12 The communication and processing circuitry 1242 shown and described along with the visual feature sharing circuitry 1244 and transceiver 1210 may provide means for receiving a request.

[0185] At block 1704, the second wireless communication device may send a message to the first wireless communication device. The message may include a plurality of features in a field of view associated with the second wireless communication device. Each of the plurality of first features may include a corresponding key point of an image captured by the second wireless communication device. In some examples, each of the plurality of features also includes a corresponding feature descriptor corresponding to the corresponding key point. In some examples, the message also includes a timestamp indicating a time at which the plurality of features were obtained at the second wireless communication device. In some examples, the second wireless communication device may send a corresponding set of features to the first wireless communication device for each of the plurality of images captured by the second wireless communication device.

[0186] In some examples, the second wireless communication device may also send a global pose of the second wireless communication device in a coordinate system. In some examples, the message may also include a relative pose of a sensor on the second wireless communication device relative to a reference system associated with the second wireless communication device. In some examples, the reference system corresponds to a vehicle body frame associated with the second wireless communication device.

[0187] In some examples, the request may include an indication of the field of view. In some examples, the indication may include a coordinate system of the field of view. In other examples, the indication may include a differential value relative to a previous set of features received from the second wireless communication device.

[0188] In some examples, the second wireless communication device may also perform a sidelink ranging operation between the first wireless communication device and the second wireless communication device. The second wireless communication device may receive a request for visual feature sharing during the sidelink ranging operation. In some examples, the second wireless communication device may send a message within a sidelink ranging measurement report.

[0189] In some examples, the message includes at least one of a unicast side link message, a multicast side link message, or a broadcast side link message. In some examples, the second wireless communication device may send the message to the first wireless communication device via a network entity that wirelessly communicates with the first wireless communication device and the second wireless communication device. Fig.12 The communication and processing circuitry 1242 shown and described together with the visual feature sharing circuitry 1244 and the transceiver 1210 may provide means for sending messages.

[0190] In one configuration, the wireless communication device 1200 includes means for receiving a request for visual feature sharing from a first wireless communication device and means for sending a message to the first wireless communication device, the message including a plurality of features in a field of view associated with a second wireless communication device, wherein each of the plurality of features includes a corresponding key point of an image captured by the second wireless communication device. In one aspect, the foregoing means may be Fig.12 The processor 1204 is shown configured to perform the functions recited by the aforementioned means. In another aspect, the aforementioned means may be a circuit or any apparatus configured to perform the functions recited by the aforementioned means.

[0191] Of course, in the above examples, the circuits included in the processor 1204 are provided only as examples, and other components for performing the functions described may be included in various aspects of the present disclosure, including but not limited to those stored in the computer-readable storage medium 1206 or Figure 1 , Figure 3 , Figure 7 and / or Fig.11 Any other suitable device or component described in any of the above and using, for example, Fig.17 Instructions of the described processes and / or algorithms.

[0192] Figures 13 to 17 The processes and / or algorithms illustrated may include additional aspects, such as any single aspect or any combination of aspects described below and / or in combination with one or more other processes described elsewhere herein.

[0193] Aspect 1: A method capable of operating at a first wireless communication device, the method comprising: sending a request for sharing visual features to a second wireless communication device; receiving a message from the second wireless communication device, the message comprising a plurality of first features of a first image captured by the second wireless communication device in a first field of view, each of the plurality of first features comprising a corresponding first key point of the first image; obtaining a plurality of second features of a second image captured by the first wireless communication device in a second field of view, each of the plurality of second features comprising a corresponding second key point of the second image; and calculating a relative pose of the first wireless communication device relative to the second wireless communication device based on an association between the plurality of first features and the plurality of second features.

[0194] Aspect 2: A method according to aspect 1, wherein each of the multiple first features also includes a corresponding first feature descriptor corresponding to the corresponding first key point, and each of the multiple second features also includes a corresponding second feature descriptor corresponding to the corresponding second key point, and the method further includes: associating the multiple first features with the multiple second features based on the first key point, the second key point, the first feature descriptor and the second feature descriptor.

[0195] Aspect 3: According to the method of Aspect 1 or 2, the method according to claim 1 also includes: receiving a first global pose of the second wireless communication device in a coordinate system; and calculating a second global pose of the first wireless communication device in the coordinate system based on the first global pose and the relative pose.

[0196] Aspect 4: A method according to Aspect 3, wherein the message also includes an additional relative pose of a sensor on the second wireless communication device relative to a reference system associated with the second wireless communication device, and wherein calculating the second global pose also includes: further calculating the second global pose based on the additional relative pose.

[0197] Aspect 5: The method of aspect 4, wherein the reference frame corresponds to a vehicle body frame associated with the second wireless communication device.

[0198] Aspect 6: A method according to any one of Aspects 1 to 5, wherein the message also includes a timestamp indicating a first time when the multiple first features were obtained at the second wireless communication device, and the calculation of the relative posture also includes: determining the mobility information of the first wireless communication device between the first time and the second time when the multiple second features were obtained at the first wireless communication device; and further calculating the relative posture based on the mobility information.

[0199] Aspect 7: The method according to any one of aspects 1 to 6, wherein the request further comprises an indication of the first field of view.

[0200] Aspect 8: The method according to aspect 7, wherein the indication includes a coordinate system of the first field of view.

[0201] Aspect 9: The method of aspect 7, wherein the indication comprises a differential value relative to a previous set of features received from the second wireless communication device.

[0202] Aspect 10: A method according to any one of Aspects 1 to 9, wherein the sending of the request for visual feature sharing further comprises: performing a sidelink ranging operation between the first wireless communication device and the second wireless communication device; and sending the request for visual feature sharing during the sidelink ranging operation.

[0203] Aspect 11: The method according to aspect 10, wherein the receiving the message further comprises: receiving the message within a sidelink ranging measurement report.

[0204] Aspect 12: The method according to any one of aspects 1 to 11, wherein the message comprises at least one of a unicast sidelink message, a multicast sidelink message, or a broadcast sidelink message.

[0205] Aspect 13: The method according to any one of aspects 1 to 8, wherein the receiving the message further comprises: receiving the message from the second wireless communication device via a network entity that wirelessly communicates with the first wireless communication device and the second wireless communication device.

[0206] Aspect 14: A method capable of operating at a wireless communication device, the method comprising: receiving a request for sharing visual features from another communication device; and sending a message to the other communication device, the message comprising a plurality of features in a field of view associated with the wireless communication device, each of the plurality of features comprising a corresponding key point of an image captured by the wireless communication device.

[0207] Aspect 15: The method according to aspect 14, wherein each of the plurality of features further comprises a corresponding feature descriptor corresponding to the corresponding keypoint.

[0208] Aspect 16: The method according to Aspect 14 or 15 further includes: sending the global pose of the wireless communication device in the coordinate system.

[0209] Aspect 17: The method according to Aspect 16, wherein the message further includes a relative pose of a sensor on the wireless communication device relative to a reference frame associated with the wireless communication device.

[0210] Aspect 18: The method of aspect 16, wherein the reference frame corresponds to a vehicle body frame associated with the wireless communication device.

[0211] Aspect 19: The method according to any one of aspects 14 to 18, wherein the message further comprises a timestamp indicating a time when the plurality of characteristics were obtained at the wireless communication device.

[0212] Aspect 20: The method according to any one of aspects 14 to 19, wherein the request further comprises an indication of the field of view.

[0213] Aspect 21: The method according to aspect 20, wherein the indication includes a coordinate system of the field of view.

[0214] Aspect 22: The method of aspect 20, wherein the indication comprises a differential value over a past set of features sent to the other communications device.

[0215] Aspect 23: A method according to any one of Aspects 14 to 22, wherein the receiving the request for sharing visual features also includes: performing a sidelink ranging operation between the other communication device and the wireless communication device; and receiving the request for sharing visual features during the sidelink ranging operation.

[0216] Aspect 24: The method according to Aspect 23, wherein the sending the message further comprises: sending the message within a sidelink ranging measurement report.

[0217] Aspect 25: The method according to any one of aspects 14 to 24, wherein the message comprises at least one of a unicast sidelink message, a multicast sidelink message, or a broadcast sidelink message.

[0218] Aspect 26: The method according to any one of aspects 14 to 22, wherein the sending the message further comprises: sending the message to the other communication device via a network entity that wirelessly communicates with the other communication device and the wireless communication device.

[0219] Aspect 27: The method according to any one of aspects 14 to 26, wherein the sending the message further comprises: sending a corresponding set of features to the other communication device for each image of a plurality of images captured by the wireless communication device.

[0220] Aspect 28: A wireless communication device, comprising: a transceiver; a memory; and a processor, the processor being coupled to the transceiver and the memory, the processor being configured to perform a method according to any one of aspects 1 to 13 or 14 to 27.

[0221] Aspect 29: A wireless communication device comprising: means for performing a method according to any one of aspects 1 to 13 or 14 to 27.

[0222] Aspect 30: An article comprising a non-transitory computer-readable medium having instructions stored therein, the instructions being executable by one or more processors of a wireless communication device to perform a method according to any one of aspects 1 to 13 or 14 to 27.

[0223] Several aspects of wireless communication networks have been presented with reference to exemplary implementations. 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.

[0224] By way of example, various aspects may be implemented within other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System for Mobile (GSM). Various aspects may also be extended to systems defined by the Third 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), IEEE802.20, 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.

[0225] Within the present disclosure, the word "exemplary" is used to mean "serving as an example, instance, or illustration". Any specific implementation or aspect described herein as "exemplary" is not necessarily to be construed as superior or superior to other aspects of the present disclosure. Likewise, the term "aspect" does not require that all aspects of the present disclosure include the discussed features, advantages, or modes of operation. The term "coupled" is used herein to refer to a direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, objects A and C may still be considered to be coupled to each other, even if they are not in direct physical contact with each other. For example, a first object may be coupled to a second object, even if the first object has never been in direct physical contact with the second object. The terms "circuit" and "circuitry" are used broadly, and they are intended to include both hardware implementations of electronic devices and conductors (where these electronic devices and conductors, when connected and configured, implement the execution of the functions described in the present disclosure, without limitation on the type of electronic circuits) and software implementations of information and instructions (where these information and instructions, when executed by a processor, implement the execution of the functions described in the present disclosure).

[0226] Figures 1 to 17 One or more of the illustrated components, steps, features, and / or functions may be rearranged and / or combined into a single component, step, feature, or function or may be embodied in several components, steps, or functions. Additional elements, components, steps, and / or functions may also be added without departing from the novel features disclosed herein. Figure 1 , Figure 3 , Figure 7 and / or Fig.11The illustrated apparatus, device and / or component may be configured to perform one or more of the methods, features or steps described herein. The novel algorithms described herein may also be effectively implemented in software and / or embedded in hardware.

[0227] It should be understood that the specific order or hierarchy of steps in the disclosed methods is an illustration of an exemplary process. It should be understood that the specific order or hierarchy of steps in these methods can be rearranged based on design preferences. The attached 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 stated herein.

[0228] The foregoing 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 apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but to conform to the full scope consistent with the text of the claims, wherein unless explicitly stated otherwise, reference to an element in the singular form is not intended to mean "one and only one", but "one or more". Unless otherwise specified, the term "some" refers to one or more. The phrase "at least one" referring to a list of items refers to any combination of those items, including a single member. As an example, "at least one of a, b or c" is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure that are currently or hereafter known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims.

Claims

1. A first wireless communication device, the first wireless communication device comprising: Transceiver; Memory; and a processor coupled to the transceiver and the memory, the processor being configured to: sending, via the transceiver, a request for visual feature sharing to a second wireless communication device; receiving, via the transceiver, a message from the second wireless communication device, the message comprising a plurality of first features of a first image captured by the second wireless communication device in a first field of view, each first feature of the plurality of first features comprising a respective first keypoint of the first image; obtaining a plurality of second features of a second image captured by the first wireless communication device in a second field of view, each second feature of the plurality of second features comprising a corresponding second key point of the second image; as well as A relative position and posture of the first wireless communication device with respect to the second wireless communication device is calculated based on associations between the plurality of first features and the plurality of second features.

2. The first wireless communication device of claim 1 , wherein each of the plurality of first features further comprises a corresponding first feature descriptor corresponding to the corresponding first keypoint, and each of the plurality of second features further comprises a corresponding second feature descriptor corresponding to the corresponding second keypoint, and wherein the processor is further configured to: The plurality of first features are associated with the plurality of second features based on the first keypoint, the second keypoint, the first feature descriptor, and the second feature descriptor.

3. The first wireless communication device of claim 1 , wherein the processor is further configured to: receiving a first global pose of the second wireless communication device in a coordinate system; and A second global pose of the first wireless communication device in the coordinate system is calculated based on the first global pose and the relative pose.

4. The first wireless communication device of claim 3, wherein the message further comprises an additional relative pose of a sensor on the second wireless communication device relative to a reference frame associated with the second wireless communication device, and wherein the processor is further configured to: The second global pose is further calculated based on the additional relative pose.

5. The first wireless communication device of claim 4, wherein the reference frame corresponds to a vehicle body frame associated with the second wireless communication device.

6. The first wireless communication device of claim 1 , wherein the message further comprises a timestamp indicating a first time at which the plurality of first characteristics were obtained at the second wireless communication device, and wherein the processor is further configured to: determining mobility information of the first wireless communication device between the first time and a second time at which the plurality of second features are obtained at the first wireless communication device; and The relative pose is further calculated based on the mobility information.

7. The first wireless communication device of claim 1, wherein the request further comprises an indication of the first field of view.

8. The first wireless communication device of claim 7, wherein the indication comprises a coordinate system of the first field of view.

9. The first wireless communication device of claim 7, wherein the indication comprises a differential value relative to a previous set of characteristics received from the second wireless communication device.

10. The first wireless communication device of claim 1, wherein the processor is further configured to: performing a sidelink ranging operation between the first wireless communication device and the second wireless communication device; and The request for visual feature sharing is sent during the sidelink ranging operation.

11. The first wireless communication device of claim 10, wherein the processor is further configured to: The message is received within a sidelink ranging measurement report.

12. The first wireless communication device of claim 1, wherein the message comprises at least one of a unicast sidelink message, a multicast sidelink message, or a broadcast sidelink message.

13. The first wireless communication device of claim 1 , wherein the processor is further configured to: The message is received from the second wireless communication device via a network entity in wireless communication with the first wireless communication device and the second wireless communication device.

14. A wireless communication device, comprising: Transceiver; Memory; and a processor coupled to the transceiver and the memory, the processor being configured to: receiving, via the transceiver, a request for visual feature sharing from another wireless communication device; and A message is sent via the transceiver to the other wireless communication device, the message comprising a plurality of features in a field of view associated with the wireless communication device, each feature of the plurality of features comprising a corresponding keypoint of an image captured by the wireless communication device.

15. The wireless communication device of claim 14, wherein each of the plurality of features further comprises a respective feature descriptor corresponding to the respective keypoint.

16. The wireless communication device of claim 14, wherein the processor is further configured to: The global position of the wireless communication device in the coordinate system is transmitted.

17. The wireless communication device of claim 16, wherein the message further comprises a relative pose of a sensor on the wireless communication device relative to a reference frame associated with the wireless communication device.

18. The wireless communication device of claim 17, wherein the reference frame corresponds to a vehicle body frame associated with the wireless communication device.

19. The wireless communication device of claim 14, wherein the message further comprises a timestamp indicating a time when the plurality of characteristics were obtained at the wireless communication device.

20. The wireless communication device of claim 14, wherein the request further comprises an indication of the field of view.

21. The wireless communication device of claim 20, wherein the indication comprises a coordinate system of the field of view.

22. The wireless communication device of claim 20, wherein the indication comprises a differential value over a past set of features sent to the other wireless communication device.

23. The wireless communication device of claim 14, wherein the processor is further configured to: performing a sidelink ranging operation between the other wireless communication device and the wireless communication device; and The request for visual feature sharing is received during the sidelink ranging operation.

24. The wireless communication device of claim 23, wherein the processor is further configured to: The message is sent within a sidelink ranging measurement report.

25. The wireless communications apparatus of claim 14, wherein the message comprises at least one of a unicast sidelink message, a multicast sidelink message, or a broadcast sidelink message.

26. The wireless communication device of claim 14, wherein the processor is further configured to: The message is sent to the other wireless communication device via a network entity that wirelessly communicates with the other wireless communication device and the wireless communication device.

27. The wireless communication device of claim 14, wherein the processor is further configured to: A respective set of features is sent to the other wireless communication device for each of a plurality of images captured by the wireless communication device.

28. A method operable at a first wireless communication device, the method comprising: sending a request for visual feature sharing to a second wireless communication device; receiving a message from the second wireless communication device, the message comprising a plurality of first features in a first field of view associated with the second wireless communication device, each first feature of the plurality of first features comprising a respective first keypoint of a first image captured by the second wireless communication device; obtaining a plurality of second features in a second field of view associated with the first wireless communication device, each second feature of the plurality of second features comprising a corresponding second keypoint of a second image captured by the first wireless communication device; as well as A relative position and posture of the first wireless communication device with respect to the second wireless communication device is calculated based on associations between the plurality of first features and the plurality of second features.

29. The method of claim 28, wherein each of the plurality of first features further comprises a respective first feature descriptor corresponding to the respective first keypoint, and each of the plurality of second features further comprises a respective second feature descriptor corresponding to the respective second keypoint, and the method further comprises: The plurality of first features are associated with the plurality of second features based on the first keypoint, the second keypoint, the first feature descriptor, and the second feature descriptor.

30. A method operable at a wireless communication device, the method comprising: receiving a request for visual feature sharing from another wireless communication device; as well as A message is sent to the other wireless communication device, the message comprising a plurality of features in a field of view associated with the wireless communication device, each feature of the plurality of features comprising a corresponding keypoint of an image captured by the wireless communication device.

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