Method and program for bistatic and multi-static sensing

Abstract

A wireless transceiver / receiver unit configured to: transmit a message to a network, such as a serving network, where the message indicates one or more channel state information (CSI) measurements supported by a WTRU; receiving a plurality of reference signals (RSs), wherein each of the plurality of RSs is associated with a plurality of configured resource sets; determining a respective sensing performance value for each of a set of configured resources associated with the plurality of RSs based on mutual information (MI) associated with the plurality of RSs; determining a respective precoding matrix indicator (PMI) set for each of the configured sets of resources based on the respective sensed performance value for each of the configured sets of resources; and transmitting a sensing report indicating a respective PMI set and a respective sensing performance value for each respective one of the configured resource sets.

Description

[0001] Cross-references to (one or more) related applications This application claims the benefit of U.S. Provisional Application No. 63 / 518,908, filed on August 11, 2023, the entire contents of which are incorporated herein by reference. Background Technology

[0002] Typically, sensing involves a beam-scanning procedure performed by a transmitter entity, where sweeping beams are generated to cover target areas in the environment (e.g., following a sequential order, and a receiver captures their reflections). In bistatic and multistatic sensing, a measurement entity (e.g., a wireless transceiver / receiver unit (WTRU)) must detect one or more copies of signals reflected from the environment from one or more sensing beams and perform measurements (e.g., delay, power, angle of arrival (AoA), etc.) to identify its scatterers. In monostatic sensing, the receiver entity coordinates localization with the transmitter. It performs detection simultaneously with transmission (e.g., in full-duplex mode) or after transmission is complete (e.g., in half-duplex mode).

[0003] A dual-base or multi-base scenario may include one or more Transmitting Receiver Points (TRPs) as transmitting entities for sensing in the downlink, and one or more Transmitting WTRUs as receivers for performing sensing measurements and reporting the measurements back to the network. Similar dual-base or multi-base scenarios may involve two or more WTRUs, two or more Base Stations (BSs), and / or Transmitting WTRUs and Receiving BSs. Summary of the Invention

[0004] A wireless transceiver unit (WTRU) may include a processor. The processor may be configured to send messages to a network, such as a serving network. The messages may indicate one or more Channel State Information (CSI) measurements supported by the WTRU. The processor may be configured to receive a plurality of Reference Signals (RS), each of which is associated with a plurality of configured resource sets. The processor may be configured to determine a corresponding sensing performance value for each of the configured resource sets associated with the plurality of RSs based on mutual information (MI) associated with the plurality of RSs. For example, the sensing performance value may be a minimum mean square error (MMSE) or mean square error (MSE) value below a threshold. For example, the sensing performance value of a configured resource set indicates the statistical error associated with a sensing metric measured for the configured resource set. In some examples, MI may be a metric characterizing the amount of information carried by the channels associated with each of the configured resource sets.

[0005] The processor can be configured to determine a corresponding set of precoded matrix indicators (PMIs) for each of the configured resource sets based on the corresponding sensing performance values ​​for each of the configured resource sets. For example, the processor can be configured to determine the PMI set based on the sensing performance values ​​of the configured resource sets being within a predetermined range.

[0006] The processor can be configured to send a sensing report indicating the corresponding PMI set and corresponding sensing performance value for each configured resource set. In some examples, the sensing report may be a sensing codebook index for each Channel State Information (CSI) Resource Indicator (CRI).

[0007] The processor can be configured to receive configuration information including spatial characteristics of multiple RS.

[0008] For example, the PMI set can be determined based on the sensing performance value of each corresponding configured resource set within a predetermined range.

[0009] The message may be an indication of the supported performance metrics for bistatic or multistatic sensing and / or the sensing codebook supported by the WTRU. The supported performance metrics for bistatic or multistatic sensing may be any combination of the following: (i) minimum mean square error (MMSE), (ii) signal-to-noise ratio (SNR), (iii) reference signal received power (RSRP), (iv) root mean square (RMS) error of ranging estimation, (v) RMS error of angle of arrival (AoA) estimation, (vi) RMS error of phase estimation, and / or (vii) RMS error of velocity estimation.

[0010] A WTRU can be configured to perform a method including one or more of the following steps. The method may include sending a message to a network, such as a serving network. The message may indicate one or more Channel State Information (CSI) measurements supported by the WTRU. The method may include receiving a plurality of Reference Signals (RS), each of which is associated with a plurality of configured resource sets. The method may include determining a corresponding sensing performance value for each of the configured resource sets associated with the plurality of RSs based on mutual information (MI) associated with the plurality of RSs. For example, the sensing performance value may be a minimum mean square error (MMSE) or mean square error (MSE) value below a threshold. For example, the sensing performance value of a configured resource set indicates the statistical error associated with a sensing metric measured for the configured resource set. In some examples, MI may be a metric characterizing the amount of information carried by the channels associated with each of the configured resource sets.

[0011] The method may include determining a corresponding set of precoded matrix indicators (PMIs) for each of the configured resource sets based on the corresponding sensing performance values ​​of each of the configured resource sets. For example, the method may include determining the PMI set based on the sensing performance values ​​of the configured resource sets being within a predetermined range.

[0012] The method may include sending a sensing report indicating the corresponding PMI set and corresponding sensing performance value for each configured resource set. In some examples, the sensing report may be a sensing codebook index for each Channel State Information (CSI) Resource Indicator (CRI).

[0013] The method may include receiving configuration information that includes the spatial characteristics of the plurality of RSs.

[0014] For example, the PMI set can be determined based on the sensing performance value of each corresponding configured resource set within a predetermined range.

[0015] The message may be an indication of the supported performance metrics for bistatic or multistatic sensing and / or the sensing codebook supported by the WTRU. The supported performance metrics for bistatic or multistatic sensing may be any combination of the following: (i) minimum mean square error (MMSE), (ii) signal-to-noise ratio (SNR), (iii) reference signal received power (RSRP), (iv) root mean square (RMS) error of ranging estimation, (v) RMS error of angle of arrival (AoA) estimation, (vi) RMS error of phase estimation, and / or (vii) RMS error of velocity estimation. Attached Figure Description

[0016] A more detailed understanding can be obtained from the following detailed description, given by way of example in conjunction with the accompanying drawings, which are attached to the detailed description below. Like the detailed description, the figures in such drawings are illustrative. Accordingly, the figures (FIG.) and the detailed description should not be considered limiting, and other equally valid examples are possible and desirable. Furthermore, the same reference numerals (“ref”) in the figures indicate the same elements, and wherein: Figure 1A This is a system diagram illustrating an example communication system in which one or more of the disclosed embodiments can be implemented.

[0017] Figure 1B The illustration shows an embodiment that can be used Figure 1A The diagram shows a system illustration of an example wireless transmit / receive unit (WTRU) used in a communication system.

[0018] Figure 1C The illustration shows an embodiment that can be used Figure 1AThe diagram illustrates an example radio access network (RAN) and an example core network (CN) used within a communication system.

[0019] Figure 1D The illustration shows an embodiment that can be used Figure 1A The diagram shows another example RAN and another example CN used in the communication system illustrated in the figure.

[0020] Figure 2 This is a system diagram illustrating an example monostatic sensing scenario performed by a transmit-receive point (TRP).

[0021] Figure 3 This is a diagram illustrating an example bistatic sensing system involving a TRP and multiple WTRUs.

[0022] Figure 4 This is a diagram illustrating an example multi-base sensing system involving a TRP and multiple WTRUs.

[0023] Figure 5 This is a system diagram illustrating an example of bistatic sensing involving a sensing beam and a sensing direction, wherein the sensing direction relates to a TRP and a WTRU.

[0024] Figure 6 This is a system diagram illustrating an example scenario involving bistatic sensing of TRP, WTRU, and multiple scatterers.

[0025] Figure 7 This is a system diagram illustrating an example of sensing CSI acquisition and reporting performed by an RS-assisted WTRU for sensing CSI acquisition.

[0026] Figure 8 This is a flowchart illustrating an example method for sensing CSI acquisition performed by a WTRU.

[0027] Figure 9 The diagram illustrates a system illustration of an example bistatic sensing measurement performed by a WTRU assisted by a sensing RS on one or more active transmission configuration indicator (TCI) states for sensing.

[0028] Figure 10 This is a flowchart illustrating an example bistatic / multistatic sensing and reporting method performed by a WTRU. Detailed Implementation

[0029] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the following description. Furthermore, embodiments and examples not specifically described herein may be practiced in place of or in combination with the embodiments and other examples expressly, implicitly, and / or inherently described, disclosed, or otherwise provided herein (collectively, the “Provided”). While various embodiments are described and / or claimed herein, in which apparatuses, systems, devices, etc., and / or any elements thereof perform operations, processes, algorithms, functions, etc., and / or any portions thereof, it should be understood that any embodiment described and / or claimed herein assumes that any apparatus, system, device, etc., and / or any element thereof is configured to perform any operation, process, algorithm, function, etc., and / or any portion thereof.

[0030] The methods, apparatus, and systems provided herein are well-suited for communications involving both wired and wireless networks. About Figures 1A to 1D An overview of various types of wireless devices and infrastructures is provided, in which various elements of the network can utilize, perform, and be arranged and / or adapted and / or configured for use with the methods, apparatuses and systems provided herein.

[0031] Figure 1A This diagram illustrates an example communication system 100 that may implement one or more of the disclosed embodiments. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, and broadcasting to multiple wireless users. The communication system 100 enables multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Zero-Tail Unique Word DFT Spread Spectrum OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), and the like.

[0032] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, Public Switched Telephone Network (PSTN) 108, Internet 110, and other networks 112. However, it will be appreciated that the disclosed embodiments are contemplated to any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRUs 102a, 102b, 102c, and 102d—any of which may be referred to as a “station” and / or “STA”—may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, and the like. Any of WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as WTRUs. Furthermore, any descriptions in this document referring to UEs may be equally applied to WTRUs (or vice versa). For example, the WTRU can be configured to execute any of the procedures or programs described herein that are performed by the UE (or vice versa).

[0033] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106 / 115, the Internet 110, and / or other networks 112. For example, base stations 114a and 114b may be base transceiver stations (BTS), Node-B, eNode B, home Node B, home eNode B, gNB, NR Node B, site controllers, access points (APs), wireless routers, and the like. Although base stations 114a and 114b are each depicted as a single element, it will be appreciated that base stations 114a and 114b may include any number of interconnected base station and / or network elements.

[0034] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for radio services to a specific geographic area, which may be relatively fixed or may change over time. The cell may also be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver per sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in a desired spatial direction.

[0035] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116. Air interface 116 can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) can be used to establish air interface 116.

[0036] More specifically, as described above, the communication system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base stations 114a and WTRUs 102a, 102b, and 102c in RAN 104 / 113 can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish air interfaces 115 / 116 / 117 using Wideband CDMA (WCDMA). WCDMA can include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​UL Packet Access (HSUPA).

[0037] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish an air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0038] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can establish an air interface 116 using a new radio (NR).

[0039] In one embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can implement LTE radio access and NR radio access together, for example, using the dual connectivity (DC) principle. Therefore, the air interface utilized by WTRUs 102a, 102b, and 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0040] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Global Microwave Access Interoperability (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), GSMEDGE (GERAN), and the like.

[0041] Figure 1ABase station 114b can be, for example, a wireless router, a home Node B, a home eNode B, or an access point, and can utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial locations, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for drone use), roads, and the like. In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRUs 102c, 102d can utilize cellular-based RATs (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish picocells or femtocells. Figure 1A As shown, base station 114b can be directly connected to Internet 110. Therefore, base station 114b does not need to access Internet 110 via CN 106 / 115.

[0042] RAN 104 / 113 can communicate with CN 106 / 115, which can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, and 102d. Data can have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. CN 106 / 115 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, and / or perform advanced security functions such as user authentication. Although in Figure 1A Although not shown, it will be understood that RAN 104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs that use the same RAT as or a different RAT than RAN 104 / 113. For example, in addition to being connected to RAN 104 / 113, which may utilize NR radio technology, CN106 / 115 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0043] CN 106 / 115 can also serve as a gateway for WTRU 102a, 102b, 102c, 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Common Old-Style Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) from the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may use the same RAT as RAN 104 / 113 or a different RAT.

[0044] Some or all of the WTRUs 102a, 102b, 102c, and 102d in communication system 100 may include multi-mode capability (e.g., WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, Figure 1A The WTRU 102c shown can be configured to communicate with base station 114a, which can employ cellular-based radio technology, and with base station 114b, which can employ IEEE 802 radio technology.

[0045] Figure 1B This is a system diagram illustrating the example WTRU 102. (Example: ...) Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keyboard 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other peripheral devices 138, etc. It will be appreciated that WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0046] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, and the like. Processor 118 may perform signal encoding, data processing, power control, input / output processing, and / or any other functions that enable WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, and transceiver 120 may be coupled to transmitting / receiving element 122. Although Figure 1B While the processor 118 and transceiver 120 are depicted as separate components, it will be understood that the processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

[0047] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, transmitting / receiving element 122 can be an antenna configured to transmit and / or receive RF signals. In one embodiment, transmitting / receiving element 122 can be, for example, a transmitter / detector configured to transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF and optical signals. It will be appreciated that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0048] Despite Figure 1B While the transmit / receive element 122 is described as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0049] Transceiver 120 can be configured to modulate signals to be transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As described above, WTRU 102 can have multimode capability. Therefore, transceiver 120 can include multiple transceivers for example enabling WTRU 102 to communicate via multiple RATs (such as NR and IEEE 802.11).

[0050] The processor 118 of WTRU 102 can be coupled to and receive user input data from: a speaker / microphone 124, a keyboard 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit). The processor 118 can also output user data to the speaker / microphone 124, keyboard 126, and / or display / touchpad 128. Furthermore, the processor 118 can access information from and store data in any suitable type of memory (such as non-removable memory 130 and / or removable memory 132). Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identity module (SIM) card, memory stick, secure digital storage (SD) card, and the like. In other embodiments, the processor 118 can access information from and store data in memory that is not physically located on WTRU 102 (such as a server or home computer (not shown)).

[0051] The processor 118 may receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0052] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via air interface 116, and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information using any suitable location determination method while remaining consistent with the embodiments.

[0053] The processor 118 may be further coupled to other peripheral devices 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or videos), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth® modules, FM radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, activity trackers, and the like. Peripheral devices 138 may include one or more sensors, which may be one or more of the following: gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors, geolocation sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, attitude sensors, biosensors, and / or humidity sensors.

[0054] WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for both uplink (UL) (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit 139 to reduce and / or substantially eliminate self-interference via hardware (e.g., a choke) or via signal processing (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WTRU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception) may be concurrent and / or simultaneous.

[0055] Figure 1C This is a system diagram illustrating RAN 104 and CN 106 according to one embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using E-UTRA radio technology. RAN 104 can also communicate with CN 106.

[0056] RAN 104 may include eNode-Bs 160a, 160b, and 160c, although it will be understood that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, for example, eNode-B 160a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a.

[0057] Each of the eNode-B 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in the UL and / or DL, and the like. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0058] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. While each of the foregoing elements is depicted as part of CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0059] The MME 162 can connect to each of the eNode-Bs 162a, 162b, and 162c in RAN 104 via the S1 interface and can be used as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, and 102c, and so on. The MME 162 can provide control plane functions for switching between RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0060] The SGW 164 can connect to each of the eNode-Bs 160a, 160b, and 160c in RAN 104 via the S1 interface. The SGW 164 can typically route and forward user data packets to / from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions such as anchoring the user plane during inter-eNode B handover, triggering paging when DL data is available for WTRUs 102a, 102b, and 102c, managing and storing the context of WTRUs 102a, 102b, and 102c, and so on.

[0061] The SGW 164 can be connected to the PGW 166, which can provide WTRU 102a, 102b, 102c with access to packet-switched networks (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0062] CN 106 can facilitate communication with other networks. For example, CN 106 can provide WTRU 102a, 102b, 102c with access to a circuit-switched network such as PSTN 108 to facilitate communication between WTRU 102a, 102b, 102c and conventional landline communication equipment. For example, CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between CN 106 and PSTN 108. Furthermore, CN 106 can provide WTRU 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0063] Despite WTRU in Figures 1A-1D While described as a wireless terminal, it is envisioned that in some representative embodiments, such a terminal may (e.g., temporarily or permanently) use a wired communication interface with a communication network.

[0064] In a representative embodiment, another network 112 may be a WLAN.

[0065] In Infrastructure Basic Services Set (BSS) mode, a WLAN may have an Access Point (AP) for the BSS and one or more Stations (STAs) associated with the AP. The AP may have access to or interfacing with a Distributed System (DS) or carry services within and / or out of the BSS to another type of wired / wireless network. Traffic originating outside the BSS destined for a STA can reach and be delivered to the STA via the AP. Traffic originating from a STA destined outside the BSS can be sent to the AP for delivery to the appropriate destination. For example, traffic between STAs within the BSS can be sent via the AP, where the source STA can send traffic to the AP, and the AP can deliver traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between a source STA and a destination STA (e.g., directly between the source STA and the destination STA) using Direct Link Establishment (DLS). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to as the "self-organizing" communication mode in this document.

[0066] When using 802.11ac infrastructure operating mode or a similar operating mode, the AP can transmit beacons on a fixed channel, such as the primary channel. The primary channel can be of a fixed width (e.g., a wide bandwidth of 20 MHz) or dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative embodiments, such as in an 802.11 system, Carrier Sense Multiple Access (CSMA / CA) with collision avoidance can be implemented. For CSMA / CA, each STA, including the AP, can listen on the primary channel. If the primary channel is listened to / detected by a particular STA and / or determined to be busy, that particular STA can back off. A single STA (e.g., only one station) can transmit at any given time within a given BSS.

[0067] High-throughput (HT) STAs can communicate using a 40 MHz wide channel, for example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels.

[0068] Very High Throughput (VHT) STAs can support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. 40 MHz and / or 80 MHz channels can be formed by combining adjacent 20 MHz channels. A 160 MHz channel can be formed by combining eight adjacent 20 MHz channels, or by combining two non-adjacent 80 MHz channels—this can be referred to as an 80+80 configuration. For the 80+80 configuration, after channel coding, the data passes through a segment resolver, which splits the data into two streams. Each stream can be processed separately using Inverse Fast Fourier Transform (IFFT) and time-domain processing. These streams can be mapped onto two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0069] 802.11af and 802.11ah support sub-1 GHz operating modes. Compared to the operating modes used in 802.11n and 802.11ac, the channel operating bandwidth and carrier in 802.11af and 802.11ah are reduced. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV Blank (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah can support metering-type control / machine-type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities (e.g., limited capabilities) including support (e.g., only support) certain and / or limited bandwidths. MTC devices may include batteries with a battery life exceeding a threshold (e.g., to maintain a very long battery life).

[0070] WLAN systems that support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The bandwidth of the primary channel can be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STAs that support the minimum bandwidth operating mode among all STAs operating in the BSS. In the example of 802.11ah, for STAs that support (e.g., only support) the 1 MHz mode (e.g., MTC type devices), the primary channel can be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier Sense and / or Network Assignment Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example because an STA (which only supports the 1 MHz operating mode) is transmitting to the AP, the entire available band can be considered busy, even if most of the band remains idle and can be available.

[0071] In the United States, the available frequency bands for 802.11ah are from 902 MHz to 928 MHz. In South Korea, the available bands are from 917.5 MHz to 923.5 MHz. In Japan, the available bands are from 916.5 MHz to 927.5 MHz. The total available bandwidth for 802.11ah is 6 MHz to 26 MHz, depending on the country code.

[0072] Figure 1D This diagram illustrates a system diagram of RAN 113 and CN 115 according to one embodiment. As described above, RAN 113 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using NR radio technology. RAN 113 can also communicate with CN 115.

[0073] RAN 113 may include gNBs 180a, 180b, and 180c, although it should be understood that RAN 113 may include any number of GNBs while remaining consistent with the embodiments. gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, GNBs 180a and 108b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, and 180c. Thus, for example, gNB 180a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a. In one embodiment, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers (not shown) to WTRU 102a. A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c can implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0074] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable digitization. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can differ for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing different numbers of OFDM symbols and / or varying absolute durations).

[0075] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in standalone and / or non-standalone configurations. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without access to other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can utilize one or more of gNBs 180a, 180b, and 180c as mobility anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in unlicensed frequency bands. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate / connect with gNBs 180a, 180b, and 180c, while also communicating / connecting with another RAN such as eNode-Bs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c, as well as one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-Bs 160a, 160b, and 160c can act as mobility anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0076] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, network slicing support, dual connectivity, interoperability between NR and E-UTRA, routing of user plane data to User Plane Functions (UPF) 184a and 184b, routing of control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, and the like. Figure 1D As shown, gNB 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0077] Figure 1DThe CN 115 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements is depicted as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0078] AMF 182a and 182b can connect to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can be used as control nodes. For example, AMF 182a and 182b can be responsible for authenticating users of WTRU 102a, 102b, and 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting specific SMF 183a and 183b, managing registration areas, terminating NAS signaling, mobility management, and so on. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the service types being used by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services that rely on Ultra Reliable Low Latency (URLLC) access, services that rely on Enhanced Massive Mobile Broadband (eMBB) access, services for Machine Type Communication (MTC) access, and so on. AMF 162 can provide control plane functions for switching between RAN 113 and other RANs (not shown) that employ other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0079] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 115 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 115 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and configure service routes through UPFs 184a and 184b. SMFs 183a and 183b can perform other functions, such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and so on. PDU session types can be IP-based, non-IP-based, Ethernet-based, and so on.

[0080] UPF 184a and 184b can be connected via the N3 interface to one or more of gNB 180a, 180b, and 180c in RAN 113. This N3 interface provides WTRU 102a, 102b, and 102c with access to a packet-switched network (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-destination PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and so on.

[0081] CN 115 can facilitate communication with other networks. For example, CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) acting as an interface between CN 115 and PSTN 108. Furthermore, CN 115 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRUs 102a, 102b, and 102c may be connected to local DNs 185a and 185b via the N3 interface to UPFs 184a and 184b and the N6 interface between UPFs 184a and 184b and data networks (DNs) 185a and 185b.

[0082] Given Figures 1A-1D and Figures 1A-1D The corresponding descriptions herein regarding one or more of the functions of WTRU 102a-d, base station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-ab, UPF184a-b, SMF 183a-b, DN 185a-b, and / or any other device described herein may be performed by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0083] Simulation devices can be designed to perform one or more tests on other devices in a laboratory environment and / or a carrier network environment. For example, one or more simulation devices can perform one or more functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices can be directly coupled to another device for testing purposes and / or can perform tests using over-the-air wireless communication.

[0084] One or more emulation devices may perform one or more functions (including all functions) but are not implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in test scenarios in a test laboratory and / or in non-deployed (e.g., testing) wired and / or wireless communication networks to perform testing of one or more components. One or more emulation devices may be test equipment. Emulation devices may transmit and / or receive data using direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas).

[0085] Methods and procedures for bistatic and multistatic sensing using wireless signals in cellular environments can be provided.

[0086] Sensing can refer to the estimation of one or more spatial characteristics (e.g., absolute or relative positioning, 3D orientation, velocity, etc.) of one or more objects that are not wirelessly connected to the system under consideration. In some wireless systems, for example, when considering integrated sensing and communication, sensing can be considered as part of the communication framework.

[0087] Depending on the relative positioning of the transmitter and one or more receivers with respect to the object being sensed, at least three sensing modes are typically established.

[0088] Figure 2 This is a system diagram 200 illustrating an example of monostatic sensing performed by a transmit-receive point (TRP). Monostatic sensing refers to a scenario where transmitter and receiver entities cooperate to localize in order to estimate one or more of the location, velocity, and / or orientation of an object (e.g., an object). Monostatic sensing can be performed by a base station (BS) (e.g., a transmit-receive point (TRP)) or a WTRU. Sensing can be applied to detect one or more objects.

[0089] Figure 3This is a system diagram 300 illustrating an example of bistatic sensing including a TRP and a WTRU. Bistatic sensing refers to a scenario in which the transmitter and receiver entities do not coordinate their localization for sensing; for example, the TRP acts as the transmitter and the WTRU acts as the receiver (e.g., as shown), or vice versa.

[0090] Figure 4 This is a system diagram 400 illustrating an example of multi-base sensing including a TRP and multiple WTRUs. Multi-base sensing refers to a scenario in which multiple receiving entities (e.g., multiple WTRUs) sense one or more objects with the assistance of a non-cooperatively positioned transmitting entity.

[0091] Monostatic sensing can require full-duplex capability at the sensing entity (e.g., WTRU or TRP), for example, the ability to simultaneously transmit a sensing signal and detect reflections from the environment. Alternatively, monostatic sensing can be implemented in half-duplex mode by performing detection on a receive window that begins when transmission is complete, for example, using detection techniques not based on the Discrete Fourier Transform (DFT) that utilizes only partially reflected signals. Because the transmitting and receiving entities are different, bistatic and multistatic sensing can be performed without using full-duplex mode.

[0092] The sensing scheme can also differentiate between active and passive sensing depending on whether the sensing involves the subsequent detection of both the transmitted, prior known signal and the reflected signal (e.g., in an active case) or whether it involves only the detection of the reflected signal (e.g., in a passive case). The methods and procedures described below generally refer to active sensing scenarios, but can also be applied to passive sensing.

[0093] Channel State Information (CSI) refers to the set of quantities that a communication entity (e.g., a TRP or WTRU) can obtain to characterize the channel state in any time, frequency, and / or spatial domain. CSI can be measured by the network and / or WTRU to obtain the UL and DL channel states, respectively, and to further optimize communication performance. When the channel reciprocity condition is met, such as in a TDD system using a reciprocal transceiver architecture, CSI can be equivalent in both UL and DL.

[0094] In some existing solutions, DL CSI can be measured by the WTRU using, for example, a set of CSI-RS signals or SS / PBCH blocks. As an example, an SS / PBCH block (SSB) can carry a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and / or a PBCH demodulation reference signal (DMRS), all of which contribute to determining DLCSI. DL CSI information can include various measurements such as RSRP, CQI, PMI, RI, etc., as configured by the network in broadband or per-subband modes.

[0095] UL CSI can be measured by the network using, for example, a Sounding Reference Signal (SRS), and / or, if the channel reciprocity condition is met, US CSI can be obtained by the WTRU in the DL and reported back to the base station. UL CSI can include measurements similar to DL CSI. For example, UL CSI can include RSRP, CQI, PMI, RI, and / or the like.

[0096] Figure 5 This is a system diagram 500 illustrating an example sensing scenario for bistatic sensing, showing the sensing beams and sensing directions. When scanning a medium for bistatic or multistatic sensing, some sensing beams may fail to reach the intended target (e.g., an object). For example, some sensing beams may fail to reach the intended target when the beam is directed in a direction that does not reveal any meaningful object or is too far away to be detected. Without guidance on the optimal beam configuration and / or direction for sensing the medium, the resources and / or energy expended by sensing transmission may be wasted on useless sensing attempts.

[0097] The WTRU can assist in network configuration and / or beam refinement for optimal bistatic and multistatic sensing orientation. For example, the WTRU can report relevant data to help optimize sensing procedures. One or more methods and procedures can be provided for bistatic and multistatic sensing using wireless signals in cellular environments.

[0098] In this article, "TRP" can be used interchangeably with "gNB".

[0099] The terms “target,” “scatterer,” and “object” are used interchangeably in this document to refer to any obstacle intended to be sensed that is not wirelessly connected to the system under consideration.

[0100] In this article, "sensing beam" can be used to refer to a spatial domain filter used for the transmission or reception of a sensing reference signal.

[0101] In this article, “sensing RS” can be used to refer to any reference signal used for bistatic or multistatic sensing.

[0102] In this article, “sensing CSI” can be used to refer to any channel measurement that can be used for sensing, obtained by a receiving entity from a combined channel including transmitters, objects, and receivers.

[0103] In this document, "sensing PMI" can be used to refer to an indication of the precoding matrix used for sensing, for example, an index in a codebook representing a predefined precoding matrix used for sensing discrete directions. Sensing PMI can be part of a sensing CSI acquisition process performed, for example, by a UE.

[0104] In this article, "codebook of precoded matrices for sensing" or "codebook for sensing" can be used to refer to any set of precoded matrices used to transmit sensing RS along a predefined set of directions.

[0105] In this document, "RS used for sensing CSI acquisition" can be used to refer to any RS used for acquiring sensing CSI information. Without loss of generality, it will be assumed to be an N-port signal, that is, it enables CSI acquisition that can sense up to N antenna ports.

[0106] In this article, “sensing TCI state” and “TCI state for sensing” can be used interchangeably to refer to the quasi-co-localization (QCL) relationship set between the sensing RS and the RS used to sense the CSI acquisition corresponding to the sensing beam.

[0107] In this article, "MPC" can be used to refer to any of the multipath components received by, for example, a UE when detecting scattered and reflected signals from the environment.

[0108] In this document, "port" and "antenna port" can be used to refer to any signal whose channel characteristics can be explicitly determined by the receiver using any suitable RS. The signal mapped to the antenna port can be transmitted by one or more physical antennas.

[0109] Figure 6 This is a system diagram 600 illustrating an example scenario of bistatic sensing using a TRP, WTRU, and multiple scatterers. Consider a cellular scenario where one or more TRPs are designed to sense the environment with the assistance of one or more WTRUs, which perform sensing measurements to derive spatial information about surrounding objects, such as their position, velocity, orientation, etc., as determined by the system or application.

[0110] The TRP can include any number of transmit-receive antennas, such as in a massive MIMO (M-MIMO) configuration. As part of the sensing configuration, N antenna ports can be signaled to the WTRU, corresponding to the maximum number of antenna ports available for transmitting sensing RS signals, sensing RS signals for CSI acquisition, or both. The WTRU can be equipped with one or more receive antennas.

[0111] A suitable RS may already exist for sensing measurements, either in the form of an existing signal modified for sensing (such as the DL Positioning Reference Signal (PRS) or UL Positioning Detection Reference Signal (SRSp) in 5G NR) or in the form of a dedicated sensing signal. A suitable RS may already exist for sensing CSI acquisition, such as CSI-RS, SSB, or any other signal.

[0112] Signal waveforms susceptible to frequency domain analysis may be applicable. For example, OFDM-like waveforms, such as CP-OFDM or DFT-s-OFDM, which include discrete samples in the time or frequency domains, may be applicable. Other waveforms may be similarly applicable.

[0113] Bistatic and multistatic sensing can be optimized by dynamically selecting one or more orientations that produce the best possible sensing performance (e.g., sensing accuracy expressed by its MMSE) and / or discarding one or more orientations that are not optimally suited for sensing.

[0114] It can realize the measurement of CSI information.

[0115] Channel metrics used for sensing can help determine the spatial orientation with the best possible sensing performance in bistatic or multistatic scenarios. These channel metrics can be denoted as sensing CSI or sensing CSI information.

[0116] Perform measurements of the sensed CSI via the WTRU and select the spatial orientation to produce the minimum possible MMSE (e.g., delay, AOA, etc.) for the quantity(s) to be sensed. Other criteria can be equally valid for the measurement and reporting of sensed CSI information by the WTRU.

[0117] The spatial orientation used for sensing can be discretized and signaled as an index in the codebook used for sensing (e.g., by means of sensing PMI). The term “sensing PMI” will be used in this description, but any other naming conventions may also apply.

[0118] The relationship between the mutual information (MI) available from a given channel and the MMSE of the estimated parameters can be expressed by the following equation (1): , The expression on the left denotes the derivative with respect to SNR; MMSE is the minimum mean square error of the quantity to be sensed; and MI is the mutual information between the input and output of the channel in the presence of additive white Gaussian noise (AWGN). Equation (1) holds regardless of the statistics of the input signal fed into the channel. MI can also be a measure of the amount of information carried by each channel associated with the configured resource set.

[0119] In some solutions, equation (1) can be used as a basis to identify instances exhibiting values ​​below a threshold. The beam and spatial orientation of the MMSE used for sensing (e.g., which may be referred to as the sensing MMSE) thus represent the most suitable orientation for sensing, as shown in equation (2) below: .

[0120] Different criteria, besides sensing MMSE, can be used to select the most appropriate direction for sensing.

[0121] A predefined set of sensing beams can be assumed. These sensing beams can be identified by appropriate indexes, including identifiers of resource sets in 5G NR, such as CSI-RS resource indicators (CRIs) or any other direct or indirect means. Furthermore, the codebook of the precoding matrices used for sensing can be a priori, with its entries identified by codebook indices marked by the sensing PMI. The codebook can represent a set of precoding matrices used to transmit sensing signals along any of the predefined direction sets used for sensing.

[0122] Figure 7 This is a system diagram 700 illustrating an example of sensing CSI acquisition and reporting performed by an RS-assisted WTRU for sensing CSI acquisition. Figure 7 In this context, several sensing beams, including a suitable RS for sensing CSI acquisition, are used by the WTRU to derive the sensing MMSE with the help of equation (1). The receiver (e.g., the WTRU) can select a suitable set of sensing beams and codebook indices that satisfy equation (2) for sensing. The beams can be identified by their CRIs, as in 5G NR, but any other identifier will be equally valid.

[0123] Sensing precoding matrix indicator (PMI) values ​​can be measured from one or more sensing beams transmitted by the TRP or other devices. One or more sensing PMI values ​​can be obtained for each sensing beam. For example, the association between sensing beams and sensing PMI values ​​can be reported as a set of sensing PMI values ​​exhibiting an MMSE below a threshold within a given CRI. For example, if the MMSE of a sensing PMI value is above a threshold, or if an MMSE cannot be obtained due to low SNR or insufficient SNR variation necessary to reliably calculate the derivative of the MI, then no sensing PMI value can be associated with a given CRI.

[0124] The obtained sensing PMI values ​​corresponding to one or more sensing beams can be reported by WTRU as part of a sensing report that includes channel measurements used for sensing.

[0125] The sensed MMSE value can be calculated from the derivative of mutual information with respect to snr according to equation (1), regardless of whether the channel is AWGN or Rayleigh type.

[0126] Assume the received constellation symbol y undergoes a variance The AWGN, located in the complex plane, is the constellation symbol in M-QAM modulation. Distance of set M At this point, MI can be obtained using the following equation (3): .

[0127] in Indicates about The known coordinates are the conditions for the expectation operator of the symbol y, and Marking The log-likelihood ratio of the transmission of to the transmission of any other symbol can be given by the following equation (4):

[0128] Based on parameters The LLR value can be calculated by WTRU by applying equation (4) or via a lookup table approximating equation (4) for each modulation order M.

[0129] The symbol may experience a frequency-flat channel response, and equations (3) and (4) can be applied directly. Alternatively or additionally, the symbol may experience the effects of a Rayleigh fading channel, whereby the frequency characteristics of the transmitted signal do not hold, and the received signal may exhibit a frequency-selective response. An LLR calculation can be performed after channel equalization to recover the frequency characteristics of the signal. The detected signal after equalization can be considered to be affected by AWGN, and its noise power can be given by the sum of thermal noise and the damage caused by the equalization process, including transceiver defects such as phase noise, nonlinearity, I / Q imbalance and / or others, which together give the combined noise power. In such a case, the SNR and the equalized signal... Values ​​(e.g., sometimes called post-detection values) can be considered for use in equation (4).

[0130] LLR calculations are reciprocal in both the UL and DL, for example in a Time Division Duplex (TDD) system where the same frequency is used in both UL and DL. This assumes the system transceivers are designed to have reciprocal responses (e.g., their behavior can be considered identical in both UL and DL). In this case, the channel states in UL and DL can be the same, and the LLR values ​​can also be the same. In other cases, such as in Frequency Division Duplex (FDD) systems, the frequencies for UL and DL can differ, and the channel states for UL and DL can differ, making their LLR calculations non-reciprocal.

[0131] In equalizing the received signal vector (Where N is the number of antenna ports used for transmitting RS acquired by sensing CSI) multiplied by one of the precoding matrices used for sensing. This generates a received signal. Afterwards, MI can be obtained. The distance between the received signal and the M ideal transmission constellation symbols can then be calculated. And insert it into equation (4) to obtain the input to equation (3). value.

[0132] After equalization, snr may not be considered constant across the frequency range, such as when the channel frequency response is not constant across the RS resources used for sensing CSI acquisition. The derivative of MI with respect to snr can be derived from the form of the following equation (5): It is approximately obtained from a set of P different SNR values, where This represents a small deviation around a given snr: in Indicates the change in snr. The j-th change in MI that follows.

[0133] The derivative of MI with respect to snr can be obtained from the expression in equation (6) below: Among them, snr eff snr represents the SNR of the equivalent Gaussian channel that produces the same MI as the actual instantaneous channel. eff The value of can be obtained through link-to-system methods, such as Mutual Information Effective SINR Mapping (MIESM) and other methods. MIESM can provide the SNR of an ideal Gaussian channel with the same MI as the actual instantaneous channel. Assuming snr eff It can be obtained as a function of snr, and its derivative can also be obtained as a function of snr from equation (6).

[0134] The link-to-system approach can be derived based on the following equation (7) for SNR. eff The expression: in It is a function used to predict BLER (e.g., MI or a different function), and and These are implementation-specific model parameters that are tuned to minimize the error between the BLER predicted by the model and the actual BLER at system-dependent modulation order and coding rate.

[0135] The derivative of the mutual information (MI) with respect to snr for a channel with a frequency-varying response can be obtained by calculating the MI over a vector Gaussian channel. In this case, obtaining the mutual information may be more complex than in equation (3).

[0136] A receiver (e.g., a WTRU) can be configured to measure subband sensed PMI values ​​corresponding to a subband set based on the MMSE criterion in equation (2), where each subband includes a subset of user-allocated bandwidth or a subset of system bandwidth. The receiver can also be configured to measure broadband sensed PMI values ​​based on broadband MMSE corresponding to a predefined frequency zone, including user-allocated bandwidth and / or system bandwidth.

[0137] For a given subband size, including the frequency region spanning a subset of frequency resources allocated for sensing CSI acquisition, the subband sensing MMSE value can be derived from equation (1). As an example, the frequency resources of the RS used for sensing CSI acquisition can be subdivided into J non-overlapping subbands in such a way as follows (where... This allows the channel frequency response at each sub-band to be considered constant, and the appropriate sensing MMSE value for each sub-band can be obtained according to equation (1). The fine-grained allocation of sensing RS resources based on the sub-band sensing MMSE value can be utilized to better satisfy a given maximum MMSE. .

[0138] Conversely, for a wider range of frequencies allocated to the RS for sensing CSI acquisition, a wideband sensing MMSE value can be derived, including the user-allocated bandwidth and / or system bandwidth. The receiver (e.g., WTRU) can be configured to report the wideband sensing MMSE. In some solutions, the wideband sensing MMSE value can be obtained based on the effective SNR, which produces the same MI as the actual channel of the current device, for example, as shown in equation (6). In some examples, the wideband sensing MMSE value can be obtained by means of the derivative of the mutual information of the vector channels generated by considering the channels at J subbands.

[0139] The receiver can be configured to report a single broadband sensed MMSE, which is calculated as the maximum of J individual subband sensed MMSE values, as shown in equation (8) below:

[0140] The receiver can be configured to report a single broadband sensed MMSE value, which is equal to the average of the subband sensed MMSE values, including the arithmetic mean shown in equation (9): This method can be generalized to applications using MMSE replacement by considering the geometric mean, harmonic mean, or any other similar averaging function. The expression in equation (7) that follows.

[0141] Depending on the implementation, other similar methods may also be considered to obtain broadband or subband PMI values ​​based on MMSE values ​​or any other suitable metric.

[0142] A sub-band or wideband precoding matrix for sensing can be obtained for multiple sensing directions, which can be predefined and represent suitable spatial directions for sensing.

[0143] The codebook for the precoding matrix used for sensing can be defined a priori, representing the set of spatial directions used for sensing in one or more sensing beams.

[0144] The codebook may include N precoding matrices (e.g., type) defined for a single layer of sensing transmission. The set of precoding matrices. Each precoding matrix may include complex coefficients to be applied to the antenna ports to generate an N-port sensing transmission signal that is effectively oriented toward the desired spatial direction. Elements of the sensing codebook may be referred to as indices (e.g., sensing PMIs), the selected values ​​of which may be associated with one or more beams by means of appropriate indicators (e.g., CRI values).

[0145] The codebook used for sensing can be based on a codebook defined for communication purposes (e.g., a codebook including a precoding matrix for MIMO transmission) or on a new codebook used for sensing.

[0146] A receiver (e.g., a WTRU) can receive one or more sensing beams. The equalized received signal vector of any of the received beams in the k-th subcarrier can be denoted as... ,in Furthermore, index k operates on the set of subcarriers allocated for sensing. The equalized received signal vector at each point in the received beam can be multiplied by the codebook (e.g., One or more (e.g., all) entries in ) to generate the k-th subcarrier (e.g., The received signals at ( ). From these signals, the receiver can derive one or more precoded vectors in broadband or subband form based on the sensing MMSE criterion or any other criterion for sensing each sensing beam.

[0147] The actual precoding matrix used by the transmitter for sensing may or may not be based on the sensed CSI feedback, which may be used by the transmitter only as non-limiting feedback information. Furthermore, the precoding matrix used for transmission may be unspecified and transparent to the receiver, and may or may not be based on the reported PMI value.

[0148] Methods and procedures for acquiring and reporting sensing CSI information can be implemented, which can be used by a transmitter entity to optimize sensing performance in bistatic or multistatic scenarios.

[0149] A receiver (e.g., a WTRU) may send a message, such as a capability information message, to the TRP upon initial system access. This message may include information about the WTRU's support for sensing CSI measurements and reporting. For example, the message may indicate one or more CSI measurements supported by the WTRU. This message may be sent during initial registration and may be transmitted via uplink control or a shared channel.

[0150] The information included in the capability message may include at least one of the following: (i) the performance metrics supported by bistatic / multistatic sensing, (ii) one or more sensing codebooks supported by the WTRU (e.g., indicated by an index in a predefined table), and / or (iii) the reported sensing CSI measurement. The performance metrics supported by bistatic / multistatic sensing may include at least one of the following: (a) sensing MMSE, (b) SNR, (c) RSRP, (d) RMS error of ranging (or delay) estimation, (e) RMS error of AoA estimation, and / or (f) RMS error of velocity estimation.

[0151] The reported sensed CSI measurements may include at least one of the following: (a) sensed codebook entries for each resource set (e.g., in the form of sensed PMI values ​​(one or more)); (b) values ​​of RSRP, SNR after detection, or both for each sensed codebook entry; (c) sensed MMSE values ​​for each sensed codebook entry; (d) whether subband, wideband, or both reporting modes are supported for any of the above quantities; and / or (e) criteria for reporting wideband measurements based on the obtained subband measurements (e.g., if requested).

[0152] Criteria for reporting broadband measurements based on the obtained subband measurements may include at least one of the following: (A) the maximum, minimum, or average value of the subband values ​​(e.g., arithmetic mean, geometric mean, etc.), (B) broadband values ​​obtained from an equivalent AWGN channel that produces the same error performance as the actual channel (e.g., the same assumption BLER), and / or (C) broadband values ​​obtained from a vector Gaussian channel that takes into account the actual channel response at J subbands.

[0153] The WTRU can be configured, indicated, or identified for measuring and reporting sensed CSI. For example, the WTRU can be configured with information about the spatial characteristics of the sensed beam (e.g., via RRC IE, DCI signaling, MAC CE, etc.). A first set of sensed RSs for sensed CSI acquisition can be used to identify RSs designed to enable sensed CSI measurements via the WTRU, and a second set of sensed RSs will be used to identify RSs designed to enable bistatic or multistatic sensed measurements via the WTRU.

[0154] For example, the WTRU can obtain configuration information about the sensing beams by means of the spatial relationship between the first and second sets of sensing RSs used for sensing CSI acquisition (e.g., as QCL characteristics). Spatial characteristics can specify which channel quantities are likely to be common in the sensing RSs and the RSs used for sensing CSI acquisition (e.g., their delay spread, average delay, Doppler spread, Doppler shift, Rx spatial filter, etc.). These can be, for example, explicitly defined or references to predefined association sets (e.g., in the form of TCI states used for sensing). Different subsets of TCI states can be defined corresponding to beams with different beamwidths, including some with wide beamwidths and others with narrow beamwidths. Narrow beams are more suitable for bistatic and multistatic sensing due to their better angular resolution. In contrast, wide beams are better suited for sensing CSI acquisition by the WTRU over a wider area with potentially multiple scatterers.

[0155] In some examples, the WTRU can obtain configuration information about the physical characteristics of the sensing beam, including angular orientation (such as azimuth and elevation, Euler rotation angle, and / or any other angular measure referenced to an absolute or relative coordinate system) and / or (e.g., in the H, V, or both planes) beamwidth.

[0156] In some examples, the WTRU can be configured to measure and report sensed CSI information using any of the following: RRC IE, DCI signaling, and / or MAC CE. Sensed CSI information can be reported as a set of wideband values ​​or subband values. In the wideband case, the network can be configured with criteria for obtaining the wideband values ​​(e.g., based on maximum, minimum, average, etc.).

[0157] The sensing CSI configuration information may include at least one of the following: (i) a first RS set for sensing CSI acquisition, transmitted in a periodic, aperiodic, or semi-persistent manner; (ii) (one or more) sensing performance metrics and their allowed ranges to select the optimal precoded matrix index in the sensing codebook (e.g., sensing MMSE below a threshold), indicated as absolute or relative values, indexes of predefined tables, etc.; and / or (iii) information regarding sensing CSI reporting.

[0158] The first RS set used for sensing CSI acquisition can be defined by the following: (a) the signal used for sensing CSI measurements (e.g., SSB, CSI-RS, etc.), (b) the number of ports N for each sensing beam, (c) the sensing resource set used for sensing CSI acquisition, specified (e.g., as a list of resource set identifiers, an index of a resource set combination table, etc.), and / or (d) the number of starting REs, RBs, symbols and slots, the comb size and comb offset specified for each resource set, and / or globally specified if no resource set is defined, and the periodicity of the REs in terms of slot number, frame, duration, etc., in the case of periodic or semi-periodic RSs used for sensing CSI acquisition.

[0159] For example, the signal used to sense CSI measurements can be the SSB signal used, although its spatial granularity and periodicity are limited. In some examples, sparse signals used for CSI measurements can be adapted for sensing (e.g., CSI-RS). In some examples, a dedicated RS may be used for measurement.

[0160] For example, the number of ports N for each sensing beam can be equal to the number of entries in the sensing codebook.

[0161] Information regarding the sensing CSI report may include at least one of the following: (A) an indication of whether the sensing CSI report is aperiodic, periodic, or semi-persistent, and periodicity in the latter two cases (e.g., in terms of the number of slots, duration, etc.), and / or (B) an indication of whether broadband or subband reporting of CSI is expected. An indication of whether broadband or subband reporting of CSI is expected may include at least one of the following: (1) the number of subbands J, as an index into a table of values ​​or predefined values; (2) the specified subband size (e.g., as an index into a table of RBs, the number of subcarriers, the frequency range, a table of predefined subband sizes, etc.); and / or (3) criteria used to obtain a broadband performance metric from the subband value set.

[0162] Criteria for obtaining a broadband performance metric from a set of subband values ​​may include at least one of the following: (1) the maximum, minimum, or average value of the J subband values ​​(e.g., arithmetic mean, geometric mean, harmonic mean, etc.), (2) a broadband metric of an equivalent AWGN channel that produces the same error performance as the actual channel (e.g., hypothetical BLER), and / or (3) a broadband metric of a vector Gaussian channel that takes into account the actual channel response at the J subbands.

[0163] Some broadband performance values ​​(e.g., sensed MMSE) can be related to MI (e.g., by equation (1)). An equivalent AWGN channel can be defined to produce the same assumed BLER as the actual channel, thus producing the same MI, in order to derive the broadband MMSE. Broadband values ​​can be established as individual subband values ​​(e.g., arithmetic mean, geometric mean, or harmonic mean). Other similar criteria can be followed to obtain broadband performance.

[0164] The WTRU can receive multiple RSs (e.g., each of which is associated with a configured resource set). For example, the WTRU can receive a first set of RSs for each sensing configuration, such as an SSB, CSI-RS, PRS, dedicated RS for sensing, etc. After receiving the first set of RSs, the WTRU can perform at least one of a number of actions.

[0165] WTRU can obtain the channel response at one or more configured resource sets by, for example, removing known values ​​of RS complex symbols.

[0166] WTRU can remove the effects of channel response by, for example, applying an equalizer to recover the frequency content of the signal, thereby obtaining equalized RS symbols and frequency-dependent detected SNR values ​​at one or more configured resource sets.

[0167] The WTRU can multiply the equalized RS symbol by each of the N precoding matrices in the sensing codebook to produce N frequency-dependent precoded signal vectors.

[0168] The WTRU can determine the sensing performance value for each of the configured resource sets associated with the multiple RSs based on the mutual information (MI) associated with them. For example, in the case of subband reporting by the WTRU, the WTRU can obtain a configured sensing performance value, such as the sensing MMSE, for each precoded signal vector at the configured subband and resource set. For example, a sensing MMSE of twice the derivative of MI with respect to the post-detection SNR can be obtained. The derivative of MI can be approximated, for example, as the ratio of the MI change caused by a measurement change in the post-detection SNR. This approximation can be accurate if, for example, the SNR change exceeds a preconfigured or fixed threshold, and if the threshold is not exceeded, a failure to obtain a sensing MMSE can be reported to the TRP.

[0169] In the case of wideband reporting, the WTRU can obtain a single wideband sensing performance metric for the expected frequency allocation for each precoded signal vector and configured resource set. The performance set and configured resource set can be based on the average of J subband performance values ​​(e.g., arithmetic mean, geometric mean, harmonic mean, etc.). The performance set and configured resource set can also be based on the maximum or minimum of the J subband performance values. Furthermore, the performance set and configured resource set can be based on a performance metric for an effective AWGN channel that will produce the same error performance as the actual channel (e.g., the same assumption BLER). Finally, the performance set and configured resource set can be based on a performance metric for a vector Gaussian channel, derived from the actual channel response considering J subbands.

[0170] The WTRU can compare the obtained performance values ​​with a configuration range for each configuration (e.g., one or more thresholds used to compare their values) and can determine a set of codebook entries (e.g., sensing PMIs) for each sensing resource set that meets certain conditions. These conditions may include PMIs whose sensing performance values ​​are within a specified range (e.g., sensing MMSE is below a threshold) and / or PMIs whose RSRP or post-detection SNR values ​​are above a threshold. Accordingly, the WTRU can determine the set of PMIs for each configured resource set based on the sensing performance values ​​of the configured resource sets.

[0171] The WTRU can send a Sensing CSI report (e.g., via uplink data or control channel). The Sensing CSI report can indicate the sensing performance values ​​for the determined PMI set and each of the configured resource sets. For example, the Sensing CSI report can be in broadband or per subband format, including a set of sensing codebook entries for each resource set whose sensing performance meets the condition set set in previous steps. The Sensing CSI report can include their corresponding post-detection SNR and Sensing MMSE values. The Sensing CSI report can include indications for those resource sets whose sensing codebook entries cannot be obtained due to, for example, low SNR and / or SNR variations that are insufficient to reliably calculate the Sensing MMSE.

[0172] Figure 8 This is a flowchart of an example method 800 for sensing CSI acquisition via a WTRU. Method 800 can be executed by any combination of the WTRU's processor, memory, and transceiver. It should be understood that the example sensing CSI acquisition method 800 may include one or more of the following. At 802, the WTRU may send a capability information message regarding supported sensing CSI measurements. For example, the WTRU may send a message to the network indicating one or more CSI measurements supported by the WTRU (e.g., as described herein).

[0173] At 804, the WTRU can receive configuration information regarding the spatial characteristics of the sensing beam and the measurement and reporting of sensing CSI. For example, the WTRU can be configured to measure and report sensing CSI on a sensing TCI state set, which includes: a first RS set for sensing CSI acquisition, defined by signal type, number of ports, resource set, periodicity, etc.; sensing performance metrics for selecting sensing PMI, such as sensing MMSE, post-detection SNR, RSRP, etc.; and / or information about sensing CSI reporting, such as content, periodicity, wideband / subband reporting mode, etc.

[0174] At 806, the WTRU can receive a first set of RSs for sensing CSI acquisition and can obtain the channel response at said resource set. For example, the WTRU can receive multiple RSs (e.g., each of said multiple RSs can be associated with a configured resource set). The WTRU can receive a first set of RSs for sensing CSI acquisition on one or more resource sets and obtain sensing CSI information via at least one of the following steps: The WTRU can estimate the channel response and obtain equalized RS symbols and their post-detection SNR. The WTRU can multiply the equalized RS symbols with a set of precoded matrices included in the sensing codebook.

[0175] At 808, the WTRU can obtain equalized RS symbols, for example, by removing the effects of the channel and multiplying them by N precoding matrices (e.g., included in the sensing codebook).

[0176] At 810, the WTRU can obtain wideband / subband sensing performance values ​​for each precoded signal vector and resource set. The WTRU can obtain wideband or subband sensing performance values ​​for each precoded vector and resource set, where the wideband value can be obtained from any of the following: the average, maximum, minimum, etc., value of individual subband values; an effective AWGN channel with the same assumed BLER performance as the actual channel; and / or the wideband value corresponding to the vector Gaussian channel obtained from the actual channel response considering the subband. In some examples, the WTRU can determine the sensing performance value of the configured resource set (e.g., each in the configured resource set) associated with the RS based on the MI associated with the RS.

[0177] At 812, the WTRU can determine a set of codebook entries having sensing performance within a specified range and / or sensing MMSE below a threshold. The WTRU can compare the sensing performance values ​​to the specified range (e.g., MMSE below the threshold) and determine a subset of sensing PMI values ​​that satisfy the performance criteria for each resource set. Accordingly, the WTRU can determine the PMI set of the configured resource set based on the sensing performance values ​​of the configured resource set.

[0178] At point 814, the WTRU can send a sensing CSI report for each resource set, including, for example, sensing codebook entries, post-detection SNR, sensing MMSDE, etc. The WTRU can also send a sensing CSI report, including, for example, a subset of the sensing PMI for each resource set (in broadband or per subband form), post-detection SNR, sensing MMSE value, etc.

[0179] At point 816, WTRU can determine whether the stopping condition has been met. If WTRU determines at point 816 that the stopping condition has been met, then method 800 terminates at point 818.

[0180] Alternatively, if the WTRU determines at 816 that the stopping condition has not yet been met, method 800 returns to 806, where the WTRU can receive another set of RSs for sensing CSI acquisition and obtain the channel response at said resource set. The WTRU can repeat the steps of method 800 until the stopping condition is met, such as after an aperiodic CSI report, or when a periodic or semi-periodic sensing CSI report is deactivated via (e.g., MAC CE or DCI).

[0181] Bistatic and multistatic sensing can be achieved. For example, methods and procedures for performing measurements on a second set of sensed RS received from a TRP or a second WTRU via a WTRU for use in bistatic and multistatic sensing.

[0182] WTRU can be configured, indicated, or identified for measuring and reporting one or more bistatic or multistatic sensing measurements.

[0183] The WTRU may obtain configuration information regarding bistatic or multistatic sensing, including at least one of the following: (i) a second set of sensing RS resources for performing bistatic or multistatic measurements transmitted in a periodic, aperiodic, or semi-persistent manner; (ii) information regarding sensing reports; (iii) the ToA of the LOS component between the TRP and the WTRU; and / or (iv) the time interval used to perform the sensing measurements, which is specified as, for example, start and end times or duration (e.g., in the number of time slots, absolute time units, etc.), or a predefined time interval.

[0184] The second sensing RS resource set can be defined as one or more of the following: (a) signals used to perform sensing measurements, including positioning signals (e.g., DL PRS, UL SRS, etc. for positioning) and / or dedicated sensing signals, (b) the number of start REs, RBs, symbols and number of time slots, comb size and comb offset (if any), and / or (c) in the case of periodic and semi-periodic RSs used for sensing, their periodicity in terms of number of time slots, frames, duration, etc.

[0185] Information about the sensing report may include an indication of whether the sensing report is non-periodic, periodic, or semi-persistent, as well as periodicity in the latter two cases (e.g., in terms of the number of time slots, duration, etc.).

[0186] Information in the sensing report can include sensing measurements for each MPC, up to the maximum number of indicated or pre-configured MPCs. For example, the sensing report can include AoA, ToA, RSRP, SNR, RTT, sensing MMSE, sensing MSE, etc.

[0187] Information about the sensing report may include one or more thresholds for successful detection of a scatterer, including at least one of minimum RSRP, minimum SNR, maximum sensing MMSE, maximum sensing MSE, etc.

[0188] Information regarding the sensing report may include an indication of whether the location, velocity, or both of the scatterer detected by the WTRU should be reported.

[0189] The WTRU can receive a subset of active states for sensing, which represents the active beams intended for bistatic / multistatic sensing via the WTRU (e.g., in the form of active TCI states for sensing). The active TCI states for sensing can include a subset of available states for sensing configured for the WTRU (e.g., via RRCIE, DCI signaling, MAC CE, etc.). The subset of active TCI states can be indicated to the WTRU via dynamic signaling (e.g., DCI, MAC CE, etc.).

[0190] Figure 9 A system diagram 900 illustrates an example of bistatic sensing measurements performed by a WTRU, which is assisted by sensing RSs on one or more active TCI states for sensing. The WTRU can be a first WTRU receiving signals from a TRP, or a second WTRU designed to perform bistatic or multistatic sensing measurements. The WTRU can receive a second set of sensing RSs corresponding to one or more active sensing states. The WTRU can perform one or more sensing measurements with the assistance of the second set of sensing RSs on one or more active sensing states, including AoA, ToA, RSRP, RTT, sensing MMSE, sensing MSE, etc., for each MPC or a subset of MPCs (up to a maximum number of MPCs). The WTRU can determine the position, velocity, or both of the identified scatterer based on the sensing measurements configured for each.

[0191] The WTRU can transmit bistatic / multistatic sensing reports via, for example, uplink data or control channels (e.g., PUCCH, PUSCH, etc.). The sensing report can include measurements and estimates of sensing measurements configured for each MPC (up to the maximum number of MPCs). The measurements and estimates can include at least one of the sensing measurements for each active state used for sensing (e.g., active TCI state used for sensing), including ToA, RTT, AoA, RSRP, SNR, etc. The measurements and estimates can include the sensing MSE, sensing MMSE, or both for each active state used for sensing. The measurements and estimates can include the position, velocity, or at least one of the identified scatterers.

[0192] Measurements and estimates can be reported for each MPC or a subset of MPCs (up to the maximum number of MPCs given by the configuration or predefined by the implementation).

[0193] WTRU can avoid reporting sensing measurements performed on any multipath component with high likelihood in LOS conditions (e.g., if its ToA matches the ToA of the LOS component received from the network as part of the configuration).

[0194] Based on configuration, the WTRU can report the location of the identified scatterer, the velocity of the identified scatterer, and / or both based on sensing measurements. The WTRU can report (e.g., only) sensing measurements (e.g., AoA, ToA, sensing MMSE, etc.).

[0195] If the sensing accuracy does not meet the minimum pre-configured or implementation-defined threshold, the WTRU can discard the corresponding measurement and include an indication of, for example, insufficient sensing accuracy in the report.

[0196] The WTRU can repeat the above steps until a stopping condition is met, such as after a non-periodic report and when a periodic or semi-periodic sensing report is deactivated via (e.g., MAC CE or DCI).

[0197] Figure 10 This is a flowchart illustrating an example bistatic / multistatic sensing and reporting method 1000 performed by a WTRU. Method 1000 can be executed by any combination of the WTRU's processor, memory, and transceiver. It should be understood that the example bistatic / multistatic sensing and reporting method 1000 may include one or more of the following.

[0198] At 1002, the WTRU can receive configuration information associated with sensing measurements and / or reporting, including a second RS set, sensing reports, the ToA of the LOS component, and / or time intervals. The WTRU can be configured to measure and report bistatic or multistatic sensing measurements, including a second sensing RS resource set for bistatic or multistatic measurements defined by one of the following: signal type, number of ports, resource set, periodicity, etc.; information about sensing reports, such as their content, periodicity, wideband / subband reporting mode, scatterer detection threshold, etc.; the ToA of the LOS component; and / or the time interval used to perform the sensing measurements.

[0199] At 1004, the WTRU can receive a subset of the activity states for sensing (e.g., the activity TCI states for sensing) indicated, for example, by MAC CE or DCI.

[0200] At 1006, the WTRU can receive a second set of sensing RS on one or more active sensing states and perform sensing measurements.

[0201] At 1008, the WTRU can send bistatic or multistatic sensing reports, including sensing measurements and sensing MMSE for each active sensing state. For example, the WTRU can send bistatic / multistatic sensing reports that include any of the following: the measured quantity, position and / or velocity, sensing MSE, sensing MMSE, or both, for each MPC or for a subset of MPCs (up to the maximum number of MPCs), and / or an indication of whether the sensing accuracy meets a pre-configured threshold.

[0202] At 1010, the WTRU can determine whether the stopping condition is met. If the WTRU determines at 1010 that the stopping condition has been met, method 1000 terminates in step 1012. Alternatively or additionally, if the WTRU determines at 1010 that the stopping condition has not been met, method 1000 returns to step 1004, where the WTRU receives a subset of the sensing activity states (e.g., sensing activity TCI states) indicated, for example, by MAC CE or DCI.

[0203] The WRU can evaluate appropriate metrics for sensing CSI information. The WRU can propose criteria to determine the optimal spatial orientation for the best possible sensing accuracy. The WRU can implement procedures for measuring and reporting sensing CSI. The WRU can implement bistatic and multistatic sensing procedures based on sensing CSI information.

[0204] The spatial orientation used for sensing can be discretized in the codebook of the precoded matrix used for sensing. During the sensing CSI acquisition and reporting phase, as part of the sensing PMI feedback, the WTRU can select and report codebook entries representing the orientation with the best possible sensing accuracy by means of a first RS for sensing CSI acquisition, which can be transmitted in periodic, aperiodic, or semi-periodic modes. The reported sensing PMI value can refer to one or more sensing beams in the set of available TCI states configured for sensing. The WTRU can evaluate sensing performance for different codebook entries based on specific performance criteria (e.g., sensing MMSE), and report the sensing PMI in periodic, aperiodic, or semi-periodic modes from said specific performance criteria until a stopping criterion is met.

[0205] During the sensing phase, the WTRU can be configured with a subset of active TCI states for sensing, which can be dynamically activated via, for example, MAC CE or DCI. A second RS for sensing can be received by the WTRU for bistatic / multistatic measurements of the configured subset of active TCI states. Sensing reports can be transmitted by the WTRU in periodic, aperiodic, or semi-persistent modes, including the position / velocity information of the sensed measurements or scatterer, until a stopping criterion is met.

Claims

1. A wireless transceiver unit (WTRU), comprising: The processor is configured as follows: Send a message to the network, the message indicating one or more Channel State Information (CSI) measurements supported by WTRU; Receive multiple reference signals (RS), wherein the multiple RS are associated with multiple configured resource sets; Based on the mutual information (MI) associated with the plurality of RSs, determine the corresponding sensing performance value for each of the configured resource sets associated with the plurality of RSs; Based on the corresponding sensing performance value of each in the configured resource set, determine the corresponding precoding matrix indicator (PMI) set for each in the configured resource set; and Send a sensing report, which indicates the corresponding PMI set and corresponding sensing performance value for each corresponding configured resource set in the configured resource set.

2. The WTRU of claim 1, wherein the processor is further configured to: Receive configuration information including the spatial characteristics of the plurality of RSs.

3. The WTRU of claim 1, wherein the PMI set is determined based on the sensing performance values ​​of each corresponding configured resource set within a predetermined range.

4. The WTRU of claim 1, wherein the message includes an indication of: 1) a performance metric supported by bistatic or multistatic sensing, or 2) a sensing codebook supported by the WTRU.

5. The WTRU of claim 4, wherein the supported performance metrics for bistatic or multistatic sensing include any one of the following: minimum mean square error (MMSE), signal-to-noise ratio (SNR), reference signal received power (RSRP), root mean square (RMS) error of ranging estimation, RMS error of angle of arrival (AoA) estimation, RMS error of phase estimation, or RMS error of velocity estimation.

6. The WTRU of claim 1, wherein the sensing performance values ​​include a minimum mean square error (MMSE) value below a threshold.

7. The WTRU of claim 1, wherein the sensing performance values ​​include mean square error (MSE) values ​​below a threshold.

8. The WTRU of claim 1, wherein MI is a measure characterizing the amount of information carried by each channel associated with the configured resource set.

9. The WTRU of claim 1, wherein the sensing report includes a sensing codebook index for each Channel State Information (CSI) RS Resource Indicator (CRI).

10. The WTRU of claim 1, wherein the sensing performance value of the configured resource set indicates a statistical error associated with a sensing metric measured for the configured resource set.

11. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: Send a message to the network, the message indicating one or more Channel State Information (CSI) measurements supported by WTRU; Receive multiple reference signals (RS), wherein the multiple RS are associated with multiple configured resource sets; Based on the mutual information (MI) associated with the plurality of RSs, determine the corresponding sensing performance value for each of the configured resource sets associated with the plurality of RSs; Based on the corresponding sensing performance value of each in the configured resource set, determine the corresponding precoding matrix indicator (PMI) set for each in the configured resource set; and Send a sensing report, which indicates the corresponding PMI set and corresponding sensing performance value for each corresponding configured resource set in the configured resource set.

12. The method of claim 11, further comprising: Receive configuration information including the spatial characteristics of the plurality of RSs.

13. The method of claim 11, wherein the PMI set is determined based on the sensing performance values ​​of each corresponding configured resource set within a predetermined range.

14. The method of claim 11, wherein the message includes an indication of: 1) a supported performance metric for bistatic or multistatic sensing, or 2) a sensing codebook supported by the WTRU.

15. The method of claim 14, wherein the supported performance metrics for bistatic or multistatic sensing include any one of the following: minimum mean square error (MMSE), signal-to-noise ratio (SNR), reference signal received power (RSRP), root mean square (RMS) error of ranging estimation, RMS error of angle of arrival (AoA) estimation, RMS error of phase estimation, or RMS error of velocity estimation.

16. The method of claim 11, wherein the sensing performance value includes a minimum mean square error (MMSE) value below a threshold.

17. The method of claim 11, wherein the sensing performance value includes a mean square error (MSE) value below a threshold.

18. The method of claim 11, wherein MI is a measure characterizing the amount of information carried by each channel associated with the configured resource set.

19. The method of claim 11, wherein the sensing report includes a sensing codebook index for each Channel State Information (CSI) RS Resource Indicator (CRI).

20. The method of claim 11, wherein the sensing performance value of the configured resource set indicates a statistical error associated with a sensing metric measured for the configured resource set.

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