WO2025025484A1

WO2025025484A1 - Methods, apparatus, and system for multi-user uplink cooperative sensing and user-grouping via measurement fusion

Info

Publication number: WO2025025484A1
Application number: PCT/CN2023/139501
Authority: WO
Inventors: Ahmed Wagdy SHABAN; Alireza Bayesteh; Jianglei Ma
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2023-08-03
Filing date: 2023-12-18
Publication date: 2025-02-06
Anticipated expiration: 2026-02-03

Abstract

Aspects of the present application relate to facilitating cooperation between a sensing reception (RX) node and a group of sensing transmission (TX) nodes, wherein the cooperation enables high-resolution sensing services that utilize low-bandwidth sensing signals. The sensing RX node may exploit a heterogeneity of the sensing signals, received at the sensing RX node, from the plurality of the sensing TX nodes. The measurements may be obtained subsequent to the sensing RX node having configured a subset of the plurality of the sensing TX nodes to transmit, to the sensing RX node, jointly designed sensing signals. The measurements may be obtained, at the sensing RX node, over a plurality of low-bandwidth frequency chunks. A fusion of these measurements may be shown to increase a time-resolution of sensing parameters that may be obtained by processing the measurements.

Description

METHODS, APPARATUS, AND SYSTEM FOR MULTI-USER UPLINK COOPERATIVE SENSING AND USER-GROUPING VIA MEASUREMENT FUSION

TECHNICAL FIELD

The present disclosure relates, generally, to wireless communication and, in particular embodiments, to sensing and, even more particularly, to multi-user uplink cooperative sensing and user-grouping via measurement fusion.

BACKGROUND

User Equipment (UE) position information is often used in cellular communication networks to improve various performance metrics for the network. Such performance metrics may, for example, include capacity, agility and efficiency. The improvement may be achieved when elements of the network exploit the position, the behavior, the mobility pattern, etc., of the UE in the context of a priori information describing a wireless environment in which the UE is operating.

A sensing system may be used to help gather UE pose information. UE pose information may be understood to include a UE location in a global coordinate system, a UE velocity and direction of movement in the global coordinate system and UE orientation information. The sensing system may also be used to help gather information about the wireless environment. “UE location” is also known as “UE position” and these two terms may be used interchangeably herein. Examples of well-known sensing systems include Radio Detection and Ranging (RADAR) and Light Detection and Ranging (LIDAR) . While the sensing system can be separate from the communication system, it may also be shown to be advantageous to gather sensing information using an integrated system. An integrated system may be shown to gather sensing information based on communication signals. Integrated systems may be shown to reduce a quantity of hardware, and commensurate cost, relative to systems that achieve both functionalities using separate hardware. Integrated systems may also be shown to reduce time, frequency or spatial resources employed.

However, using an integrated system, wherein communication system hardware performs sensing of UE pose and environment information, may be shown to be a highly challenging and open problem. The difficulty of the problem relates to a plurality of factors, such as limited resolution of the communication system hardware, dynamicity inherent in the environment and a relatively large number of objects whose electromagnetic properties and position are to be sensed.

Accordingly, integrated sensing and communication (also known as integrated communication and sensing, joint sensing and communication and other, similar, names) is a desirable feature in communication systems.

SUMMARY

Aspects of the present application relate to facilitating cooperation between a sensing RX node and a group of sensing TX nodes, wherein the cooperation enables high-resolution sensing services that utilize low-bandwidth sensing signals. The sensing RX node may exploit a heterogeneity of the sensing signals, received at the sensing RX node, from the plurality of sensing TX nodes. The measurements may be obtained subsequent to the sensing RX node having configured a subset of the plurality of sensing TX nodes to transmit, to the sensing RX node, jointly designed sensing signals. The measurements may be obtained, at the sensing RX node, over a plurality of low-bandwidth frequency chunks. A fusion of these measurements may be shown to increase a time-resolution of sensing parameters that may be obtained by processing the measurements.

Existing approaches for fusing measurements may be shown to be limited to the use of a plurality of frequency chunks to enhance the sensing accuracy of a single sensing node. In the existing approaches, measurements are collected over a plurality of frequency bands that may be contiguously allocated in a spectrum. Additionally, the measurements belong, in a way, either by being transmitted, received, reflected or scattered, only to a single sensing node. Moreover, the measurements that are fused may be shown to be related to the same sensing parameters. The parameters may be shown to be associated with the single sensing node. It follows that existing approaches related fusing measurements may not enable determination of parameters belonging to a plurality of sensing nodes.

Some aspects of the present application relate to joint design, joint configuration and/or joint optimization of uplink sensing signals. Uplink sensing signals may be transmitted from a plurality of sensing TX nodes and received, at a sensing RX node, over a plurality of low-bandwidth frequency chunks. These frequency chunks may be associated with different frequency carriers and/or different sensing frequency layers. This joint design and configuration of the uplink sensing signals and signaling procedures may enhance the fusibility of the measurements and, thereby, result in estimates of sensing parameters that have higher time-resolution than estimates of sensing parameters available based on non-fused measurements.

According to an aspect of the present disclosure, there is provided a method of sensing. The method includes selecting a given sensing TX node for inclusion in a first plurality of sensing TX nodes, the selecting based on correlation between sensing parameters associated with the given sensing TX node and sensing parameters associated with at least one sensing TX node in the first plurality of sensing TX nodes. The method further includes transmitting, to the first plurality of sensing TX nodes, a configuration for uplink sensing signals, receiving, from the first plurality of the sensing TX nodes, uplink sensing signals and processing measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements. An apparatus is also provided to carry out this method and a computer-readable medium is provided storing instructions to cause a processor to carry out this method.

According to an aspect of the present disclosure, there is provided a method of sensing. The method includes transmitting, to a selected sensing transmission (TX) node among a plurality of sensing TX nodes, an indication that the selected sensing TX node has been selected as a lead sensing TX node and transmitting, to the lead sensing TX node indications identifying a first plurality of the sensing TX nodes among the plurality of the sensing TX nodes and configuration information for side-link communication with the first plurality of the sensing TX nodes. The method further includes receiving, from the first plurality of the sensing TX nodes, uplink sensing signals and processing measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements. An apparatus is also provided to carry out this method and a computer-readable medium is provided storing instructions to cause a processor to carry out this method.

According to an aspect of the present disclosure, there is provided a method. The method includes receiving, at a selected sensing TX node among a plurality of sensing TX nodes, an indication that the selected sensing TX node has been assigned as a lead sensing TX node for a first plurality of the sensing TX nodes among the plurality of the sensing TX nodes, receiving, at the lead sensing TX node, a downlink sensing signal, where the downlink sensing signal is a common downlink sensing signal that is also received at the sensing TX nodes of the first plurality of the sensing TX nodes, processing, at the lead sensing TX node, obtained measurements of the downlink sensing signal, to, thereby, obtain sensing parameters and transmitting the sensing parameters. A sensing TX node is also provided to carry out this method and a computer-readable medium is provided storing instructions to cause a processor to carry out this method.

According to an aspect of the present disclosure, there is provided a method. The method includes receiving, at a given sensing TX node among a plurality of the sensing TX nodes configuration information for a downlink sensing signal and configuration information for obtaining sensing parameters. The method further includes receiving, at the given sensing TX node, the downlink sensing signal, transmitting sensing measurements, the sensing measurements obtained by processing, according to the configuration information for obtaining sensing parameters, measurements of the downlink sensing signal, receiving, at the given sensing TX node from a lead sensing TX node, sensing measurements obtained by the lead sensing TX node and obtaining, at the given sensing TX node, a correlation between the sensing measurements obtained by the lead sensing TX node and the sensing measurements obtained by the given sensing TX node. The method further includes responsive to determining that the correlation exceeds a threshold, transmitting, to a sensing reception (RX) node, an indication that the correlation exceeds the threshold. A sensing TX node is also provided to carry out this method and a computer-readable medium is provided storing instructions to cause a processor to carry out this method.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present embodiments, and the advantages thereof, reference is now made, by way of example, to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates, in a schematic diagram, a communication system in which embodiments of the disclosure may occur, the communication system includes multiple example electronic devices and multiple example transmit receive points along with various networks;

FIG. 2 illustrates, in a block diagram, the communication system of FIG. 1, the communication system includes multiple example electronic devices, an example terrestrial transmit receive point and an example non-terrestrial transmit receive point along with various networks;

FIG. 3 illustrates, as a block diagram, elements of an example electronic device of FIG. 2, elements of an example terrestrial transmit receive point of FIG. 2 and elements of an example non-terrestrial transmit receive point of FIG. 2, in accordance with aspects of the present application;

FIG. 4 illustrates, as a block diagram, various modules that may be included in an example electronic device, an example terrestrial transmit receive point and an example non-terrestrial transmit receive point, in accordance with aspects of the present application;

FIG. 5 illustrates, as a block diagram, a sensing management function, in accordance with aspects of the present application;

FIG. 6 illustrates a network including a plurality of sensing transmission (TX) nodes, a sensing reception (RX) node, a sensing management function and a plurality of environment objects, in accordance with aspects of the present application;

FIG. 7 illustrates a plurality of power delay profiles and a corresponding plurality of relative power delay profiles, in accordance with aspects of the present application;

FIG. 8 illustrates a graphical representation of a sensing signal, in accordance with aspects of the present application;

FIG. 9 illustrates an example sensing pattern configuration, in accordance with aspects of the present application;

FIG. 10A illustrates, in a signal flow diagram, a flow of information, sensing signals and feedback, in accordance with aspects of the present application; and

FIG. 10B illustrates a continuation of the signal flow diagram of FIG. 10A.

DETAILED DESCRIPTION

For illustrative purposes, specific example embodiments will now be explained in greater detail in conjunction with the figures.

The embodiments set forth herein represent information sufficient to practice the claimed subject matter and illustrate ways of practicing such subject matter. Upon reading the following description in light of the accompanying figures, those of skill in the art will understand the concepts of the claimed subject matter and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

Moreover, it will be appreciated that any module, component, or device disclosed herein that executes instructions may include, or otherwise have access to, a non-transitory computer/processor readable storage medium or media for storage of information, such as computer/processor readable instructions, data structures, program modules and/or other data. A non-exhaustive list of examples of non-transitory computer/processor readable storage media includes magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, optical disks such as compact disc read-only memory (CD-ROM) , digital video discs or digital versatile discs (i.e., DVDs) , Blu-ray Disc^TM, or other optical storage, volatile and non-volatile, removable and non-removable media implemented in any method or technology, random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable read-only memory (EEPROM) , flash memory or other memory technology. Any such non-transitory computer/processor storage media may be part of a device or accessible or connectable thereto. Computer/processor readable/executable instructions to implement an application or module described herein may be stored or otherwise held by such non-transitory computer/processor readable storage media.

Referring to FIG. 1, as an illustrative example without limitation, a simplified schematic illustration of a communication system is provided. The communication system 100 comprises a radio access network 120. The radio access network 120 may be a next generation (e.g., sixth generation, “6G, ” or later) radio access network, or a legacy (e.g., 5G, 4G, 3G or 2G) radio access network. One or more communication electronic devices (ED) 110a, 110b, 110c, 110d, 110e, 110f, 110g, 110h, 110i, 110j (generically referred to as 110) may be interconnected to one another or connected to one or more network nodes (170a, 170b, generically referred to as 170) in the radio access network 120. A core network 130 may be a part of the communication system and may be dependent or independent of the radio access technology used in the communication system 100. Also, the communication system 100 comprises a public switched telephone network (PSTN) 140, the internet 150, and other networks 160.

FIG. 2 illustrates an example communication system 100. In general, the communication system 100 enables multiple wireless or wired elements to communicate data and other content. The purpose of the communication system 100 may be to provide content, such as voice, data, video, and/or text, via broadcast, multicast, groupcast and unicast, etc. The communication system 100 may operate by sharing resources, such as carrier spectrum bandwidth, between its constituent elements. The communication system 100 may include a terrestrial communication system and/or a non-terrestrial communication system. The communication system 100 may provide a wide range of communication services and applications (such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility, etc. ) . The communication system 100 may provide a high degree of availability and robustness through a joint operation of a terrestrial communication system and a non-terrestrial communication system. For example, integrating a non-terrestrial communication system (or components thereof) into a terrestrial communication system can result in what may be considered a heterogeneous network comprising multiple layers. Compared to conventional communication networks, the heterogeneous network may achieve better overall performance through efficient multi-link joint operation, more flexible functionality sharing and faster physical layer link switching between terrestrial networks and non-terrestrial networks.

The terrestrial communication system and the non-terrestrial communication system could be considered sub-systems of the communication system. In the example shown in FIG. 2, the communication system 100 includes electronic devices (ED) 110a, 110b, 110c, 110d (generically referred to as ED 110) , radio access networks (RANs) 120a, 120b, a non-terrestrial communication network 120c, a core network 130, a public switched telephone network (PSTN) 140, the Internet 150 and other networks 160. The RANs 120a, 120b include respective base stations (BSs) 170a, 170b, which may be generically referred to as terrestrial transmit and receive points (T-TRPs) 170a, 170b. The non-terrestrial communication network 120c includes an access node 172, which may be generically referred to as a non-terrestrial transmit and receive point (NT-TRP) 172.

Any ED 110 may be alternatively or additionally configured to interface, access, or communicate with any T-TRP 170a, 170b and NT-TRP 172, the Internet 150, the core network 130, the PSTN 140, the other networks 160, or any combination of the preceding. In some examples, the ED 110a may communicate an uplink and/or downlink transmission over a terrestrial air interface 190a with T-TRP 170a. In some examples, the EDs 110a, 110b, 110c and 110d may also communicate directly with one another via one or more sidelink air interfaces 190b. In some examples, the ED 110d may communicate an uplink and/or downlink transmission over a non-terrestrial air interface 190c with NT-TRP 172.

The air interfaces 190a and 190b may use similar communication technology, such as any suitable radio access technology. For example, the communication system 100 may implement one or more channel access methods, such as code division multiple access (CDMA) , space division multiple access (SDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal FDMA (OFDMA) , single-carrier FDMA (SC-FDMA, also known as discrete Fourier transform spread OFDMA, DFT-s-OFDMA) in the air interfaces 190a and 190b. The air interfaces 190a and 190b may utilize other higher dimension signal spaces, which may involve a combination of orthogonal and/or non-orthogonal dimensions.

The non-terrestrial air interface 190c can enable communication between the ED 110d and one or multiple NT-TRPs 172 via a wireless link or simply a link. For some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of EDs 110 and one or multiple NT-TRPs 172 for multicast transmission.

The RANs 120a and 120b are in communication with the core network 130 to provide the EDs 110a, 110b, 110c with various services such as voice, data and other services. The RANs 120a and 120b and/or the core network 130 may be in direct or indirect communication with one or more other RANs (not shown) , which may or may not be directly served by core network 130 and may, or may not, employ the same radio access technology as RAN 120a, RAN 120b or both. The core network 130 may also serve as a gateway access between (i) the RANs 120a and 120b or the EDs 110a, 110b, 110c or both, and (ii) other networks (such as the PSTN 140, the Internet 150, and the other networks 160) . In addition, some or all of the EDs 110a, 110b, 110c may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies and/or protocols. Instead of wireless communication (or in addition thereto) , the EDs 110a, 110b, 110c may communicate via wired communication channels to a service provider or switch (not shown) and to the Internet 150. The PSTN 140 may include circuit switched telephone networks for providing plain old telephone service (POTS) . The Internet 150 may include a network of computers and subnets (intranets) or both and incorporate protocols, such as Internet Protocol (IP) , Transmission Control Protocol (TCP) , User Datagram Protocol (UDP) . The EDs 110a, 110b, 110c may be multimode devices capable of operation according to multiple radio access technologies and may incorporate multiple transceivers necessary to support such.

FIG. 3 illustrates another example of an ED 110 and a base station 170a, 170b and/or 170c. The ED 110 is used to connect persons, objects, machines, etc. The ED 110 may be widely used in various scenarios including, for example, cellular communications, device-to-device (D2D) , vehicle to everything (V2X) , peer-to-peer (P2P) , machine-to-machine (M2M) , machine-type communications (MTC) , Internet of things (IoT) , virtual reality (VR) , augmented reality (AR) , mixed reality (MR) , metaverse, digital twin, industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility, etc.

Each ED 110 represents any suitable end user device for wireless operation and may include such devices (or may be referred to) as a user equipment/device (UE) , a wireless transmit/receive unit (WTRU) , a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a station (STA) , a machine type communication (MTC) device, a personal digital assistant (PDA) , a smartphone, a laptop, a computer, a tablet, a wireless sensor, a consumer electronics device, wearable devices such as a watch, head mounted equipment, a pair of glasses, a smart book, a vehicle, a car, a truck, a bus, a train, or an IoT device, wearable devices (such as a watch, a pair of glasses, head mounted equipment, etc. ) , an industrial device, or an apparatus in (e.g., communication module, modem, or chip) or comprising the forgoing devices, among other possibilities. Future generation EDs 110 may be referred to using other terms. The base stations 170a and 170b each T-TRPs and will, hereafter, be referred to as T-TRP 170. Also shown in FIG. 3, a NT-TRP will hereafter be referred to as NT-TRP 172. Each ED 110 connected to the T-TRP 170 and/or the NT-TRP 172 can be dynamically or semi-statically turned-on (i.e., established, activated or enabled) , turned-off (i.e., released, deactivated or disabled) and/or configured in response to one of more of: connection availability; and connection necessity.

The ED 110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is illustrated to avoid congestion in the drawing. One, some, or all of the antennas 204 may, alternatively, be panels. The transmitter 201 and the receiver 203 may be integrated, e.g., as a transceiver. The transceiver is configured to modulate data or other content for transmission by the at least one antenna 204 or by a network interface controller (NIC) . The transceiver may also be configured to demodulate data or other content received by the at least one antenna 204. Each transceiver includes any suitable structure for generating signals for wireless or wired transmission and/or processing signals received wirelessly or by wire. Each antenna 204 includes any suitable structure for transmitting and/or receiving wireless or wired signals.

The ED 110 includes at least one memory 208. The memory 208 stores instructions and data used, generated, or collected by the ED 110. For example, the memory 208 could store software instructions or modules configured to implement some or all of the functionality and/or embodiments described herein and that are executed by one or more processing unit (s) (e.g., a processor 210) . Each memory 208 includes any suitable volatile and/or non-volatile storage and retrieval device (s) . Any suitable type of memory may be used, such as random access memory (RAM) , read only memory (ROM) , hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, on-processor cache and the like.

The ED 110 may further include one or more input/output devices (not shown) or interfaces (such as a wired interface to the Internet 150 in FIG. 1) . The input/output devices or interfaces permit interaction with a user or other devices in the network. Each input/output device or interface includes any suitable structure for providing information to, or receiving information from, a user, and/or for network interface communications. Suitable structures include, for example, a speaker, a microphone, a keypad, a keyboard, a display or a touch screen, etc.

The ED 110 includes the processor 210 for performing operations including those operations related to preparing a transmission for uplink transmission to the NT-TRP 172 and/or the T-TRP 170, those operations related to processing downlink transmissions received from the NT-TRP 172 and/or the T-TRP 170, and those operations related to processing sidelink transmission to and from another ED 110. Processing operations related to preparing a transmission for uplink transmission may include operations such as encoding, modulating, transmit beamforming and generating symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receive beamforming, demodulating and decoding received symbols. Depending upon the embodiment, a downlink transmission may be received by the receiver 203, possibly using receive beamforming, and the processor 210 may extract signaling from the downlink transmission (e.g., by detecting and/or decoding the signaling) . An example of signaling may be a reference signal transmitted by the NT-TRP 172 and/or by the T-TRP 170. In some embodiments, the processor 210 implements the transmit beamforming and/or the receive beamforming based on the indication of beam direction, e.g., beam angle information (BAI) , received from the T-TRP 170. In some embodiments, the processor 210 may perform operations relating to network access (e.g., initial access) and/or downlink synchronization, such as operations relating to detecting a synchronization sequence, decoding and obtaining the system information, etc. In some embodiments, the processor 210 may perform channel estimation, e.g., using a reference signal received from the NT-TRP 172 and/or from the T-TRP 170.

Although not illustrated, the processor 210 may form part of the transmitter 201 and/or part of the receiver 203. Although not illustrated, the memory 208 may form part of the processor 210.

The processor 210, the processing components of the transmitter 201 and the processing components of the receiver 203 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory (e.g., in the memory 208) . Alternatively, some or all of the processor 210, the processing components of the transmitter 201 and the processing components of the receiver 203 may each be implemented using dedicated circuitry, such as a programmed field-programmable gate array (FPGA) , an application-specific integrated circuit (ASIC) , or a hardware accelerator such as a graphics processing unit (GPU) or an artificial intelligence (AI) accelerator.

The T-TRP 170 may be known by other names in some implementations, such as a base station, a base transceiver station (BTS) , a radio base station, a network node, a network device, a device on the network side, a transmit/receive node, a Node B, an evolved NodeB (eNodeB or eNB) , a Home eNodeB, a next Generation NodeB (gNB) , a transmission point (TP) , a site controller, an access point (AP) , a wireless router, a relay station, a remote radio head, a terrestrial node, a terrestrial network device, a terrestrial base station, a base band unit (BBU) , a remote radio unit (RRU) , an active antenna unit (AAU) , a remote radio head (RRH) , a central unit (CU) , a distributed unit (DU) , a positioning node, among other possibilities. The T-TRP 170 may be a macro BS, a pico BS, a relay node, a donor node, or the like, or combinations thereof. The T-TRP 170 may refer to the forgoing devices or refer to apparatus (e.g., a communication module, a modem or a chip) in the forgoing devices.

In some embodiments, the parts of the T-TRP 170 may be distributed. For example, some of the modules of the T-TRP 170 may be located remote from the equipment that houses the antennas 256 for the T-TRP 170, and may be coupled to the equipment that houses the antennas 256 over a communication link (not shown) sometimes known as front haul, such as common public radio interface (CPRI) . Therefore, in some embodiments, the term T-TRP 170 may also refer to modules on the network side that perform processing operations, such as determining the location of the ED 110, resource allocation (scheduling) , message generation, and encoding/decoding, and that are not necessarily part of the equipment that houses the antennas 256 of the T-TRP 170. The modules may also be coupled to other T-TRPs. In some embodiments, the T-TRP 170 may actually be a plurality of T-TRPs that are operating together to serve the ED 110, e.g., through the use of coordinated multipoint transmissions.

As illustrated in FIG. 3, the T-TRP 170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is illustrated to avoid congestion in the drawing. One, some, or all of the antennas 256 may, alternatively, be panels. The transmitter 252 and the receiver 254 may be integrated as a transceiver. The T-TRP 170 further includes a processor 260 for performing operations including those related to: preparing a transmission for downlink transmission to the ED 110; processing an uplink transmission received from the ED 110; preparing a transmission for backhaul transmission to the NT-TRP 172; and processing a transmission received over backhaul from the NT-TRP 172. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulating, precoding (e.g., multiple input multiple output, “MIMO, ” precoding) , transmit beamforming and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over backhaul may include operations such as receive beamforming, demodulating received symbols and decoding received symbols. The processor 260 may also perform operations relating to network access (e.g., initial access) and/or downlink synchronization, such as generating the content of synchronization signal blocks (SSBs) , generating the system information, etc. In some embodiments, the processor 260 also generates an indication of beam direction, e.g., BAI, which may be scheduled for transmission by a scheduler 253. The processor 260 performs other network-side processing operations described herein, such as determining the location of the ED 110, determining where to deploy the NT-TRP 172, etc. In some embodiments, the processor 260 may generate signaling, e.g., to configure one or more parameters of the ED 110 and/or one or more parameters of the NT-TRP 172. Any signaling generated by the processor 260 is sent by the transmitter 252. Note that “signaling, ” as used herein, may alternatively be called control signaling. Signaling may be transmitted in a physical layer control channel, e.g., a physical downlink control channel (PDCCH) , in which case the signaling may be known as dynamic signaling. Signaling transmitted in a downlink physical layer control channel may be known as Downlink Control Information (DCI) . Signaling transmitted in an uplink physical layer control channel may be known as Uplink Control Information (UCI) . Signaling transmitted in a sidelink physical layer control channel may be known as Sidelink Control Information (SCI) . Signaling may be included in a higher-layer (e.g., higher than physical layer) packet transmitted in a physical layer data channel, e.g., in a physical downlink shared channel (PDSCH) , in which case the signaling may be known as higher-layer signaling, static signaling, or semi-static signaling. Higher-layer signaling may also refer to Radio Resource Control (RRC) protocol signaling or Media Access Control –Control Element (MAC-CE) signaling.

The scheduler 253 may be coupled to the processor 260. The scheduler 253 may be included within, or operated separately from, the T-TRP 170. The scheduler 253 may schedule uplink, downlink, sidelink and/or backhaul transmissions, including issuing scheduling grants and/or configuring scheduling-free (e.g., “configured grant” ) resources. The T-TRP 170 further includes a memory 258 for storing information and data. The memory 258 stores instructions and data used, generated, or collected by the T-TRP 170. For example, the memory 258 could store software instructions or modules configured to implement some or all of the functionality and/or embodiments described herein and that are executed by the processor 260.

Although not illustrated, the processor 260 may form part of the transmitter 252 and/or part of the receiver 254. Also, although not illustrated, the processor 260 may implement the scheduler 253. Although not illustrated, the memory 258 may form part of the processor 260.

The processor 260, the scheduler 253, the processing components of the transmitter 252 and the processing components of the receiver 254 may each be implemented by the same, or different one of, one or more processors that are configured to execute instructions stored in a memory, e.g., in the memory 258. Alternatively, some or all of the processor 260, the scheduler 253, the processing components of the transmitter 252 and the processing components of the receiver 254 may be implemented using dedicated circuitry, such as a programmed FPGA, a hardware accelerator (e.g., a GPU or an AI accelerator) or an ASIC.

Notably, the NT-TRP 172 is illustrated as a drone only as an example, the NT-TRP 172 may be implemented in any suitable non-terrestrial form, such as satellites and high altitude platforms, including international mobile telecommunication base stations and unmanned aerial vehicles, for example. Also, the NT-TRP 172 may be known by other names in some implementations, such as a non-terrestrial node, a non-terrestrial network device, or a non-terrestrial base station. The NT-TRP 172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is illustrated to avoid congestion in the drawing. One, some, or all of the antennas may alternatively be panels. The transmitter 272 and the receiver 274 may be integrated as a transceiver. The NT-TRP 172 further includes a processor 276 for performing operations including those related to: preparing a transmission for downlink transmission to the ED 110; processing an uplink transmission received from the ED 110; preparing a transmission for backhaul transmission to T-TRP 170; and processing a transmission received over backhaul from the T-TRP 170. Processing operations related to preparing a transmission for downlink or backhaul transmission may include operations such as encoding, modulating, precoding (e.g., MIMO precoding) , transmit beamforming and generating symbols for transmission. Processing operations related to processing received transmissions in the uplink or over backhaul may include operations such as receive beamforming, demodulating received signals and decoding received symbols. In some embodiments, the processor 276 implements the transmit beamforming and/or receive beamforming based on beam direction information (e.g., BAI) received from the T-TRP 170. In some embodiments, the processor 276 may generate signaling, e.g., to configure one or more parameters of the ED 110. In some embodiments, the NT-TRP 172 implements physical layer processing but does not implement higher layer functions such as functions at the medium access control (MAC) or radio link control (RLC) layer. As this is only an example, more generally, the NT-TRP 172 may implement higher layer functions in addition to physical layer processing.

The NT-TRP 172 further includes a memory 278 for storing information and data. Although not illustrated, the processor 276 may form part of the transmitter 272 and/or part of the receiver 274. Although not illustrated, the memory 278 may form part of the processor 276.

The processor 276, the processing components of the transmitter 272 and the processing components of the receiver 274 may each be implemented by the same or different one or more processors that are configured to execute instructions stored in a memory, e.g., in the memory 278. Alternatively, some or all of the processor 276, the processing components of the transmitter 272 and the processing components of the receiver 274 may be implemented using dedicated circuitry, such as a programmed FPGA, a CPU, a hardware accelerator (e.g., a GPU or an AI accelerator) or an ASIC. In some embodiments, the NT-TRP 172 may actually be a plurality of NT-TRPs that are operating together to serve the ED 110, e.g., through coordinated multipoint transmissions.

The T-TRP 170, the NT-TRP 172, and/or the ED 110 may include other components, but these have been omitted for the sake of clarity.

One or more steps of the embodiment methods provided herein may be performed by corresponding units or modules, according to FIG. 4. FIG. 4 illustrates units or modules in a device, such as in the ED 110, in the T-TRP 170 or in the NT-TRP 172. For example, a signal may be transmitted by a transmitting unit or by a transmitting module. A signal may be received by a receiving unit or by a receiving module. A signal may be processed by a processing unit or by a processing module. Other steps may be performed by an artificial intelligence (AI) or machine learning (ML) module. The respective units or modules may be implemented using hardware, one or more components or devices that execute software, or a combination thereof. For instance, one or more of the units or modules may be a circuit such as an integrated circuit. Examples of an integrated circuit include a programmed FPGA, a CPU, a GPU or an ASIC. For instance, one or more of the units or modules may be logical such as a logical function performed by a circuit, by a portion of an integrated circuit, or by software instructions executed by a processor. It will be appreciated that where the modules are implemented using software for execution by a processor, for example, the modules may be retrieved by a processor, in whole or part as needed, individually or together for processing, in single or multiple instances, and that the modules themselves may include instructions for further deployment and instantiation.

Additional details regarding the EDs 110, the T-TRP 170 and the NT-TRP 172 are known to those of skill in the art. As such, these details are omitted here.

An air interface generally includes a number of components and associated parameters that collectively specify how a transmission is to be sent and/or received over a wireless communications link between two or more communicating devices. For example, an air interface may include one or more components defining the waveform (s) , frame structure (s) , multiple access scheme (s) , protocol (s) , coding scheme (s) and/or modulation scheme (s) for conveying information (e.g., data) over a wireless communications link. The wireless communications link may support a link between a radio access network and user equipment (e.g., a “Uu” link) , and/or the wireless communications link may support a link between device and device, such as between two user equipments (e.g., a “sidelink” ) , and/or the wireless communications link may support a link between a non-terrestrial (NT) -communication network and user equipment (UE) . The following are some examples for the above components.

A waveform component may specify a shape and form of a signal being transmitted. Waveform options may include orthogonal multiple access waveforms and non-orthogonal multiple access waveforms. Non-limiting examples of such waveform options include Orthogonal Frequency Division Multiplexing (OFDM) , Direct Fourier Transform spread OFDM (DFT-OFDM) , Filtered OFDM (f-OFDM) , Time windowing OFDM, Filter Bank Multicarrier (FBMC) , Universal Filtered Multicarrier (UFMC) , Generalized Frequency Division Multiplexing (GFDM) , Wavelet Packet Modulation (WPM) , Faster Than Nyquist (FTN) Waveform and low Peak to Average Power Ratio Waveform (low PAPR WF) .

A frame structure component may specify a configuration of a frame or group of frames. The frame structure component may indicate one or more of a time, frequency, pilot signature, code or other parameter of the frame or group of frames. More details of frame structure will be discussed hereinafter.

A multiple access scheme component may specify multiple access technique options, including technologies defining how communicating devices share a common physical channel, such as: TDMA; FDMA; CDMA; SDMA; OFDMA; SC-FDMA; Low Density Signature Multicarrier CDMA (LDS-MC-CDMA) ; Non-Orthogonal Multiple Access (NOMA) ; Pattern Division Multiple Access (PDMA) ; Lattice Partition Multiple Access (LPMA) ; Resource Spread Multiple Access (RSMA) ; and Sparse Code Multiple Access (SCMA) . Furthermore, multiple access technique options may include: scheduled access vs. non-scheduled access, also known as grant-free access; non-orthogonal multiple access vs. orthogonal multiple access, e.g., via a dedicated channel resource (e.g., no sharing between multiple communicating devices) ; contention-based shared channel resources vs. non-contention-based shared channel resources; and cognitive radio-based access.

A hybrid automatic repeat request (HARQ) protocol component may specify how a transmission and/or a re-transmission is to be made. Non-limiting examples of transmission and/or re-transmission mechanism options include those that specify a scheduled data pipe size, a signaling mechanism for transmission and/or re-transmission and a re-transmission mechanism.

A coding and modulation component may specify how information being transmitted may be encoded/decoded and modulated/demodulated for transmission/reception purposes. Coding may refer to methods of error detection and forward error correction. Non-limiting examples of coding options include turbo trellis codes, turbo product codes, fountain codes, low-density parity check codes and polar codes. Modulation may refer, simply, to the constellation (including, for example, the modulation technique and order) , or more specifically to various types of advanced modulation methods such as hierarchical modulation and low PAPR modulation.

In some embodiments, the air interface may be a “one-size-fits-all” concept. For example, it may be that the components within the air interface cannot be changed or adapted once the air interface is defined. In some implementations, only limited parameters or modes of an air interface, such as a cyclic prefix (CP) length or a MIMO mode, can be configured. In some embodiments, an air interface design may provide a unified or flexible framework to support frequencies below known 6 GHz bands and frequencies beyond the 6 GHz bands (e.g., mmWave bands) for both licensed and unlicensed access. As an example, flexibility of a configurable air interface provided by a scalable numerology and symbol duration may allow for transmission parameter optimization for different spectrum bands and for different services/devices. As another example, a unified air interface may be self-contained in a frequency domain and a frequency domain self-contained design may support more flexible RAN slicing through channel resource sharing between different services in both frequency and time.

A frame structure is a feature of the wireless communication physical layer that defines a time domain signal transmission structure to, e.g., allow for timing reference and timing alignment of basic time domain transmission units. Wireless communication between communicating devices may occur on time-frequency resources governed by a frame structure. The frame structure may, sometimes, instead be called a radio frame structure.

Depending upon the frame structure and/or configuration of frames in the frame structure, frequency division duplex (FDD) and/or time-division duplex (TDD) and/or full duplex (FD) communication may be possible. FDD communication is when transmissions in different directions (e.g., uplink vs. downlink) occur in different frequency bands. TDD communication is when transmissions in different directions (e.g., uplink vs. downlink) occur over different time durations. FD communication is when transmission and reception occurs on the same time-frequency resource, i.e., a device can both transmit and receive on the same frequency resource contemporaneously.

One example of a frame structure is a frame structure, specified for use in the known long-term evolution (LTE) cellular systems, having the following specifications: each frame is 10 ms in duration; each frame has 10 subframes, which subframes are each 1 ms in duration; each subframe includes two slots, each of which slots is 0.5 ms in duration; each slot is for the transmission of seven OFDM symbols (assuming normal CP) ; each OFDM symbol has a symbol duration and a particular bandwidth (or partial bandwidth or bandwidth partition) related to the number of subcarriers and subcarrier spacing; the frame structure is based on OFDM waveform parameters such as subcarrier spacing and CP length (where the CP has a fixed length or limited length options) ; and the switching gap between uplink and downlink in TDD is specified as the integer time of OFDM symbol duration.

Another example of a frame structure is a frame structure, specified for use in the known new radio (NR) cellular systems, having the following specifications: multiple subcarrier spacings are supported, each subcarrier spacing corresponding to a respective numerology; the frame structure depends on the numerology but, in any case, the frame length is set at 10 ms and each frame consists of ten subframes, each subframe of 1 ms duration; a slot is defined as 14 OFDM symbols; and slot length depends upon the numerology. For example, the NR frame structure for normal CP 15 kHz subcarrier spacing ( “numerology 1” ) and the NR frame structure for normal CP 30 kHz subcarrier spacing ( “numerology 2” ) are different. For 15 kHz subcarrier spacing, the slot length is 1 ms and, for 30 kHz subcarrier spacing, the slot length is 0.5 ms.The NR frame structure may have more flexibility than the LTE frame structure.

Another example of a frame structure is, e.g., for use in a 6G network or a later network. In a flexible frame structure, a symbol block may be defined to have a duration that is the minimum duration of time that may be scheduled in the flexible frame structure. A symbol block may be a unit of transmission having an optional redundancy portion (e.g., CP portion) and an information (e.g., data) portion. An OFDM symbol is an example of a symbol block. A symbol block may alternatively be called a symbol. Embodiments of flexible frame structures include different parameters that may be configurable, e.g., frame length, subframe length, symbol block length, etc. A non-exhaustive list of possible configurable parameters, in some embodiments of a flexible frame structure, includes: frame length; subframe duration; slot configuration; subcarrier spacing (SCS) ; flexible transmission duration of basic transmission unit; and flexible switch gap.

The frame length need not be limited to 10 ms and the frame length may be configurable and change over time. In some embodiments, each frame includes one or multiple downlink synchronization channels and/or one or multiple downlink broadcast channels and each synchronization channel and/or broadcast channel may be transmitted in a different direction by different beamforming. The frame length may be more than one possible value and configured based on the application scenario. For example, autonomous vehicles may require relatively fast initial access, in which case the frame length may be set to 5 ms for autonomous vehicle applications. As another example, smart meters on houses may not require fast initial access, in which case the frame length may be set as 20 ms for smart meter applications.

A subframe might or might not be defined in the flexible frame structure, depending upon the implementation. For example, a frame may be defined to include slots, but no subframes. In frames in which a subframe is defined, e.g., for time domain alignment, the duration of the subframe may be configurable. For example, a subframe may be configured to have a length of 0.1 ms or 0.2 ms or 0.5 ms or 1 ms or 2 ms or 5 ms, etc. In some embodiments, if a subframe is not needed in a particular scenario, then the subframe length may be defined to be the same as the frame length or not defined.

A slot might or might not be defined in the flexible frame structure, depending upon the implementation. In frames in which a slot is defined, then the definition of a slot (e.g., in time duration and/or in number of symbol blocks) may be configurable. In one embodiment, the slot configuration is common to all UEs 110 or a group of UEs 110. For this case, the slot configuration information may be transmitted to the UEs 110 in a broadcast channel or common control channel (s) . In other embodiments, the slot configuration may be UE specific, in which case the slot configuration information may be transmitted in a UE-specific control channel. In some embodiments, the slot configuration signaling can be transmitted together with frame configuration signaling and/or subframe configuration signaling. In other embodiments, the slot configuration may be transmitted independently from the frame configuration signaling and/or subframe configuration signaling. In general, the slot configuration may be system common, base station common, UE group common or UE specific.

The SCS may range from 15 KHz to 480 KHz. The SCS may vary with the frequency of the spectrum and/or maximum UE speed to minimize the impact of Doppler shift and phase noise. In some examples, there may be separate transmission and reception frames and the SCS of symbols in the reception frame structure may be configured independently from the SCS of symbols in the transmission frame structure. The SCS in a reception frame may be different from the SCS in a transmission frame. In some examples, the SCS of each transmission frame may be half the SCS of each reception frame. If the SCS between a reception frame and a transmission frame is different, the difference does not necessarily have to scale by a factor of two, e.g., if more flexible symbol durations are implemented using inverse discrete Fourier transform (IDFT) instead of fast Fourier transform (FFT) . Additional examples of frame structures can be used with different SCSs.

The basic transmission unit may be a symbol block (alternatively called a symbol) , which, in general, includes a redundancy portion (referred to as the CP) and an information (e.g., data) portion. In some embodiments, the CP may be omitted from the symbol block. The CP length may be flexible and configurable. The CP length may be fixed within a frame or flexible within a frame and the CP length may possibly change from one frame to another, or from one group of frames to another group of frames, or from one subframe to another subframe, or from one slot to another slot, or dynamically from one scheduling to another scheduling. The information (e.g., data) portion may be flexible and configurable. Another possible parameter relating to a symbol block that may be defined is ratio of CP duration to information (e.g., data) duration. In some embodiments, the symbol block length may be adjusted according to: a channel condition (e.g., multi-path delay, Doppler) ; and/or a latency requirement; and/or an available time duration. As another example, a symbol block length may be adjusted to fit an available time duration in the frame.

A frame may include both a downlink portion, for downlink transmissions from a base station 170, and an uplink portion, for uplink transmissions from the UEs 110. A gap may be present between each uplink and downlink portion, which gap is referred to as a switching gap. The switching gap length (duration) may be configurable. A switching gap duration may be fixed within a frame or flexible within a frame and a switching gap duration may possibly change from one frame to another, or from one group of frames to another group of frames, or from one subframe to another subframe, or from one slot to another slot, or dynamically from one scheduling to another scheduling.

A device, such as a base station 170, may provide coverage over a cell. Wireless communication with the device may occur over one or more carrier frequencies. A carrier frequency will be referred to as a carrier. A carrier may alternatively be called a component carrier (CC) . A carrier may be characterized by its bandwidth and a reference frequency, e.g., the center frequency, the lowest frequency or the highest frequency of the carrier. A carrier may be on a licensed spectrum or an unlicensed spectrum. Wireless communication with the device may also, or instead, occur over one or more bandwidth parts (BWPs) . For example, a carrier may have one or more BWPs. More generally, wireless communication with the device may occur over spectrum. The spectrum may comprise one or more carriers and/or one or more BWPs.

A cell may include one or multiple downlink resources and, optionally, one or multiple uplink resources. A cell may include one or multiple uplink resources and, optionally, one or multiple downlink resources. A cell may include both one or multiple downlink resources and one or multiple uplink resources. As an example, a cell might only include one downlink carrier/BWP, or only include one uplink carrier/BWP, or include multiple downlink carriers/BWPs, or include multiple uplink carriers/BWPs, or include one downlink carrier/BWP and one uplink carrier/BWP, or include one downlink carrier/BWP and multiple uplink carriers/BWPs, or include multiple downlink carriers/BWPs and one uplink carrier/BWP, or include multiple downlink carriers/BWPs and multiple uplink carriers/BWPs. In some embodiments, a cell may, instead or additionally, include one or multiple sidelink resources, including sidelink transmitting and receiving resources.

A BWP is a set of contiguous or non-contiguous frequency subcarriers on a carrier, or a set of contiguous or non-contiguous frequency subcarriers on multiple carriers, or a set of non-contiguous or contiguous frequency subcarriers, which may have one or more carriers. Notably, it should be understood that the terms “bandwidth part (BWP) , ” “frequency sub-bands, ” “frequency bands” and “frequency chunks” refer to the same concept, that is, a contiguous interval/resource in the frequency domain.

In some embodiments, a carrier may have one or more BWPs, e.g., a carrier may have a bandwidth of 20 MHz and consist of one BWP, or a carrier may have a bandwidth of 80 MHz and consist of two adjacent contiguous BWPs, etc. In other embodiments, a BWP may have one or more carriers, e.g., a BWP may have a bandwidth of 40 MHz and consist of two adjacent contiguous carriers, where each carrier has a bandwidth of 20 MHz. In some embodiments, a BWP may comprise non-contiguous spectrum resources, which consists of multiple non-contiguous multiple carriers, where the first carrier of the non-contiguous multiple carriers may be in the mmW band, the second carrier may be in a low band (such as the 2 GHz band) , the third carrier (if it exists) may be in THz band and the fourth carrier (if it exists) may be in visible light band. Resources in one carrier which belong to the BWP may be contiguous or non-contiguous. In some embodiments, a BWP has non-contiguous spectrum resources on one carrier.

Wireless communication may occur over an occupied bandwidth. The occupied bandwidth may be defined as the width of a frequency band such that, below the lower and above the upper frequency limits, the mean powers emitted are each equal to a specified percentage, β/2, of the total mean transmitted power, for example, the value of β/2 is taken as 0.5%.

The carrier, the BWP or the occupied bandwidth may be signaled by a network device (e.g., by a base station 170) dynamically, e.g., in physical layer control signaling such as the known downlink control channel (DCI) , or semi-statically, e.g., in radio resource control (RRC) signaling or in signaling in the medium access control (MAC) layer, or be predefined based on the application scenario; or be determined by the UE 110 as a function of other parameters that are known by the UE 110, or may be fixed, e.g., by a standard.

UE position information is often used in cellular communication networks to improve various performance metrics for the network. Such performance metrics may, for example, include capacity, agility and efficiency. The improvement may be achieved when elements of the network exploit the position, the behavior, the mobility pattern, etc., of the UE in the context of a priori information describing a wireless environment in which the UE is operating.

A sensing system may be used to help gather UE pose information, including UE location in a global coordinate system, UE velocity and direction of movement in the global coordinate system, orientation information and the information about the wireless environment. “Location” is also known as “position” and these two terms may be used interchangeably herein. Examples of well-known sensing systems include RADAR (Radio Detection and Ranging) and LIDAR (Light Detection and Ranging) . While the sensing system is typically separate from the communication system, it could be advantageous to gather the information using an integrated system, which reduces the hardware (and cost) in the system as well as the time, frequency or spatial resources needed to perform both functionalities. However, using the communication system hardware to perform sensing of UE pose and environment information is a highly challenging and open problem. The difficulty of the problem relates to factors such as the limited resolution of the communication system, the dynamicity of the environment, and the huge number of objects whose electromagnetic properties and position are to be estimated.

Accordingly, integrated sensing and communication (also known as integrated communication and sensing) is a desirable feature in existing and future communication systems.

Any or all of the EDs 110 and BS 170 may be sensing nodes in the system 100. Sensing nodes are network entities that perform sensing by transmitting and receiving sensing signals. Some sensing nodes are communication equipment that perform both communications and sensing. However, it is possible that some sensing nodes do not perform communications and are, instead, dedicated to sensing. The sensing agent 174 is an example of a sensing node that is dedicated to sensing. Unlike the EDs 110 and BS 170, the sensing agent 174 does not transmit or receive communication signals. However, the sensing agent 174 may communicate configuration information, sensing information, signaling information, or other information within the communication system 100. The sensing agent 174 may be in communication with the core network 130 to communicate information with the rest of the communication system 100. By way of example, the sensing agent 174 may determine the location of the ED 110a, and transmit this information to the base station 170a via the core network 130. Although only one sensing agent 174 is shown in FIG. 2, any number of sensing agents may be implemented in the communication system 100. In some embodiments, one or more sensing agents may be implemented at one or more of the RANs 120.

A sensing node may combine sensing-based techniques with reference signal-based techniques to enhance UE pose determination. This type of sensing node may also be known as a sensing management function (SMF) . In some networks, the SMF may also be known as a location management function (LMF) . The SMF may be implemented as a physically independent entity located at the core network 130 with connection to the multiple BSs 170. In other aspects of the present application, the SMF may be implemented as a logical entity co-located inside a BS 170 through logic carried out by the processor 260.

As shown in FIG. 5, an SMF 176, when implemented as a physically independent entity, includes at least one processor 290, at least one transmitter 282, at least one receiver 284, one or more antennas 286 and at least one memory 288. A transceiver, not shown, may be used instead of the transmitter 282 and the receiver 284. A scheduler 283 may be coupled to the processor 290. The scheduler 283 may be included within or operated separately from the SMF 176. The processor 290 implements various processing operations of the SMF 176, such as signal coding, data processing, power control, input/output processing or any other functionality. The processor 290 can also be configured to implement some or all of the functionality and/or embodiments described in more detail above. Each processor 290 includes any suitable processing or computing device configured to perform one or more operations. Each processor 290 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array or application specific integrated circuit.

A reference signal-based pose determination technique belongs to an “active” pose estimation paradigm. In an active pose estimation paradigm, the enquirer (e.g., the UE 110) of pose information takes part in process of determining the pose of the enquirer. The enquirer may transmit or receive (or both) a signal specific to pose determination process. Positioning techniques based on a global navigation satellite system (GNSS) such as Global Positioning System (GPS) are other examples of the active pose estimation paradigm.

In contrast, a sensing technique, based on radar for example, may be considered as belonging to a “passive” pose determination paradigm. In a passive pose determination paradigm, the target is oblivious to the pose determination process.

By integrating sensing and communications in one system, the system need not operate according to only a single paradigm. Thus, the combination of sensing-based techniques and reference signal-based techniques can yield enhanced pose determination.

The enhanced pose determination may, for example, include obtaining UE channel sub-space information, which is particularly useful for UE channel reconstruction at the sensing node, especially for a beam-based operation and communication. The UE channel sub-space is a subset of the entire algebraic space, defined over the spatial domain, in which the entire channel from the TP to the UE lies. Accordingly, the UE channel sub-space defines the TP-to-UE channel with very high accuracy. The signals transmitted over other sub-spaces result in a negligible contribution to the UE channel. Knowledge of the UE channel sub-space helps to reduce the effort needed for channel measurement at the UE and channel reconstruction at the network-side. Therefore, the combination of sensing-based techniques and reference signal-based techniques may enable the UE channel reconstruction with much less overhead as compared to traditional methods. Sub-space information can also facilitate sub-space-based sensing to reduce sensing complexity and improve sensing accuracy.

In some embodiments of integrated sensing and communication, a same radio access technology (RAT) is used for sensing and communication. This avoids the need to multiplex two different RATs under one carrier spectrum, or necessitating two different carrier spectrums for the two different RATs.

In embodiments that integrate sensing and communication under one RAT, a first set of channels may be used to transmit a sensing signal and a second set of channels may be used to transmit a communications signal. In some embodiments, each channel in the first set of channels and each channel in the second set of channels is a logical channel, a transport channel or a physical channel.

At the physical layer, communication and sensing may be performed via separate physical channels. For example, a first physical downlink shared channel PDSCH-C is defined for data communication, while a second physical downlink shared channel PDSCH-Sis defined for sensing. Similarly, separate physical uplink shared channels (PUSCH) , PUSCH-C and PUSCH-S, could be defined for uplink communication and sensing.

In another example, the same PDSCH and PUSCH could be also used for both communication and sensing, with separate logical layer channels and/or transport layer channels defined for communication and sensing. Note also that control channel (s) and data channel (s) for sensing can have the same or different channel structure (format) , occupy same or different frequency bands or bandwidth parts.

In a further example, a common physical downlink control channel (PDCCH) and a common physical uplink control channel (PUCCH) may be used to carry control information for both sensing and communication. Alternatively, separate physical layer control channels may be used to carry separate control information for communication and sensing. For example, PUCCH-Sand PUCCH-C could be used for uplink control for sensing and communication respectively and PDCCH-Sand PDCCH-C for downlink control for sensing and communication respectively.

Different combinations of shared and dedicated channels for sensing and communication, at each of the physical, transport, and logical layers, are possible.

The term RADAR originates from the phrase Radio Detection and Ranging; however, expressions with different forms of capitalization (e.g., Radar and radar) are equally valid and now more common. Radar is typically used for detecting a presence and a location of an object. A radar system radiates radio frequency energy and receives echoes of the energy reflected from one or more targets. The system determines the pose of a given target based on the echoes returned from the given target. The radiated energy can be in the form of an energy pulse or a continuous wave, which can be expressed or defined by a particular waveform. Examples of waveforms used in radar include frequency modulated continuous wave (FMCW) and ultra-wideband (UWB) waveforms.

Radar systems can be monostatic, bi-static or multi-static. In a monostatic radar system, the radar signal transmitter and receiver are co-located, such as being integrated in a transceiver. In a bi-static radar system, the transmitter and receiver are spatially separated, and the distance of separation is comparable to, or larger than, the expected target distance (often referred to as the range) . In a multi-static radar system, two or more radar components are spatially diverse but with a shared area of coverage. A multi-static radar is also referred to as a multisite or netted radar.

Terrestrial radar applications encounter challenges such as multipath propagation and shadowing impairments. Another challenge is the problem of identifiability because terrestrial targets have similar physical attributes. Integrating sensing into a communication system is likely to suffer from these same challenges, and more.

Communication nodes can be either half-duplex or full-duplex. A half-duplex node cannot both transmit and receive using the same physical resources (time, frequency, etc. ) ; conversely, a full-duplex node can transmit and receive using the same physical resources. Existing commercial wireless communications networks are all half-duplex. Even if full-duplex communications networks become practical in the future, it is expected that at least some of the nodes in the network will still be half-duplex nodes because half-duplex devices are less complex, and have lower cost and lower power consumption. In particular, full-duplex implementation is more challenging at higher frequencies (e.g., in millimeter wave bands) and very challenging for small and low-cost devices, such as femtocell base stations and UEs.

The limitation of half-duplex nodes in the communications network presents further challenges toward integrating sensing and communications into the devices and systems of the communications network. For example, both half-duplex and full-duplex nodes can perform bi-static or multi-static sensing, but monostatic sensing typically requires the sensing node have full-duplex capability. A half-duplex node may perform monostatic sensing with certain limitations, such as in a pulsed radar with a specific duty cycle and ranging capability.

Properties of a sensing signal, or a signal used for both sensing and communication, include the waveform of the signal and the frame structure of the signal. The frame structure defines the time-domain boundaries of the signal. The waveform describes the shape of the signal as a function of time and frequency. Examples of waveforms that can be used for a sensing signal include ultra-wide band (UWB) pulse, Frequency-Modulated Continuous Wave (FMCW) or “chirp, ” orthogonal frequency-division multiplexing (OFDM) , cyclic prefix (CP) -OFDM and Discrete Fourier Transform spread (DFT-s) -OFDM. The example waveform called FMCW, or chirp, which can be used for a sensing signal may also be called a linear frequency modulated (LFM) waveform.

In an embodiment, the sensing signal is a linear chirp signal with bandwidth B and time duration T. Such a linear chirp signal is generally known from its use in FMCW radar systems. A linear chirp signal is defined by an increase in frequency from an initial frequency, f_chirp0, at an initial time, t_chirp0, to a final frequency, f_chirp1, at a final time, t_chirp1 where the relation between the frequency (f) and time (t) can be expressed as a linear relation of f-f_chirp0= α (t-t_chirp0) , whereis defined as the chirp slope. The bandwidth of the linear chirp signal may be defined as B=f_chirp11f_chirp0 and the time duration of the linear chirp signal may be defined as T=t_chirp1-t_chirp0. Such linear chirp signal can be presented asin the baseband representation.

Precoding, as used herein, may refer to any coding operation (s) or modulation (s) that transform an input signal into an output signal. Precoding may be performed in different domains and typically transforms the input signal in a first domain to an output signal in a second domain. Precoding may include linear operations.

A terrestrial communication system may also be referred to as a land-based or ground-based communication system, although a terrestrial communication system can also, or instead, be implemented on or in water. The non-terrestrial communication system may bridge coverage gaps in underserved areas by extending the coverage of cellular networks through the use of non-terrestrial nodes, which will be key to establishing global, seamless coverage and providing mobile broadband services to unserved/underserved regions. In the current case, it is hardly possible to implement terrestrial access-points/base-stations infrastructure in areas like oceans, mountains, forests, or other remote areas.

The terrestrial communication system may be a wireless communications system using 5G technology and/or later generation wireless technology (e.g., 6G or later) . In some examples, the terrestrial communication system may also accommodate some legacy wireless technologies (e.g., 3G or 4G wireless technology) . The non-terrestrial communication system may be a communications system using satellite constellations, like conventional Geo-Stationary Orbit (GEO) satellites, which utilize broadcast public/popular contents to a local server. The non-terrestrial communication system may be a communications system using low earth orbit (LEO) satellites, which are known to establish a better balance between large coverage area and propagation path-loss/delay. The non-terrestrial communication system may be a communications system using stabilized satellites in very low earth orbits (VLEO) technologies, thereby substantially reducing the costs for launching satellites to lower orbits. The non-terrestrial communication system may be a communications system using high altitude platforms (HAPs) , which are known to provide a low path-loss air interface for the users with limited power budget. The non-terrestrial communication system may be a communications system using Unmanned Aerial Vehicles (UAVs) (or unmanned aerial system, “UAS” ) achieving a dense deployment, since their coverage can be limited to a local area, such as airborne, balloon, quadcopter, drones, etc. In some examples, GEO satellites, LEO satellites, UAVs, HAPs and VLEOs may be horizontal and two-dimensional. In some examples, UAVs, HAPs and VLEOs may be coupled to integrate satellite communications to cellular networks. Emerging 3D vertical networks consist of many moving (other than geostationary satellites) and high-altitude access points such as UAVs, HAPs and VLEOs.

MIMO technology allows an antenna array of multiple antennas to perform signal transmissions and receptions to meet high transmission rate requirements. The ED 110 and the T-TRP 170 and/or the NT-TRP may use MIMO to communicate using wireless resource blocks. MIMO utilizes multiple antennas at the transmitter to transmit wireless resource blocks over parallel wireless signals. It follows that multiple antennas may be utilized at the receiver. MIMO may beamform parallel wireless signals for reliable multipath transmission of a wireless resource block. MIMO may bond parallel wireless signals that transport different data to increase the data rate of the wireless resource block.

In recent years, a MIMO (large-scale MIMO) wireless communication system with the T-TRP 170 and/or the NT-TRP 172 configured with a large number of antennas has gained wide attention from academia and industry. In the large-scale MIMO system, the T-TRP 170, and/or the NT-TRP 172, is generally configured with more than ten antenna units (see antennas 256 and antennas 280 in FIG. 3) . The T-TRP 170, and/or the NT-TRP 172, is generally operable to serve dozens (such as 40) of EDs 110. A large number of antenna units of the T-TRP 170 and the NT-TRP 172 can greatly increase the degree of spatial freedom of wireless communication, greatly improve the transmission rate, spectral efficiency and power efficiency, and, to a large extent, reduce interference between cells. The increase of the number of antennas allows for each antenna unit to be made in a smaller size with a lower cost. Using the degree of spatial freedom provided by the large-scale antenna units, the T-TRP 170 and the NT-TRP 172 of each cell can communicate with many EDs 110 in the cell on the same time-frequency resource at the same time, thus greatly increasing the spectral efficiency. A large number of antenna units of the T-TRP 170 and/or the NT-TRP 172 also enable each user to have better spatial directivity for uplink and downlink transmission, so that the transmitting power of the T-TRP 170 and/or the NT-TRP 172 and an ED 110 is reduced, and the power efficiency is correspondingly increased. When the antenna number of the T-TRP 170 and/or the NT-TRP 172 is sufficiently large, random channels between each ED 110 and the T-TRP 170 and/or the NT-TRP 172 can approach orthogonality such that interference between cells and users and the effect of noise can be reduced. The plurality of advantages described hereinbefore enable large-scale MIMO to have a magnificent application prospect.

A MIMO system may include a receiver connected to a receive (Rx) antenna, a transmitter connected to transmit (Tx) antenna and a signal processor connected to the transmitter and the receiver. Each of the Rx antenna and the Tx antenna may include a plurality of antennas. For instance, the Rx antenna may have a uniform linear array (ULA) antenna, in which the plurality of antennas are arranged in line at even intervals. When a radio frequency (RF) signal is transmitted through the Tx antenna, the Rx antenna may receive a signal reflected and returned from a forward target.

A non-exhaustive list of possible unit or possible configurable parameters or in some embodiments of a MIMO system include: a panel; and a beam.

A panel is a unit of an antenna group, or antenna array, or antenna sub-array, which unit can control a Tx beam or a Rx beam independently.

A beam may be formed by performing amplitude and/or phase weighting on data transmitted or received by at least one antenna port. A beam may be formed by using another method, for example, adjusting a related parameter of an antenna unit. The beam may include a Tx beam and/or a Rx beam. The transmit beam indicates distribution of signal strength formed in different directions in space after a signal is transmitted through an antenna. The receive beam indicates distribution of signal strength that is of a wireless signal received from an antenna and that is in different directions in space. Beam information may include a beam identifier, or an antenna port (s) identifier, or a channel state information reference signal (CSI-RS) resource identifier, or a SSB resource identifier, or a sounding reference signal (SRS) resource identifier, or other reference signal resource identifier.

Next generation wireless communication systems may be referred to as “beyond 5G” communication systems or referred to as sixth generation (6G) communication systems. In the next generation wireless communication systems, it is expected that nodes, including network nodes and UEs, will be able to perform communication and sensing functionalities simultaneously, while maintaining relatively high spectral efficiency.

On one hand, it may be shown that most of the envisioned sensing-related applications and use-cases of next generation wireless communication systems benefit from meeting stringent key performance indicator (KPI) thresholds. The KPI thresholds may, for example, relate to accuracy, reliability, latency, update rate, low-power requirements and availability. It may be shown that current 5G systems can neither support nor provide certain sensing information, such as three-dimensional orientation. It may further be shown that current 5G systems cannot detect shapes of objects in environment maps. It may still further be shown that current 5G systems cannot meet most of the stringent KPI thresholds for the envisioned sensing applications. For instance, considering position as a sensing information, according to 3GPP Technical Report R1-2009842 TR 38 857 v 0.4.0 on 5G positioning (hereby incorporated herein by reference) , synchronized 5G systems can barely provide positioning accuracies of 2.99 meters and 1.11 meters with positioning methods working over frequency range 1 (FR1) and frequency range 2 (FR2) , respectively, in outdoor environments. Moreover, for unsynchronized 5G systems, the accuracy deteriorates significantly, such that unsynchronized 5G systems may barely achieve 10.9 meters and 9.11 meters with positioning methods working over FR1 and FR2, respectively, in outdoor environments.

On the other hand, a majority of the sensing-related applications may be shown to employ relatively high time-resolution channel information (e.g., CSI at the transmitter and/or the receiver, and power delay profile) . The same high time-resolution channel information may be shown to be employed in a majority of the use cases, either sensing-based use cases, such as positioning, or communication-based use cases, such as sensing-assisted communication applications (e.g., sensing-assisted beamforming) .

FIG. 6 illustrates a network including a plurality of sensing transmission (TX) nodes 602-A, 602-B, 602-C, 602-D, 602-E, 602-F, 602-G, 602-H, 602-I, 602-J, 602-K, 602-L, 602-M (collectively or individually 602) , a sensing reception (RX) node 604 and an SMF 176. The environment in which the network operates may be seen to be defined by a plurality of environment objects 606-1, 606-2, 606-3.

Obtaining relatively high time-resolution information may be shown to involve allocating a relatively large bandwidth for all the nodes involved in the sensing procedures. In bi-static sensing applications, the nodes involved in the sensing procedures may be, e.g., the sensing TX nodes 602 and the sensing RX nodes 604. In a positioning example, wherein the goal is to estimate positions of two targets separated by 10 cm, it may be shown to be beneficial to receive, from three different sensing TX nodes 602, at least three pilot signals, each pilot signal having a bandwidth of at least 3 GHz. In a sensing-assisted communication example, wherein the goal is to resolve two channel paths with so-called inter-delays of 1 ns, it may be shown to be beneficial to receive signals with bandwidth of at least 1 GHz. The resolvability of dominant channel paths may be shown to influence a performance of beamforming procedures, since different channel paths may have different directions and, accordingly, different beamforming directions.

Transmitting, receiving and processing ultra-high bandwidth signals may not always be affordable by a given network node, due to the known scarcity of the radio spectrum and the ever-increasing number of users/nodes sharing the spectrum. It may be shown to not be feasible to process ultra-high bandwidth signals at high-end UEs, due to power limitations, e.g., the high-end UE being in low-power mode. It may be shown to not be feasible to process ultra-high bandwidth signals at low-end UEs, due to the limited capabilities of the hardware circuitry that defines low-end UE. Furthermore, utilizing such ultra-high bandwidth signals may be shown to introduce large biases and distortion into transmitted sensing signals or received sensing signals. The biases and distortion may be shown to significantly reduce a performance gain, due to use of the relatively larger bandwidth. A further issue with handling ultra-high bandwidth signals may be shown to be created when sensing is coupled with a massive-MIMO transmitter and/or a massive-MIMO receiver. Such handling may be shown to cause a spatial-wideband effect, defined by a delay across an antenna aperture being comparable to a symbol time. This spatial-wideband effect may be shown to create a spatial-time selectivity that degrades overall performance.

The transmission, receipt and processing of sensing signals that have limited-bandwidth allocations, which may be carried out to avoid the complications, outlined hereinbefore, of transmitting, receiving and processing of ultra-high-bandwidth sensing signals, may be shown to be based on low-resolution measurements. For example, only low-resolution CSI or low-resolution power delay profiles (PDPs) may be obtained at a majority of receivers, where the receivers may be UEs or network nodes. A PDP may be defined as a plurality of time-domain characteristics of a communication channel between a TX-RX pair, captured based on their time-domain resolution. A PDP may be understood to provide an indication of intensity for a signal received through a multipath channel, with the intensity expressed as a function of time delay. Notably, PDPs may be seen as core machinery for time-based sensing parameter estimation. It follows that sensing signals with limited-bandwidth allocations may be shown to significantly limit the ability of a given network to enable high-resolution, network-wide sensing services.

It may be considered to be desirable to establish methods for obtaining reliable, high-resolution, network-wide sensing information through the use of low-bandwidth sensing signals.

Aspects of the present application relate to facilitating cooperation between a sensing RX node 604 and a group of sensing TX nodes 602 (e.g., UEs) , wherein the cooperation enables high-resolution sensing services that utilize low-bandwidth sensing signals. The sensing RX node 604 exploits a heterogeneity of the sensing signals, received at the sensing RX node 604, from the plurality of sensing TX nodes 602. The heterogeneity of the sensing signals may be expressed in terms of spectrum allocation, in that the allocation of distinct spectrum to each of the uplink sensing signals allows for fusion, at the sensing RX node 604, of measurements of the uplink sensing signals received from the sensing TX nodes 602. The measurements may be obtained subsequent to the sensing RX node 604 having configured a subset of the plurality of sensing TX nodes 602 to transmit, to the sensing RX node 604, jointly-designed sensing signals. The measurements may be obtained, at the sensing RX node 604, over a plurality of low-bandwidth frequency chunks. Each low-bandwidth frequency chunk may be associated with a different frequency carrier or a different sensing frequency layer. The measurements may be obtained, at the sensing RX node 604, for sensing signals received from a plurality of sensing TX nodes 602. A fusion of these measurements may be shown to increase a time-resolution of sensing parameters that may be obtained by processing the measurements. The sensing parameters may be considered to be the sensing information that is to be obtained by the sensing procedures. In this way, the network avoids transmitting, receiving and processing ultra-high bandwidth sensing signals among different nodes, yet the network may still be shown to be able to provide high resolution sensing services.

Fusion of a plurality of measurements may be shown to involve sensing TX node-grouping mechanisms and measurement selection mechanisms. The sensing TX node-grouping mechanisms may also be called “user-grouping” mechanisms. The measurement selection mechanisms may be used to establish whether the collected measurements, received at the sensing RX node 604 from a plurality of sensing TX nodes 602, are fusible. Fusing measurements may be shown to result in estimates for sensing parameters that have higher time-resolution estimates for sensing parameters obtained based on individual (non-fused) measurements. Accordingly, some aspects of the present application are related to user-grouping mechanisms and other aspects of the present application are related to measurement selection mechanisms. The measurement selection mechanisms are part of the user-grouping mechanisms. For instances, if one sensing TX node is providing, to a sensing RX node, a plurality of measurements, the sensing RX node may carry out measurement selection mechanisms to decide whether to accept all of the plurality of measurements or to accept only a portion of the plurality of measurements. The sensing TX node grouping mechanisms may involve selecting a first plurality 610 (see FIG. 6) of the sensing TX nodes 602. The first plurality 610, which may also be referenced as the first fusion group 610, may be selected based on demonstrating relatively high spatial correlation in terms of their locations and/or their environmental conditions (e.g., outdoor/indoor, highway/street/corridor, near to same skyscraper, etc. ) according to historical and/or offline position and environment information.

To further enhance sensing TX node grouping mechanisms, including measurement selection mechanisms, and, consequently, to further enhance a fusibility of the measurements, a second, finer, plurality 612 (see FIG. 6) of the sensing TX nodes 602 may be selected. The second plurality 612, which may also be referenced as the second fusion group 612, may be a subset of the first plurality 610 of the sensing TX nodes 602. The second plurality 612 may be constructed in a collaborative and distributed manner. The second plurality 612 of sensing TX nodes 602 may be constructed based on correlations indicated, to the sensing RX node 604, by at least one member of the second plurality 612 of sensing TX nodes 602. The correlations may be between sensing parameters obtained by members of the first plurality 610 of the sensing TX nodes 602 and sensing parameters obtained by the lead sensing TX node 602-L. Indeed, in some instances, the second plurality 612 of sensing TX nodes 602 may include all of the first plurality 610 of the sensing TX nodes 602.

Existing approaches for fusing measurements may be shown to be limited to the use of a plurality of frequency chunks to enhance the sensing accuracy of a single sensing TX/RX node. In the existing approaches, measurements are collected over a plurality of frequency bands that may be contiguously allocated in a spectrum. Additionally, the measurements belong, in a way, either by being transmitted, received, reflected or scattered, only to a single sensing TX/RX node. Moreover, the measurements that are fused may be shown to be related to the same sensing parameters. The parameters may be shown to be associated with the single sensing TX/RX node. It follows that existing approaches related fusing measurements may not enable determination of parameters belonging to a plurality of sensing nodes.

Some aspects of the present application relate to joint design, joint configuration and/or joint optimization of uplink sensing signals. Uplink sensing signals may be transmitted from a plurality of sensing TX nodes/UEs 602 and received, at the sensing RX node 604, over a plurality of low-bandwidth frequency chunks. These frequency chunks may be associated with different frequency carriers and/or different sensing frequency layers. This joint design and configuration of the uplink sensing signals and signaling procedures may enhance the fusibility of the measurements and, thereby, result in estimates of sensing parameters that have higher time-resolution than estimates of sensing parameters available based on non-fused measurements.

In practice, active sensing TX nodes 602 and passive sensing TX nodes 602, including objects that neighbor each other, may experience correlated channel conditions and, accordingly, may result in a determination of correlated sensing parameters. The correlation of channel conditions may be due to one or more of: a proximity of sensing TX nodes 602 (e.g., UEs) in terms of location; a unity of the sensing transmitter or sensing receiver; and the sensing TX nodes 602 having a common environment, e.g., having one or more common scatterers or reflectors of their incoming/outgoing signals. Such correlation might not be directly captured by the values of the sensing parameters, themselves. Instead, the correlation may be determined on the basis of metrics defined for relative values of the sensing parameters. For example, consider channel multi-path delays as the sensing parameter of interest. Two or more of the sensing TX nodes 602 may be associated with different values measured for channel multi-path delays. However, the two or more of the sensing TX nodes 602 may have correlated inter-delays (delay differences between channel paths of each sensing TX node 602) and correlated amplitudes. Accordingly, aspects of the present applications are related to methods and systems for measuring and capturing the correlation of relative values of the sensing parameters, e.g., the correlation of the relative values of the inter-delays. Additionally, some aspects of the present application are related to enabling a mapping between the relative values of the sensing parameters, e.g., the inter-delays, and the sensing parameters themselves, e.g., the channel multi-path delays.

Existing approaches may be shown to exploit spatial correlation between sensing TX nodes 602 to save power for sensing procedures. In particular, the existing approaches may be shown to utilize estimates of sensing parameters that are related to a given sensing TX node and apply the estimates to a set of sensing TX nodes that are spatially correlated with the given sensing TX node. As a result, the obtained estimates of sensing parameters, related to the set of sensing TX nodes, may have low resolution and/or accuracy and may suffer from relatively large estimation biases.

One advantage of the sensing methods representative of some aspects of the present application is the provision of a viable solution for relatively high-resolution sensing services using relatively low-bandwidth sensing signals. Utilizing relatively low-bandwidth sensing signals may be shown to expand the relatively high-resolution sensing capabilities of next generation wireless systems through increasing the number of sensing TX nodes potentially participating in the relatively high-resolution sensing activities. The sensing activities may, for example, include providing measurements and/or transmitting uplink sensing signals. The increase in number of sensing TX nodes may involve including low-end UEs and/or low-capability UEs, such as drones and IoT devices (e.g., low-end IoT devices) .

Another advantage of the sensing methods representative of some aspects of the present application is a flexibility in sensing pattern, which flexibility may be expressed in terms of allocation of time resources and frequency resources among the sensing TX nodes that are to participate in the sensing activities. The flexibility may be shown to allow for so-called opportunistic resource allocation. Opportunistic resource allocation, in turn, may be shown to alleviate, as they arise, any resource allocation problems in a given network, thereby providing a freedom to prioritize sensing functions or communication functions based on the involved applications. For example, in a case of prioritizing communication functions, a network sensing RX node (e.g., a base station) may allocate, for sensing procedures, time-frequency resources spread over a wide time span and a wide spectrum span, in such a way that avoids interference with already allocated communication resources.

A further advantage of the sensing methods representative of some aspects of the present application is a reduction of a power consumption associated with, and a computational complexity burden associated with, obtaining relatively high-resolution sensing parameters at the sensing TX nodes 602. Transmitting, receiving and processing relatively low-bandwidth sensing signals may be shown to be more efficient, in terms of power consumption, computational complexity and time-resolution gain, than transmitting, receiving and processing ultra-high bandwidth sensing signals.

According to aspects of the present application, there is provided a method of obtaining sensing parameters. For example, the sensing parameters may include a power delay profile (PDP) and channel state information (CSI) for a plurality of the sensing TX nodes 602. The method may include transmitting, to a sensing TX node 602, an indication that the sensing TX node 602 has been selected as a lead sensing TX node 602-L. The method may include transmitting, to the lead sensing TX node 602-L, configuration information for side-link communication with a first plurality 610 of sensing TX nodes 602 and configuration information for a common, narrow-band, downlink sensing signal. The method may include transmitting to the first plurality 610 of sensing TX nodes 602, configuration information and thresholds that are related to constructing a second plurality 612 of sensing TX nodes 602. The method may include transmitting, to the first plurality 610 of sensing TX nodes 602, indications identifying a subset of the first plurality 610 of sensing TX nodes 602. As discussed hereinbefore, in some instances, the second plurality 612 of sensing TX nodes 602 may include all of the first plurality 610 of the sensing TX nodes 602. The method may include transmitting, to the first plurality 610 of sensing TX nodes 602, configuration information for a common, narrow-band, downlink sensing signal. The method may include receiving, from the sensing TX nodes 602 of the second plurality 612, an indication that they are members of the second plurality 612. The method may include transmitting, to the sensing TX nodes 602 of the second plurality 612, configuration information for a plurality of uplink low-bandwidth sensing signals. The method may include receiving, from the sensing TX nodes 602 of the second plurality 612, a plurality of low-bandwidth uplink sensing signals. The method may include processing measurements of the plurality of low-bandwidth uplink sensing signals to, thereby, obtain sensing parameters for the second plurality 612 of the sensing TX nodes 602.

According to an aspect of the present application, there is provided a method of facilitating obtaining sensing parameters for a plurality of sensing TX nodes 602. The method may include receiving, at a sensing TX node 602, an indication that the sensing TX node 602 has been assigned as a lead sensing TX node 602-L for a first plurality 610 of sensing TX nodes 602. The method may include receiving, at the lead sensing TX node 602-L, a common, narrow-band, downlink sensing signal. The downlink sensing signal may be received according to configuration information that was received in advance. The method may include processing, at the lead sensing TX node 602-L, measurements of the received common, narrow-band, downlink sensing signal to obtain sensing parameters, e.g., PDPs, Angle of Arrival (AoA) and Time of Flight (ToF) . The method may include transmitting, to the sensing TX nodes 602 of the first plurality 610, the sensing parameters, according to configuration information. The method may include transmitting, to the sensing RX node 604, a low-bandwidth uplink sensing signal according to the configuration information received from the sensing RX node 604.

According to an aspect of the present disclosure, there is provided a method of facilitating obtaining sensing parameters for a plurality of the sensing TX nodes 602. The method may include receiving, at the plurality of the sensing TX nodes 602, which form a first plurality 610, configuration information for a common, narrow-band, downlink sensing signal. The method may include receiving configuration information for sensing parameters, including sensing parameter thresholds. The method may include receiving, at the sensing TX nodes 602 of the first plurality 610, the common, narrow-band, downlink sensing signal. The method may include processing, at sensing TX nodes 602 of the first plurality 610, measurements of the common, narrow-band, downlink sensing signal to obtain sensing parameters, e.g., PDP, AoA and ToF, according to the received configuration information. The method may include receiving, at the sensing TX nodes 602 of the first plurality 610, from a lead sensing TX node 602-L, sensing parameters obtained at the lead sensing TX node 602-L. The method may include correlating, at the sensing TX nodes 602 of the first plurality 610, the sensing parameters obtained at the lead sensing TX node 602-L with the sensing parameters obtained at the sensing TX nodes 602 of the first plurality 610 to, thereby, determine whether the sensing parameters obtained at the sensing TX nodes 602 of the first plurality 610 are sufficiently close to the sensing parameters obtained at the lead sensing TX node 602-L according to the sensing parameter thresholds. The method may include transmitting, to the sensing RX node 604, an indication of having correlation values that exceed the sensing parameter thresholds, from a subset of the sensing TX nodes 602 of the first plurality 610, a second plurality 612 of sensing TX nodes 602. The second plurality 612 of sensing TX nodes 602 may be selected for having correlation values that exceed the thresholds. The method may include receiving, at the sensing TX nodes 602 of the second plurality 612, configuration information for a plurality of low-bandwidth uplink sensing signals. The method may include transmitting, the low-bandwidth uplink sensing signals. Notably, in some instances, there may be “too many” sensing TX nodes 602, in the second plurality 612 of sensing TX nodes 602. That is, “too many” sensing TX nodes 602 may indicate that they have correlation higher than the threshold. Under such circumstances, the sensing RX node 604 may further select a subset of these sensing TX nodes 602. For example, the sensing RX node 604 may select, for inclusion in the second plurality 612, only those sensing TX nodes 602 associated with the X measurements that have the highest correlation. For another example, the sensing RX node 604 may select, for inclusion in the second plurality 612, only those sensing TX nodes 602 associated with positions that are among the X closest positions sensing RX node 604.

It may be considered that there are four main node types that are involved in the sensing procedures representative of some aspects of the present application. The four main node types include an SMF 176, a sensing RX node 604, a lead sensing TX node 602-L and a non-lead sensing TX node 602.

The SMF 176 (see FIG. 5) may be implemented as a discrete physical network entity or as a logical network entity associated with one or more physical entities. The SMF 176 may orchestrate sensing procedures representative of aspects of the present application. If the SMF 176 is implemented as a logical network entity, the sensing RX node 604 may implement the SMF functionality in whole or in part. The main duties of the SMF 176 include: managing time resources; managing frequency resources; managing configurations of sensing signals; managing configurations of sensing patterns; distribution of sensing signal configurations; distribution of historical sensing area-specific environment information; distribution of offline sensing area-specific environment information; distribution of sensing signals; distribution of sensing pattern configurations; distribution of pre-defined sensing thresholds for sensing TX nodes 602; distribution of sensing fusion group thresholds for sensing TX nodes 602; collecting measurements from the sensing RX node 604; preprocessing the measurements; and fusing the measurements to obtain sensing parameters and channel parameters related to a given group of the sensing TX nodes 602.

The sensing RX node 604 may be implemented as a network node that is configured to transmit common, narrow-band downlink sensing signals to a plurality of sensing TX nodes 602 and receive, according to a received configuration, a plurality of uplink sensing signals from the plurality of the sensing TX nodes 602. The main duties of the sensing RX node 604 include: receiving, from the SMF 176, parts of a configuration of sensing signals; transmitting, to a plurality of the sensing TX nodes 602, a common, downlink sensing signal; and receiving a plurality of uplink sensing signals based on the configuration defined by the SMF 176.

The lead sensing TX node 602-L may be implemented as a network node or as a UE. A main role of the lead sensing TX node 602-L, in the sensing procedures and the fusion procedures outlined herein, is to act as a reference point for the fusion groups. Indeed, the lead sensing TX node 602-L may accomplish aspects of this role by sharing, with a plurality of non-lead sensing TX nodes 602, sensing parameters, which have been obtained at the lead sensing TX node 602-L, by processing received downlink sensing signals. The sharing may be shown to allow for checking, at a given non-lead sensing TX node 602, for a level of similarity, or correlation, between the shared sensing parameters obtained at the lead sensing TX node 602-L and further sensing parameters, obtained by processing the same received downlink sensing signals at the given non-lead sensing TX node 602.

Main duties of the lead sensing TX node 602-L include: receiving, from the SMF 176, a configuration of uplink sensing signals; receiving, from the SMF 176, a configuration of a sensing pattern; receiving, from the SMF 176, configurations and time-frequency resource allocations for side-link communications with a plurality of non-lead sensing TX nodes 602; receiving, from the sensing RX node 604, a common, narrow-band downlink sensing signal; transmitting, to a plurality of non-lead sensing TX nodes 602, sensing parameters obtained at the lead sensing TX node 602-L; and transmitting, to the sensing RX node 604, an uplink sensing signal based on the configuration defined by the SMF 176.

On one hand, if the lead sensing TX node 602-L is implemented as a UE, then the lead sensing TX node 602-L may communicate with the non-lead sensing TX nodes 602 using sidelink communication channels. As discussed hereinbefore, the SMF 176 may send configuration and the resource allocation to indicate these sidelink channels. On the other hand, if the lead sensing TX node 602-L is implemented as a network node, then the lead sensing TX node 602-L may communicate with the non-lead sensing TX nodes 602 using downlink channels.

A non-lead sensing TX node 602 may be implemented as a UE. The main duties of a non-lead sensing TX node 602 include: receiving, from the SMF 176, a configuration of uplink sensing signals; receiving, from the SMF 176, a configuration of a sensing pattern; receiving, from the SMF 176, an indication of a fusion group correlation threshold; receiving, from the sensing RX node 604, a common, narrow-band downlink sensing signal; receiving, from the lead sensing TX node 602-L, sensing parameters; in a case wherein the sensing RX node 604 has a part of the SMF 176 or can act as a network node, transmitting, to the sensing RX node 604, an indication of a correlation of sensing parameters obtained at the non-lead sensing TX node 602 and sensing parameters received from the lead sensing TX node 602-L; and, responsive to specific thresholds being exceeded, transmitting, to the sensing RX node 604, an uplink sensing signal based on the configuration defined by the SMF 176.

Some aspects of the present application relate to allowing cooperation between a plurality of the sensing TX nodes (lead 602-L and non-lead 602) and a sensing RX node 604. The cooperation may be shown to allow for transmission, to the sensing RX node 604 from the plurality of the sensing TX nodes (lead 602-L and non-lead 602) , jointly designed sensing signals over a jointly-allocated spectrum. The jointly designed sensing signals may feature a plurality of low bandwidth frequency chunks associated with different frequency carriers/sensing frequency layers. Conveniently, use of the jointly designed sensing signals may be shown to increase a resolution and/or an accuracy of the sensing parameters that may be extracted by processing measurements of received versions of these sensing signals. The receiving and processing may take place at the sensing RX node 604 and may involve fusing the measurements.

Some measurement fusion procedures, which may also be called bandwidth splicing procedures, may be shown to involve fusing measurements and interpolating measurements, where the measurements have been obtained for a plurality of received uplink sensing signals. The uplink sensing signals may have been received over a plurality of spectrum allocations. The spectrum allocations of the uplink sensing signals may be either contiguous or non-contiguous. Notably, the uplink sensing signals are transmitted from a sensing TX node 602 and received by a sensing RX node 604, at which the fusion and interpolation takes place. The measurements have a property that the measurements that are taken for the received uplink sensing signals may be shown to be functions of sensing parameters that are similar, in relative terms. This property may be shown to make viable the fusibility of the measurements. It may be shown that a time-resolution of, and/or an accuracy of, sensing parameter estimates obtained by processing fused measurements is higher than a time-resolution of, and/or an accuracy of, sensing parameter estimates obtained by processing measurements that have not been fused, that is, measurements that have been processed individually. The higher time-resolution may be shown to be due to an aggregate spectrum allocation of fused measurements being wider than a spectrum allocation associated with individual measurements.

Some aspects of the present application relate to procedures for fusing measurements that have been obtained on the basis of uplink sensing signals received from a plurality of the sensing TX nodes 602. The plurality of the sensing TX nodes 602 may be spatially correlated. The sensing signals may be transmitted over a plurality of spectrum allocations. The spectrum allocations may be contiguous spectrum allocations or non-contiguous spectrum allocations. It is preferred that the spectrum allocations be non-contiguous. Non-contiguous spectrum allocations are associated with measurement-fusion-related improvements in resolution and/or accuracy of the sensing parameter estimates relative to sensing parameter estimates associated with estimates of the sensing parameters obtainable by fusing measurements of the uplink sensing signals with contiguous spectrum allocations.

It may be shown that obtaining measurements of sensing signals received from a plurality of the sensing TX nodes 602 and then fusing the measurements does not always directly lead to improved time-resolution in the estimates of the sensing parameters.

One reason for the lack of improvement may be understood to be related to an aggregate spectrum allocation of the fused measurements span being almost as wide as a span of the spectrum allocations of individual measurements. In other words, the sensing signals associated with the measurements may have been allocated similar carrier frequency/frequency layers with high overlap between their spectrum allocations. It follows that a proper joint design of the sensing signals transmitted by the plurality of the sensing TX nodes 602, the spectral allocations of the sensing signals and the temporal allocations of the sensing signals may have a significant impact on the size of a gain in resolution and/or accuracy associated with the procedure of fusing the measurements.

Another reason for the lack of improvement may be understood to be that the measurements, obtained based on the sensing signals received from the plurality of the sensing TX nodes 602, may not all be highly correlated. In other words, these measurements may carry different information about different sensing parameters. It follows that fusing the measurements may not result in improvements in resolution and/or in accuracy. Instead, fusing the measurements may lead to introducing large biases to the estimates of the sensing parameters. It may be shown that the more the sensing parameters of a first sensing TX node 602 are correlated with the sensing parameters of a second sensing TX node 602, the higher the associated improvement in resolution and/or in accuracy.

A problem may be identified in that those measurements, e.g., PDPs and/or CSI, at a given sensing RX node 604, that are associated with uplink sensing signals being transmitted from different sensing TX nodes 602, may be less correlated than is desirable. One reason for this problem may be understood to be that the uplink sensing signals associated with these measurements may experience different channel conditions and less correlated environments. This experience of less correlated environments may occur responsive to a wide spatial separation of the sensing TX nodes 602 or responsive to the sensing TX nodes 602 being widely distributed across a large sensing area. It may be shown that the closer the sensing TX nodes 602 are to each other in terms of distance, e.g., spatially confined in a small area, the higher the probability that their associated channel parameters (the parameters being sensed using the sensing signals) are correlated. Similarly, there may also be shown to be a higher probability that the measurements of the uplink sensing signals are correlated.

In some aspects of the present application, PDP may be used as a channel measurement associated with receiving the sensing signals at the sensing RX node 604. More particularly, the PDP may be understood to be useful for estimating delays and amplitudes associated with dominant channel paths between each sensing TX node 602 and the sensing RX node 604. Notably, a given PDP may be associated with a given sensing signal, a given sensing TX node 602 and a given low-bandwidth frequency chunk.

Due to the transmission, from a plurality of the sensing TX nodes 602, of a plurality of uplink sensing signals over a plurality of low-bandwidth frequency chunks, which are associated with different frequency carriers/sensing frequency layers, the sensing RX node 604 may obtain a plurality of PDPs. Notably, each PDP may be associated with a given sensing signal, transmitted by a given sensing TX node 602 over a given low-bandwidth frequency chunk.

A first PDP 700-Ais illustrated in FIG. 7. For each of three dominant channel paths, the first PDP 700-Ais associated with two parameters: a delay, τ_1, i; and an amplitude, p_1, i. The first PDP 700-Ais associated with a sensing signal received, at the sensing RX node 604, from a first sensing TX node 602-A. The first PDP 700-Amay be seen, in FIG. 7, to include contributions from a first path (i=1, with a delay, τ_1, 1, and an amplitude, p_1, 1) , a second path (i=2, with a delay, τ_1, 2, and an amplitude, p_1, 2) and a third path (i=3, with a delay, τ_1, 3, and an amplitude, p_1, 3) .

A second PDP 700-B is illustrated in FIG. 7. For each of three dominant channel paths, the second PDP 700-B is associated with two parameters: a delay, τ_2, i; and an amplitude, p_2, i. The second PDP 700-B is associated with a sensing signal received, at the sensing RX node 604, from a second sensing TX node 602-B. The second PDP 700-B may be seen, in FIG. 7, to include contributions from a first path (i=1, with a delay, τ_2, 1, and an amplitude, p_2, 1) , a second path (i=2, with a delay, τ_2, 2, and an amplitude, p_2, 2) and a third path (i=3, with a delay, τ_2, 3, and an amplitude, p_2, 3) .

A K^th PDP 700-K is illustrated in FIG. 7. For each of three dominant channel paths, the K^th PDP 700-K is associated with two parameters: delay, τ_K, i; and amplitude, p_K, i. The K^th PDP 700-K is associated with a sensing signal received, at the sensing RX node 604, from a K^th sensing TX node 602-K. The K^th PDP 700-K may be seen, in FIG. 7, to include contributions from a first path (i=1, with a delay, τ_K, 1, and an amplitude, p_K, 1) , a second path (i=2, with a delay, τ_K, 2, and an amplitude, p_K, 2) and a third path (i=3, with a delay, τ_K, 3, and an amplitude, p_K, 3) .

The parameters of the dominant channel paths of the PDPs 700 of the sensing TX nodes 602 may be viewed as indistinguishable. The indistinguishability may be blamed on the associated uplink sensing signals having low-bandwidth individual spectrum allocations. It may further be viewed that measurements of the uplink sensing signals may not be directly fusible due to presence of big mismatches between the different PDPs. It may be seen in FIG. 7 that there are big mismatches between the first PDP 700-A, the second PDP 700-B and the K^th PDP 700-K.

There may be two types of mismatches between the PDPs 700 obtained for distinct sensing TX nodes 602.

A first type of mismatch may be understood to exist in the value of the first delay, τ_k, 1, that is, τ_1, 1≠τ_2, 1. The first delay, τ_k, 1, may be understood to include a time of flight, which may be represented as τ_k, 1, ToF, over the first path (i=1) of an uplink sensing signal from the k^th sensing TX node 602-k to the sensing RX node 604. The first delay, τ_k, 1, may also be understood to include a synchronization error between the k^th sensing TX node 602-k and the sensing RX node 604.

The second type of mismatch may be understood to exist in the value of inter-arrival times. An inter-arrival time may be understood to be representative of a difference between delays of uplink sensing signals from a given sensing TX node 602 as the sensing signals travel distinct paths. It might be expected that a first inter-arrival time, |τ_1, 2-τ_1, 1|, for the uplink sensing signals from the first sensing TX node 602-Awould be similar to a second inter-arrival time, |τ_2, 2-τ_2, 1|, for the sensing signals from the second sensing TX node 602-B. For various reasons, the second type of mismatch may exist between the first inter-arrival time and the second inter-arrival time.

To this point, the fusing that has been discussed has been a fusion of the measurements of the uplink sensing signal. More accurately, the fusing may be understood to involve fusing of PDPs 700. It may be shown that a “proper” fusing of relatively low-resolution PDPs, at the sensing RX node 604, will lead to a single, improved-resolution PDP. However, to “properly” fuse PDPs, it may be seen as important to reduce the two types of mismatch discussed hereinbefore.

One approach to reducing the two types of mismatch involves using a procedure to approximately align, in the delay domain, the relatively low-resolution PDPs 700. The approximate aligning procedure may involve time-shifting the relatively low-resolution PDPs 700 by approximate estimates their respective highest peaks, τ_k, off. Additionally, the approximate aligning procedure may involve taking into account approximate estimates of ToFs, τ_k, ToF, associated with each relatively low-resolution PDP 700-k.

FIG. 7 illustrates a result of the approximate aligning procedure, wherein each of the relatively low-resolution PDPs 700-k is mapped to a corresponding relative PDP (an “rPDP” ) 700-kr. Indeed, the first PDP 700-Ais mapped to a corresponding first relative PDP 700-Ar, the second PDP 700-B is mapped to a corresponding second relative PDP 700-Br and the Kth PDP 700-K is mapped to a corresponding Kth relative PDP 700-Kr. The first relative PDP 700-Ar, the second relative PDP 700-Br and the Kth relative PDP 700-Kr may be collectively or individually referenced, herein, as 700r.

The first rPDP 700-Ar may be obtained by subtracting a first factor, [|τ_1, off| or |τ_1, ToF|] , from the uplink signal measurements, such that {τ_1, 1, τ_1, 2, ..., τ_1, 3} - [|τ_1, off| or |τ_1, ToF|] maps to {τ′_1, 1, τ′_1, 2, ..., τ′_1, 3} . The second rPDP 700-Ar may be obtained by subtracting a second factor, [|τ_2, off| or |τ_2, ToF|] , from the uplink signal measurements, such that {τ_2, 1, τ_2, 2, ..., τ_2, 3} - [|τ_2, off| or |τ_2, ToF|] maps to {τ′_2, 1, τ′_2, 2, ..., τ′_2, 3} . The K^th rPDP 700-Kr may be obtained by subtracting a K^th factor, [|τ_K, off| or |τ_K, ToF|] , from the uplink signal measurements, such that {τ_K, 1, τ_K, 2, ..., τ_K, 3} - [|τ_K, off| or |τ_K, ToF|] maps to {τ′_K, 1, τ′_K, 2, ..., τ′_K, 3} .

When all K of the relatively low-resolution PDPs 700 have been mapped to a corresponding rPDP 700r, the correlation between the relative sensing parameters of the rPDPs 700r may be shown to be more pronounced than the correlation between the real sensing parameters of the relatively low-resolution PDPs 700. Accordingly, the rPDPs 700r may be considered feasibly fusible.

It is expected that there will still be mismatches among the sensing parameters associated with the rPDPs

700r. The mismatches may, for example, be due to the different inter-arrival times associated with sensing signals received from different sensing TX nodes 602. These mismatches may be shown to directly affect the quality of the fusion procedures.

It may be shown that the more spatially correlated the sensing TX nodes 602 are, the lower these mismatches are. When the mismatches are low, it follows that the quality of the output of the fusion procedure may be improved. Thus, a metric indicative of a spread of the mismatches may be used as an indication of the quality the expected output of the fusion procedure.

A metric, στ_rms, indicative of mismatch spread of rPDPs 700r may be defined aswhere τ′_k, 1 may be understood to represent a relative delay for an uplink sensing signal on the i^th path from the k^th sensing TX node 602-k andIt may be shown that a value for the metric, στ_rms, has some dependence upon distances between the sensing TX nodes 602. That is, greater distances between the sensing TX nodes 602 may be shown to be associated with larger values for the metric, στ_rms. For example, assuming that K=2 and assuming that the two sensing TX nodes 602 have the same positions, i.e., one of the two sensing TX nodes 602 sits on top of the other of the two sensing TX nodes 602, it may be shown that the value for the metric, στ_rms, is almost zero.

A minimum delay, στ_min, among pairs of paths is another metric that may be shown to directly affect the quality of the fusion procedure. The minimum delay, στ_min, may be mathematically defined as στ_min=min_k, i (τ_k, i+1-τ_k, i) . It may be shown that an increase in the minimum delay, στ_min, is associated with a reduction in the sensitivity, to mismatch spread of rPDPs 700r, of the fusion procedure.

It also may be shown that the minimum delay, στ_min, is mainly related to the environment and a manner in which objects (scatterers or reflectors of the sensing signals) in the environment are spatially separated and oriented. It may be shown that one environment with objects that more spatially separated and oriented than objects in another environment is expected to have a greater minimum delay, στ_min.

Notably, the minimum delay, στ_min, may have some dependence on the position of the sensing TX nodes 602. Indeed, the minimum delay, στ_min, may not be very sensitive to the variation of the positions of the sensing TX nodes 602 within a spatial area defining a group of the sensing TX nodes 602. This lack of sensitivity may be especially true when the sensing TX nodes 602 are far away from the objects that are associated with the dominant channel paths. Notably, the sensitivity of the fusion procedures to mismatches of PDPs 700r may be reduced when the minimum delay, στ_min, is much greater than the metric, στ_rms, that is indicative of mismatch spread of rPDPs 700r. That is, the sensitivity of the fusion procedures to mismatches of PDPs 700r may be reduced when στ_min >> στ_rms.

In view of the respective impacts of various ones of the metrics discussed hereinbefore on the fusion procedure, some aspects of the present application relate to preprocessing the PDPs 700r. Indeed, the PDPs 700 may be preprocessed, in a “pre-fusion” stage, in a manner that exploits a spatial correlation among a plurality of the sensing TX nodes 602 to, thereby, capture a relatively high mathematical correlation among a plurality of measurements obtained at the sensing RX node 604. This capture of relatively high mathematical correlation may be achieved by creating and processing a set of relative measurements, e.g., relative PDPs 700r. Beneficially, the correlation between relative measurements may be measured and captured. In contrast, correlation between the collected measurements, e.g., PDPs 700, may not be easily measured and captured.

As discussed hereinbefore, the pre-fusion stage may involve shifting the collected PDPs 700, in time, by a plurality of time-shifts. In some aspects of the present application, the plurality of time-shifts may be determined based on detecting the offset delay, τ_k, off, associated with highest peak of an envelope of each collected PDP 700, i.e., {τ_1, off, τ_2, off, ..., τ_K, off} . In another aspects of the present application, the plurality of time-shifts may be determined based on a time-of-flight (ToF) delay, τ_k, ToF, between the sensing TX nodes 602 and the sensing RX node 604, i.e., {τ_1, ToF, τ_2, ToF, ..., τ_K, ToF} . The pre-fusion stage may be shown to result in a plurality of relative measurements, e.g., relative PDPs 700r, that may be shown to facilitate fusion procedures carried out at the sensing RX node 604.

Some aspects of the present application relate to grouping of the sensing TX nodes 602 and measurement selection that allows for proper measurement fusion at the sensing RX node 604. The grouping of the sensing TX nodes 602 and the measurements selection for the fusion process may be shown to have two stages: a coarse grouping and selection stage; and a fine grouping and selection stage. The coarse grouping and selection stage may be performed by a network node or a sensing RX node 604. The coarse grouping and selection may be based on some environment-specific historical information and position information for a plurality of the sensing TX nodes 602. This coarse grouping and selection stage may be shown to result in the first fusion group 610 (see FIG. 6) , which may also be called a “coarse” fusion group 610. The fine grouping and selection stage may be carried out at sensing TX nodes 602 in the first fusion group 610. The fine grouping and selection stage may be initiated by receiving, from the sensing RX node 604, a narrowband, common probing signal. The fine grouping and selection stage may be performed, by the sensing TX nodes 602 in the first fusion group 610, in a distributive and collaborative manner. It may be considered that a goal of the fine grouping and selection stage is to allow the sensing RX node 604 to construct a second fusion group 612 (a “fine” fusion group, see FIG. 6) . As discussed hereinbefore, in some instances, the second plurality 612 of sensing TX nodes 602 may include all of the first plurality 610 of the sensing TX nodes 602. This may occur when historical information about the first plurality 610 of the sensing TX nodes 602 are tight and there exists precise position information about positions of the sensing TX nodes 602 in the first plurality 610.

Correlation information, related to sensing parameters obtained at the sensing TX nodes 602, may be captured at the sensing RX node 604 or at a network node. The correlation information may be implicitly collected by a lead sensing TX node 602-L on the basis of processing measurements obtained at the lead sensing TX node 602-L. Indeed, the lead sensing TX node 602-L may share sensing parameters with the plurality of the sensing TX nodes 602 that belong to the first fusion group 610. Notably, these sensing parameters may correspond to the measurements of the narrowband, common downlink sensing signal transmitted by the sensing RX node 604 and received by the sensing TX nodes 602 in the first fusion group 610. A given sensing TX node 602 in the first fusion group 610 may be configured to compare measurements of the limited-bandwidth probing signal, made at the given sensing TX node 602, to measurements of the limited-bandwidth probing signal, made at the lead sensing TX node 602-L, and shared by the lead sensing TX node 602-L over side-link communication channels. Any sensing TX node 602 in the first fusion group 610, whose probing signal measurements are found have a value, of a correlation with the probing measurements of the lead sensing TX node 602-L, that exceeds a preconfigured threshold value may automatically become a member of the second fusion group 612. The sensing TX nodes 602 of the second fusion group 612 may transmit low-bandwidth uplink sensing signals to the sensing RX node 604, according to specific configurations, over a plurality of frequency chunks with different frequency carriers or frequency layers. The transmission of the low-bandwidth uplink sensing signals may be shown to allow fusion of measurements at the sensing RX node 604 and a relatively high-resolution estimation of the sensing parameters.

Some aspects of the present application relate to methods that facilitate sensing TX node grouping and measurement selection. These methods may relate to constructing the first fusion group 610 and the second fusion group 612 (see FIG. 6) . In aspects of the present application, the first fusion group 610 may be constructed based on position information of the sensing TX nodes 602 in a given sensing vicinity in combination with some historical or offline information, for the given sensing vicinity, about the minimum delay, στ_min, and the metric, στ_rms, that is indicative of mismatch spread of rPDPs.

For an example area with a relatively small minimum delay, στ_min, an example area with a relatively large metric, στ_rms, indicative of mismatch spread or an example area with roughly the same value for the minimum delay, στ_min, and the metric, στ_rms, indicative of mismatch spread, στ_min ≈ στ_rms, a network entity tasked with grouping sensing TX nodes may be shown to have a tendency to group sensing TX nodes 602 into a relatively small group that has a small radius. The converse is also true. That is, for an example area with a relatively large minimum delay, στ_min, or an example area with a relatively small metric, στ_rms, indicative of mismatch spread, a network entity tasked with grouping sensing TX nodes 602 may be shown to have a tendency to group sensing TX nodes 602 into a relatively large group that has a large radius. A required accuracy of sensed parameters may be a factor controlling the width of sensing group. For example, if the required accuracy is very high, there will be a tendency to group sensing TX nodes 602 into a relatively small group that has a small radius.

As part of the first fusion group 610, the network entity, as represented by the SMF 176, may select a lead sensing TX node 602-L. The lead sensing TX node 602-L may be selected on the basis of having a position that is closer to a mean of positions of all the sensing TX nodes 602 in the first fusion group 610. Moreover, this lead sensing TX node 602-L may be capable of transmitting and communicating over sidelinks and may be willing to share sensing parameters with the rest of the sensing TX nodes 602 in the first fusion group 610. In some embodiments, the lead sensing TX node 602-L may be selected based on a capability report. The capability report may include indications of TX capabilities, RX capabilities, available power modes and the like.

In aspects of the present application, the process of establishing the second fusion group 612 starts when the sensing RX node 604 transmits a common, narrow-band downlink sensing signal to all of the sensing TX nodes 602 in the first fusion group 610. One main usage of this common, narrow-band downlink sensing signal is to allow for further fine selection of the relatively highly spatially correlated sensing TX nodes 602. Such fine selection may be shown to allow for determination of highly correlated sensing parameters in a distributive and collaborative manner.

Based on receiving, at a given sensing TX node 602 in the first fusion group 610, the common, narrow-band downlink sensing signal, the given sensing TX node 602 may determine a sensing parameter based on the available information and the capabilities of the given sensing TX node 602. The sensing parameter may, for one example, be an offset delay, τ_k, off. The sensing parameter may, for another example, be a time-of-flight delay, τ_k, ToF.

The given sensing TX node 602 may then shift a PDP by one of these sensing parameters to, thereby, determine a coarse or low-resolution rPDP. Moreover, in some aspects of the present application, some sensing TX nodes 602 may perform some angle of arrival (AoA) measurements on the common, narrow-band downlink sensing signal. The AoA measurements may be shown to allow for establishing coarse rPDPs. AoA measurements may be utilized in further checking a correlation level among the sensing TX nodes 602 in the first fusion group 610. Then, the lead sensing TX node 602-L may broadcast, to all the sensing TX nodes 602 in the first fusion group 610, coarse rPDPs and/or an indication of an AoA. The broadcasting may depend on sidelink communication channel configurations and resource allocations.

Upon receiving, from the lead sensing TX node 602-L, the coarse rPDP and the indication of an AoA associated with receipt of the common, narrow-band downlink sensing signal, each sensing TX node 602 in the first fusion group 610 may act to obtain a correlation value for a comparison of its own rPDP and AoA with the coarse rPDP and the indication of an AoA received from the lead sensing TX node 602-L. Some of the sensing TX nodes 602 may obtain a correlation value that exceeds a preconfigured threshold correlation value received in advanced of carrying out the obtaining of the correlation value. The preconfigured threshold correlation value received may, for example, have been received from a network node. The preconfigured threshold correlation value may, for example, be expressed as 95%for rPDP. Rather than determining that an rPDP correlation value exceeds a preconfigured threshold correlation value, the sensing TX nodes 602 may determine that an AoA is within a preconfigured threshold which may, for example for AoA, be expressed as ±5 degrees.

Alternatively, a given sensing TX node 602 may transmit, to the sensing RX node 604, an indication indicating that the given sensing TX node 602 has obtained sensing parameters with a relatively high correlation with sensing parameters obtained at the lead sensing TX node 602-L.

The second fusion group 612 may include all the sensing TX nodes 602, within the first fusion group 610, that have indicated, to the sensing RX node 604, a relatively high correlation with sensing parameters obtained by the lead sensing TX node 602. In some embodiments, the second fusion group 612 may be constructed as a subset of the sensing TX nodes 602 in the first fusion group 610 that have indicated, to the sensing RX node 604, correlation with the lead sensing TX node 602-L, based on capability reports and power modes/levels instead of relatively high sensing parameter correlation.

In certain appropriate scenarios, the sensing RX node 604 may determine not to carry out the process of establishing the second fusion group 612. The sensing RX node 604 may not transmit the common message and measure the correlation. Instead, the sensing RX node 604 may directly instruct the sensing TX nodes 602 in the first fusion group 610 to commence sending uplink sensing signals. One example appropriate scenario may occur when the respective positions of the sensing TX nodes 602 in the first fusion group 610 are very close to each other, and the statistical offline data has been recently updated. Accordingly, the process of establishing the second fusion group 612 may be considered optional.

As discussed hereinbefore, the spectral resource allocation and the temporal resource allocation of the uplink sensing signals play a role in allowing for “proper” fusion of the measurements. So-called “proper” fusion of the measurements may be shown to result in sensing parameters with relatively higher resolution and/or accuracy. The spectral resource allocation and the temporal resource allocation of the uplink sensing signals may be understood to be related to the joint design of the sensing pattern of the uplink sensing signals.

It should be readily understood, from the foregoing, that the uplink sensing signals are to be transmitted, over a plurality of low-bandwidth frequency chunks associated with different frequency carriers/sensing frequency layers, to the sensing RX node 604 by the plurality of the sensing TX nodes 602 that belong to the second fusion group 612.

The specifications of the joint design of the sensing pattern of the uplink sensing signals may be the same for all types of waveforms utilized in carrying these sensing signals over the wireless channels. The aspects include, but are not limited to, aspects of LFM-based (chirp-based) joint sensing signal design and aspects of CP-OFDM joint sensing signal design.

However, the specifications of the joint design of the sensing pattern of the uplink sensing signals may differ from one waveform to another. In the present application, a chirp-based joint sensing pattern and sensing signal design are used an example for specifications of joint design of the sensing pattern of the uplink sensing signals that are to be transmitted from a plurality of the sensing TX nodes 602 over a plurality of low-bandwidth frequency chunks associated with different frequency carriers/sensing frequency layers.

Assuming that a k^th sensing TX node 602-k, in the second fusion group 612, is transmitting a chirp-based uplink sensing signal, x_k, the transmitted uplink sensing signal may be represented aswhere α_k is the chirp rate of the sensing signal, t_k is the starting time of the sensing signal, T_k is the duration of the sensing signal and f_k is the starting frequency of the sensing signal. These terms are illustrated relative to a graphical representation of a sensing signal in FIG. 8.

Notably, in a scenario wherein all sensing TX nodes 602 transmit uplink sensing signals with the same chirp rate, α, the reception processes, at the sensing RX node 604, and the receiver structure may be regarded as simplified relative to the reception processes and the receiver structure that are to be used when the sensing TX nodes 602 transmit uplink sensing signals with distinct chirp rates, α.

Sensing pattern configurations may include parameters representative of a total spectrum span, F_span, and a total time span, T_span, for all K uplink sensing signals. An example sensing pattern configuration is illustrated in FIG. 9, for K=5. FIG. 9 illustrates a first uplink sensing signal 902-1, a second uplink sensing signal 902-2, a third uplink sensing signal 902-3, a fourth uplink sensing signal 902-4 and a fifth uplink sensing signal 902-5 (individually or collectively 902) . FIG. 9 features labels added for the total spectrum span, F_span, and the total time span, T_span. It may be shown that these parameters are related to a preferred resolution and/or accuracy of the measurement fusion process. Particularly, the time resolution of the estimates of the sensing parameters associated to the uplink sensing signals 902 can be shown to be inversely proportional to the total spectrum span, F_span. Additionally, the frequency/Doppler resolution of the estimates of the sensing parameters associated to the uplink sensing signals 902 can be shown to be inversely proportional to total time span, T_span.

The sensing pattern may feature contiguous spectrum allocation, i.e., all K frequency chunks are consecutive in the spectrum domain. Alternatively, the sensing pattern may feature non-contiguous spectrum allocation. Notably, non-contiguous spectrum allocation is more preferable than contiguous spectrum allocation for achieving higher resolution and/or accuracy for a given amount of the sensing resource overhead.

In some cases, some of the sensing TX nodes 602 may be allowed to transmit uplink sensing signals 902 with the same starting time, t_k (see the fourth uplink sensing signal 902-4 and the fifth uplink sensing signal 902-5 in FIG. 9) . In such as cases, however, it is expected that those sensing TX nodes 602 will transmit the uplink sensing signals 902 with distinct starting frequencies, f_k. The distinct starting frequencies, f_k, may be shown to allow for aggregation of bandwidth when measurements of the uplink sensing signals 902 are fused at the sensing RX node 604.

FIG. 10A, in combination with FIG. 10B, illustrates, in a signal flow diagram, a flow of information, sensing signals and feedback associated with aspects of the present application. For the purposes of simplifying FIGS. 10A and 10B, it may be assumed that the sensing RX node 604 includes the SMF 176. It may be expected that the SMF 176 is configured to control and handle sensing resources for the sensing RX node 604 and for the plurality of the sensing TX nodes 602.

Before a signalling procedure represented by the signal flow of FIGS. 10A and 10B begins, a sensing area may be defined. The signalling procedure may then begin with a recall (step 1002) , by the SMF 176, of sensing-area-specific information, e.g., στ_min and στ_rms. The recall (step 1002) may also involve the SMF 176 recalling stored position information for the sensing TX nodes 602 in the sensing area. The recall (step 1002) may also involve the SMF 176 recalling historical and/or offline environment data.

Optionally, the sensing TX nodes 602 may transmit (step 1004) , to the sensing RX node 604, capability reports. The capability reports may include, for a few examples, indications of capabilities of transmitting over multiple frequency chunks, indications of maximum supported bandwidth, indications of dynamic ranges, indications of capabilities of performing time/Doppler measurements and angular measurements and indications of abilities for transmitting and/or receiving over sidelink communication channels. The SMF 176 may receive (step 1006) the capability reports from the sensing TX nodes 602 in the sensing area.

Also, optionally, the sensing TX nodes 602 may transmit (step 1008) , to the sensing RX node 604, position information.

Based on the historical and/or offline environment data and the position information of the sensing TX nodes 602 (either received in step 1010 or recalled in step 1002) , the SMF 176 may select (step 1012) , from among the sensing TX nodes 602, a lead sensing TX node 602-L. The SMF 176 may select (step 1012) , from among the sensing TX nodes 602, a plurality of the sensing TX nodes 602 to be part of a first fusion group, as discussed hereinbefore. The SMF 176 may, subsequently, transmit (step 1014) , to the lead sensing TX node 602-L, configurations. The SMF 176 may also transmit (step 1014) , to the other sensing TX nodes 602 in the first fusion group, the same configurations. The configurations may include resource allocation for a common, narrowband, downlink sensing signal.

Notably, in a case wherein the SMF 176 is distinct from the sensing RX node 604, the SMF 176 may also transmit (not shown) the same configurations to the sensing RX node 604. Further notably, if the SMF 176 is a logical entity, it may be considered inaccurate to indicate that the SMF 176 “transmits” the configurations. Instead, the configurations may be understood to be transmitted by a physical entity, such as the sensing RX node 604 or another network node, like a TRP (not shown in FIG. 10A) . Even further notably, the signaling of configuration parameters to the sensing RX node 604 can be carried out through Xn signaling, since configuration transmission may be considered to be so-called “backhaul signaling, ” which may be considered to be distinct from so-called “access signaling. ” The transmitting (step 1014) of the configurations may also include transmitting, to the sensing TX nodes 602, an indication of a location for the sensing RX node 604. The transmitting (step 1014) may be accomplished using control signalling, e.g., RRC control signalling or MAC-CE control signalling. The lead sensing TX node 602-L receives (step 1016-L) configurations for the first fusion group. The configurations may include identities (IDs) of the sensing TX nodes 602 in the first fusion group. The configurations may include resource allocations for side link communication. Furthermore, the other sensing TX nodes 602 in the first fusion group may receive (step 1016) , from the SMF 176, configurations for the first fusion group. The configurations may include an ID of the lead sensing TX node 602-L. The configurations may include resource allocations for sidelink communication. The configurations may include correlation/similarity thresholds.

Subsequently, the sensing RX node 604 may transmit (step 1018) a common, narrow-band downlink sensing signal towards the sensing TX nodes 602 in the first fusion group. The transmitting (step 1018) may be carried out, by the sensing RX node 604, according to the configuration defined by the SMF 176. Upon receiving (step 1020-L, step 1020) the common, narrow-band downlink sensing signal, each sensing TX node 602-L, 602 may process measurements of the sensing signals to determine (step 1022-L, step 1022) a PDP and/or an AoA. The processing of the measurements may allow the sensing TX nodes 602-L, 602 to estimate either τ_k, off or τ_k, ToF. Based upon τ_k, off or τ_k, ToF, the sensing TX nodes 602-L, 602 may determine respective rPDPs.

The lead sensing TX node 602-L may then transmit (step 1024-L) , to the sensing TX nodes 602 in the first fusion group, indications of the obtained sensing parameters (e.g., rPDP, AoA) . A given sensing TX node 602 in the first fusion group, upon receiving (step 1026) , from the lead sensing TX node 602-L, the indications, may correlate (step 1028) the indications with the respective sensing parameters (e.g., rPDP, AoA) obtained at the given sensing TX node 602. That is, the given sensing TX node 602 may check (step 1028) whether there exists a correlation with sensing parameters, received (step 1024) from the lead sensing TX node 602-L, that exceeds an appropriate one of the thresholds received (step 1016) from the SMF 176. Each sensing TX node 602 whose sensing parameters correlate with the sensing parameters from the lead sensing TX node 602-L, may transmit (step 1030) , to the SMF 176, an indication of the correlation. It follows that, upon receiving (step 1032) the indication from a given sensing TX node 602, the SMF 176 may include the given sensing TX node 602 in a second fusion group. The SMF 176 transmits (step 1034) , to the sensing TX nodes 602 in the second fusion group, configurations. The configurations may define, for uplink sensing signals, a sensing pattern and a time-frequency resource allocation. Accordingly, the sensing TX nodes 602-L, 602 in the second fusion group, upon receiving (step 1036-L, step 1036) the configurations, may transmit (step 1038-L, step 1038) , to the sensing RX node 604, a plurality of uplink sensing signals. The sensing RX node 604 may receive (step 1040) the uplink sensing signals over a plurality of low-bandwidth frequency chunks associated with different frequency carriers/sensing frequency layers, according to configurations established by the SMF 176. The sensing RX node 604 may preprocess (step 1042) measurements of the plurality of the received uplink sensing signals to obtain a plurality of individual relative measurements, e.g., rPDPs, and fuse the plurality of individual relative measurements. It may be shown that the fused relative measurements, obtained by fusing the plurality of individual relative measurements, have a higher resolution and/or higher accuracy than any one of the individual relative measurements. On the basis of the preprocessing (step 1042) , the sensing RX node 604 may update (step 1044) existing estimates of relative measurements associated with each sensing TX node 602.

It should be appreciated that one or more steps of the embodiment methods provided herein may be performed by corresponding units or modules. For example, data may be transmitted by a transmitting unit or a transmitting module. Data may be received by a receiving unit or a receiving module. Data may be processed by a processing unit or a processing module. The respective units/modules may be hardware, software, or a combination thereof. For instance, one or more of the units/modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs) . It will be appreciated that where the modules are software, they may be retrieved by a processor, in whole or part as needed, individually or together for processing, in single or multiple instances as required, and that the modules themselves may include instructions for further deployment and instantiation.

Although a combination of features is shown in the illustrated embodiments, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system or method designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.

Although this disclosure has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the disclosure, will be apparent to persons skilled in the art upon reference to the description. It is therefore intended that the appended claims encompass any such modifications or embodiments.

Claims

A method of sensing, the method comprising:

selecting a given sensing TX node for inclusion in a first plurality of sensing TX nodes, the selecting based on correlation between:

sensing parameters associated with the given sensing TX node; and

sensing parameters associated with at least one sensing TX node in the first plurality of sensing TX nodes;

transmitting, to the first plurality of sensing TX nodes, a configuration for uplink sensing signals;

receiving, from the first plurality of the sensing TX nodes, uplink sensing signals; and

processing measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements.
The method of claim 1, wherein the sensing parameters, obtained by processing measurements of the uplink sensing signals, comprise a power delay profile.
The method of claim 1 or claim 2, wherein the sensing parameters, obtained by processing measurements of the uplink sensing signals, comprise channel state information.
The method of any one of claims 1 to 3, further comprising transmitting, to the first plurality of the sensing TX nodes, configuration information related to constructing a second plurality of the sensing TX nodes.
The method of claim 4, wherein the configuration information comprises a threshold.
The method of any one of claims 1 to 5, further comprising transmitting, to a network node, indications identifying a subset of the sensing TX nodes among the first plurality of the sensing TX nodes.
The method of any one of claims 1 to 6, wherein the configuration for the uplink sensing signals comprises an allocation of distinct frequency resources to each uplink sensing signal.
An apparatus comprising:

a memory storing instructions;

a processor, wherein the processor is caused, by executing the instructions, to:

select a given sensing TX node for inclusion in a first plurality of sensing TX nodes, the selecting based on correlation between:

sensing parameters associated with the given sensing TX node; and

sensing parameters associated with at least one sensing TX node in the first plurality of sensing TX nodes;

transmit, to the first plurality of sensing TX nodes, a configuration for uplink sensing signals;

receive, from the first plurality of the sensing TX nodes, uplink sensing signals; and

process measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements.
A computer-readable medium storing instructions, wherein the instructions, upon execution by a processor, cause the processor to:

select a given sensing TX node for inclusion in a first plurality of sensing TX nodes, the selecting based on correlation between:

sensing parameters associated with the given sensing TX node; and

sensing parameters associated with at least one sensing TX node in the first plurality of sensing TX nodes;

transmit, to the first plurality of sensing TX nodes, a configuration for uplink sensing signals;

receive, from the first plurality of the sensing TX nodes, uplink sensing signals; and

process measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements.
A method of sensing, the method comprising:

transmitting, to a selected sensing transmission (TX) node among a plurality of sensing TX nodes, an indication that the selected sensing TX node has been selected as a lead sensing TX node;

transmitting, to the lead sensing TX node:

indications identifying a first plurality of the sensing TX nodes among the plurality of the sensing TX nodes; and

configuration information for side-link communication with the first plurality of the sensing TX nodes;

transmitting, to each sensing TX node among the first plurality of the sensing TX nodes, a threshold related to constructing a second plurality of the sensing TX nodes;

receiving, from the first plurality of the sensing TX nodes, uplink sensing signals; and

processing measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements.
The method of claim 10, wherein the sensing parameters comprise a power delay profile.
The method of claim 10 or claim 11, wherein the sensing parameters comprise channel state information.
The method of any one of claims 10 to 12, further comprising receiving, from a given sensing TX node, an indication that the given sensing TX node has determined a value that exceeds the threshold.
The method of any one of claims 10 to 13, further comprising transmitting, to a given sensing TX node among the second plurality of sensing TX nodes, configuration information for an uplink sensing signal.
The method of any one of claims 10 to 14, further comprising receiving, from the second plurality of the sensing TX nodes, a plurality of uplink sensing signals.
An apparatus comprising:

a memory storing instructions;

a processor, wherein the processor is caused, by executing the instructions, to:

transmit, to a selected sensing transmission (TX) node among a plurality of sensing TX nodes, an indication that the selected sensing TX node has been selected as a lead sensing TX node;

transmitting, to the lead sensing TX node:

indications identifying a first plurality of the sensing TX nodes among the plurality of the sensing TX nodes; and

configuration information for side-link communication with the first plurality of the sensing TX nodes;

transmit, to each sensing TX node among the first plurality of the sensing TX nodes, a threshold related to constructing a second plurality of the sensing TX nodes;

receive, from the first plurality of the sensing TX nodes, uplink sensing signals; and

process measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements.
A computer-readable medium storing instructions, wherein the instructions, upon execution by a processor, cause the processor to:

transmit, to a selected sensing transmission (TX) node among a plurality of sensing TX nodes, an indication that the selected sensing TX node has been selected as a lead sensing TX node;

transmit, to the lead sensing TX node:

indications identifying a first plurality of the sensing TX nodes among the plurality of the sensing TX nodes; and

configuration information for side-link communication with the first plurality of the sensing TX nodes;

transmit, to each sensing TX node among the first plurality of the sensing TX nodes, a threshold related to constructing a second plurality of the sensing TX nodes;

receive, from the first plurality of the sensing TX nodes, uplink sensing signals; and

process measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements.
A method comprising:

receiving an indication that a selected sensing TX node has been assigned as a lead sensing TX node for a first plurality of sensing TX nodes among a plurality of sensing TX nodes;

receiving a downlink sensing signal, where the downlink sensing signal is a common downlink sensing signal that is intended for the sensing TX nodes of the first plurality of the sensing TX nodes;

processing obtained measurements of the downlink sensing signal, to, thereby, obtain sensing parameters; and

transmitting the sensing parameters.
The method of claim 18, further comprising receiving, before receiving the downlink sensing signal, configuration information for the downlink sensing signal.
The method of claim 18 or claim 19, wherein the sensing parameters comprise a relative power delay profile.
The method of any one of claims 18 to 20, wherein the sensing parameters comprise an angle of arrival.
The method of any one of claims 18 to 21, wherein the sensing parameters comprise a time of flight.
The method of any one of claims 18 to 22, further comprising transmitting, to the sensing TX nodes of the first plurality of the sensing TX nodes, the sensing parameters.
The method of any one of claims 18 to 23, further comprising:

receiving configuration information for an uplink sensing signal; and

transmitting, according to the configuration information, a sensing signal.
An apparatus comprising:

a memory storing instructions;

a processor, wherein the processor is caused, by executing the instructions, to:

receive an indication that the apparatus has been assigned as a lead sensing TX node for a first plurality of sensing TX nodes among a plurality of sensing TX nodes;

receive a downlink sensing signal, where the downlink sensing signal is a common downlink sensing signal that is intended for the sensing TX nodes of the first plurality of the sensing TX nodes;

process obtained measurements of the downlink sensing signal, to, thereby, obtain sensing parameters; and

transmit the sensing parameters.
A computer-readable medium storing instructions, wherein the instructions, upon execution by a processor, cause the processor to:

receive an indication that a selected sensing TX node has been assigned as a lead sensing TX node for a first plurality of sensing TX nodes among a plurality of sensing TX nodes;

receive a downlink sensing signal, where the downlink sensing signal is a common downlink sensing signal that is intended for the sensing TX nodes of the first plurality of the sensing TX nodes;

process obtained measurements of the downlink sensing signal, to, thereby, obtain sensing parameters; and

transmit the sensing parameters.
A method comprising:

receiving configuration information for a downlink sensing signal and configuration information for obtaining sensing parameters;

receiving the downlink sensing signal;

transmitting sensing measurements, the sensing measurements obtained by processing, according to the configuration information for obtaining sensing parameters, measurements of the downlink sensing signal;

receiving, from a lead sensing TX node, sensing measurements obtained by the lead sensing TX node;

obtaining a correlation between:

the sensing measurements obtained by the lead sensing TX node; and

the sensing measurements obtained by the processing the measurements of the downlink sensing signal; and

responsive to determining that the correlation exceeds a threshold, transmitting, to a sensing reception (RX) node, an indication that the correlation exceeds the threshold.
The method of claim 27, further comprising receiving configuration information for an uplink sensing signal.
The method of claim 28, further comprising transmitting the uplink sensing signals according to the configuration information for the uplink sensing signals.
The method of any one of claims 27 to 29, wherein the sensing measurements comprise a relative power delay profile.
The method of any one of claims 27 to 30, wherein the sensing measurements comprise an angle of arrival.
An apparatus comprising:

a memory storing instructions;

a processor, wherein the processor is caused, by executing the instructions, to:

receive:

configuration information for a downlink sensing signal; and

configuration information for obtaining sensing parameters;

receive the downlink sensing signal;

transmit sensing measurements, the sensing measurements obtained by processing, according to the configuration information for obtaining sensing parameters, measurements of the downlink sensing signal;

receive, from a lead sensing TX node, sensing measurements obtained by the lead sensing TX node;

obtain a correlation between:

the sensing measurements obtained by the lead sensing TX node; and

the sensing measurements obtained by the processing the measurements of the downlink sensing signal; and

transmit, to a sensing reception (RX) node, an indication that the correlation exceeds the threshold.
A computer-readable medium storing instructions, wherein the instructions, upon execution by a processor, cause the processor to:

receive:

configuration information for a downlink sensing signal; and

configuration information for obtaining sensing parameters;

receive the downlink sensing signal;

transmit sensing measurements, the sensing measurements obtained by processing, according to the configuration information for obtaining sensing parameters, measurements of the downlink sensing signal;

receive, from a lead sensing TX node, sensing measurements obtained by the lead sensing TX node;

obtain a correlation between:

the sensing measurements obtained by the lead sensing TX node; and

the sensing measurements obtained by the processing the measurements of the downlink sensing signal; and

transmit, to a sensing reception (RX) node, an indication that the correlation exceeds the threshold.
An apparatus comprising a processor configured to cause the apparatus to perform the method of any one of claims 1 to 7, 10 to 15, 18 to 24, and 27 to 31.
A computer-readable medium storing instructions, wherein the instructions, upon execution by a computer, cause the computer to perform the method of any one of claims 1 to 7, 10 to 15, 18 to 24, and 27 to 31.
A computer program comprising instructions, wherein the instructions, upon execution by a computer, cause the computer to perform the method of any one of claims 1 to 7, 10 to 15, 18 to 24, and 27 to 31.
A system comprising a sensing reception (RX) node and a lead sensing transmission (TX) node among a plurality of sensing TX nodes, wherein:

the sensing RX node is configured to receive uplink sensing signals from a first plurality of the plurality of sensing TX nodes, and process measurements of the uplink sensing signals to, thereby, obtain sensing parameters, where the processing the measurements includes fusing the measurements;

the lead sensing TX node is configured to receive a downlink sensing signal, where the downlink sensing signal is a common downlink sensing signal that is intended for the sensing TX nodes of the first plurality of the sensing TX nodes;

the lead sensing TX node is further configured to process obtained measurements of the downlink sensing signal to obtain sensing parameters, and

the lead sensing TX node is further configured to transmit the sensing parameters to the sensing TX nodes of the first plurality of the sensing TX nodes, to enable the sensing TX nodes of the first plurality of the sensing TX nodes to indicate a correlation to used for the uplink sensing signals.