Method, apparatus and system for low power mode user equipment localization

Abstract

Aspects of the present application relate to configuring a target user equipment, in a manner that takes into account various power or energy modes (e.g., conventional power, low power, very low power) of the target user equipment, altering the input positioning signal with minimal baseband processing or without baseband processing. By configuring the target user equipment prior to entering one of multiple low power modes, various aspects of the present application may benefit from operating in the context of the target user equipment that is not in a connected state. Through proper configuration of the positioning signal, parameters reported by the anchor node to the position acquisition node can enable the position acquisition node to acquire the position of the target user equipment, even if the target user equipment is in one of a plurality of low-power modes.

Description

Technical Field

[0001] The present application relates generally to user equipment positioning, and in particular embodiments, to positioning of user equipment in a low power mode. Background Art

[0002] The energy efficiency of wireless communication systems has improved in recent years. Therefore, it is expected that the design of future wireless communication systems will aim to improve the overall energy efficiency of terminals and infrastructure while meeting strict connectivity constraints. The design of such future wireless communication systems may include energy-aware schemes and may introduce new operation modes, such as several degrees of low-power operation modes. Summary of the invention

[0003] Various aspects of the present application involve configuring a target user equipment (UE) by changing an input positioning signal with minimal baseband processing or without baseband processing in a manner that takes into account various power / energy modes (conventional power, low power, and extremely low power) of the target UE. It should be noted that various power / energy modes are expected to dominate future wireless communication systems. By configuring the target UE before entering one of multiple low power modes, various aspects of the present application can benefit from operating in the context of a target UE that is not in a connected state. Through appropriate configuration of the positioning signal, the parameters reported by the anchor node to the location acquisition node can enable the location acquisition node to obtain the location of the target UE, even if the target UE is in one of multiple low power modes. It should be noted that the location acquisition node can be implemented as a location management function (LMF) or a sensing management function (SMF).

[0004] Traditional positioning procedures may require baseband signal processing. Baseband signal processing may involve the use of high-power devices such as analog-to-digital converters. Such use of high-power devices may increase the energy required to collect and process measurements at devices used to perform or assist with traditional positioning procedures. In addition, traditional positioning procedures may use computationally intensive operations at these devices.

[0005] Traditional positioning procedures can use a small number of anchor nodes with fixed positions to provide positioning reference signals (PRS). This traditional method may result in a relatively large average distance between the anchor node and the target user UE. The relatively large average distance may directly result in a relatively large average power required to receive the PRS at the target UE. Using multiple devices may directly increase the average energy and power required for traditional positioning procedures.

[0006] Conventional positioning procedures may also use a relatively high level of synchronization between all terminals (anchor nodes and / or target UEs) to achieve acceptable positioning accuracy. A relatively high level of synchronization may incur overhead and latency in conventional positioning procedures. Overhead and latency may implicitly increase the overall energy consumption used to obtain accurate location information.

[0007] As is well known, a disadvantage of the conventional positioning process is that it is developed for the purpose of obtaining the position of the target UE with conventional energy consumption and through conventional power transmission when the target UE is in a connected state.

[0008] By configuring the target UE before entering one of a plurality of low power modes, various aspects of the present application can obtain the location of the target UE that is not in a connected state. By configuring the target UE to change the incoming positioning signal with minimal or no baseband processing, various aspects of the present application can obtain the location of the target UE when the target UE is in one of a plurality of power / energy modes.

[0009] According to one aspect of the present application, a method for obtaining the position of a target UE is provided. The method includes: before the target UE enters a low power mode, sending configuration information of a first positioning signal to the target UE. The method optionally includes: sending an indication to a network node that the network node has been assigned as an anchor node for the target UE. The method also includes: sending the configuration information of the first positioning signal to the network anchor node. The method also includes: receiving an indication of multiple parameters from the network anchor node, wherein the multiple parameters are obtained by the network anchor node from a second positioning signal, and the second positioning signal is received from the target UE at the network anchor node. The second positioning signal is based on the first positioning signal. The method also includes: obtaining the location information of the target UE from the multiple parameters.

[0010] According to one aspect of the present application, a method for facilitating acquisition of the location of a target UE is provided. The method may optionally include: initially receiving an indication at a network node that the network node has been assigned as an anchor node for the target UE. The method includes: receiving configuration information at the network anchor node. The method also includes: receiving a second positioning signal at the network anchor node, wherein the second positioning signal corresponds to a first positioning signal changed by the target UE, wherein the first positioning signal has been defined in the configuration information. The method also includes: acquiring a plurality of parameters from the second positioning signal at the network anchor node. The method also includes: sending an indication of the plurality of parameters from the network anchor node to a position acquisition node.

[0011] According to one aspect of the present application, a method for facilitating acquisition of the position of a target UE is provided. The method comprises: receiving configuration information of a positioning signal at the target UE; receiving a first positioning signal at the target UE according to the configuration information; changing the first positioning signal at the target UE to generate a second positioning signal; and sending the second positioning signal at the target UE.

[0012] According to other aspects of the present application, a device, a processor of the device, and a computer program product for being executed by the device are provided, wherein the device executes any one of the above methods.

[0013] According to another aspect of the present application, a system is provided, comprising a first network node for acquiring a location of a target user equipment and a second network node communicating with the first network node. The first network node is used to send configuration information of a first positioning signal, and receive multiple parameters acquired from a second positioning signal according to the first positioning signal, so as to acquire the location information of the target UE from the multiple parameters. The second network node is used to receive the second positioning signal from the target UE, and send an indication of the multiple parameters acquired from the second positioning signal to the first network node, wherein the second positioning signal corresponds to the first positioning signal changed by the target UE. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more fully understand the embodiments of the present invention and its advantages, the following description is made by way of example with reference to the accompanying drawings, in which:

[0015] Figure 1 A communication system is shown in the schematic diagram, in which the embodiments of the present invention may be implemented, and the communication system includes: a plurality of exemplary electronic devices and a plurality of exemplary transmission reception points and various networks;

[0016] Figure 2 The block diagram shows Figure 1 A communication system, the communication system comprising: a plurality of exemplary electronic devices, exemplary ground transmission reception points and exemplary non-ground transmission reception points and various networks;

[0017] Figure 3 As a block diagram, it shows the various aspects of the present application. Figure 2 Elements of an exemplary electronic device of Figure 2 Elements of an exemplary ground transmission receiving point and Figure 2 Elements of an exemplary non-terrestrial transmission reception point;

[0018] Figure 4As a block diagram, various modules that may be included in an exemplary electronic device, an exemplary ground transmission and reception point, and an exemplary non-ground transmission and reception point according to various aspects of the present application are shown;

[0019] Figure 5 As a block diagram, a sensing management function according to various aspects of the present application is shown;

[0020] Figure 6 The present invention shows a signal in a positioning process for a target UE in the context of multiple terminals according to various aspects of the present application, including Figure 5 A sensing management function, a positioning signal transmission / reception anchor (TX / RX-AN) node and multiple positioning signal reception (RX-AN) nodes;

[0021] Figure 7 It is shown that according to various aspects of the present application Figure 5 Exemplary steps in a method for orchestrating a positioning process at a sensing management function;

[0022] Figure 8 It is shown that according to various aspects of the present application Figure 6 Exemplary steps in a method for performing a positioning process at a TX / RX-AN node;

[0023] Fig. 9 It is shown that according to various aspects of the present application Figure 6 Exemplary steps in a method for performing a positioning procedure at a target UE;

[0024] Fig.10 It is shown that according to various aspects of the present application Figure 6 Exemplary steps in a method for performing a positioning procedure at one of the RX-AN nodes of the embodiment of the present invention;

[0025] Fig.11 It shows that according to various aspects of the present application Figure 6 The target UE may include a matched filter;

[0026] Fig.12 It is shown that a TX-AN node transmits a first positioning signal according to various aspects of the present application, and the first positioning signal is changed by a target UE into a second positioning signal received by a RX-AN node;

[0027] Fig.13A The TX-AN node according to various aspects of the present application transmits a first positioning signal received by the RX-AN node;

[0028] Fig. 13B It is shown that a TX-AN node transmits a first positioning signal according to various aspects of the present application, and the first positioning signal is changed by a target UE into a second positioning signal received by a RX-AN node;

[0029] Fig. 13C An ellipse according to various aspects of the present application is shown, wherein a focus is located at Fig.13A The other focus is located at the TX-AN node. Fig.13A At the RX-AN node location;

[0030] Fig.14 It is shown that according to various aspects of the present application, Fig.13A The RX-AN node uses the first matched filter and can be composed of Fig.13A A second matched filter used by the RX-AN node;

[0031] Fig.15A The TX-AN node according to various aspects of the present application transmits a first positioning signal, which is changed by the target UE into a second positioning signal received by each of the RX-AN node pair;

[0032] Fig. 15B A hyperbola according to various aspects of the present application is shown, wherein a focus is located at Fig.15A At the location of each of the RX-AN node pairs;

[0033] Fig.16 It is shown that a TX-AN node transmits a first positioning signal according to various aspects of the present application, and the first positioning signal is changed by a target UE into a second positioning signal received by a RX-AN node;

[0034] Fig.17 A resource grid defined by frequency slots and time slots according to various aspects of the present application is shown, so that Figure 5 The sensing management function is capable of allocating resources to sensing of a target UE in a specific low power mode among a plurality of low power modes;

[0035] Fig.18 A strategy for enhancing distinguishability of received chirp-based positioning signals by configuring transmission of the chirp-based positioning signals to be performed using different chirp rates according to various aspects of the present application is shown;

[0036] Fig.19 A resource grid defined by frequency slots and time slots is shown, wherein a given time / frequency resource may have a chirp-based positioning signal defined to use one chirp rate or multiple chirp rates in accordance with various aspects of the present application;

[0037] Fig. 20 The signal flow diagram shows the various aspects of the present application. Figure 5 The communication between the sensing management function, TX-AN node, RX-AN node and UE. DETAILED DESCRIPTION

[0038] For illustrative purposes, specific exemplary embodiments will be explained in greater detail below with reference to the accompanying drawings.

[0039] The embodiments set forth herein represent information sufficient to practice the claimed subject matter and illustrate methods of practicing such subject matter. After reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the claimed subject matter and will recognize that the application of these concepts is not specifically mentioned herein. It should be understood that these concepts and applications are within the scope of the present invention and the appended claims.

[0040] In addition, it should be understood that any module, component or device disclosed herein for executing instructions may include or otherwise access one or more non-transitory computer / processor readable storage media for storing information, such as computer / processor readable instructions, data structures, program modules and / or other data. A non-exhaustive list of examples of non-transitory computer / processor readable storage media includes magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, compact disc read-only memory (CD-ROM), digital video disc or digital versatile disc (DVD), Blu-ray disc TM Optical disks, or other optical storage, volatile and non-volatile, removable and non-removable media implemented in any method or technology, random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology. Any of these non-transitory computer / processor storage media can be part of a device or can be accessed or connected by a device. Computer / processor readable / executable instructions for implementing the applications or modules described herein can be stored or otherwise saved by such non-transitory computer / processor readable storage media.

[0041] refer to Figure 1, a simplified schematic diagram of a communication system is provided as an illustrative example but not limiting. The communication system 100 includes a radio access network 120. The radio access network 120 may be a next generation (e.g., sixth generation (6G) or higher) radio access network, or a conventional (e.g., 5G, 4G, 3G, or 2G) radio access network. One or more communication electronic devices (electric devices, ED) 110a, 110b, 110c, 110d, 110e, 110f, 110g, 110h, 110i, 110j (generally referred to as 110) may be interconnected with each other or connected to one or more network nodes (170a and 170b, generally referred to as 170) in the radio access network 120. The core network 130 may be part of the communication system and may be dependent on or independent of the radio access technology used in the communication system 100. In addition, the communication system 100 includes a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160.

[0042] Figure 2 An exemplary communication system 100 is shown. In general, the communication system 100 enables multiple wireless or wired elements to send data and other content. The purpose of the communication system 100 can be to provide content such as voice, data, video and / or text through broadcast, multicast and unicast, etc. The communication system 100 can be operated by sharing resources such as carrier spectrum bandwidth between its constituent elements. The communication system 100 may include a ground communication system and / or a non-ground communication system. The communication system 100 can provide a wide range of communication services and applications (such as earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery and mobility). The communication system 100 can provide a high degree of availability and robustness through the joint operation of the ground communication system and the non-ground communication system. For example, integrating a non-ground communication system (or its components) into a ground communication system can produce a heterogeneous network including multiple layers. Compared with traditional communication networks, heterogeneous networks can achieve better overall performance through efficient multi-link joint operation, more flexible function sharing, and faster physical layer link switching between ground networks and non-ground networks.

[0043] Terrestrial communication systems and non-terrestrial communication systems can be considered as subsystems of the communication system. Figure 2In the example shown, the communication system 100 includes electronic devices (EDs) 110a, 110b, 110c, 110d (generally referred to as ED 110), radio access networks (RANs) 120a and 120b, non-terrestrial communication networks 120c, core networks 130, public switched telephone networks (PSTNs) 140, the Internet 150, and other networks 160. The RANs 120a and 120b include corresponding base stations (BSs) 170a and 170b, which may be generally referred to as terrestrial transmit and receive points (T-TRPs) 170a and 170b. The non-terrestrial communication network 120c includes an access node 172, which may be generally referred to as a non-terrestrial transmit and receive point (NT-TRP) 172.

[0044] Alternatively or in addition, any ED 110 may be used to connect, access or communicate with any T-TRP 170a, T-TRP 170b and NT-TRP 172, the Internet 150, the core network 130, the PSTN 140, other networks 160, or any combination of the foregoing. In some examples, ED 110a may communicate with T-TRP 170a for uplink and / or downlink transmissions via a ground air interface 190a. In some examples, ED 110a, ED 110b, ED 110c, and ED 110d may also communicate directly with each other via one or more sidelink air interfaces 190b. In some examples, ED 110d may communicate with NT-TRP 172 for uplink and / or downlink transmissions via a non-ground air interface 190c.

[0045] The air interfaces 190a and 190b may use similar communication technologies, such as any applicable wireless access technology. For example, the communication system 100 may implement one or more channel access methods in the air interfaces 190a and 190b, such as code division multiple access (CDMA), space division multiple access (SDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or direct Fourier transform spread OFDMA (DFT-OFDMA). The air interfaces 190a and 190b may utilize other higher dimensional signal spaces, which may involve a combination of orthogonal and / or non-orthogonal dimensions.

[0046] The non-terrestrial air interface 190c can enable communication between ED 110d and one or more NT-TRPs 172 via a wireless link or a simple link. In some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of EDs 110 and one or more NT-TRPs 175 for multicast transmission.

[0047] The RAN 120a and RAN 120b communicate with the core network 130 to provide various services, such as voice, data, and other services to the ED 110a, ED 110b, and ED 110c. The RAN 120a and RAN 120b and / or the core network 130 may communicate directly or indirectly with one or more other RANs (not shown), which may or may not be directly served by the core network 130 and may or may not use the same radio access technology as the RAN 120a and / or RAN 120b. The core network 130 may also serve as a gateway access between (i) the RAN 120a and RAN 120b and / or the ED 110a, ED 110b, and ED 110c and (ii) other networks (e.g., the PSTN 140, the Internet 150, and other networks 160). In addition, some or all of ED 110a, ED 110b, and ED 110c may include functionality to communicate with different wireless networks over different wireless links using different wireless technologies and / or protocols. ED 110a, ED 110b, and ED 110c may communicate with a service provider or switch (not shown) and with the Internet 150 over a wired communication channel instead of wirelessly (or in addition to wirelessly). PSTN 140 may include a circuit-switched telephone network for providing plain old telephone service (POTS). Internet 150 may include a network of computers and / or subnets (intranets) and incorporate protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), etc. ED 110a, ED 110b, and ED 110c may be multi-mode devices capable of operating according to a variety of wireless access technologies and may include multiple transceivers required to support these technologies.

[0048] Figure 3Another example of ED 110 and base stations 170a, 170b and / or 170c is shown. ED 110 is used to connect people, objects, machines, etc. ED 110 can be widely used in various scenarios, such as cellular communication, device-to-device (D2D), vehicle to everything (V2X), peer-to-peer (P2P), machine-to-machine (M2M), machine-type communications (MTC), Internet of Things (IOT), virtual reality (VR), augmented reality (AR), mixed reality (MR), metaverse, digital twin, industrial control, unmanned driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drone, robot, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and mobility.

[0049] Each ED 110 represents any suitable end-user device for wireless operation, and may include (or may be referred to as): user equipment / device (UE), wireless transmit / receive unit (WTRU), mobile station, fixed or mobile user unit, cellular phone, station (STA), machine type communication (MTC) equipment, personal digital assistant (PDA), smart phone, laptop, computer, tablet, wireless sensor, consumer electronic device, watch, head-mounted device, glasses and other wearable devices, smart book, vehicle, car, truck, bus, train or IoT device, industrial equipment, or devices in the above devices (such as communication module, modem or chip), etc. The next generation ED 110 may be referred to using other terms. Base stations 170a and 170b are T-TRPs, hereinafter referred to as T-TRP 170. Also in Figure 3 , NT-TRP is hereinafter referred to as NT-TRP 172. Each ED 110 connected to T-TRP 170 and / or NT-TRP 172 can be dynamically or semi-statically opened (i.e., established, activated or enabled), closed (i.e., released, deactivated or disabled) and / or used in response to one or more of the following: connection availability and connection necessity.

[0050] ED 110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is shown. Alternatively, one, some or all of the antennas 204 can be panels. Transmitter 201 and receiver 203 can, for example, be integrated into a transceiver. The transceiver is used to modulate data or other content for transmission by at least one antenna 204 or through a network interface controller (NIC). The transceiver can also be used to demodulate data or other content received by at least one antenna 204. Each transceiver includes: any suitable structure for generating signals for wireless or wired transmission and / or for processing signals received by wireless or wired means. Each antenna 204 includes: any suitable structure for sending and / or receiving wireless signals or wired signals.

[0051] ED 110 includes at least one memory 208. Memory 208 stores instructions and data used, generated, or collected by ED 110. For example, memory 208 may store software instructions or modules that are used to implement some or all of the functions and / or embodiments described herein and are executed by one or more processing units (e.g., processor 210). Each memory 208 includes any suitable one or more volatile and / or non-volatile storage and retrieval devices. Any suitable type of memory may be used, for example, random-access memory (RAM), read-only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, processor cache.

[0052] ED 110 may also include one or more input / output devices (not shown) or interfaces (e.g., Figure 1 The input / output devices support interaction with users or other devices in the network. Each input / output device includes any suitable structure for providing information to or receiving information from a user, for example, by operating as: a speaker, microphone, keypad, keyboard, display or touch screen, including network interface communications.

[0053] ED 110 includes a processor 210 for performing various operations, including operations related to preparing transmissions for uplink transmission to NT-TRP 172 and / or T-TRP 170, operations related to processing downlink transmissions received from NT-TRP 172 and / or T-TRP 170, and operations related to processing sidelink transmissions to and from another ED 110. Processing operations related to preparing transmissions for uplink transmissions may include operations such as encoding, modulation, transmit beamforming, and generating symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receive beamforming, demodulation, and decoding received symbols. According to an embodiment, the downlink transmission may be received by receiver 203, possibly using receive beamforming, and processor 210 may extract signaling from the downlink transmission (e.g., by detecting and / or decoding the signaling). An example of signaling may be a reference signal sent by NT-TRP 172 and / or by T-TRP 170. In some embodiments, the processor 210 implements transmit beamforming and / or receive beamforming according to an indication of a beam direction, such as beam angle information (BAI), received from the T-TRP 170. In some embodiments, the processor 210 may perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as operations related to detecting a synchronization sequence, decoding, and obtaining system information. In some embodiments, the processor 210 may perform channel estimation, for example, using a reference signal received from the NT-TRP 172 and / or from the T-TRP 170.

[0054] The processor 210 may be a part of the transmitter 201 and / or a part of the receiver 203, but is not shown in the figure. The memory 208 may be a part of the processor 210, but is not shown in the figure.

[0055] The processor 210, the processing components of the transmitter 201, and the processing components of the receiver 203 may be implemented by the same processor or different processors in one or more processors, and the one or more processors are used to execute instructions stored in a memory (e.g., memory 208). Alternatively, some or all of the processor 210, the processing components of the transmitter 201, and the processing components of the receiver 203 may be implemented using a programmed field-programmable gate array (FPGA), a central processing unit (CPU), a graphic processing unit (GPU), or an application-specific integrated circuit (ASIC) or other dedicated circuit.

[0056] In some implementations, T-TRP 170 may be referred to by other names: base station, base transceiver station (BTS), wireless base station, network node, network device, network side device, transmitting / receiving node, node B, evolved NodeB (eNodeB or eNB), home base station, next generation base station (gNB), transmission point (TP), site controller, access point (AP), wireless router, relay station, remote radio head, ground node, ground network device, ground base station, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distribution unit (DU), positioning node, etc. T-TRP 170 may be a macro BS, a micro BS, a relay node, a host node, etc., or a combination thereof. T-TRP 170 may refer to the aforementioned device, or may refer to a device in the aforementioned device (eg, a communication module, a modem, or a chip).

[0057] In some embodiments, various parts of T-TRP 170 may be distributed. For example, some modules of T-TRP 170 may be located away from the device that houses antenna 256 of T-TRP 170, and may be coupled to the device that houses antenna 256 through a communication link (not shown) sometimes referred to as a fronthaul, such as a common public radio interface (CPRI). Therefore, in some embodiments, the term T-TRP 170 may also refer to a module that performs processing operations such as ED 110 location determination, resource allocation (scheduling), message generation, and encoding / decoding on the network side, and these modules are not necessarily part of the device that houses antenna 256 of T-TRP 170. These modules may also be coupled to other T-TRPs. In some embodiments, T-TRP 170 may actually be multiple T-TRPs that operate together to serve ED 110 by using coordinated multi-point transmission or the like.

[0058] like Figure 3As shown, T-TRP 170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is shown. Alternatively, one, some or all of the antennas 256 may be panels. Transmitter 252 and receiver 254 may be integrated as a transceiver. T-TRP 170 also includes a processor 260 for performing various operations, including operations related to preparing transmissions for downlink transmission to ED 110, processing uplink transmissions received from ED 110, preparing transmissions for backhaul transmission to NT-TRP 172, and processing transmissions received from NT-TRP 172 via backhaul. Processing operations related to preparing transmissions for downlink transmission or backhaul transmission may include operations such as coding, modulation, precoding (e.g., multiple input multiple output (MIMO) precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received uplink transmissions or transmissions received through backhaul may include operations such as receive beamforming, demodulating received symbols, and decoding received symbols. Processor 260 may also perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as generating the content of a synchronization signal block (SSB) and generating system information. In some embodiments, processor 260 also generates an indication of a beam direction, such as a BAI, which may be scheduled for transmission by scheduler 253. Processor 260 performs other network-side processing operations described herein, such as determining the location of ED 110 and determining the location of deploying NT-TRP 172. In some embodiments, processor 260 may generate, for example, signaling for configuring one or more parameters of ED110 and / or one or more parameters of NT-TRP 172. Any signaling generated by processor 260 is sent by transmitter 252. It should be noted that, alternatively, "signaling" used in this article may be referred to as control signaling. Dynamic signaling can be sent in a control channel such as a physical downlink control channel (PDCCH), and static or semi-static high-layer signaling can be included in a message sent in a data channel such as a physical downlink shared channel (PDSCH).

[0059] The scheduler 253 may be coupled to the processor 260. The scheduler 253 may be included in the T-TRP 170 or may operate separately from the T-TRP 170. The scheduler 253 may schedule uplink, downlink, and / or backhaul transmissions, including issuing scheduling grants and / or configuring unscheduled (“configured grants”) resources. The T-TRP 170 also includes a memory 258 for storing information and data. The memory 258 stores instructions and data used, generated, or collected by the T-TRP 170. For example, the memory 258 may store software instructions or modules that are used to implement some or all of the functionality and / or embodiments described herein and are executed by the processor 260.

[0060] Processor 260 may be part of transmitter 252 and / or part of receiver 254, but is not shown. Similarly, processor 260 may implement scheduler 253, but is not shown. Memory 258 may be part of processor 260, but is not shown.

[0061] The processor 260, the scheduler 253, the processing components of the transmitter 252, and the processing components of the receiver 254 may be implemented by the same processor or different processors in one or more processors, and the one or more processors are used to execute instructions stored in a memory (e.g., the memory 258). Alternatively, some or all of the processor 260, the scheduler 253, the processing components of the transmitter 252, and the processing components of the receiver 254 may be implemented using a dedicated circuit such as an FPGA, a CPU, a GPU, or an ASIC.

[0062] It should be noted that the NT-TRP 172 is shown as a drone only as an example, but the NT-TRP 172 can be implemented in any suitable non-ground form, such as a high-altitude platform, a satellite, a high-altitude platform as an international mobile communication base station, and an unmanned aerial vehicle, which will be discussed below. In addition, the NT-TRP 172 may use other names in some implementations, such as a non-ground node, a non-ground network device, or a non-ground base station. The NT-TRP 172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is shown. Alternatively, one, part, or all of the antennas can be panels. The transmitter 272 and the receiver 274 can be integrated into a transceiver. NT-TRP 172 also includes a processor 276 for performing operations, including operations related to preparing transmissions for downlink transmission to ED 110, processing uplink transmissions received from ED 110, preparing transmissions for backhaul transmission to T-TRP 170, and processing transmissions received from T-TRP 170 via backhaul. Processing operations related to preparing transmissions for downlink transmission or backhaul transmission may include operations such as encoding, modulation, precoding (e.g., MIMO precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to processing received uplink transmissions or transmissions received via backhaul may include operations such as receive beamforming, demodulating received signals, and decoding received symbols. In some embodiments, processor 276 implements transmit beamforming and / or receive beamforming based on beam direction information (e.g., BAI) received from T-TRP 170. In some embodiments, processor 276 may generate signaling, such as for configuring one or more parameters of ED 110. In some embodiments, NT-TRP 172 implements physical layer processing but does not implement higher layer functions such as functions of the medium access control (MAC) or radio link control (RLC) layers. Since this is only an example, in general, NT-TRP 172 may implement higher layer functions in addition to physical layer processing.

[0063] NT-TRP 172 also includes a memory 278 for storing information and data. Processor 276 may be part of transmitter 272 and / or part of receiver 274, but is not shown. Memory 278 may be part of processor 276, but is not shown.

[0064] The processor 276, the processing components of the transmitter 272, and the processing components of the receiver 274 can be implemented by the same processor or different processors in one or more processors, and the one or more processors are used to execute instructions stored in a memory (e.g., memory 278). Alternatively, some or all of the processor 276, the processing components of the transmitter 272, and the processing components of the receiver 274 can be implemented using a programmed FPGA, CPU, GPU, or ASIC or other dedicated circuit. In some embodiments, the NT-TRP 172 can actually be a plurality of NT-TRPs that operate together to serve the ED 110 through coordinated multi-point transmission or the like.

[0065] The T-TRP 170, NT-TRP 172, and / or ED 110 may include other components, but these components have been omitted for clarity.

[0066] One or more steps of the example methods provided herein may be performed by Figure 4 The corresponding unit or module provided is executed. Figure 4 Units or modules in devices such as ED 110, T-TRP 170, or NT-TRP 172 are shown. For example, a signal can be sent by a sending unit or a sending module. The signal can be received by a receiving unit or a receiving module. The signal can be processed by a processing unit or a processing module. Other steps can be performed by artificial intelligence (AI) or machine learning (ML) modules. The corresponding units or modules can be implemented using hardware, one or more components or devices that execute software, or a combination thereof. For example, one or more of these units or modules can be integrated circuits, such as programmed FPGAs, CPUs, GPUs, or ASICs. It should be understood that if these modules are implemented by (for example) a processor using software for execution, these modules can be retrieved by the processor in whole or in part as needed, retrieved individually or collectively for processing, retrieved in one or more instances, and these modules themselves may include instructions for further deployment and instantiation.

[0067] Other details about ED 110, T-TRP 170 and NT-TRP 172 are known to those skilled in the art. Therefore, these details are omitted here.

[0068] In cellular communication networks, UE location information is often used to improve various performance indicators of the network. For example, these performance indicators can include capacity, agility, and efficiency. Improvements can be achieved when network elements utilize the UE's location, behavior, mobility patterns, etc. in the context of prior information describing the wireless environment in which the UE operates.

[0069] The sensing system can be used to help collect UE posture information, including the UE's position in the global coordinate system, the UE speed and the direction of movement in the global coordinate system, the orientation information, and information about the wireless environment. "Location" is also called "position", and the two terms can be used interchangeably in this article. Examples of well-known sensing systems include radar (wireless detection and ranging) and lidar (light detection and ranging). Although sensing systems are typically separated from communication systems, it may be advantageous to collect information using an integrated system, which reduces the hardware (and cost) in the system and the time, frequency, or space resources required to perform both functions. However, using communication system hardware to perform sensing of UE posture and environmental information is a very challenging and open problem. The difficulty of this problem is related to factors such as the limited resolution of the communication system, the dynamics of the environment, and the large number of objects whose electromagnetic properties and positions need to be estimated.

[0070] Therefore, integrated sensing and communication (also called integrated communication and sensing) is a desirable feature in existing and future communication systems.

[0071] Any or all of ED 110 and BS 170 may be sensing nodes in system 100. A sensing node is a network entity that performs sensing by sending and receiving sensing signals. Some sensing nodes are communication devices that perform both communication and sensing. However, some sensing nodes may not perform communication but are instead dedicated to sensing. Sensing agent 174 is an example of a sensing node dedicated to sensing. Unlike ED 110 and BS 170, sensing agent 174 does not send or receive communication signals. However, sensing agent 174 may send configuration information, sensing information, signaling information, or other information within communication system 100. Sensing agent 174 may communicate with core network 130 to communicate information with the rest of communication system 100. For example, sensing agent 174 may determine the location of ED 110a and send the information to base station 170a via core network 130. Although Figure 2 Only one sensing agent 174 is shown in the figure, but any number of sensing agents may be implemented in the communication system 100. In some embodiments, one or more sensing agents 174 may be implemented at one or more RANs 120.

[0072] The sensing node can combine sensing-based technology with reference signal-based technology to enhance the determination of UE posture. This type of sensing node may also be referred to as a sensing management function (SMF). In some networks, SMF may also be referred to as a location management function (LMF). SMF may be implemented as a physically independent entity located at a core network 130, which is connected to multiple BSs 170. In other aspects of the present application, SMF may be implemented as a logical entity co-located inside BS 170 by logic executed by processor 260.

[0073] like Figure 5 As shown, when implemented as a physically independent entity, the SMF 176 includes at least one processor 290, at least one transmitter 282, at least one receiver 284, one or more antennas 286, and at least one memory 288. A transceiver (not shown) can be used instead of the transmitter 282 and the receiver 284. A scheduler 283 can be coupled to the processor 290. The scheduler 283 can be included in the SMF 176 or can be run separately from the SMF 176. The processor 290 implements various processing operations of the SMF 176, such as signal encoding, data processing, power control, input / output processing, or any other function. The processor 290 can also be used to implement some or all of the functions and / or embodiments described in detail above. Each processor 290 includes any suitable processing or computing device for performing one or more operations. For example, each processor 290 may include a microprocessor, a microcontroller, a digital signal processor, a field programmable gate array, or an application-specific integrated circuit.

[0074] Reference signal-based attitude determination techniques belong to the "active" attitude estimation paradigm. In the active attitude estimation paradigm, the inquirer of attitude information (e.g., UE 110) participates in the process of determining the inquirer's attitude. The inquirer can send and / or receive signals specific to the attitude determination process. Positioning techniques based on global navigation satellite systems (GNSS) such as the known Global Positioning System (GPS) are other examples of the active attitude estimation paradigm.

[0075] In contrast, sensing techniques based on, for example, radar, can be considered to belong to the "passive" attitude determination paradigm. In the passive attitude determination paradigm, the target has no knowledge of the attitude determination process.

[0076] By integrating sensing and communication in one system, the system does not need to operate according to only a single paradigm. Therefore, a combination of sensing-based techniques and reference signal-based techniques can produce enhanced attitude determination.

[0077] For example, enhanced posture determination may include obtaining UE channel subspace information, which is particularly useful for UE channel reconstruction at the sensing node, especially for beam-based operations and communications. The UE channel subspace is a subset of the entire algebraic space, defined in the spatial domain where the entire channel from the TP to the UE is located. Therefore, the UE channel subspace defines the channel from the TP to the UE with very high accuracy. The impact of signals sent through other subspaces on the UE channel is negligible. Understanding the UE channel subspace helps reduce the workload required for UE channel measurement and network-side channel reconstruction. Therefore, compared with traditional methods, the combination of sensing-based techniques and reference signal-based techniques can enable UE channel reconstruction with less overhead. Subspace information can also facilitate subspace-based sensing to reduce sensing complexity and improve sensing accuracy.

[0078] In some embodiments of integrated sensing and communication, the same radio access technology (RAT) is used for sensing and communication. This avoids multiplexing two different RATs under one carrier spectrum, or avoids the need to use two different carrier spectrums for two different RATs.

[0079] In an embodiment of integrating sensing and communication under one RAT, the first set of channels may be used to send sensing signals and the second set of channels may be used to send communication signals. In some embodiments, each channel in the first set of channels and each channel in the second set of channels is a logical channel, a transport channel or a physical channel.

[0080] At the physical layer, communication and sensing can be performed via separate physical channels. For example, a first physical downlink shared channel, PDSCH-C, is defined for data communication, while a second physical downlink shared channel, PDSCH-S, is defined for sensing. Similarly, separate physical uplink shared channels (PUSCH), PUSCH-C and PUSCH-S, can be defined for uplink communication and sensing.

[0081] In another example, the same PDSCH and PUSCH may also be used for both communication and sensing, where separate logical layer channels and / or transport layer channels are defined for communication and sensing. It should also be noted that one or more control channels and one or more data channels used for sensing may have the same or different channel structures (formats), occupying the same or different frequency bands or bandwidth portions.

[0082] In yet another example, a common physical downlink control channel (PDCCH) and a common physical uplink control channel (PUCCH) can be used to carry control information for both sensing and communication. Alternatively, separate physical layer control channels can be used to carry separate control information for communication and sensing. For example, PUCCH-S and PUCCH-C can be used for uplink control of sensing and communication, respectively, and PDCCH-S and PDCCH-C can be used for downlink control of sensing and communication, respectively.

[0083] At each of the physical, transport, and logical layers, there may be different combinations of shared and dedicated channels for sensing and communication.

[0084] The word "RADAR" originates from the phrase "radio detection and ranging"; however, expressions with different capitalizations (e.g., "Radar" and "radar") are equally valid and are now more common. Radar is commonly used to detect the presence and location of objects. A radar system radiates radio frequency energy and receives echoes of energy reflected from one or more targets. The system determines the position of a given target based on the echoes returned from the given target. The radiated energy can be in the form of energy pulses or continuous waves, which can be represented or defined by a specific waveform. Examples of waveforms used in radar include frequency modulated continuous wave (FMCW) and ultra-wideband (UWB) waveforms.

[0085] Radar systems can be monostatic, bistatic, or multistatic. In a monostatic radar system, the radar signal transmitter and receiver are co-located, for example integrated into the transceiver. In a bistatic radar system, the transmitter and receiver are spatially separated and separated by a distance equivalent to or greater than the expected target distance (commonly referred to as range). In a multistatic radar system, two or more radar components are spatially distinct but have a common coverage area. Multistatic radars are also called multistation or mesh radars.

[0086] Ground-based radar applications face challenges such as multipath propagation and shadowing. Another challenge is the identifiability issue, as ground targets have similar physical properties. Integrating sensing into communications systems is likely to face these same challenges, and more.

[0087] Communication nodes can be half-duplex or full-duplex. Half-duplex nodes cannot use the same physical resources (time, frequency, etc.) to send and receive at the same time; in contrast, full-duplex nodes can use the same physical resources to send and receive. Existing commercial wireless communication networks are all half-duplex. Even if full-duplex communication networks become feasible in the future, it is expected that at least some of the nodes in the network will still be half-duplex nodes, because half-duplex devices are less complex and have lower costs and lower power consumption. Specifically, full-duplex implementations are more challenging at higher frequencies (for example, in the millimeter wave bands), which is very challenging for small, low-cost devices (such as femtocell base stations and UEs).

[0088] The limitations of half-duplex nodes in communication networks create further challenges for integrating sensing and communication into devices and systems in communication networks. For example, both half-duplex and full-duplex nodes can perform bistatic or multistatic sensing, but monostatic sensing generally requires the sensing node to have full-duplex capability. Half-duplex nodes can perform monostatic sensing under certain restrictions, such as in pulsed radars with specific duty cycles and ranging capabilities.

[0089] The characteristics of the sensing signal or the signal used for sensing and communication at the same time include the waveform of the signal and the frame structure of the signal. The frame structure defines the time domain boundaries of the signal. The waveform describes the shape of the signal as a function of time and frequency. Examples of waveforms that can be used for sensing signals include ultra-wideband (UWB) pulses, frequency-modulated continuous waves (FMCW) or "chirps", orthogonal frequency-division multiplexing (OFDM), cyclic prefix (CP)-OFDM and discrete Fourier transform spread (DFT-s)-OFDM.

[0090] In one embodiment, the sensing signal is a linear chirp signal with a bandwidth of B and a duration of T. Such a linear chirp signal is well known for use in FMCW radar systems. The linear chirp signal is composed of a frequency that changes from an initial time t to a chprp0 The starting frequency f chirp0 Increase to the final time t chirp1 The final frequency f chirp Definition, where the relationship between frequency (f) and time (t) can be expressed as ff chirp0 =α(tt chirp0 ), where The bandwidth of a linear chirp signal can be defined as B = f chirp1 -f chirp0 , the duration (period) of the linear chirp signal can be defined as T = t chirp1 -t chirp0 In baseband representation, this linear chirp signal can be expressed as

[0091] As used herein, precoding may refer to any one or more coding operations or modulations that convert an input signal into an output signal. Precoding may be performed in different domains and typically converts an input signal in a first domain into an output signal in a second domain. Precoding may include linear operations.

[0092] A panel is a unit of an antenna group, antenna array, or antenna subarray that can independently control a Tx beam or an Rx beam.

[0093] A beam may be formed by performing amplitude and / or phase weighting on data sent or received by at least one antenna port. A beam may be formed by other methods (e.g., adjusting relevant parameters of an antenna unit). A beam may include a Tx beam and / or an Rx beam. The transmit beam indicates the distribution of signal strength formed in different directions in space after a signal is sent through an antenna. The receive beam indicates the distribution of signal strength in different directions in space of a wireless signal received from an antenna. The beam information may include a beam identifier, an antenna port identifier, a channel state information reference signal (CSI-RS) resource identifier, an SSB resource identifier, a sounding reference signal (SRS) resource identifier, or other reference signal resource identifiers.

[0094] For future wireless communication systems that have introduced new operating modes such as low-power operating modes, it can be seen that various functions can be applied to the new operating modes. For example, the sensing method can be applied to the low-power mode. Similarly, the communication method can be applied to the low-power mode.

[0095] Although high-precision positioning is often viewed as a goal that conflicts with energy efficiency, this is not strictly true. In fact, accurate positioning can reduce overall power consumption. Location information is expected to be provided as a service to network users. Similarly, location information can also be used to facilitate other services and functions provided by the network in location-aware communications. For example, location information can be used to facilitate initial access, beam training and synchronization, thereby enhancing network resource management. Obviously, the availability of location information at network nodes can help reduce system design complexity, reduce signaling overhead and reduce latency for many communication and sensing processes, thereby reducing overall power consumption.

[0096] Current positioning techniques such as downlink Time Difference of Arrival (DL-TDoA), downlink Angle of Departure (DL-AoD), multi-cell round triptime (Multi-RTT) and their uplink variants are designed without considering energy consumption. Low-power positioning methods can be discussed from two different perspectives, namely the network perspective and the UE perspective.

[0097] From the UE's perspective, current positioning procedures require the UE to be in a connected state to receive and process synchronization signal blocks (SSBs), and to receive, decode and process positioning reference signals (PRSs). These current positioning procedures require frequent "waking up" of the UE, i.e., transitioning the UE from the RRC_IDLE state to the RRC_CONNECTED state. These current positioning procedures may directly increase energy consumption at the UE, where a relatively large amount of signaling operations are required between the UE and the network node to transition from the RRC_IDLE state to the RRC_CONNECTED state. In addition, these current positioning procedures may shorten the duration that the UE is expected to spend in an energy-saving mode (e.g., the RRC_IDLE state). In addition, it is known that decoding and processing SSBs and PRSs at the UE involves computationally intensive digital processing, which involves turning on high-power hardware, such as analog-to-digital converters (ADCs). It should be understood that although various aspects of the present application are discussed in the context of RRC operational states, other new states corresponding to a wider range of operational states and different power modes may be introduced in the future.

[0098] From a network perspective, it can be considered that the current positioning methods have two main problems related to increased power consumption. The first problem is related to the high transmission power of PRS (downlink) or SRS (uplink) required to ensure coverage and reliable reception at other network nodes or UEs. In particular, it is known that the current positioning process relies on the use of a small number of fixed-position network nodes as anchor nodes that send positioning reference signals for locating UEs. Therefore, there is a high probability that most fixed-position anchor points are far away from the target UE (the UE being located), thereby increasing the power and energy required to send PRS. This first problem also exists in the current positioning process in the uplink direction. The second problem is related to the high signaling and feedback overhead required to achieve the high synchronization level required between the UE and the network nodes or between the anchor points themselves. For example, in a multi-cell RTT positioning process, each anchor point can send a dedicated PRS and receive a dedicated SRS. This indirectly increases the overall energy consumption of the positioning process.

[0099] It is reported that the 3rd Generation Partnership Project (3GPP) will develop global standards for the fifth generation (5G) mobile wireless communication networks. In version 17 of the global standard (available from www.3gpp.org), there are some work items on RRC_INACTIVE state positioning. These work items can perform positioning procedures during the RRC_INACTIVE state. However, these work items do not focus on low power consumption. Instead, these work items seem to be introduced to reduce the latency of transitioning from the RRC_IDLE state to the RRC_CONNECTED state. Since the processes performed by the UE in the RRC_INACTIVE state (receiving signaling, sensing, and collecting measurements) are reduced compared to the processes performed by the UE in the RRC_CONNECTED state, the reduction in power consumption can be regarded as a result of the execution of these work items. It can be considered that the positioning process in these work items is the same as the workflow of the current positioning process, which still uses a relatively high energy consumption digital baseband processing process and still relies on a small number of fixed anchor points when positioning.

[0100] The digital baseband processing process related to downlink positioning performed at the UE includes: estimating the downlink reference signal time difference (DL RSTD); estimating the downlink position reference signal reference signal received power (DL PRS-RSRP); estimating the downlink position reference signal reference signal received path power (DL PRS-RSRPP); estimating the UE ERx-Tx time difference.

[0101] In US Pat. No. 11,290,960, it is proposed to use passive components in a device (such as a UE) in an RF circuit (see US Pat. No. 11,290,960). Figure 2 ). It is proposed to equip the device with some passive components and circuits. The passive components and circuits can be used when the device is in the RRC_IDLE state or in the RRC_INACTIVE state or more generally in a low power mode. The passive components and circuits can be used to forward / reflect an input signal from a first terminal so that the forwarded / reflected signal is received at a second terminal. The device can switch between an active mode and a passive mode, wherein each mode operates in a different device state. The device can switch to an active mode in response to switching to an RRC_CONNECTED state. The device can switch to a passive mode in response to switching to an RRC_IDLE state or an RRC_INACTIVE state or more generally to a low power mode. It can be seen that this switching can enable the device to save power. Conveniently, when the device is in the RRC_IDLE state or the RRC_INACTIVE state, the device can perform extended functions that are normally not available in these states without waking up the device.

[0102] In PCT / CN2021 / 075136, it is proposed that a network entity can be used to detect a UE even when the UE is in an idle / sleep state. In this method, the network entity sends a common sensing signal with a center frequency f0. Each different UE is used to detect a UE at a different frequency f0. k The super UE or repeater assists the TRP in receiving the reflection of the common sensing signal. In this way, the TRP can detect the presence of each UE and the approximate location of each UE.

[0103] Various aspects of the present application relate to a positioning method customized for UEs in low power mode and ultra-low power mode. The positioning method can solve the shortcomings of traditional positioning methods, and the positioning method can adapt to different aspects of various states / modes of UEs.

[0104] Conveniently, the positioning method representing various aspects of the present application can have relatively low power consumption, relatively low computational complexity burden, and relatively high accuracy, while relaxing the synchronization level between terminals. In fact, compared with the current positioning method, the power consumption of the positioning method representing various aspects of the present application can be relatively low. This relatively low power consumption can be achieved by using a chirp-based reference signal, which can be processed at the UE by RF-dominated processing or pure RF and passive processing. This relatively low power consumption can also be achieved by utilizing a connected UE (a UE with the ability and willingness to cooperate) adjacent to the UE whose position is to be determined. The connected UE can be used as an anchor node capable of sending a positioning reference signal. Short-range communication can be achieved using adjacent connected UEs. In the future, the UE referred to as a "connected UE" herein does not have to be in a known RRC_CONNECTED state (based on the NR definition) to perform sensing tasks representing various aspects of the present application. Therefore, it should be understood that the general term "network node" for RX-AN can refer to a UE that is in a connected state or not in a connected state.

[0105] As is well known, the link budget for reliable reception of transmitted reference signals decreases as the range increases. The positioning method representing various aspects of the present application can simplify the processing and detection operations at the anchor node. This simplification can reduce the power consumption at the anchor node. The positioning method representing various aspects of the present application can also result in a reduction in synchronization error.

[0106] Various aspects of the present application are directed to tailoring positioning methods to accommodate capabilities associated with UEs in different power modes.It is safe to assume that the power or energy state or mode of a UE can be one of three modes: normal power mode, low power mode, and very low power mode.

[0107] In normal power mode, the UE has medium to high energy. Therefore, the UE can turn on the RF analog circuits and baseband digital circuits at the same time. In addition, the UE can process computationally intensive operations. In addition, the normal power mode is expected to enable the UE to process and transmit RF signals at relatively high power so that the RF signals can be reliably received at the network node, which is usually located relatively far away from the UE.

[0108] In low power mode, the UE has low energy. Therefore, the UE cannot turn on the RF analog circuits and the full baseband digital circuits at the same time. In addition, the UE cannot process computationally intensive operations. Instead, the UE can only turn on the RF analog circuits. In addition, the UE can perform limited digital processing using low-rate ADCs, etc. In addition, the low power mode is expected to enable the UE to process and send RF signals with sufficient power to be reliably received at the network node, which is usually located relatively far away from the UE.

[0109] In very low power mode (class A or class B as defined herein), the UE has very low energy levels. Therefore, the UE cannot send RF signals with sufficient power to be reliably received at the network node. In addition, depending on the energy the UE has, the UE may decide to turn off the digital baseband circuitry and allow pure analog RF or passive RF processing (this is referred to herein as very low power mode class B) or allow analog RF processing as well as limited digital processing (this is referred to herein as very low power mode class A).

[0110] It is well known that UEs in different low power modes are prone to losing tight synchronization with network nodes over time. This loss of tight synchronization can be attributed to the failure to send or receive synchronization signals. In order to save power, the decision not to send or receive synchronization signals can be implemented. The loss of tight synchronization can be attributed to internal drift of the internal UE clock, which is known to benefit from continuous maintenance. The loss of tight synchronization may directly increase the difficulty of performing the positioning process and may significantly reduce the accuracy of any positioning process performed. For example, a synchronization error of 10 nanoseconds may result in a positioning error of 3 meters. Therefore, various aspects of the present application can be understood as taking into account relaxed synchronization constraints. That is, various aspects of the present application can be understood as including countermeasures to reduce the loss of tight synchronization.

[0111] Some aspects of the present application relate to a positioning process for a UE in a low power mode. Other aspects of the present application relate to a positioning process for a UE in an extremely low power mode. Various aspects of the present application relate to sending and receiving specially designed chirp-based positioning signals at all terminals (including anchor nodes, connected UEs, and UEs in low power mode) using analog RF-dominated processing. Various aspects of the present application can be implemented using a chirp-based positioning technique based on "ping-pong" (transmission-processing-retransmission / backscattering). In various aspects of the present application, a certain anchor node sends (first branch) a chirp-based positioning signal. Upon receiving an input chirp-based positioning signal, the target UE backscatters or broadcasts (second branch) a received chirp-based positioning signal or a time-shifted version of the received chirp-based positioning signal. When a chirp-based positioning signal is received from a target UE at an anchor node, the anchor node can process the chirp-based positioning signal. Various aspects of the present application can naturally reduce the synchronization error between the target UE and the anchor node. Various aspects of the present application can enable the chirp-based positioning signal from the target UE to be received at multiple anchor nodes in the second branch. Multiple anchor nodes can be efficiently utilized to reduce synchronization errors between anchor nodes. Therefore, the reliability of the positioning process can be improved, and the accuracy of the positioning process can be improved.

[0112] Various aspects of the present application can be applied to the scenario where a UE in low power mode is located with relatively high accuracy. Due to the relatively long time in low power mode, the synchronization between the UE and one or more network nodes may be loose. Four main nodes / terminals are involved in the various aspects of the present application: SMF 176, transmit anchor point (TX-AN), receive anchor point (RX-AN) and target UE.

[0113] As described above, SMF 176 is a physical or logical network entity that can be assigned the responsibility of arranging the positioning process representing various aspects of the present application. SMF 176 can be co-located with other network functions or entities at a network node; therefore, in the case where TX-AN or RX-AN is a network node, SMF 176 can also be the same network node as TX-AN or RX-AN. The main responsibilities of SMF 176 include: managing time and frequency resources; managing positioning signal configuration; monitoring the status of UEs in a given area; sending positioning signal configuration to TX-AN, RX-AN and target UE; receiving measurement information from RX-AN; processing measurement information to determine the corresponding position of the target UE.

[0114] TX-AN is a node, i.e. a network node or a UE in RRC_CONNECTED state, used to send positioning reference signals according to the configuration provided by SMF 176. The location of the TX-AN node is known at SMF 176. The main responsibilities of TX-AN include: receiving positioning signal configuration from SMF 176; sending positioning reference signals according to the positioning signal configuration.

[0115] RX-AN is a node, i.e. a network node or a UE in the RRC-CONNECTED state, which is used to reliably receive sensing reference signals and process the sensing reference signals to collect some measurements according to the configuration provided by SMF 176. The location of the RX-AN node is known at SMF 176. The main responsibilities of RX-AN include: receiving positioning signal configuration from SMF 176; receiving backscattered or time-shifted positioning reference signals; collecting measurements of received signals; performing parameter estimation according to the positioning signal configuration defined by SMF 176 to obtain estimated parameters; and feeding back the estimated parameters and collected measurements to SMF176. It should be noted that in some positioning processes, some nodes are used as RX-AN nodes and TX-AN nodes.

[0116] The target UE is a UE in one of the low power modes. Various aspects of the present application relate to the target of positioning the target UE. The target UE is used to interact with the positioning reference signal to a minimum. The main responsibilities of the target UE include: indicating to the SMF 176 the selected low power mode that the target UE is about to enter among multiple different low power modes; receiving the positioning signal configuration from the SMF 176 before entering the selected low power mode; receiving the positioning signal; applying a signature to the positioning signal to obtain a signature positioning signal; time shifting and retransmitting or backscattering the signature positioning signal.

[0117] Various aspects of the present application relate to a positioning process of a target UE in a low power mode. The positioning process covers a large area and uses an anchor node and a target UE to send signals with a normal power configuration.

[0118] Figure 6 Signals in a positioning procedure for a target UE 606 in the context of multiple terminals are shown. The terminal includes a node 602 that is a combination of a TX-AN node and an RX-AN node, a first RX-AN node 604-1, and a second RX-AN node 604-2. Another network entity (e.g., SMF 176) can be used to orchestrate the positioning procedure, collect data measured at different terminals, and determine the location of the target UE 606. As described above, SMF 176 can be an independent network entity or a logical function implemented by TRP 170 or any network node.

[0119] Figure 71 shows exemplary steps in a method of orchestrating a positioning procedure at the SMF 176. Before the target UE 606 enters a low power mode, the SMF 176 provides (step 702) a positioning signal configuration for all terminals involved in the positioning process. The positioning signal configuration may include chirp-based positioning signal parameters, such as chirp rate α, duration T, start frequency f, and the like. i The positioning signal configuration may also include time and frequency resources, transmission power and period of the chirp-based positioning signal. The SMF 176 then sends (step 704) an anchor node (TX / RX-AN node 602, first RX-AN node 604-1, second RX-AN node 604-2) allocation for the target UE 606. In general, the SMF 176 may allocate (step 704) a positioning TRP 170 (network node - Figure 6 ) or other connected UEs as anchor nodes. SMF 176 may allocate (step 704) a single TX-AN node and associate the single TX-AN node with multiple RX-AN nodes. SMF 176 is expected to allocate (step 704) the role of the TX-AN node to a node that is capable of receiving chirp-based positioning signals in addition to being capable of sending chirp-based positioning signals. It can be seen that the TX-AN node can be more accurately referred to as a TX / RX-AN node (e.g., Figure 6 In some cases, for the reliability of the positioning process, the SMF 176 may allocate (step 704) more than one TX-AN node. In the case of allocating more than one TX-AN node, different positioning signal configurations (e.g., different starting frequencies f ) may be provided (step 702) for each TX-AN node. i ).

[0120] Figure 8 Exemplary steps in a method of performing a positioning procedure at a TX / RX-AN node 602 are shown. The assigned TX / RX-AN node 602 initially receives (step 802) assignment and positioning signal configuration information from the SMF 176. The TX / RX-AN 602 node then sends (step 804) a first or "forward" chirp-based positioning signal in accordance with the positioning signal configuration information. In the event that the SMF 176 assigns multiple TX / RX-AN nodes, the SMF 176 may provide the i-th TX / RX-AN node with the positioning signal configuration information, the positioning signal configuration information including a common chirp rate α and a starting frequency f for the i-th TX / RX-AN node. i Each starting frequency f can be selected for all i∈{1,…,N} in a way that maintains the orthogonality between the chirp-based positioning signals sent by the anchor nodes serving a given target UE in a given frequency domain. i .

[0121] In the case where the SMF 176 allocates N TX / RX-AN nodes, the chirp-based positioning signal sent by the i-th TX / RX-AN node (where i=1, ..., N) may be referred to as c i (t). In these cases, the target UE 606 is expected to receive N chirp-based positioning signals, each of which is transmitted with a different delay (i.e., ) received, where is a delay term representing the flight time / propagation delay associated with the forward (F) path from the i-th TX / RX-AN node to the target UE 606. The N received chirp-based positioning signals may be referred to as “forward / first hop” chirp-based positioning signals. These chirp-based positioning signals may be mathematically represented as

[0122] Under normal channel conditions, the SMF 176 may expect to allocate (step 704) only a single TX / RX-AN node, i.e., N=1, such as Figure 6 In addition, a single TX / RX-AN node 602 is expected to be approximately the closest anchor node to the target UE 606. This proximity can provide advantages for reliable reception of the chirp-based forward positioning signal at the target UE 606. This proximity can provide advantages for reliable reception of the second or "reverse" chirp-based positioning signal at the TX / RX-AN node 602.

[0123] In the case where there are more than one TX / RX-AN node, the chirp rate of the chirp signal can be expected to have the same common chirp rate α, and the number N of chirp-based positioning signals being transmitted does not need to be known at the target UE 606. The target UE 606 can activate the matched filter 1100 configured with the common chirp rate α (see Fig.11 ). It can be seen that the target UE 606 can process the received chirp-based positioning signal to obtain multiple peaks At the target UE 606, the multiple peaks may be interpreted as multiple detected delay values. It should be noted that the target UE 606 may detect these peaks based on the local clock of the target UE 606. Therefore, it should be clearly understood that the detected delay value is affected by the TX-to-UE ("TX-UE") synchronization error between the network clock and the local clock of the target UE 606. The delay can be expressed as Among them, Δt i =t i -t0 represents the TX-UE synchronization error, t iis the time at the i-th TX / RX-AN node, and t0 is the time at the local clock of the target UE 606. It should be noted that the starting frequency f i The value of may be uniquely mapped to each of the multiple TX / RX-AN nodes and the target UE 606. In other words, in a system having multiple TX / RX-AN nodes and thus multiple starting frequencies f i In the case of i belongs to a single target UE 606. In addition, a common set of RX / AN nodes may be associated with multiple TX / RX-AN nodes, or different sets of RX / AN nodes may be associated with corresponding TX / RX-AN nodes, in order to locate a single target UE 606. The decision between these options may be made at the SMF 176 and may be based on achieving a particular accuracy and / or a particular reliability level for a given positioning procedure.

[0124] Fig. 9 Exemplary steps in a method of performing a positioning procedure at a target UE 606 are shown. The target UE 606 initially receives (step 902) positioning signal configuration information from the SMF 176. In response to receiving (step 904) a chirp-based forward positioning signal, the target UE 606 may broadcast (step 910) a time-shifted chirp-based reverse positioning signal. The time-shifted reverse chirp signal may be understood to have the same parameters as the parameters of the forward chirp signal.

[0125] In response to receiving (step 904) more than one chirp-based forward positioning signal, the target UE 606 can broadcast (step 910) multiple time-shifted chirp-based reverse positioning signals, wherein one time-shifted chirp-based reverse positioning signal corresponds to each RX-AN node set. Each time-shifted chirp-based reverse positioning signal can be expected to have the same parameters as the corresponding one chirp-based forward positioning signal.

[0126] exist Figure 6 In the example shown, the target UE 606 receives (step 904) a chirp-based forward positioning signal The processing of the chirp-based forward positioning signal (step 906) may enable the target UE 606 to convert the detected delay value One way in which the target UE 606 can process (step 906) the chirp-based forward positioning signal is to pass the received chirp-based forward positioning signal through a matched filter (see Fig.11 ).

[0127] The target UE 606 may then wait (step 908) for a fixed delay amount (time shift) before broadcasting (step 910) a time-shifted chirp-based reverse positioning signal. In practice, the fixed delay amount may be in the processing delay τ pr After that, it is generated. pr The detected delay value Compared to the non-negligible case, the SMF 176 can set a fixed delay amount that the target UE 606 can wait (step 908). The fixed delay amount can be provided by the SMF 176 to the target UE 606 as part of providing (step 702) the positioning signal configuration information to all terminals involved in the positioning process.

[0128] It should be noted that the method performed by the target UE 606 (see Fig. 9 ) may be understood to include processing (step 906) a chirp-based forward positioning signal, wherein the processing (step 906) may involve both RF processing and some limited digital processing. The RF processing (step 906) may involve matched filtering, etc. The digital processing (step 906) may involve detecting a peak after matched filtering in the case of multiple TX / RX-AN nodes and waiting (step 908) for a time shift before broadcasting (step 910) a time-shifted chirp-based reverse positioning signal. In some embodiments, the RF processing (step 906) may involve de-chirping the received signal, etc. De-chirping the received signal may be performed by multiplying the received signal by The digital processing (step 906) may involve detecting the beat frequency of the de-chirped signal by, for example, an FFT operation.

[0129] Another way to achieve the time shift of the chirp-based reverse positioning signal is frequency shift. Given the characteristics of the chirp-based positioning signal, the time shift can be equivalent to the amount frequency shift.

[0130] Fig.10Exemplary steps in a method of performing a positioning procedure at one of the RX-AN nodes 604-1, 604-2 (collectively or individually 604) are shown. The RX-AN node 604 initially receives (step 1002) allocation and positioning signal configuration information from the SMF 176. Upon receiving (step 1006) a chirp-based reverse positioning signal from the target UE 606, the RX-AN node 604 may process (step 1008) the received chirp-based reverse positioning signal. Similarly, upon receiving (step 806) a chirp-based reverse positioning signal from the target UE 606, the TX / RX-AN node 602 may process (step 808) the received chirp-based reverse positioning signal. In various aspects of the present application, the RX-AN node 604 may process (step 1008) the received chirp-based reverse positioning signal using a simple matched filter to detect a composite delay associated with the received chirp-based reverse positioning signal. Similarly, the TX / RX-AN node 602 may process (step 808) the received chirp-based reverse positioning signal using a simple matched filter to detect the composite delay associated with the received chirp-based reverse positioning signal.

[0131] Since the reverse chirp signal is processed at the TX / RX-AN node 602 and the RX-AN nodes 604-1, 604-2 according to their respective clocks, and it is assumed that their respective clocks are synchronized with the network, the flight time in the reverse direction can be expressed as j = TX1, RX1, RX2, where represents the distance between the receiver (TX / RX-AN 602, RX-AN 604-1, RX-AN 604-2) and the target UE 606, and c represents the speed of light. The composite delay can be understood as the sum of the first delays in the forward direction, that is, (See Figure 6 ) and the different propagation delays in the reverse direction, i.e. and (See Figure 6 ). Therefore, the composite delay on the forward and reverse paths can be expressed as

[0132] Detecting the composite delay by processing (step 1008 for RX-AN node 604 and step 808 for TX / RX-AN node 602) allows estimating the relative distance between the receiver performing the processing and the target UE 606 in differential mode without TX-UE synchronization error.

[0133] For a scenario with a set of RX-AN nodes and the number of RX-AN nodes in the set being M, the relative distance between the receiver including the TX / RX-AN node and the target UE 606 can be expressed as .

[0134] It should be noted that the composite delay value detected by the TX / RX-AN node 602 can be expressed as Therefore, as part of the process (step 808), the TX / RX-AN node 602 may directly estimate the distance between the TX / RX-AN node 602 and the target UE 606. The distance value estimated by the RX-AN node 604 as part of the process (step 1008) may be understood as a composite distance that includes the distance between the TX / RX-AN node 602 and the target UE 606. and the distance between the RX-AN node 604 and the target UE 606

[0135] Upon completing processing of the received chirp-based reverse positioning signal (step 808), the TX / RX-AN node 602 may send (step 810) to the SMF 176 an indication of parameters of the chirp-based reverse positioning signal, including the estimated distance Similarly, upon completing processing of the received chirp-based reverse positioning signal (step 1008), the RX-AN node 604 may send (step 1010) to the SMF 176 an indication of parameters of the chirp-based reverse positioning signal, including the estimated composite distance

[0136] The SMF 176 may receive (step 706) parameter indications including an estimated distance Indications and estimated composite distances The SMF 176 may then process (step 708) the parameter to obtain the location information of the target UE 606. Recall that the target UE 606 is still in low power mode. In practice, it should be clear that the SMF 176 may use the estimated distance Combine the estimated composite distance To determine the unknown distance

[0137] In the case where the SMF 176 is co-located with any other network node (e.g., the TX / RX-AN node 602, the first RX-AN node 604-1, or the second RX-AN node 604-2), the Figures 7 to 10 The transmission and reception in the method are appropriately modified, and the modifications are obvious to those skilled in the art.

[0138] Various aspects of the present application relate to a positioning process for a UE in an extremely low power mode. As described above, the extremely low power mode can be divided into a "Class A" extremely low power mode and a "Class B" extremely low power mode. Specifically, various aspects of the present application relate to trying to locate and synchronize a given UE in an extremely low power (ELP) mode without turning on the TX RF circuit for a given ELP-UE. The TX RF circuit is typically turned on to send RF signals at a conventional transmission power and range. Various aspects of the present application promote the use of backscatter communications to create a chirp-based reverse positioning signal. In these aspects of the present application, the receiver of the chirp-based reverse positioning signal is not a transmitter of the chirp-based forward positioning signal, as is the case with TX / RX-AN 602 above. The anchor node in these aspects of the present application can be a transmitter (TX-AN node) or a receiver (RX-AN node) of a chirp-based positioning signal. In addition, the RX-AN node can be selected from the connected UEs and the network nodes adjacent to the target ELP-UE so that the corresponding distance between the RX-AN node and the target ELP-UE is small enough to reliably receive the backscattered chirp-based positioning signal at the RX-AN node. This is in contrast to the various aspects of the present application set forth above, in which the RX-AN node may be relatively far away from the target UE 606 due to the target UE 606 having the ability to transmit at conventional power.

[0139] Various aspects of the present application relate to enabling an ELP-UE to embed a unique RF signature in a chirp-based reverse positioning signal. The embedding can be achieved by frequency shifting a specific time portion of a chirp-based forward positioning signal. The offset can cause the chirp-based reverse positioning signal to appear at a receiver as two chirp-based positioning signals with two different starting frequencies and two different periods but with the same chirp rate. The two chirp-based positioning signals can be used at the receiver to obtain information about the ELP-UE position and information about the TX-UE synchronization error.

[0140] Fig.12 An i-th TX-AN node 1202-i, a j-th ELP-UE 1206-j, and a l-th RX-AN node 1204-l are shown. The j-th ELP-UE 1206-j is understood to be in Class B very low power mode. Fig.12 The i-th TX-AN node 1202-i is shown transmitting a chirp-based forward positioning signal at a chirp rate α and a bandwidth B between t=0 and t=T. According to various aspects of the present application, the jth ELP-UE 1206-j can detect the chirp-based forward positioning signal. The RF domain signature is applied by frequency shifting, where the frequency shift amount is f j , so that the chirp-based reverse positioning signal Sent from the jth ELP-UE 1206-j. Chirp-based reverse positioning signal It can be expressed as With respect to the timing of the i-th TX-AN node 1202-i, arrive The signature is applied at the jth ELP-UE 1206-j within the time range of f. The range is defined as including the application signature f j The period Ω.

[0141] Start time instance The item in the time range in which the signature can be applied is It can be called the "corrected start time". In fact, the corrected start time It can be defined as Among them, Δt ij,TX-UE represents the time deviation between the clock at the jth ELP-UE 1206-j and the clock at the i-th TX-AN node 1202-i (also called "TX-UE synchronization error").

[0142] It should be noted that the time instance can be preconfigured to be larger than the maximum propagation delay. In addition, the time instance It can be preconfigured to be larger than the timing deviation between devices in a given area, or larger than the allowed timing deviation for a predetermined set of applications. It can be preconfigured to be smaller than the sum of the smaller delay and the period T.

[0143] The signature f of the jth ELP-UE 1206-j j Can be configured to work on multiple ELP-UEs ( Fig.12 Therefore, the signature f of the j-th ELP-UE 1206-j is unique. j can be mapped to the ELP-UE identity (“ELP-UE ID”), so that by detecting the signature f j , a receiver (which may be SMF 176) based on the parameters of the chirped reverse positioning signal may obtain the identification of the jth ELP-UE 1206-j.

[0144] The first RX-AN node 1204-1 may apply analog RF chirp compression (eg, implemented as a matched filter), where the chirp rate is α. The application of analog RF chirp compression may enable the first RX-AN node 1204-1 to obtain a composite delay The lth RX-AN node 1204-1 may process the composite delay to obtain a composite distance from the ith TX-AN node 1202-i to the jth ELP-UE 1206-j and from the jth ELP-UE 1206-j to the lth RX-AN node 1204-1. The lth RX-AN node 1204-1 may process the received chirp-based positioning signal to obtain a composite delay The composite delay An indication of the timing offset between the jth ELP-UE 1206-j and the i-th TX-AN node 1202-i may be provided. The l-th RX-AN node 1204-1 may process the received chirp-based positioning signal to obtain a signature f of the j-th ELP-UE 1206-j. j According to the signature f j , the lth RX-AN node 1204-1 can obtain the ELP-UE ID of the jth ELP-UE 1206-j. As described below, these parameters (three bits of information: composite distance, composite delay and ELP-UE ID) can be used by the SMF 176 to obtain the precise location of the jth ELP-UE 1206-j and eliminate ambiguity in synchronization.

[0145] Various aspects of the present application relate to a positioning procedure for an ELP-UE in a Class B extremely low power mode.

[0146] Fig.13A The i-th TX-AN node 1302-i, the j-th ELP-UE 1306-j and the l-th RX-AN node 1304-1 are shown. The j-th ELP-UE 1306-j is understood to be in Class B extremely low power mode. Due to limited power, such ELP-UE is not used to generate and send positioning signals in the reverse direction, so the positioning process is subject to some constraints. The constraints include only using RX-AN nodes that are relatively close to the ELP-UE, because these nodes are the only nodes that can be expected to reliably receive backscattered chirp-based positioning signals from the ELP-UE. This constraint may limit the possibility of finding an RX-AN that is relatively closely synchronized with the TX-AN node. Therefore, the positioning process can be understood to take into account various synchronization errors between the ELP-UE and the RX-AN nodes and between the ELP-UE and the TX-AN nodes.

[0147] When Fig.13AAs shown, the i-th TX-AN node 1302-i sends a chirp-based forward positioning signal at a chirp rate α and a bandwidth B between t=0 and t=T. The positioning process is initialized when the chirp-based forward positioning signal is received and processed. When multiple RX-AN nodes ( Fig.13A The first RX-AN node 1304-1 in FIG. 1 may process the chirp-based forward positioning signal. Fig.14 FIG. 1 shows a first matched filter 1400-A that can be used by the first RX-AN node 1304-1. The first RX-AN node 1304-1 uses the first matched filter 1400-A to process the chirp-based forward positioning signal. The lth RX-AN node 1304-1 can be enabled to il +Δt il,TX-RX The first peak value 1401 is detected at It can be understood as corresponding to the chirp-based forward positioning signal time) to traverse the line-of-sight (LOS) link between the i-th TX-AN node 1302-i and the l-th RX-AN node 1304-l, where Δt il,TX-RX Represents the relative timing deviation between the i-th TX-AN node 1302-i and the l-th RX-AN node 1304-l.

[0148] It is expected that the jth ELP-UE 1306-j can backscatter the chirp-based forward positioning signal, thereby creating a backscattered chirp-based reverse positioning signal (See Fig. 13B ). For example, by using the first matched filter 1400-A to process the chirp-based reverse positioning signal The lth RX-AN node 1304-1 can be A second peak 1402 is detected at Fig.14 The second peak 1402 can be understood as a chirp-based reverse positioning signal corresponding to backscattering. The first part of .

[0149] For example, by using the second matched filter 1400-B (see Fig.14 ) Processing reverse positioning signal This enables the lth RX-AN node to The third peak 1403 is detected at the jth ELP-UE 1306-j. The third peak 1403 may be understood as corresponding to the reverse positioning signal received from the jth ELP-UE 1306-j. The second part of the reverse positioning signal The second part can be understood as including the signature f j part.

[0150] It can be shown that the three peaks 1401, 1402, 1403 can be reliably detected at various RX-AN nodes, wherein the three peaks 1401, 1402, 1403 are largely different in terms of signal strength (amplitude) and frequency. In particular, since the signal corresponding to the first peak has the smallest distance propagated from the i-th TX-AN node, the first peak can be much stronger than the other two peaks. In addition, due to the applied signature f j , the third peak can have a much higher frequency component. The application of the signature can be converted to a relatively large time delay after compression / matched filtering

[0151] Therefore, due to the chirp-based positioning signal The total signal received at the lth RA-AN node 1304-1 can be regarded as the superposition of three chirp-based positioning signals, wherein each chirp-based positioning signal has the same chirp rate but different delays and amplitudes. Fig.14 As shown, the detection of the three chirp-based positioning signals can be achieved using two matched filters 1400-A and 1400-B. The first matched filter 1400-A can be used to detect the first two chirp-based positioning signals, i.e., the chirp-based LOS positioning signal and the first part of the backscattered chirp-based positioning signal that does not have the ELP-UE signature. The second matched filter 1400-B can be used to detect the part of the backscattered chirp-based positioning signal that has the ELP-UE signature.

[0152] Using the first matched filter 1400-A, the lth RX-AN node 1304-1 can il +Δt il,TX-RX The first peak 1401 is detected at the position of the first RX-AN node 1304-1. According to the detection, the lth RX-AN node 1304-1 can obtain the TX-RX synchronization error Δt between the lth RX-AN node 1304-1 and the i-th TX-AN node 1302-i. il,TX-RX The estimated value can be obtained based on the distance d between the i-th TX-AN node 1302-i and the l-th RX-AN node 1304-l. il (ie d il =‖F i -F l ‖, where F i represents the position of the i-th TX-AN node 1302-i, F lThe first RX-AN node 1304-1 can use the distance d il To estimate the LOS delay τ il It can be seen that the lth RX-AN node 1304-1 can be obtained by subtracting the estimated LOS delay τ il , the TX-RX synchronization error Δt is estimated based on the detection position of the first peak 1401 il,TX-RX , the first peak 1401 is understood to be at τ il +Δt il,TX-RX Detected at.

[0153] Using the first matched filter 1400-A, the lth RX-AN node 1304-1 can The second peak 1402 is detected at 1402. Since the TX-RX synchronization error Δt has been obtained previously il,TX-RX The estimated value of the lth RX-AN node 1304-1 can obtain the composite flight time The composite flight time can be understood as representing the i-th flight time from the i-th TX-AN node 1304-i to the j-th ELP-UE 1306-j and the lth flight time from the jth ELP-UE 1306-j to the RX-AN node 1304-l Add. Based on the composite flight time The estimated value of the composite distance The composite distance can be understood as the i-th distance from the i-th TX-AN node 1304-i to the j-th ELP-UE 1306-j and the lth distance from the jth ELP-UE 1306-j to the lth RX-AN node 1304-l Add.

[0154] Recall that an ellipse can be defined as the sum of the distances from the two foci to each given point on the ellipse contour being the same as all other points on the ellipse contour. and using the positions (F) of the i-th TX-AN node 1304-i and the l-th RX-AN node 1304-l i ,F l ) as the two foci of the ellipse 1308, defining the ellipse 1308 (see Fig. 13C). The jth ELP-UE 1306-j can be expected to be located at a position on the ellipse defined in this manner. If multiple RX-AN nodes detect forward and reverse positioning signals respectively, the position of the jth ELP-UE 1306-j can be estimated by finding the intersection of the corresponding multiple ellipses, where one ellipse is defined for each of the multiple RX-AN nodes.

[0155] The detection value of the third peak 1403 can be regarded as the sum of four items Conveniently, as described above, estimates of two of these terms may already be obtained: the TX-RX synchronization error Δt il,TX-RX and time shift By subtracting the estimated values ​​of the two items obtained from the detected value of the third peak 1403, the lth RX-AN node 1304-1 can obtain the received signal deviation By ignoring the flight time term from the jth ELP-UE 1306-j to the lth RX-AN node 1304-l The lth RX-AN node 1304-1 may obtain the corrected start time A rough estimate of the start time after correction Estimated values ​​and preconfigured time instances The lth RX-AN node 1304-1 may obtain the difference between the two items. The estimated value of .

[0156] Recall that the corrected start time Defined as a preconfigured time instance and TX-UE synchronization error Δt ij,TX-UE sum Therefore, the difference It can be regarded as the TX-UE synchronization error Δt ij,TX-UE In fact, due to the corrected start time A rough estimate of the received signal bias is more precisely The estimated value of TX-UE synchronization error Δt ij,TX-UE The estimated value of can be determined from the relation Using the estimated difference, the relationship can be restated as Use the estimated difference as (i.e., as the TX-UE synchronization error Δt ij,TX-UE The estimated value of In general, due to the limited range of backscatter communication, when using the backscatter of the forward positioning signal, The situation can be regarded as a common situation.

[0157] The first RX-AN node 1304-1 may send to the SMF 176 (step 1010, Fig.10 ) includes the sum of the estimated distances Parameters, TX-UE synchronization error Δt ij,TX-UE The estimated value and signature f j In response to receiving (step 706, Figure 7 ) to the values ​​of these parameters, SMF 176 can determine to report the same signature f j Therefore, SMF 176 can jointly process (step 708, Figure 7 ) parameter, thereby obtaining the value of the signature f j The location of the associated j-th ELP-UE 1206-j.

[0158] In the case where some angle-based measurements can be performed at the lth RX-AN node 1304-l, it is possible to obtain the position of the jth ELP-UE 1206-j even by a single RX-UE node 1304-l. In fact, the lth RX-AN node 1304-l can perform angle of arrival (AoA) detection of the LOS forward positioning signal and AoA detection of the reverse positioning signal. The lth RX-AN node 1304-l can then determine the relative angle θ between the chirp-based forward positioning signal and the chirp-based reverse positioning signal. The position of the jth ELP-UE 1206-j can be considered to be located at the ray 1310 (see FIG. 1 ) emitted from the lth RX-AN node 1304-l at an angle θ. Fig. 13C ) and using composite distance The position F of the i-th TX-AN node 1202-i i and the position F of the lth RX-AN node 1304-1 l The intersection between the defined ellipses 1308.

[0159] Various aspects of the present application are directed to a second Class B positioning procedure for ELP-UE in Class B extremely low power mode. The second Class B positioning procedure has reduced computational complexity, but at the expense of relying on tight synchronization between a given RX-AN node and a corresponding TX-AN node.

[0160] Fig.15A A scenario is shown including an i-th TX-AN node 1502-i, an l-th RX-AN node 1504-l, a k-th RX-AN node 1504-k, and a j-th ELP-UE 1506-j.

[0161] In order to achieve the goal of reducing the computational complexity of the RX-AN node 1504 to a certain extent, the second Class B positioning process only utilizes the portion of the backscattered chirp-based positioning signal that includes the signature of the j-th ELP-UE 1506-j. At the l-th RX-AN node 1504-1, by processing only the portion of the backscattered chirp-based positioning signal that includes the signature of the j-th ELP-UE 1506-j, Since the frequency interval is relatively large, the method of the second type B positioning process can reduce the computational complexity. In addition, it can be seen that, in contrast to the first type B positioning process described above involving the detection of three peaks, the second type B positioning process only involves the detection of one peak.

[0162] In operation, the i-th TX-AN node 1502-i transmits a chirp-based forward positioning signal. The j-th ELP-UE 1506-j backscatters the chirp-based forward positioning signal and simultaneously responds to the chirp-based forward positioning signal f j The lth RX-AN node 1504-1 and the kth RX-AN node 1504-k receive the backscattered chirp-based positioning signal. The lth RX-AN node 1504-1 can use matched filtering to estimate (i.e., find) the location of Given a sufficiently large signature f j , the lth RX-AN node 1504-1 can obtain the signature f j The value of the lth received signal deviation The lth RX-AN node 1204-1 can also measure the lth AoAθ of the backscattered positioning signal l In a similar manner, the kth RX-AN node 1204-k may obtain the signature f j , kth received signal deviation and the kth AoAθ k The value of .

[0163] The first RX-AN node 1204-1 may send to the SMF 176 (step 1010, Fig.10 ) parameter set, including signature f j , the lth received signal deviation δ l and the lth AoAθ l The k-th RX-AN node 1204-k may also send (step 1010, Fig.10 ) parameter set, including signature f j , the kth received signal deviation δ k and the kth AoAθ k An indication of the value of .

[0164] SMF 176 can be based on the signature f j The corresponding value of identifies the received from the lth RX-AN node 1204-1 (step 706, Figure 7 ) and the parameter set received from the k-th RX-AN node 1204-k (step 706, Figure 7 ) corresponds to the same ELP-UE, i.e., the j-th ELP-UE 1206-j. The SMF 176 may (step 708, Figure 7 ) received parameters to determine the deviation δ of the two received signals k and δ l Then, SMF 176 can obtain the time difference according to the received signal deviation difference. Get the time difference The corrected start time can be eliminated Recall that the corrected start time Exists in the lth received signal deviation δ l and the kth received signal deviation δ k According to the time difference SMF 176 can determine the distance difference Given distance difference The position of the jth ELP-UE 1206-j can be located at the hyperbola 1508 (see Fig. 15B ), the hyperbola 1508 defines two foci: for the lth RX-AN node 1204-1, the focal point is located at position F l For the kth RX-AN node 1204-k, the focus is located at position F k Place.

[0165] The SMF 176 may obtain the estimated position of the jth ELP-UE 1206-j as a hyperbola 1508 with the lth AoAθ l The lth ray 1510-1 emitted from the lth RX-AN node 1204-1 and the kth AoAθ k The intersection point of the k-th ray 1510-k emanating from the k-th RX-AN node 1204-k.

[0166] The second type B positioning process can be extended to scenarios with more than two RX-AN nodes and more than one TX-AN node. Increasing the number of anchor nodes can improve the accuracy of the estimated position of the jth ELP-UE 1506-j.

[0167] Various aspects of the present application relate to positioning procedures for ELP-UE in Class A extremely low power mode.

[0168] The Class A positioning process is tailored for ELP-UEs that are unable to transmit signals at conventional power and conventional range. However, these ELP-UEs are understood to be able to process received signals through analog RF processing and a limited amount of digital processing, and then reflect the processed signals through a backscatter-based receiver. Specifically, relative to many of the positioning processes discussed previously, this Class A positioning process can improve the accuracy of ELP-UE positioning, but at the cost of higher power consumption due to the need for additional digital processing.

[0169] Fig.16 A scenario is shown including an i-th TX-AN node 1602-i, an l-th RX-AN node 1604-l, and a j-th ELP-UE 1606-j.

[0170] Start time instance may represent the time instance at which the jth ELP-UE 1606-j has been preconfigured to start applying its signature.

[0171] Start time instance It can be defined with reference to the clock (or time frame) at the i-th TX-AN node 1602-i. It should be noted that in this aspect of the present application, the time instance The forward flight time of the positioning signal sent by the i-th TX-AN node 1602-i measured at the j-th ELP-UE 1606-j may be determined based on the forward flight time of the positioning signal sent by the i-th TX-AN node 1602-i. Specifically, the jth ELP-UE 1606-j can be used to fix After applying its signature, the predefined fixed delay τ fix From the flight time The time instance when the jth ELP-UE 1606-j starts applying the signature can be expressed in combination with the clock inside the jth ELP-UE 1606-j as The time instance when the jth ELP-UE 1606-j starts applying the signature can be expressed in combination with the clock inside the i-th TX-AN node 1602-i as It can be seen that the corrected start time It can be estimated as Recall that in one aspect of the present application, the corrected start time Defined as The start time is preconfigured.

[0172] from Modified to The j-th ELP-UE 1606-j may be enabled to detect the signal transmitted by the i-th TX-AN node 1602-i (step 804, Figure 8 ) has been received. That is, the j-th ELP-UE 1606-j can estimate the flight time In addition to RF simulation processing, estimating flight time The tasks of can also use limited digital processing. It can be seen that for this Class A positioning process, the power consumption may be higher than the power consumption associated with those Class B positioning processes that do not involve any digital processing.

[0173] Conveniently, by enabling the jth ELP-UE 1606-j to estimate the i-th flight time The lth RX-AN node 1604-1 and any other RX-AN nodes (not shown) may estimate the TX-UE synchronization error Δt between the jth ELP-UE 1606-j and the i-th TX-AN node 1602-i. ij,TX-UE Recall that in various aspects of the present application set forth above, the TX-UE synchronization error Δt ij,TX-UE Specifically, recall that after determining the estimated difference Based on this, and taking into account that this difference represents another difference Δt ij,TX-UE - The estimated value of TX-UE synchronization error Δt ij,TX-UE The upper bound of the value of can be approximated. It can be considered that In the case of , the difference can be simplified to TX-UE synchronization error Δt ij,TX-UE This simplification may be reasonable due to the limited range of backscatter communications. That is, the distance from the jth ELP-UE 1606-j to the lth RX-AN node 1604-l is can be considered to be relatively small, so at this distance Flight time on It can also be considered as relatively small.

[0174] TX-UE synchronization error Δt at the lth RX-AN node 1604-1 ij,TX-UE The estimation of can be achieved by detecting three peaks. As mentioned above, the three peaks can be found at Δt il,TX-RX , and Detected at.

[0175] The above introduces the relation The corrected start time is associated with three terms, of which only one term τ fix It is known at the lth RX-AN node 1604-1. This relationship can be rearranged as

[0176] By the third peak Subtract the second peak from the detected value The detection value of the lth RX-AN node 1604-1 can obtain As mentioned above, through the relationship Among them, the term τ fix represents a predefined fixed delay, which can be compared with the TX-UE synchronization error Δt ij,TX-UE Therefore, the lth RX-AN node 1604-1 can obtain the difference value from Subtract the predefined fixed delay τ from fix , get the TX-UE synchronization error Δt ij,TX-UE The estimated value of .

[0177] Various aspects of the present application relate to the manner in which the SMF 176 can obtain positioning information for multiple target UEs having different power capabilities in a given service area. In the various aspects of the present application set forth above, the SMF 176 can be used to obtain positioning information for multiple target UEs, all of which have the same power capability. The power capability is defined as low power or very low power. In the case of a low power mode target UE, it has been discussed that the SMF 176 can use different starting frequencies f i Assigned to different TX-AN nodes. In the case of extremely low power mode target UE, it has been discussed that SMF 176 can assign different signatures f i Assigned to different target UEs.

[0178] Since serving low power mode target UEs involves configuring the TX-AN node, and serving very low power mode target UEs involves configuring the target UEs, serving target UEs with mixed power capabilities in a particular area is somewhat complex. This complexity can be seen as due to the possibility that multiple chirp-based positioning signals received at a given receiver may interfere with each other when the chirp-based positioning signals are associated with the task of determining the positions of target UEs with different power capabilities.

[0179] In addition to frequency, time and slope intervals, various aspects of the present application also involve appropriate handling of the spatial intervals of anchor points. It should be clearly understood that the positioning signal sent from a low-power UE and the positioning signal sent from an extremely low power (ELP) UE have two different ranges. The probability that the positioning signal that can be received by the RX-AN node for receiving the positioning signal sent from the ELP-UE interferes with the positioning signal that can be received by the RX-AN node for receiving the positioning signal sent from the LP-UE is low. However, the probability that the positioning signal that can be received by the RX-AN node for receiving the positioning signal sent from the LP-UE interferes with the positioning signal that can be received by the RX-AN node for receiving the positioning signal sent from the ELP-UE is high. It can be seen from this that it is recommended to use a relatively wide time and / or frequency interval between the positioning signal to be sent from the ELP-UE and the positioning signal to be sent from the LP-UE, at least in the vicinity of the LP-UE. It should be noted that it can be considered that the difference in chirp rate is unlikely to result in complete orthogonality.

[0180] Various aspects of the present application address this complexity by configuring chirp-based positioning signals to be distinguishable at the intended receiver.

[0181] In one aspect of the present application, by configuring the transmission of the chirp-based positioning signal to be performed using different time and frequency resources, the distinguishability of the received chirp-based positioning signal can be enhanced, such as Fig.17 shown. Fig.17 A resource grid 1700 defined by frequency slots and time slots is shown. In the resources defined by a specific frequency slot in combination with a specific time slot and specific to serving low-power UEs, the SMF 176 can configure the TX-AN node to use a specific starting frequency f i In the resources defined by different frequency slots in combination with different time slots and specific to serving very low power UEs, the SMF 176 may configure the target UE to use a specific signature f j .

[0182] In another aspect of the present application, the distinguishability of the received chirp-based positioning signals can be enhanced by configuring the transmission of the chirp-based positioning signals to be performed using different chirp rates, such as Fig.18 As shown. Fig.18 In graph 1800 , four chirp-based positioning signals are shown using a first chirp rate α1 , and four chirp-based positioning signals are shown using a first chirp rate α2 .

[0183] In yet another aspect of the present application, the distinguishability of received chirp-based positioning signals may be enhanced by configuring the transmission of chirp-based positioning signals to be performed using a hybrid approach, wherein a mix of different time and frequency resources is defined and different chirp rates are used within the defined resources, such as Fig.19 shown. Fig.19 A resource grid 1900 defined by frequency slots and time slots is shown. Fig.19 A given time / frequency resource in may have a chirp-based positioning signal defined to use one chirp rate or multiple chirp rates.

[0184] Fig. 20 The communication between SMF 176, TX-AN node 2002, RX-AN node 2004 and UE 2006 is shown in the signal flow diagram. UE 2006 can be understood to represent a low power UE or an extremely low power UE. Initially, SMF 176 can provide UE 2006 (step 702, see Figure 7 ) Based on the chirped positioning signal configuration, it is expected that UE 2006 will enter a low power mode. Alternatively, SMF 176 may provide UE 2006 with (step 702, see Figure 7 ) backscatter configuration, it is expected that UE 2006 will enter a very low power mode. These configurations can be provided through control signaling (e.g., RRC signaling) or as part of a media access control-control element ("MAC-CE") (step 702).

[0185] UE 2006 may then send (step 2012) a mode / status report including an indication that UE 2006 is about to enter a low power mode or an extreme power mode. Upon receiving (step 2014) the mode / status report, SMF 176 may assign (step 704) an anchor node (TX-AN node 2002, RX-AN node 2004) to the target UE 2006. This assignment (step 704) may be based in part on coarse positioning information about the target UE 2006, taking into account the type of low power mode indicated in the mode / status report.

[0186] For example, in response to a mode / state report indicating an extremely low power mode of the target UE 2006, the SMF 176 may allocate an anchor node that is proximate to the target UE 2006. Such proximities may enhance the likelihood of reliable reception of the backscattered chirp-based positioning signal associated with the ELP-specific positioning procedure described above at the anchor node. The SMF 176 may transmit a chirp-based positioning signal configuration to both the TX-AN node 2002 and the RX-AN node 2004 while allocating the transmission (step 704) (step 702).

[0187] After receiving (step 1002) the anchor point assignment and chirp-based positioning signal configuration, the RX-AN node 2004 may send (step 2016) a LOS indication to the TX-AN node 2002. The TX-AN may respond by sending (step 2018) a request for some angle measurements to the RX-AN node 2004. The transmission of the LOS indication (step 2016) and the transmission of the request (step 2018) are optional and may be used when the SMF 176 fails to find multiple RX-AN nodes or when there is a need to increase the reliability and accuracy of various positioning procedures.

[0188] The TX-AN node 2002 sends (step 804) a chirp-based forward positioning signal. The chirp-based forward positioning signal can be regarded as a simulated PRS.

[0189] As part of entering low power mode, the target UE 2006 can turn on a matched filter. Upon receiving (step 904) the chirp-based forward positioning signal, the target UE 2006 can obtain some measurements and process (step 906) the chirp-based forward positioning signal. As described above, the processing (step 906) can involve both RF processing (e.g., matched filtering) and some limited digital processing. Then, the target UE 2006 can send (step 910) a chirp-based reverse positioning signal.

[0190] As part of entering the very low power mode, the target UE 2006 can turn on the backscatter receiver. Upon receiving (step 904) the chirp-based forward positioning signal, the target UE 2006 can backscatter (i.e., transmit) (step 910) the chirp-based reverse positioning signal to which the signature is applied. The transmission of the chirp-based reverse positioning signal to which the signature is applied (step 910) can be regarded as the analog counterpart of transmitting a digital SRS.

[0191] The RX-AN node 2004 may receive (step 1006) the chirp-based reverse positioning signal and process (step 1008) the measurement value of the chirp-based reverse positioning signal to obtain the parameter. The RX-AN node 2004 may then send (step 1010) a parameter indication to 176 or another network entity.

[0192] Similarly, the TX-AN node 2002 may receive (step 806) a chirp-based reverse positioning signal and process (step 808) the measurement value of the chirp-based reverse positioning signal to obtain the parameter. The TX-AN node 2002 may then send (step 810) a parameter indication to the SMF 176 or another network entity.

[0193] Upon receiving (step 706) the parameter, SMF 176 may process (step 708) the parameter to obtain location information of the target UE 2006.

[0194] In the case where the SMF 176 is co-located with any other network node (e.g., TX-AN node 2002 or RX-AN node 2004), the Fig. 20 The transmission and reception in the method are appropriately modified, and the modifications are obvious to those skilled in the art.

[0195] It should be understood that one or more steps in the embodiment method provided herein can be performed by corresponding units or modules. For example, data can be sent by a sending unit or a sending module. Data can be received by a receiving unit or a receiving module. Data can be processed by a processing unit or a processing module. The corresponding unit / module can be hardware, software, or a combination thereof. For example, one or more units / modules can be integrated circuits, such as field programmable gate arrays (FPGA) or application-specific integrated circuits (ASIC). It should be understood that if these modules are software, these modules can be retrieved in whole or in part by a processor as needed, retrieved individually or collectively for processing, retrieved in one or more instances as needed, and these modules themselves can include instructions for further deployment and instantiation.

[0196] Although combinations of features are shown in the illustrated embodiments, it is not necessary to combine all of the features to achieve the advantages of the various embodiments of the present invention. In other words, a system or method designed according to an embodiment of the present invention does not necessarily include all of the features shown in any one of the accompanying drawings or in all of the parts schematically shown in the accompanying drawings. In addition, selected features of an exemplary embodiment may be combined with selected features of other exemplary embodiments.

[0197] Although the present invention has been described with reference to illustrative embodiments, this description is not intended to be interpreted in a limiting sense. Various modifications and combinations of the illustrative embodiments and other embodiments of the present invention will be apparent to those skilled in the art with reference to this specification. Therefore, the appended claims are intended to cover any such modifications or embodiments.

Claims

1. A method for obtaining a location of a target user equipment (UE), characterized in that: The method comprises: Before the target UE enters the low power mode, sending configuration information of a first positioning signal to the target UE; Sending the configuration information of the first positioning signal to a network anchor node; receiving an indication of a plurality of parameters from the network anchor node, wherein the plurality of parameters are obtained by the network anchor node from a second positioning signal, the second positioning signal being received at the network anchor node from the target UE, the second positioning signal being based on the first positioning signal; The location information of the target UE is obtained from the multiple parameters.

2. The method according to claim 1, characterized in that The first positioning signal comprises a frequency modulated continuous wave signal.

3. The method according to claim 1 or 2, characterized in that: The configuration information includes one or more of the following: chirp rate, start frequency, signature frequency, time delay of fixed duration, duration, time and frequency resources, transmission power or period.

4. The method according to any one of claims 1 to 3, characterized in that The network anchor node is UE.

5. The method according to any one of claims 1 to 3, characterized in that The network anchor node is a network node with a fixed location.

6. The method according to any one of claims 1 to 5, characterized in that Also includes: An indication is sent to the network anchor node that the network anchor node has been assigned as an anchor node for the target UE.

7. A method for facilitating obtaining a location of a target user equipment (UE), characterized in that: The method comprises: Receiving configuration information at a network anchor node; receiving a second positioning signal at the network anchor node, wherein the second positioning signal corresponds to a first positioning signal changed by the target UE, wherein the first positioning signal has been defined in the configuration information; Acquiring, at the network anchor node, a plurality of parameters from the second positioning signal; An indication of the plurality of parameters is sent from the network anchor node to a location acquisition node.

8. The method according to claim 76, characterized in that The multiple parameters include one or more of the following: an estimated value of the distance between the network anchor node and the target UE, or an arrival angle of the second positioning signal.

9. The method according to claim 7 or 86, characterized in that: Also includes: The first positioning signal is sent from the network anchor node according to the configuration information.

10. The method according to any one of claims 7 to 96, characterized in that The network anchor node is UE.

11. The method according to any one of claims 7 to 96, characterized in that The network anchor node is a network node with a fixed location.

12. The method according to any one of claims 7 to 11, characterized in that Also includes: An indication is received at the network anchor node that the network anchor node has been assigned as an anchor node for the target UE.

13. A method for facilitating obtaining a location of a target user equipment (UE), characterized in that: The method comprises: Receiving configuration information of a positioning signal at the target UE; Receiving a first positioning signal at the target UE according to the configuration information; Changing the first positioning signal at the target UE to generate a second positioning signal; The second positioning signal is sent at the target UE.

14. The method according to claim 13, characterized in that The changing the first positioning signal includes time shifting the first positioning signal.

15. The method according to claim 13, characterized in that The sending the second positioning signal includes backscattering the first positioning signal.

16. The method according to claim 15, characterized in that The altering of the first positioning signal includes applying a signature to the first positioning signal during the backscattering.

17. The method according to claim 16, characterized in that The signature includes the frequencies specified in the configuration information.

18. The method according to claim 16, characterized in that The application is started after a delay, an indication of the delay being included in the configuration information.

19. A device, characterized in that: The apparatus comprises a processor configured to cause the apparatus to perform a method according to any one of claims 1 to 18.

20. A processor of a device, characterized in that: The processor is configured to cause the apparatus to perform the method according to any one of claims 1 to 18.

21. A computer program product, characterized in that The computer program product comprises instructions which, when the program is executed by a computer, cause the computer to perform the method according to any one of claims 1 to 18.

22. A system, characterized in that: include: A first network node for acquiring a location of a target user equipment (UE), wherein the first network node is configured to send configuration information of a first positioning signal, and receive a plurality of parameters acquired from a second positioning signal according to the first positioning signal, so as to acquire location information of the target UE from the plurality of parameters; a second network node in communication with the first network node, wherein the second network node is configured to receive the second positioning signal from the target UE and send an indication of the plurality of parameters obtained from the second positioning signal to the first network node, wherein the second positioning signal corresponds to the first positioning signal changed by the target UE.

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