Sensing-assisted positioning of mobile devices

Abstract

Some embodiments of the invention provide a location management function that receives a sensing-based profile from a sensor system, the sensing-based profile comprising a sensing-based observation of a UE; and receives a reference signal-based observation of the UE from a communication system. The location management function can derive a location hypothesis from the sensing-based observation and can determine UE identity information of the UE from the reference signal-based observation. By processing the reference signal-based observation in conjunction with the sensing-based observation, the location management function can determine an association between the sensing-based observation and the reference signal-based observation. The location management function can then send an indication of the location hypothesis derived from the sensing-based observation to the UE with the UE identity information determined from the reference signal-based observation.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application No. 16 / 939,579, filed July 27, 2020, entitled “SENSING-ASSISTED POSITIONING OF MOBILE DEVICES,” which is incorporated by reference herein in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates generally to positioning procedures of mobile devices, and in particular embodiments, to using sensing to assist in positioning. BACKGROUND

[0004] User equipment (UE) location information is used in cellular communication networks to improve various performance metrics of the network. Such performance metrics can include capacity, agility, and efficiency, for example. Improvements can be realized when elements of the network utilize the location, behavior, mobility patterns, etc. of the UE in the context of a priori information describing the wireless environment in which the UE operates. The a priori information can be collected by a sensing system separate from the communication system. Alternatively, using an integrated system to collect the a priori information can be advantageous to reduce hardware (and cost) in the system; however, building a radio frequency map of the wireless environment using the same hardware as the communication system is a highly challenging and open problem. The difficulty of this problem is related to factors such as the limited resolution of the communication system, the dynamic nature of the environment, and the large number of objects whose electromagnetic characteristics and locations need to be estimated.

[0005] It is known to use a UE to assist in determining the UE’s location. In downlink observed time difference of arrival (OTDOA), the UE receives downlink signals from a serving base station and multiple neighboring base stations. The UE then determines the time difference between the arrival of the downlink signals. The UE sends the time difference information to the base stations. The base stations determine the location of the UE based on the time difference information. OTDOA suffers from synchronization errors due to residual bias and skew when the transmitting and receiving points are different BSs. In uplink time difference of arrival (U-TDOA), a high-sensitivity receiver receives uplink transmissions from the UE at a base station. The receiver determines the time difference of arrival, thereby determining the UE’s location. It is known that U-TDOA is affected by timestamp delays due to variations in processing time. The positioning accuracy using OTDOA or U-TDOA depends on the processing capabilities of the UE. Processing capabilities can include, for example, the sampling rate implemented at the UE. SUMMARY

[0006] The location management function can combine the sensing-based technique with the reference signal-based technique to enhance the location determination. The location management function can receive a sensing-based profile from a sensor system, the sensing-based profile comprising a sensing-based observation of a UE; and can receive a reference signal-based observation of the UE from a communication system. The location management function can derive a location hypothesis from the sensing-based observation, and can determine UE identity information of the UE from the reference signal-based observation. By processing the reference signal-based observation in conjunction with the sensing-based observation, the location management function can determine an association between the sensing-based observation and the reference signal-based observation. The location management function can then send an indication of the location hypothesis derived from the sensing-based observation to the UE with the UE identity information determined from the reference signal-based observation.

[0007] Based on various aspects of the present application, the sensor system and the communication system are part of the same transmission point device, avoiding synchronization issues. Moreover, since the baseband signal processing does not rely on the UE, limited UE baseband processing capabilities do not hinder aspects of the present application to determine a location hypothesis of a UE. When deriving a location hypothesis from a sensing-based observation, the location management function can use Doppler analysis techniques to decouple echoes from moving UEs and static clutter.

[0008] According to an aspect of the present application, a method of indicating a location of a device to the device is provided. The method comprises obtaining a sensing-based profile from a profile origin, the sensing-based profile comprising a sensing-based observation of the device; obtaining a reference signal-based observation; sending an indication of a location hypothesis to a device associated with device identity information based on an association between the location hypothesis and the device identity information. The location hypothesis is derived from the sensing-based observation. The device identity information of the device is determined from the reference signal-based observation. The reference signal-based observation is processed in conjunction with the sensing-based observation to determine the association between the location hypothesis and the device identity information. Moreover, aspects of the present application provide an apparatus for performing the present method and a computer readable medium for causing a processor to perform the present method. BRIEF DESCRIPTION OF DRAWINGS

[0009] For a more complete understanding of the present embodiments and their advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which:

[0010] Figure 1 A communication system in which embodiments of the present application can be implemented is shown in schematic form and comprises an exemplary user equipment and an exemplary location management function;

[0011] Figure 2 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram

[0012] Figure 3 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram

[0013] Figure 4 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram

[0014] Figure 5 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram

[0015] Figure 6 An example user equipment of a communication system is illustrated in a block diagram An example user equipment of a communication system is illustrated in a block diagram

[0016] An example user equipment of a communication system is illustrated in a block diagram Figure 7 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram

[0017] Figure 8 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram

[0018] Figure 9A An example user equipment of a communication system is illustrated in a block diagram An example user equipment of a communication system is illustrated in a block diagram

[0019] An example user equipment of a communication system is illustrated in a block diagram Figure 9B An example user equipment of a communication system is illustrated in a block diagram An example user equipment of a communication system is illustrated in a block diagram

[0020] An example user equipment of a communication system is illustrated in a block diagram Figure 10 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram An example user equipment of a communication system is illustrated in a block diagram

[0021] An example user equipment of a communication system is illustrated in a block diagram Figure 11 An example user equipment of a communication system is illustrated in a block diagram Figure 1 An example user equipment of a communication system is illustrated in a block diagram An example user equipment of a communication system is illustrated in a block diagram

[0022] An example user equipment of a communication system is illustrated in a block diagram Figure 12 An example user equipment of a communication system is illustrated in a block diagram Figure 1observing and position indication round interactions between elements of a network, including three base stations, two user equipments, and a location management function;

[0023] Figure 13 Exemplary steps in a method of operating a location management function are shown, provided in accordance with aspects of the present application;

[0024] Figure 14 It is shown that a first sensing round can include multiple observations, and in accordance with aspects of the present application, a sensing frame can be formed from multiple observations;

[0025] Figure 15 It is shown that a method of operating a user equipment, provided in accordance with aspects of the present application, Figure 1 a first plot of transmit power of a base station of the network relative to time, and Figure 1 a second plot of receive power of the base station relative to time;

[0026] Figure 16 It is shown that a method of operating a user equipment, provided in accordance with aspects of the present application, Figure 15 a first plot of transmit power of a base station of the network relative to time, and Figure 1 a second plot of receive power of the base station relative to time;

[0027] Figure 17 Some signaling involved in implementing the mechanisms described above is shown in a signal flow diagram, in which a user equipment is used to transmit an uplink UE-associated indicator, in accordance with aspects of the present application;

[0028] Figure 18 It is shown that a method of operating a user equipment, provided in accordance with aspects of the present application, Figure 1 a single base station of the network as a source of four beams;

[0029] Figure 19 It is shown that a method of operating a user equipment, provided in accordance with aspects of the present application, DETAILED DESCRIPTION

[0030] For illustrative purposes, specific exemplary embodiments will be described in greater detail below with reference to the accompanying drawings.

[0031] The embodiments set forth herein represent information sufficient to enable those skilled in the art to practice the claimed subject matter and illustrate the best modes of practicing the claimed subject matter. The subject matter of the present application is, however, subject to additional variations and practices, and it is understood that

[0032] Furthermore, it should be understood that any module, component, or device disclosing executable instructions herein 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 tape cassettes, magnetic tape, disk storage or other magnetic storage devices, compact disc read-only memory (CD-ROM), digital video disc or digital versatile disc (DVD), and Blu-ray disc. TM Optical discs or other optical storage devices; 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 storage technologies. Any such non-transitory computer / processor storage medium may be part of a device or may be accessed or connected to a device. Computer / processor-readable / executable instructions used to implement the applications or modules described herein may be stored or otherwise preserved by such non-transitory computer / processor-readable storage media.

[0033] While current communication systems are equipped to extensively estimate UE location, future networks aim to determine UE location with centimeter-level accuracy and extremely high robustness. In addition to location information, pose information is also required. "Pose" information refers to information about the UE's velocity and orientation (attitude). Several factors make obtaining accurate UE location and pose information difficult. First, terrestrial radio channels can cause impairments, such as multipath interference and shadowing. These impairments may be considered detrimental to obtaining accurate pose information. Second, interference from neighboring cells (due to frequency reuse) can manifest as additive noise, exhibiting both short-term and long-term dependencies. This interference can be proven to affect the accuracy of location estimation. Third, due to regulatory caps on permissible electromagnetic (EM) radiation, the accuracy of location estimation is further limited by the maximum power that the communication system can radiate. Fourth, the accuracy of location estimation is even further limited by the bandwidth limitations of the entire system.

[0034] Figure 1An example communication system 100 is shown in schematic form. Generally, the communication system 100 is capable of transmitting data and other content among a plurality of wireless or wireline elements. The purpose of the communication system 100 can be to provide content (voice, data, video, text) through broadcast, narrowcast, user equipment to user equipment, etc. The communication system 100 can operate efficiently by sharing resources such as bandwidth.

[0035] In the present example, the communication system 100 includes first, second, and third user equipment (UE) 110A, 110B, and 110C (individually or collectively, UEs 110), first and second radio access networks (RANs) 120A and 120B (individually or collectively, RANs 120), a core network 130, a public switched telephone network (PSTN) 140, the Internet 150, other networks 160, and a location management function (LMF) 190. More generally, each UE 110 can be referred to as an electronic device. Although Figure 1 A certain number of these components or elements are shown, but any reasonable number of these components or elements can be included in the communication system 100.

[0036] The UEs 110 are used for operation and / or communication in the communication system 100. For example, the UEs 110 are used for transmitting and / or receiving over wireless communication channels. Each UE 110 represents any suitable end-user device for wireless operation and can include (or be referred to as) a wireless transmit / receive unit (WTRU), a mobile station, a mobile user unit, a cellular telephone, a station (STA), a machine-type communication (MTC) device, an Internet of Things (IoT) device, a personal digital assistant (PDA), a smartphone, a notebook, a computer, a touchpad, a wireless sensor, or a consumer electronics device.

[0037] In Figure 1In particular embodiments, the first RAN 120A includes a first base station 170A, and the second RAN includes a second base station 170B (singularly or collectively 170). A base station 170 can also be referred to as an anchor point or a transmit point (TP). Each base station 170 is configured to wirelessly interface with one or more UEs 110 through an interface to enable access to any of the base stations 170, core network 130, PSTN 140, Internet 150, and / or other networks 160. For example, a base station 170 can include (or can be) one or more of several well-known devices, such as a base transceiver station (BTS), a base station (NodeB), an evolved NodeB (eNodeB), a Home eNodeB, a next generation base station (gNodeB), a transmission and receive point (TRP), a site controller, an access point (AP), or a wireless router. Any UE 110 can optionally or additionally be configured to interface with any other base station 170, Internet 150, core network 130, PSTN 140, other networks 160, or any combination of the above. The communication system 100 can include a RAN, such as RAN 120B, in which a corresponding base station 170B accesses the core network 130 via the Internet 150, as shown.

[0038] The UEs 110 and base stations 170 are examples of communication devices that can be used to implement some or all of the functionality and / or embodiments described herein. In particular embodiments, the UEs 110 and base stations 170 can be configured to implement the functionality described herein. Figure 1In the illustrated embodiment, the first base station 170A is part of a first RAN 120A, which can include other base stations (not shown), one or more base station controllers (BSCs) (not shown), one or more radio network controllers (RNCs) (not shown), relay nodes (not shown), elements (not shown), and / or devices (not shown). Any of the base stations 170 can be a standalone element as illustrated, or can be distributed across multiple elements in the corresponding RAN 120, etc. Likewise, the second base station 170B is part of a second RAN 120B, which can include other base stations, elements, and / or devices. Each base station 170 transmits and / or receives wireless signals within a particular geographic area, sometimes referred to as a “cell” or “coverage area.” A cell can be further divided into cell sectors. For example, a base station 170 can use multiple transceivers to provide service for multiple sectors. In some embodiments, there can be established pico cells or femto cells supported by wireless access technologies. In some embodiments, multiple transceivers can be used for each cell by using multiple-input multiple-output (MIMO) techniques, etc. The number of RANs 120 illustrated is merely exemplary. Any number of RANs can be considered when designing the communication system 100.

[0039] The base stations 170 communicate with the one or more UEs 110 through one or more air interfaces 180 using radio frequency (RF), microwave, infrared (IR), visible light (VL) communication links, etc. The air interfaces 180 can utilize any suitable wireless access technology. For example, the communication system 100 can implement one or more channel access schemes, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA), among others, on the air interfaces 180.

[0040] The base stations 170 can implement a universal mobile telecommunications system (UMTS) terrestrial radio access (UTRA) to establish the air interface 180 using wideband CDMA (WCDMA). In this case, the base stations 170 can implement protocols such as high speed packet access (HSPA), evolved HSPA (HSPA+), optionally including high speed downlink packet access (HSDPA), high speed packet uplink access (HSUPA), or both. Alternatively, the base stations 170 can implement LTE, LTE-A, LTE-B, and / or 5G new radio (NR) using E-UTRA. It is contemplated that the communication system 100 can use multiple access technologies including schemes as described above. Other wireless technologies for implementing the air interface can include IEEE 802.11, 802.15, 802.16, CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, IS-2000, IS-95, IS-856, GSM, EDGE, and GERAN. Of course, other multiple access schemes and wireless protocols can be utilized.

[0041] The RAN 120 is in communication with the core network 130 to provide the UEs 110 with access to various services, such as voice, data, and other communication services. The RAN 120 and / or the core network 130 can be in direct or indirect communication with one or more other RANs (not shown) that can or can not be directly served by the core network 130 and can or can not utilize the same radio access technology as the first RAN 120A and / or the second RAN 120B. The core network 130 can also serve as a gateway for the RAN 120 or UEs 110 or both to access other networks (such as the PSTN 140, the Internet 150, and the other networks 160) as well.

[0042] The UEs 110 can communicate with one another using wireless communication links, such as radio frequency (RF), microwave, infrared (IR) wireless communication links, visible light (VL) communication links, etc. The UEs 110 can communicate with one another through one or more sidelink (SL) air interfaces 180. The SL air interface 180 can use any suitable wireless access technology and can be substantially similar to, or different from, the air interface 180 over which the UEs 110 communicate with one or more base stations 170. For example, the communication system 100 can implement one or more channel access methods in the SL air interface 180, such as CDMA, TDMA, FDMA, OFDMA, or SC-FDMA. In some embodiments, the SL air interface 180 can be implemented at least partially over unlicensed spectrum.

[0043] Some or all of the UEs 110 can include functionality for communicating over different wireless links with different wireless networks using different wireless technologies and / or protocols. The UEs 110 can communicate with a service provider or switch (not shown) and with the Internet 150 through wired communication channels, without wireless communication (or in addition to wireless communication). The PSTN 140 can include a circuit- switched telephone network that provides the plain old telephone service (POTS). The Internet 150 can include computer networks and / or subnetworks (intranets) and includes protocols such as the Internet Protocol (IP), the transmission control protocol (TCP), and the user datagram protocol (UDP). The UEs 110 can be multi-mode devices capable of operating according to multiple wireless access technologies and include multiple transceivers needed to support multiple wireless access technologies.

[0044] Figure 2 、 Figure 3 and Figure 4 Exemplary devices that can implement the methods and teachings provided herein are shown. In particular, Figure 2 An exemplary UE 110 is shown, Figure 3 An exemplary base station 170 is shown, Figure 4 An exemplary location management function 190 is shown. Figure 1 These components can be used in the communication system 100, or any other suitable system.

[0045] As Figure 2As shown, the UE 110 includes at least one processing unit 200. The processing unit 200 implements various processing operations of the UE 110. For example, the processing unit 200 could perform signal coding, data processing, power control, input / output processing, or any other functionality enabling the UE 110 to operate in the communication system 100. The processing unit 200 can also be used to implement some or all of the functionality and / or embodiments described above. Each processing unit 200 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 200 could, for example, be a microprocessor, microcontroller, digital signal processor, field programmable gate array, application specific integrated circuit, or the like.

[0046] The UE 110 also includes at least one transceiver 202. The transceiver 202 is used to modulate data or other content for transmission by at least one antenna or network interface controller (NIC) 204. The transceiver 202 is also used to demodulate data or other content received by the at least one antenna 204. Each transceiver 202 includes any suitable structure for generating a signal for transmission or processing a signal received via a wireless or wired medium. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals. One or multiple transceivers 202 could be used in the UE 110. One or multiple antennas 204 could be used in the UE 110. Although the transceiver 202 is shown as a single functional unit, the transceiver 202 could also be implemented using at least one transmitter and at least one separate receiver.

[0047] The UE 110 also includes one or more input / output devices 206 or interfaces (such as a wired interface to the Internet 150). The input / output devices 206 support interactions with a user or other devices in the network. Each input / output device 206 includes any suitable structure for providing information to or receiving information from a user, including network interface communications, such as a speaker, microphone, keypad, keyboard, display, or touch screen.

[0048] In addition, UE 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 for implementing some or all of the functions and / or embodiments described above and executed by one or more processing units 200. Each memory 208 includes any suitable one or more volatile and / or non-volatile storage and retrieval devices. Any suitable type of memory can be used, such as random access memory (RAM), read-only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, etc.

[0049] like Figure 3 As shown, base station 170 includes at least one processing unit 350, at least one transmitter 352, at least one receiver 354, one or more antennas 356, at least one memory 358, and one or more input / output devices or interfaces 366. Transceivers (not shown) may be used instead of transmitters 352 and receivers 354. Scheduler 353 may be coupled to processing unit 350. Scheduler 353 may be included within base station 170 or operate separately from base station 170. Processing unit 350 implements various processing operations of base station 170, such as signal encoding, data processing, power control, input / output processing, or any other functions. Processing unit 350 may also be used to implement some or all of the functions and / or embodiments described in more detail above. Each processing unit 350 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 350 may include a microprocessor, microcontroller, digital signal processor, field-programmable gate array, or application-specific integrated circuit.

[0050] Each transmitter 352 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each receiver 354 includes any suitable structure for processing signals received from one or more EDs or other devices wirelessly or wired. Although illustrated separately, at least one transmitter 352 and at least one receiver 354 can be combined into a transceiver. Each antenna 356 includes any suitable structure for transmitting and / or receiving wireless or wired signals. Although illustrated as being coupled to both the transmitter 352 and the receiver 354, one or more antennas 356 can be coupled to one or more transmitters 352, one or more separate antennas 356 can be coupled to one or more receivers 354. Each memory 358 includes any suitable volatile and / or non-volatile storage and retrieval devices, such as those described above in connection with UE 110. The memory 358 stores instructions and data used, generated, or collected by the base station 170. For example, the memory 358 could store software

[0051] Each input / output device 366 can interact with a user or other devices in the network. Each input / output device 366 includes any suitable structure for providing information to or receiving information from a user, including an network interface communication.

[0052] In some aspects of the application, the location management function (LMF) 190 can be implemented as a physical, standalone entity located at the core network 130 and connected to a plurality of BSs 170. In other aspects of the application, the LMF 190 can be implemented as a logical entity co-located within the BS 170 by logic executed by the processing unit 350.

[0053] As Figure 4As shown, the LMF 190, when implemented as a physical standalone entity, includes at least one processing unit 450, at least one transmitter 452, at least one receiver 454, one or more antennas 456, at least one memory 458, and one or more input / output devices or interfaces 466. A transceiver (not shown) can be used instead of the transmitter 452 and receiver 454. A scheduler 453 can be coupled to the processing unit 450. The scheduler 453 can be included within the LMF 190 or operate separately from the LMF 190. The processing unit 450 implements various processing operations of the LMF 190, e.g., signal coding, data processing, power control, input / output processing, or any other functionality. The processing unit 450 can also be used to implement

[0054] Each transmitter 452 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each receiver 454 includes any suitable structure for processing signals received from one or more BSs 170, UEs 110, or other devices via wireless or wired transmission. Although shown as separate components, at least one transmitter 452 and at least one receiver 454 can be combined into a transceiver. Each antenna 456 includes any suitable structure for transmitting and / or receiving wireless or wired signals. Although the common antennas 456 are shown coupled to both the transmitters 452 and receivers 454, one or more antennas 456 can be coupled to one or more transmitters 452, and one or more separate antennas 456 can be coupled to one or more receivers 454. Each memory 458 includes any suitable volatile and / or non-volatile storage and retrieval devices, such as those described above in connection with the UE 110. The memory 458 stores instructions and data used, generated, or collected by the LMF 190. For example, the memory 458 could store software

[0055] Each input / output device 466 can interact with a user of the network or with other devices. Each input / output device 466 includes any suitable structure for providing information to or receiving information from a user, including a network interface communication.

[0056] The term RADAR (Radar) is an acronym for the phrase radio azimuth direction and ranging. However, the term RADAR does not necessarily always have all capital letters; "RADAR," "Radar," and "radar" are equally valid. Radar is commonly used to detect the presence and location of objects. A system that uses a type of radar called "pulse radar" radiates pulses of energy and receives the return echoes from one or more targets. The system determines the pose of a given target from the return echoes from the given target. A system that uses another type of radar called "pulse compression radar" uses the same energy as a pulse radar system. However, in a pulse compression radar system, the energy is spread in time and frequency to reduce the instantaneous radiated power.

[0057] Given that radar systems are often used in spaceborne applications, a free space channel model can be used to approximate (i.e., ignore impairments such as multipath propagation and shadowing) the operation of a radar system. As such, in a free space channel model, a radar system can radiate pulses with sufficient power such that the received return echoes have sufficient power to accomplish the task of estimating the characteristics of a moving target. These characteristics can include, for example, velocity and position.

[0058] In ground-based applications, multipath propagation and shadowing are major impairments. Because of these impairments, return echoes are attenuated, making pose estimation difficult. The radar cross section (RCS) of mobile device users and vehicles is not significant. Thus, in the presence of stronger return echoes received from clutter with more significant RCS, the weak return echoes from mobile device users and vehicles are often not perceived by commercial radar receivers due to the inherent noise.

[0059] Another challenge of using radar systems for ground-based applications, as compared to airborne applications, is the problem of identifiability. In airborne applications, mobile targets such as airplanes, fighter jets, and missiles have different attributes that allow the targets to be distinguished from one another based on the return echoes of the pulses alone. For example, the radar cross section of a civilian airplane is larger than the radar cross section of a fighter jet. In addition, civilian airplanes typically fly at lower speeds and are less maneuverable than fighter jets. Furthermore, the speed of a missile is typically three times faster than the speed of the fastest airplane.

[0060] A ground-based radar system can be tasked with determining the position of each of hundreds of UEs 110 within a cell. Assuming that the return echoes from the UEs 110 have a detectable strength, typically, the return echoes do not allow for a distinction between the UEs 110. The target of an airborne radar system can be considered binary in that the target can be either friendly or enemy. In contrast, given the task of determining the position of many UEs 110, a ground-based radar system has a target that can be classified as a multiple hypothesis testing problem.

[0061] From a different perspective, target identifiability can be seen as a problem of associating observations with targets. This association problem is inherent to any passive remote sensing system, radar being one of them.

[0062] The impairments of pose estimation include system complexity and non-cooperation. Non-cooperation is related to the traditional intent of radar systems, namely to sense targets that are intrinsically non-cooperative, e.g., missiles; cars that exceed speed limits; celestial bodies; or fighter jets. When the target is active, i.e., the target is able to receive and respond to radar signals, and the target is willing to cooperate, identifiability can be considered not a problem. For example, a UE 110 in a cellular network can have an obligation to cooperate with elements of the cellular network, or can have an obligation to follow some guidelines that have been established for the cellular network. Unfortunately, when active pose estimation benefits from cooperation, active pose estimation is affected by system complexity.

[0063] The system complexity impairments of pose estimation include a wide variety of problems, including problems related to synchronization and problems related to limited spectral / spatial resolution of targets. The synchronization problem can be expressed as a problem related to the receiver of a sensing signal not knowing precisely the time and frequency reference of the transmitter of the sensing signal. It is noted that in a single-static radar setup, both the transmitting node and the receiving node are run by the same clock, and the time reference is intrinsically the same. Even in a double-static or multi-static setup, where the transmitter of a sensing signal and the receiver of a sensing signal are not co-located, the synchronization problem can be solved by frequent and accurate clock calibration. Such calibration can be achieved through a high-speed and low-latency backhaul link between the transmitter and the receiver. Achieving perfect synchronization between a UE 110 and a network entity that the UE 110 is to synchronize with can be considered a challenging problem.

[0064] Factors that contribute to errors in radio frequency (RF)-based positioning systems (passive and active) include: resolution; synchronization; association; non-line-of-sight (NLoS) signals; signal-to-noise ratio (SNR).

[0065] Clock synchronization between UEs 110 and BSs 170, as well as the limited capabilities of each UE 110, are significant problems that impede the implementation of centimeter-level positioning using the positioning subsystem within current cellular systems. Solving these two problems can be seen as a step toward achieving sub-meter position estimation accuracy. It is noted that sub-meter position estimation accuracy is expected to be a feature of the next generation of cellular systems. The next generation of cellular systems can be referred to as “6G”.

[0066] The problem of clock synchronization can be solved by using a radar system for determining the positioning of the UEs 110. Positioning using a radar system can prove to be immune to the effects of incomplete synchronization, for two main reasons: (1) radar systems utilize clocks that are highly stable against adversarial systems and environmental influences; (2) transmission, reception, and processing typically occur at the same anchor node, and reference a single timer and oscillator.

[0067] The problem of limited capabilities of each UE 110 can be solved in a manner that is completely different from the manner in which the problem of synchronization is solved. As many use cases emerge, users of a particular cellular network can have different processing capabilities and resources. For example, processing capabilities can be related to sampling rate and peak-to-average power ratio (PAPR). For example, resources can be related to transmit power.

[0068] In a reference signal-based positioning system (also known as an active positioning system), the BS 170 transmits some baseband symbols in a downlink (DL) RF reference signal. The UE 110 receives the DL reference signal, processes the DL reference signal to extract the baseband symbols, and responds to the DL reference signal using an upload (UL) RF reference signal, which can be based in part on processing the extracted baseband symbols.

[0069] The accuracy of a given reference signal-based positioning system can be seen as dependent on the capabilities of the weakest node that processes the DL reference signal. The capabilities of a given UE 110 in a cellular system are typically not as good as the capabilities of a BS 170 in the same cellular system. It is difficult to guarantee a minimum positioning accuracy for all UEs 110 of different use cases of the entire cellular system.

[0070] It is suggested herein to leverage a (passive) sensor positioning system to circumvent the various problems that exist in active positioning systems. These problems include the problem of synchronization and the problem of limited hardware capabilities.

[0071] An inherent characteristic of terrestrial cellular communication networks is that multipath signals and multi-agent environments cause difficulties when a BS 170 attempts to determine the location of a given UE 110 based on echoes of RF (e.g., radar) signals originating from the BS 170.

[0072] In particular, multipath propagation in the cellular network leads to multiple radar echoes received at the BS 170 from targets of different sizes and countless electrical properties. For the receiver at the BS 170, in order to be able to estimate the range and the angle to a particular UE 110, the task of the receiver is to isolate the radar echoes of the particular UE 110 from all received radar echoes, including radar echoes from other objects in the environment. It can be shown that the amount of power of an echo from an object (particular UE 110 or other object) depends on the size, shape and dielectric properties of the object. Unfortunately, other objects (buildings, ground, leaves, etc. that the receiver is not interested in) can show to produce radar echoes that are many orders of magnitude larger than the radar echoes caused by the UE 110. The radar echoes of interest can show to be masked by the larger radar echoes. The RCS of the UE 110 is smaller than the RCS of the other objects. In summary, proper decoupling of the radar echoes received from static objects from the radar echoes received from the UE 110 is an important problem to be solved.

[0073] Given the presence of multiple agents in the environment, determining the location of a particular UE 110 using a sensing-based system is impeded. Indeed, a given cellular communication network is crowded with many UEs 110. The location will be determined for each of the UEs 110.

[0074] Using a sensing-based system external to the cellular communication system, such as a radar system, can be seen as allowing to determine the location of a particular UE 110.

[0075] Unfortunately, the observation by the sensing-based system, such as radar echoes, provides little information that can be usefully exploited to infer the identity of the particular UE 110 associated with a particular radar echo. That is, given multiple radar echoes received from multiple UEs 110, there is expected to be ambiguity as to which radar echo is associated with which UE 110, and vice versa.

[0076] When there is an incorrect association observed with a particular UE 110, there is expected to be an impact on the accuracy of the location estimate of the particular UE 110. In fact, some of the impact on the accuracy can be described as catastrophic. An inaccurate location estimate can show to lead to erratic jumps (in the range of tens of meters to hundreds of meters) of the estimated location of the particular UE 110 at consecutive times. Given the typically limited kinematics of the UE 110, such a location jump is physically unreasonable.

[0077] Conventional methods involving BS 170 and UE 110 exchanging DL and UL reference signals in a cellular communication system to allow determination of the location of UE 110 are well known. Similarly, methods using a sensing-based system separate from the cellular communication system, such as a radar system, to allow determination of the location of UE 110 are also well known. Furthermore, methods combining the reference signal exchange method and the hardware-based sensing-based system method have also been the subject of research.

[0078] It can be shown that the implementation method of combining the reference signal exchange method and the hardware-based sensing-based system method is not simple. In fact, the reference signal exchange method and the hardware-based sensing-based system method can be considered as relying on fundamentally different technologies.

[0079] In light of the above, according to aspects of the present application, a location management function receives from a sensor system a sensing-based profile that can determine a sensing-based observation of a UE, and from a communication system a reference signal-based observation of the UE. The location management function can derive from the sensing-based observation a particular location hypothesis, and can determine from the reference signal-based observation UE identity information of the UE. By processing the reference signal-based observation in conjunction with the sensing-based observation, the location management function can determine an association between the sensing-based observation and the reference signal-based observation. The location management function can then send to the UE having the UE identity information determined from the reference signal-based observation an indication of the particular location hypothesis associated with the UE, wherein the particular location hypothesis has been derived from the sensing-based observation.

[0080] According to aspects of the present application, a sensor system radiates an energy pulse, and receives from one or more UEs 110 a return of the pulse. Due to the shared nature of the wireless medium through which the pulse propagates, it is clear that a single pulse can result in radar returns from multiple UEs 110. The sensor system records each radar return for processing. Processing the information in these recorded radar returns condenses the information into a limited set of features. For example, the features can include: round-trip delay; angle of arrival; Doppler shift; received power. These features can be referred to hereinafter as "observations".

[0081] Figure 5 Interactions between base station 170, UE 110, and location management function 190 are illustrated in a flowchart. Base station 170 includes sensor system 502 and communication system 504.

[0082] Generally, the location determination starts with a sensing round, continues with a reference signal exchange round, continues with a processing round, and ends with a location indication round. It is noted that the sensing round and the reference signal exchange round can occur in any order, or even simultaneously.

[0083] Initially, the sensor system 502 transmits a sensing signal, which can be, for example, a radar pulse. During a sensing round, the sensor system 502 receives echoes of the sensing signal from the UE 110 and other objects in the environment of the communication system 100.

[0084] The sensor system 502 can then acquire (step 506) a sensing-based profile. The sensing-based profile can represent geometric range measurements and / or angle measurements. Recall that a radar-based sensor system typically uses a transceiver (not specifically shown) that rotates continuously 360 degrees around a central axis. It is noted that a radar-based sensor system does not necessarily mechanically rotate to direct the direction of the beam. In other radar-based sensor systems, the beam can be electronically rotated while the hardware remains static. Geometric range measurements can be understood to relate to the distance between the transceiver and the origin of the echo. Angle measurements can be understood to relate to an angular span that is offset from a reference angle on a circle around the central axis, where the origin of the echo can be characterized by the angular span of the received echo. After the acquisition (step 506) of the sensing-based profile is completed, the BS 170 transmits the sensing-based profile to the location management function 190. The location management function 190 acquires (step 507) the sensing-based profile. In the context of the acquisition (step 507) of the sensing-based profile by the LMF 190, the BS 170 can be referred to generally as the profile origin.

[0085] During normal operation, the communication system 504 transmits a downlink (DL) reference signal, which can be received and processed by various entities in the communication system 100, including the UE 110. The DL reference signal is typically a high-power and wideband signal.

[0086] Upon reception of the DL reference signal, the UE 110 can acquire (step 508) a UE- reference signal (UE-RS)-based observation. The UE 110 can then transmit an uplink (UL) reference signal to the base station 170. The UL reference signal can include the UE-RS-based observation and an indication of the identity of the UE 110. Alternatively, or additionally, the UE 110 can transmit the UE-RS-based observation to the location management function 190 together with an indication of the identity of the UE 110. The location management function 190 acquires (step 509) the BS-RS-based observation.

[0087] The communication system 504 receives the UE-RS based observations from the UE 110. Conveniently, as described above, the UE-RS based observations include UE identification information of the UE 110 that has taken the UE-RS based observations. In response to receiving the UE-RS based observations, the base station 170 can take BS-RS based observations. The base station 170 can then transmit the BS-RS based observations to the location management function 190. Conveniently, the BS-RS based observations include the UE identification received as part of the UE-RS based observations.

[0088] Upon receiving both the sensing based profile and the RS based observations, the location management function 190 can process (step 510) the profile and the observations.

[0089] In one aspect, the processing (step 510) of the sensing based profile can be done through Doppler analysis. The location management function 190 can use Doppler analysis to separate echoes originating from the (mobile) UE 110 from echoes originating from (static) clutter in the environment. Echoes originating from the (mobile) UE 110 can be considered foreground signals. Echoes originating from the (static) clutter can be considered background signals.

[0090] Based on the combined geometry range measurements and angle measurements, a sensing based observation can be determined based on the profile, and the location management function 190 can derive a location associated with the UE 110 as the origin of the echoes from the sensing based observation.

[0091] The processing (step 510) of the sensing based profile and the BS-RS based observations can involve determining a sensing based observation from the sensing based profile, and can subsequently result in matching a particular one of the BS-RS based observations with a particular one of the sensing based observations. It is noted that since the location has been derived from the sensing based observation, and the UE identification information has been determined from the BS-RS based observation, the processing (step 510) can partly comprise associating the location derived from the particular sensing based observation with the UE identification information determined from the particular BS-RS based observation.

[0092] The location management function 190 can then transmit (step 511) an indication of the location derived from the sensing based observation to the UE 110 with the UE identification information determined from the reference signal based observations. It is noted that the indication of the location is not necessarily intended for transmission (step 511) to the UE 110. Rather, the indication of the location can be used for other tasks. The other tasks include predicting future mobility of the UE 110. The other tasks include managing beams transmitted from the BS 170. Beam management will be discussed below.

[0093] For example, the sensed observation can be a round trip time (RTT) measurement. In this case, for matching purposes, it is convenient that the BS-RS based observation is also an RTT measurement.

[0094] The RTT can be thought of as the time taken for a signal to travel from the BS 170 to the UE 110 and then back to the BS 170. For the sensor system 502, in one example, the outbound signal is a radar pulse and the inbound signal is an echo of the radar pulse. For the communication system 504, the outbound signal is a DL reference signal and the inbound signal is an UL reference signal including a UE-RS based observation.

[0095] In Figure 5 , there is only one BS 170 in the network. Therefore, it can be considered that the measurements performed at the BS 170 will be affected by clock biasing. The clock biasing can be understood by reviewing the curve shown in Figure 6 . The curve shown in Figure 6 includes a first line T BS (t) representing a base station time frame and a second line T UE (t) representing a user equipment time frame. The first line is described by a first function T BS (t) = t. The second line is described by a second function T UE (t) = at + b, where a represents a UE clock skew and b represents a UE clock bias.

[0096] The reference signal transmitted by the BS 170 at time t 1,n arrives at the UE 110 at time t 2,n = t 1,n + t, where t is a one-way propagation delay. The UE 110 receives the DL reference signal, processes the DL reference signal, accesses data to obtain a UE-RS based observation, and transmits an UL reference signal including the UE-RS based observation to the base station 170. Each of these four actions incurs a UE delay, A n , where

[0097] A n = receive delay + processing delay + access delay + transmit delay.

[0098] The UL reference signal transmitted by the UE 110 at time t 3,n arrives at the BS 170 at time t 4,n = t 3,n + t.

[0099] The communication system 504 can determine a reference signal round trip time, RTT p . The RTT pThis involves obtaining the time (time t) for transmitting the DL reference signal. 1,n ) and the time of receiving the UL reference signal (time t) 4,n The difference between them. That is,

[0100]

[0101] In obtaining (step 506) the sensed round-trip time (RTT) s In this case, it should be noted that there is no delay at UE 110 because the radar pulse is merely reflected, not processed. Therefore, once the radar pulse arrives at UE 110 and RTT... s =2τ, the echo leaves UE 110. If based on the sensing round-trip time (RTT)... s It is based on RS-based round-trip time (RTT). p If we consider this, then we can consider Δ n =0, to perform RRT s Estimate. It can also be assumed that, with the UE delay Δ observed based on RS... n With the component close to zero, the expected processing (step 510) profile (to determine the sense-based observation) and observations are performed in the sense-based observation (RTT). s ) and RS-based observation (RTT) p The accuracy of finding a match between ) will be improved.

[0102] The UE latency Δ depends on the hardware speed, access mechanism, and the amount of processing performed on the received data within the protocol stack at UE 110. n It can be several orders of magnitude larger than the one-way propagation delay τ. The problem is that this leads to an expectation, namely, RTT... p >>RTT s .

[0103] However, this application relates to UE 110 determining UE delay Δ n The estimated value Δ′ n And estimate Δ′ n Report to location management function 190. Upon receiving the estimated Δ′ n Subsequently, the configuration file and observation processing at location management function 190 (step 510) may involve the BS-RS-based observation RTT. p Application correction. The location management function 190 can subtract the estimated Δ′ from it. n RTT p ′=RTT p -Δ′ n To determine the observation RTT based on BS-RS p Corrected version RTT pThe location management function 190 can then attempt to find a match between the corrected RS-based observed RTT p and the sensing-based observed RTT s .

[0104] Furthermore, if the BS 170 has an estimate a' of the UE clock skew a, a more accurate correction to the RS-based observation can be determined from In aspects of the application, the estimate a' of the UE clock skew a can be determined by the UE 110. In other aspects of the application, the estimate a' of the UE clock skew a can be determined through a network-wide synchronization procedure.

[0105] As noted above, the LMF 190 receives a sensing-based profile and a BS-RS based observed RTT p . The processing (step 510) of the sensing-based profile and the BS-RS based observation can involve determining a sensing-based observed RTT s from the sensing-based profile, and can subsequently result in matching a particular one of the BS-RS based observed RTT p to a particular one of the sensing-based observed RTT s .

[0106] According to aspects of the application, in the case of proper synchronization between the BS 170 and the UE 110, the LMF 190 can receive and process RS-based one-way observations. That is, the LMF 190 can receive observations based on only DL reference signals (from the BS 170 to the UE 110) and / or only UL reference signals (from the UE 110 to the BS 170). When processing (step 510) the observations in this case, the LMF 190 can expect to match the RS-based one-way observations to a value representing half of the sensing-based observed RTT s .

[0107] In the foregoing, the UE 110's position hypothesis is derived using sensing at only one BS 170. This can be referred to as "single-static sensing." In aspects of the application, the UE 110's position hypothesis can be derived using two BSs 170. This can be referred to as "double-static sensing."

[0108] In scenarios where the communication subsystem and the sensing subsystem use a uniform wide pulse broadband waveform (e.g., used in the context of OFDM) and the base station does not have a full-duplex radio, single-static configuration can run into problems. The problem can be related to the power gap between the transmission pulse and the reception echo. Typically, the power in the transmission pulse is so strong and the power in the reception echo is so weak that, no matter how isolated the transmission / reception chains are, even a small leakage / induction from the transmission side to the reception side causes the reception echo to be completely drowned out. To solve this problem, a double-static sensing configuration can be used. In a double-static sensing configuration, the transmission point (TP) that transmits the sensing signal (pulse) is different from the TP that receives the echo. In this way, the radio on the reception side is not drowned out by the high-power signal on the transmission side because the distance between the transmission side and the reception side is large.

[0109] The range data obtained based on the profile obtained at the TP of the reception echo cannot be called RTT because the pulse does not make a "return" trip. Instead, the range data obtained based on the profile obtained at the TP of the reception echo can be called bi-centric range (BCR) data. When the BCR data is generated during the sensing round, the equivalent amount should be generated during the reference signal exchange round, therefore. The equivalent amount facilitates the matching in the observation processing step. The collection of the BCR data is illustrated in the flowchart of Figure 7 The first BS 170A transmits a downlink reference signal (DL-RS). In response to receiving the DL-RS, the UE 110 transmits an uplink reference signal (UL-RS) to the second BS 170B. In the manner familiar from the first embodiment described above, the intra-UE delay is minimized.

[0110] In one aspect of the application, the intra-UE delay is minimized by carrying the UL-RS immediately to the DL-RS. In another aspect of the application, the impact of the intra-UE delay on the accuracy of the BCR data can be minimized by the UE 110 accurately measuring and reporting the intra-UE delay to the location management function 190, so that the observation based on the BS-RS can be calibrated.

[0111] In the flowchart of Figure 7 The interaction between the first base station 170A, the second base station 170B, the UE 110, and the location management function 190 is illustrated in the flowchart of Figure 5the sensor system 502 in the first base station 170A. Although not specifically shown, the first base station 170A and the second base station 170B can be understood to include sensor systems similar to the sensor system 502 in the UE 110 and the sensor system 504 in the communication system 100. Figure 5 the communication system 504 in the first base station 170A. Although not specifically shown, the first base station 170A and the second base station 170B can be understood to include communication systems similar to the communication system 504 in the UE 110 and the communication system 504 in the communication system 100.

[0112] Initially, the first base station 170A transmits a sensing signal, which can be, for example, a radar pulse. During the sensing round, the sensor system of the second base station 170B receives echoes of the sensing signal from the UE 110 and other objects in the environment of the communication system 100.

[0113] The sensor system can then acquire (step 706) a sensing-based profile based on the sensing. Upon completion of the acquisition (step 706) of the sensing-based profile, the second base station 170B transmits the sensing-based profile to the location management function 190. The location management function 190 acquires (step 707) the sensing-based profile. In the context of the acquisition (step 707) of the sensing-based profile by the LMF 190, the BS 170 can be referred to generally as a profile origin.

[0114] The first BS 170A transmits a downlink (DL) reference signal that is receivable by the UE 110. The DL reference signal can be a high-power wideband signal. In accordance with aspects of the application, the UE 110 is used to receive the DL reference signal and generate an upload (UL) reference signal (RS). The UE 110 then transmits the UL-RS to the second BS 170B.

[0115] The communication system of the second BS 170B receives the UL reference signal (RS) from the UE 110. Conveniently, as described above, the UL-RS includes identification information of the UE 110 that has generated the UL-RS. In response to receiving the UL-RS, the communication system acquires (step 708) BS-RS-based observations. Based on particular BS-RS-based observations, the communication system can determine the identification information of the UE 110 and associate the identification information with the particular BS-RS-based observations.

[0116] At least some of the BS-RS-based observations acquired by the communication system in step 708 are of the same type and from the same UE 110 (in the context of multiple UEs 110) as at least some of the sensing-based observations that can be determined by the sensing system based on the acquired sensing-based profile in step 706. Upon completion of the acquisition (step 708) of the BS-RS-based observations, the second BS 170B transmits the BS-RS-based observations to the location management function 190. The location management function 190 acquires (step 709) the BS-RS-based observations.

[0117] The location management function 190 processes (step 710) the sensing-based profile obtained in step 707 to determine sensing-based observations and to derive a location of the UE 110. In one aspect, the processing (step 710) of the sensing-based profile can be done through Doppler analysis. The location management function 190 can use Doppler analysis to separate echoes from the (mobile) UE 110 from echoes from (static) clutter in the environment, which can be treated as background signals.

[0118] The location management function 190 also processes (step 710) the BS-RS based observations obtained in step 709 to determine UE identification information of the UE 110 from the BS-RS based observations.

[0119] Based on the same observations, the processing (step 710) of the location management function 190 can involve obtaining sensing-based observations from the sensing-based profile and can subsequently match certain BS-RS based observations with certain sensing-based observations. It is noted that since the sensing-based observations are associated with location hypotheses and the RS based observations are associated with UE identification information, the matching (step 710) can be used to associate locations with UE identification information.

[0120] The location management function 190 can then send (step 711) an indication of the location to the UE 110 associated with the UE identification information. It is noted that the indication of the location is not necessarily intended for sending (step 711) to the UE 110. Rather, the indication of the location can be used for other tasks. Other tasks include predicting future mobility of the UE 110. Other tasks include managing beams transmitted from the BS 170. Beam management will be discussed below.

[0121] Thus, it can be seen that a dual-static sensing configuration can be used such that the receive side radio is not overwhelmed by the high power signal from the transmit side.

[0122] Figure 7 The method outlined in the Summary can not be effective in locating all UEs 110 with different use cases.

[0123] For example, in one aspect, the processing (step 710) of the sensing-based profile has been described as being done through Doppler analysis. Doppler analysis is used to separate echoes from the (mobile) UE 110 from echoes from (static) clutter in the environment. It is noted that a given UE 110 can be fixed (e.g., an Internet of Things device) or have a variable speed (e.g., in a vehicle, the UE 110 can occasionally stop).

[0124] There are scenarios in which the UE 110 has an unimportant RCS, so that it cannot be detected even after Doppler analysis. One example of such a scenario is a pedestrian walking on a street.

[0125] There are scenarios in which the UE 110 cannot receive DL reference signals or transmit UL reference signals. A given UE 110 can not be able to transmit / receive with a signal-to-noise ratio (SNR) sufficient to allow accurate geometric measurements to be made or with a bandwidth sufficient to allow accurate geometric measurements to be made.

[0126] To Figure 7 The discussion phase of the method shown, the propagation phenomenon known as "multipath", i.e. the interaction of the signal with the clutter through reflection / refraction, is the only propagation phenomenon considered. It should be noted that there is another propagation phenomenon, known as "shadowing". Shadowing occurs when the direct path (line of sight in three-dimensional Euclidean space) connecting the UE 110 and the BS 170 is blocked by an object that attenuates (by absorption) all the energy of the line of sight of this propagating signal or sufficiently attenuates the propagating signal so that the received SNR of the direct propagating signal is below the detection threshold of the hardware at the UE 110.

[0127] Without considering the way in which shadowing occurs, shadowing causes a phenomenon known as non-Line-of-Sight (NLoS), which means that the strongest signal is received from an indirect path, without the receiver knowing that the path is indirect. Therefore, any range / angle estimation has a bias caused by the additional distance that the signal has travelled compared to the direct path. Since this shadowing bias is additive (in a similar way to a clock bias), the shadowing bias will break the association of the position information with the UE identity information according to the matching between the sensing-based observations and the RS-based observations. The break can be mitigated when the sensing signal (impulse) and the DL reference signal are transmitted at the same power in the same frequency range. The latter is usually not the case, since the large power, wide bandwidth and high frequency of the sensing signal are its defining characteristics.

[0128] A solution that partially solves these problems involves the UEs 110 communicating between them using Sidelink (SL) communication. Figure 8The interactions between the first base station 170A, the second base station 170B, the first UE 110A, the second UE 110B, the third UE 110, and the location management function 190 are illustrated in the form of a flowchart. The location management function 190 can create a cluster of UEs 110 and select one or more candidate UEs 110 as a cluster head (CH). The UE 110 selected as the CH (when there is only one) preferably has characteristics that are well suited for the CH. That is, the UE 110 selected as the CH should: be mobile; have no power limitations; have no bandwidth limitations; and have a LoS link to the BS 170.

[0129] In Figure 8 , it is considered that the first UE 110A has been selected as the CH.

[0130] Initially, the location management function 190 sends (step 802) an indication of the SL communication schedule to the UEs 110 in addition to an indication of the selection of the first UE 110A as the CH.

[0131] According to the SL communication schedule, the first UE 110A exchanges SL communications with the second UE 110B and the third UE 110C. Through this exchange, the first UE 110A, as the CH, acquires inter-UE measurements. For both examples, the first UE 110A can use ranging and proximity discovery to acquire inter-UE measurements associated with each UE 110 in the cluster.

[0132] The first UE 110A then sends an indication of its cluster head identifier (ID) and the inter-UE measurements acquired based on the SL communications with the other UEs 110 to the location management function 190. The location management function 190 receives (step 804) the cluster head ID and receives (step 806) the inter-UE measurements. The location management function 190 then proceeds to acquire (step 808) a profile and observations of the first UE 110A, which can be acquired, for example, in the form of a flowchart of Figure 5 or in the form of a flowchart of Figure 7 .

[0133] By processing (step 810) the configuration files and observations acquired in step 808, the location management function 190 can acquire the location of the first UE 110A. By processing the inter-UE measurements in conjunction with the location of the first UE 110A, the location management function 190 can determine the respective locations of the other UEs 110 in the cluster. In determining the locations, the location management function 190 sends (step 811) the locations to the UEs 110. It is noted that the indication of the locations is not necessarily for sending (step 811) to the UEs 110. Rather, the indication of the locations can be for other tasks. The other tasks include predicting the future mobility of the UEs 110. The other tasks include managing the beams sent from the BSs 170. Beam management will be discussed below.

[0134] Unfortunately, there is still ambiguity in matching (in steps 510, 710, or 810) certain RS-based observations with certain sensing-based observations when there are multiple UEs 110 in the environment.

[0135] It has been noted above that a sensing round includes the sensor system 502 sending a sensing signal. In fact, the sensor system 502 can send multiple successive sensing signals.

[0136] It has also been discussed that the Doppler analysis portion of the processing (in steps 510, 710, or 810) of the sensing-based configuration files can be used to separate foreground signals from background signals. The foreground signals are assumed to be due to echoes of the UEs 110. The background signals are assumed to be due to echoes of other objects, including static clutter. Unfortunately, the echoes of the other objects can be disproportionately large relative to the echoes of the UEs 110.

[0137] The Doppler analysis portion of the processing (in steps 510, 710, or 810) of the sensing-based configuration files can be a full Doppler analysis that includes an estimate of the non-zero velocity of the UEs 110. In this case, each object of clutter can be treated as a static object with zero velocity as part of the clutter cancellation process. It can be shown that longer duration sensing rounds make the separation of foreground signals from background signals better. In the case of range radar, one result of the Doppler analysis portion of the processing (in steps 510, 710, or 810) of the sensing-based configuration files can be seen as a processed power delay profile (processed PDP), and in the case of direction radar, as a processed power angle profile (processed PAP).

[0138] Figure 9A An example processed PDP is shown in FIG. 6. Figure 9B An example processed PAP is shown in FIG. 7.

[0139] Upon completion of the clutter cancellation process, the location management function 190 can be used to estimate (i) round-trip time (RTT) based on the processed PDP, and / or (ii) angle-of-arrival (AoA) measurements based on the processed PAP estimates, and / or (iii) velocity based on all peaks found in the profile (PDP and / or PAP).

[0140] At any given time in the communication system 100, more than one BS 170 can transmit sensing signals and reference signals. Thus, the location management function (LMF) 190 can receive RS-based observations and can receive sensing-based profiles from each of more than one BS 170.

[0141] In the case of range radar, in response to receiving the sensing-based profiles, the LMF 190 can determine a plurality of round-trip-time (RTT) measurements for each BS 170. The processed PDP associated with a particular BS 170 can be considered to have a time axis and a PDP functional axis (see Figure 9A ). The plurality of RTT measurements can be determined as the time axis value for each peak of the processed PDP. That is, if there are three peaks in the processed PDP, the LMF 190 will identify three RTT measurements.

[0142] The LMF 190 can designate one of the plurality of BSs 170 as a time reference. The LMF 190 can then obtain a plurality of RTT-difference-of-arrival (RTTDoA) scalar values for each BS 170 based on subtracting the RTT measurement of the time reference BS 170 from the RTT measurements of each BS 170. It should be clear that there is no value in obtaining the RTTDoA scalar value for the time reference BS 170 in this manner.

[0143] In the case of direction radar, in response to receiving the sensing-based profiles, the LMF 190 can determine a plurality of angle-of-arrival (AoA) measurements for each BS 170. The processed PAP associated with a particular BS 170 can be considered to have an angle axis and a PAP functional axis (see Figure 9B ). The plurality of AoA measurements can be determined as the angle axis value for each peak of the processed PAP. That is, if there are three peaks in the processed PAP, the LMF 190 will identify three AoA measurements.

[0144] The LMF 190 can designate one of multiple BS 170s as the space reference. The LMF 190 can then obtain multiple angle-difference-of-arrival (ADoA) scalar values ​​for each BS 170 (excluding the space reference BS 170) based on subtracting the AoA measurement of the space reference BS 170 from the AoA measurement of each BS 170 (excluding the space reference BS 170). It should be clear that obtaining the ADoA scalar value of the space reference BS 170 in this manner is of no value.

[0145] It should be noted that in some cases, the time reference BS 170 and the space reference BS 170 can be the same BS 170.

[0146] By collecting the scalar value of each non-reference BS 170, multiple difference vectors can be generated at LMF 190.

[0147] Multiple sense-based position hypothesis vectors can be determined by combining a scalar value formed from each difference vector.

[0148] For those BS 170s that differ from the time reference BS 170 and the spatial reference BS 170, the RTTDoA or ADoA obtained can be paired with each other to form multiple location hypothesis vectors.

[0149] exist Figure 10 The flowchart illustrates the sensing round interaction between the first base station 170A, the second base station 170B, the third base station 170C, the first UE 110A, the second UE 110B, and the location management function 190. Although not specifically shown, the first base station 170A, the second base station 170B, and the third base station 170C can be understood to include similar... Figure 5 The sensor system 502 in the image. Although not specifically shown, the first base station 170A, the second base station 170B, and the third base station 170C can be understood to include sensor systems similar to... Figure 5 The communication system 504 in the middle.

[0150] Each BS 170's sensor system transmits a sensing signal, which may be, for example, a radar pulse. During a sensing round, each BS 170 receives echoes of the sensing signal from the UE 110 and other objects in the communication system 100 environment.

[0151] The sensor system of the first BS 170A can acquire a sensing-based profile upon receiving an echo (step 1006A). The sensor system of the first BS 170B can acquire a sensing-based profile upon receiving an echo (step 1006B). The sensor system of the first BS 170C can acquire a sensing-based profile upon receiving an echo (step 1006C).

[0152] The sense-based profile may include geometric range measurements and angle measurements. Upon completion of the acquisition of each sense-based profile (steps 1006A, 1006B, and 1006C), each BS 170 sends the sense-based profile to the location management function 190. The location management function 190 acquires (steps 1007A, 1007B, and 1007C) the sense-based profile. In the context of the LMF 190 acquiring (step 1007) the sense-based profile, the BS 170 may generally be referred to as the profile origin.

[0153] exist Figure 11 The flowchart illustrates a reference signal exchange round interaction between a first base station 170A, a second base station 170B, a third base station 170C, a first UE 110A, a second UE 110B, and a location management function 190. Although not specifically shown, the first base station 170A, the second base station 170B, and the third base station 170C can be understood to include similar functions. Figure 5 The sensor system 502 in the image. Although not specifically shown, the first base station 170A, the second base station 170B, and the third base station 170C can be understood to include sensor systems similar to... Figure 5 The communication system 504 in the middle.

[0154] Figure 11 The flowchart can be considered as Figure 10 The continuation of the flowchart.

[0155] The first BS 170A transmits a downlink (DL) reference signal (RS) that can be received by the first UE 110A and the second UE 110B. The DL reference signal can be a high-power broadband signal. According to various aspects of this application, each UE 110 is used to receive the DL-RS and generate an upload (UL) RS. Then, each UE 110 transmits the UL-RS to the first BS 170A.

[0156] The communication system of the first BS 170A receives the UL-RS from each UE 110. Conveniently, as described above, the UL-RS includes identification information of the UE 110 that has generated the UL-RS. In response to receiving the UL-RS, the communication system of the first BS 170A obtains (step 1108A) BS-RS based observations. Based on a particular BS-RS based observation, the communication system can determine the identification information of the UE 110 and associate the identification information with the particular BS-RS based observation.

[0157] At least some of the BS-RS based observations obtained by the communication system of the first BS 170A in step 1108A are from the same UE 110 as at least some of the sensing based profiles obtained by the sensing system of the first BS 170A in step 1006A. Further, at least some of the BS-RS based observations obtained by the communication system of the first BS 170A in step 1108A are of the same type as the sensing based observations that can be determined by the LMF 190 from the sensing based profiles.

[0158] After completion of the obtaining of the BS-RS based observations (step 1108A), the first BS 170A sends the BS-RS based observations to the location management function 190. The location management function 190 obtains (step 1109A) the BS-RS based observations.

[0159] The second BS 170B sends DL-RS that can be received by the first UE 110A and the second UE 110B. The DL reference signals can be high power wideband signals. In accordance with aspects of the application, each UE 110 is used to receive the DL-RS and generate UL-RS. Each UE 110 then sends the UL-RS to the second BS 170B.

[0160] The communication system of the second BS 170B receives the UL-RS from each UE 110. Conveniently, as described above, the UL-RS includes identification information of the UE 110 that has generated the UL-RS. In response to receiving the UL-RS, the communication system of the second BS 170B obtains (step 1108B) BS-RS based observations. Based on a particular BS-RS based observation, the communication system can determine the identification information of the UE 110 and associate the identification information with the particular BS-RS based observation.

[0161] At least some of the BS-RS based observations acquired by the communication system of the second BS 170B in step 1108B come from the same UEs 110 as at least some of the sensing based profiles acquired by the sensing system of the second BS 170B in step 1006B. Further, at least some of the BS-RS based observations acquired by the communication system of the first BS 170B in step 1108B are of the same type as sensing based observations that can be determined by the LMF 190 from the sensing based profiles.

[0162] After completion of acquisition of the BS-RS based profiles (step 1108B), the second BS 170B sends the BS-RS based profiles to the location management function 190. The location management function 190 acquires (step 1109B) the BS-RS based profiles.

[0163] The third BS 170C transmits DL-RS that can be received by the first UE 110A and the second UE 110B. The DL reference signals can be high power wideband signals. In accordance with aspects of the application, each UE 110 is configured to receive the DL-RS and generate UL-RS. Each UE 110 then transmits the UL-RS to the third BS 170C.

[0164] The communication system of the third BS 170C receives the UL-RS from each UE 110. Conveniently, as described above, the UL-RS includes identification information of the UE 110 that generated the UL-RS. In response to receiving the UL-RS, the communication system of the third BS 170C acquires (step 1108C) BS-RS based observations. Based on particular BS-RS based observations, the communication system can determine identification information of the UE 110 and associate the identification information with the particular BS-RS based observations.

[0165] At least some of the BS-RS based observations acquired by the communication system of the third BS 170C in step 1108C come from the same UEs 110 as at least some of the sensing based profiles acquired by the sensing system of the third BS 170C in step 1006C. Further, at least some of the BS-RS based observations acquired by the communication system of the first BS 170C in step 1108C are of the same type as sensing based observations that can be determined by the LMF 190 from the sensing based profiles.

[0166] After completion of acquisition of the BS-RS based observations (step 1108C), the third BS 170C sends the BS-RS based observations to the location management function 190. The location management function 190 acquires (step 1109C) the BS-RS based observations.

[0167] exist Figure 12 The flowchart illustrates the observation processing round and location indication round interactions between the first base station 170A, the second base station 170B, the third base station 170C, the first UE 110A, the second UE 110B, and the location management function 190. Although not specifically shown, the first base station 170A, the second base station 170B, and the third base station 170C can be understood to include similar functions. Figure 5 The sensor system 502 in the image. Although not specifically shown, the first base station 170A, the second base station 170B, and the third base station 170C can be understood to include sensor systems similar to... Figure 5 The communication system 504 in the middle.

[0168] Figure 12 The flowchart can be considered as Figure 8 The continuation of the flowchart.

[0169] Location management function 190 processes (step 1210) the sense-based profile obtained in steps 1007A, 1007B, and 1007C as part of deriving multiple sense-based location hypothesis vectors. Processing of the sense-based profile (step 1210) may include cleanup, which, in one aspect, can be performed using Doppler analysis. Location management function 190 can use Doppler analysis to separate echoes from the (mobile) UE 110 from echoes from (static) clutter in the environment, which can be considered background signals.

[0170] The location management function 190 also processes (step 1210) the BS-RS-based observations acquired in steps 1109A, 1109B, and 1109C to determine the UE identification information of the UE 110 and the RS-based location hypothesis vector from the BS-RS-based observations.

[0171] Based on the same observation, the processing of the location management function 190 (step 1210) can match a specific location hypothesis vector in the RS-based location hypothesis vector with a specific location hypothesis vector in the sensing-based location hypothesis vector. It should be noted that, since the sensing-based location hypothesis vector can be considered more accurate than the RS-based location hypothesis vector, and the RS-based location hypothesis vector is associated with UE identification information, the matching (step 1210) can be used to associate the sensing-based location hypothesis vector of the first UE with the first UE identification information obtained from the RS-based observation, and to associate the sensing-based location hypothesis vector of the second UE with the second UE identification information obtained from the RS-based observation.

[0172] The location management function 190 can then send (step 1211A) an indication of the first UE's sensed-based position hypothesis vector to the first UE 110A associated with the first UE identity information. The location management function 190 can also send (step 1211B) an indication of the second UE's sensed-based position hypothesis vector to the second UE 110B associated with the second UE identity information. Note that the indication of the position is not necessarily intended for transmission (steps 1211A, 1211B) to the UEs 110. Rather, the indication of the position can be used for other tasks. The other tasks include predicting future mobility of the UEs 110. The other tasks include managing beams transmitted from the BSs 170. Beam management is discussed below.

[0173] Figure 13 Exemplary steps in a method of operating the LMF 190 are shown. Figure 13 The method of the LMF 190 begins with obtaining (step 1307) a sensed-based profile. In the context of the LMF 190, the obtaining (step 1307) of the sensed-based profile can be found in the obtaining steps 1007A, 1007B, and 1007C. The LMF 190 also obtains (step 1309) a RS-based observation. In the context of the LMF 190, the obtaining (step 1309) of the RS-based observation can be found in the obtaining steps 1009A, 1009B, and 1009C. Figure 10 Figure 11 The LMF 190 processes (step 1310) the sensed-based profile obtained in step 1307 and the BS-RS based observation obtained in step 1309 to determine a plurality of sensed-based position hypothesis vectors, a plurality of RS-based position hypothesis vectors, and associate a selected sensed-based position hypothesis vector with UE identity information for each UE 110. The location management function 190 can then send (step 1311) an indication of the respective selected sensed-based position hypothesis vector to the UEs 110 associated with the different UE identity information.

[0174] As shown in Figure 13 The processing (step 1310) of the profile and the observation includes a plurality of sub-steps. The processing (step 1310) of the observation includes determining (step 1312) a sensed-based observation from the sensed-based profile and deriving (step 1314) a sensed-based position hypothesis vector from the sensed-based observation. In addition, the processing (step 1310) of the observation includes determining (step 1316) a RS-based position hypothesis vector for each UE 110 and the UE identity information from the reference signal based observation. Even further, the processing (step 1310) of the observation includes determining (step 1318) a match between a particular sensed-based position hypothesis vector and a particular RS-based position hypothesis vector.

[0175] ​According to an example, the sensing-based observation (step 1314) can be considered in more detail from the sensing-based profile (step 1312).

[0176] As mentioned above, the sensing-based observation (step 1312) can be determined (step 1307) based on the acquired sensing-based profile.

[0177] Consider that: the sensing-based PDP received at the LMF 190 from the first BS 170A has peaks at 4 and 6 s; the sensing-based PDP received at the LMF 190 from the second BS 170B has peaks at 2 and 3.5 s; the sensing-based PDP received at the LMF 190 from the third BS 170C has peaks at 1 and 3 s. The LMF 190 can designate the third BS 170C as the time reference. The LMF 190 can implement a subtraction of the time axis values {1, 3} associated with the peaks of the sensing-based PDP of the third BS 170C from the time axis values {4, 6} associated with the peaks of the sensing-based PDP of the other two BSs 170. The set of two RTT time axis values associated with the peaks in the sensing-based PDP of the first BS 170A can be converted by subtraction into a difference vector of four RTT DoA scalar values, {4 - 1, 4 - 3, 6 - 1, 6 - 3} = {3, 1, 5, 3}, and the difference vector of four RTT DoA scalar values can be associated with the first BS 170A. Similarly, the set of two RTT time axis values associated with the peaks in the sensing-based PDP of the second BS 170B can be converted by subtraction into a difference vector of four RTT DoA scalar values, {2 - 1, 2 - 3, 3.5 - 1, 3.5 - 3} = {1, -1, 2.5, 0.5}, and the difference vector of four RTT DoA scalar values can be associated with the second BS 170B.

[0178] The LMF 190 can then generate a plurality of sensing-based position hypothesis vectors, where each sensing-based position hypothesis vector has a potential for a location corresponding to one of the UEs 110. Each sensing-based position hypothesis vector can be generated by selecting one RTT DoA scalar value from the difference vector associated with the first BS 170A and selecting one RTT DoA scalar value from the difference vector associated with the second BS 170B. Thus, for the present example with four RTT DoA scalar values, 16 position hypothesis vectors can be generated in this manner.

[0179] As described above, step 1318 involves determining a match between a particular sensing-based position hypothesis vector and a particular RS-based position hypothesis vector. Since the sensing-based observations have been organized into 16 sensing-based position hypothesis vectors based on sensing-based RTT DoA scalar values, the LMF 190 can also arrange the RS-based observations taken in step 1309 into RS-based position hypothesis vectors based on RS-based RTT DoA scalar values.

[0180] The LMF 190 can obtain a first RS-based RTT DoA scalar value for the first UE 110A by subtracting the RS-based RTT observation for the first UE 110A received from the third BS 170C from the RS-based RTT observation for the first UE 110A received from the first BS 170A.

[0181] The LMF 190 can obtain a second RS-based RTT DoA scalar value for the first UE 110A by subtracting the RS-based RTT observation for the first UE 110A received from the third BS 170C from the RS-based RTT observation for the first UE 110A received from the second BS 170B.

[0182] The first and second RS-based RTT DoA scalar values for the first UE 110A can be used to form a RS-based position hypothesis vector for the first UE 110A.

[0183] The LMF 190 can obtain a first RS-based RTT DoA scalar value for the second UE 110B by subtracting the RS-based RTT observation for the second UE 110B received from the third BS 170C from the RS-based RTT observation for the second UE 110B received from the first BS 170A.

[0184] The LMF 190 can obtain a second RS-based RTT DoA scalar value for the second UE 110B by subtracting the RS-based RTT observation for the second UE 110B received from the third BS 170C from the RS-based RTT observation for the second UE 110B received from the second BS 170B.

[0185] The first and second RS-based RTT DoA scalar values for the second UE 110B can be used to form a RS-based position hypothesis vector for the second UE 110B.

[0186] Before determining a match between a particular sensing-based location hypothesis vector and a particular RS-based location hypothesis vector, the LMF 190 can be used to filter out those sensing-based location hypothesis vectors that are determined to be irrelevant among the 16 sensing-based location hypothesis vectors.

[0187] This filtering can be thought of as narrowing the space of hypotheses. For example, there can be a map (or well-defined boundaries) of the deployment area in which the UE 110 can be found. Some of the 16 sensing-based location hypothesis vectors can be found to be outside the deployment area and thus can be filtered out as irrelevant. Some of the 16 sensing-based location hypothesis vectors can be found to be related to locations with low probability and thus can be filtered out as irrelevant. Some sensing-based location hypothesis vectors can also be filtered out based on prior information available for the individual UE 110. The prior information can include previous locations of the UE 110, movement patterns of the UE 110, etc.

[0188] It is noted that the accuracy of each location hypothesis vector can be thought of as directly related to the degree to which a correct match between a sensing-based location hypothesis vector and a RS-based location hypothesis vector is found. Strategies to reduce the location error include increasing the size of each location hypothesis vector.

[0189] One way in which the size of the location hypothesis vector can be increased involves including more features in the location hypothesis vector acquired at a single BS 170 (step 1008). Example features for inclusion in the location hypothesis vector can include: packed range; angle; and power.

[0190] Another way in which the size of the location hypothesis vector can be increased involves concatenating features observed at several BSs 170 into a single large location hypothesis vector.

[0191] Advantageously, in higher dimensional spaces, there is a greater distance (e.g., Euclidean distance) between points representing sensing-based observations and RS-based observations. Thus, in higher dimensional spaces, a match between a particular sensing-based location hypothesis vector and a particular RS-based location hypothesis vector can be found with reduced probability of error.

[0192] As noted above, the probability of error in finding a match between a particular sensing-based location hypothesis vector and a particular RS-based location hypothesis vector can be reduced by increasing the size of the location hypothesis vector. The increase can be achieved by including more features for a single BS. These features can include packed range, angle, and power. The increase can also be achieved by concatenating features from multiple BSs in a single large location hypothesis vector. Regardless, the general idea is to bring the association problem to a higher dimensional space where the distance (e.g., Euclidean distance) between points can be greater.

[0193] Figure 14 The first sensing round 1402-1 is shown to include multiple observations. In the example shown, the multiple includes N observations. The second sensing round 1402-2 also includes N observations. Furthermore, the Rth sensing round 1402-R includes N observations. Additionally, the (R+1)th sensing round 1402-R+1 includes N observations.

[0194] The dimension of the position hypothesis vector can also be increased by clustering observations over time. Specifically, LMF 190 can concatenate observations from the current round and several previous rounds to form a longer position hypothesis vector.

[0195] exist Figure 14 In this context, the current round is referred to as sensing round R 1402-R. LMF 190 can specify a first sensing frame 1404-1 as including sensing round R 1402-R and previous rounds, including sensing rounds 1402-1 and 1402-2. LMF 190 can then concatenate all (R×N) observations in the first sensing frame 1404-1 to form a first position hypothesis vector. LMF 190 can specify a second sensing frame 1404-2 as including sensing round (R+1) 1402-R+1 and previous rounds, including sensing rounds 1402-2 and sensing round R 1402-R. LMF 190 can then concatenate all (R×N) observations in the second sensing frame 1404-2 to form a second position hypothesis vector.

[0196] It should be noted that using several consecutive sensing rounds does not mean that the interval between localizations will be longer, which would result in the UE110 being localized less frequently, thus leading to a location estimation delay. Instead, localization can be considered to still occur in response to each sensing round 1402. The cascading of observations collected in sensing frames 1404, which include multiple sensing rounds, can be considered to be related to the so-called "sliding window".

[0197] UE 110 can provide some assistance with the processing of configuration files and observations performed at LMF 190.

[0198] In fact, the UE 110 can be used to detect a sensing signal (e.g., a radar pulse) received from the sensor system 502 of the BS 170 and operate on the detected signal. It is known that the detected signal is transmitted at a relatively high power and a relatively wide frequency band. Because of these features, the sensing signal typically appears as white noise in the UE 110. An example high-power wideband sensing signal is used in pulsed radar. However, there are other types of sensing signals, such as the type of sensing signal used in pulsed-compression frequency modulated continuous wave (FMCW) radar. The type of sensing signal used in pulsed-compression FMCW is known to allow the UE 110 to detect the presence of the sensing signal.

[0199] It is important to note that detecting the sensing signal should be recognized as separate from decoding the sensing signal. The UE 110 can be able to detect the presence of the sensing signal by checking whether a signature can be found in the raw samples output from the analog-to-digital converter. For example, the UE 110 can recognize a cyclical behavior in the phase of the sensing signal. For another example, the UE 110 can detect a pattern in the power fluctuations. The same UE 110 can not be able to estimate small-scale parameters from the sensing signal, where estimating these parameters depends on calibration of specific components.

[0200] Figure 15 A first curve 1500-1 of transmit power of the BS 170 versus time and a second curve 1500-2 of receive power of the BS 170 versus time are shown. The first curve 1500-1 shows transmission of a sensing pulse 1502.

[0201] At each of the three UEs 110, the sensing pulse 1502 produces an echo signal 1504, as expected. The first UE 110A causes a first echo signal 1504-1. The second UE 110B causes a second echo signal 1504-2. The third UE 110C causes a third echo signal 1504-3.

[0202] However, in addition, at each of the three UEs 110, a sensing pulse 1502 is detected. In response to the detection, each UE transmits a wideband UE association indicator 1506. The first UE 110A transmits a first uplink (UL) UE association indicator 1506-1. The second UE 110B transmits a second UL UE association indicator 1506-2. The third UE 110C transmits a third UL UE association indicator 1506-3. Each UL UE association indicator 1506 can include identification information of the UE 110 that transmitted the UL UE association indicator 1506. Thus, it can be seen that the UL UE association indicators 1506 to help the LMF 190 associate the echo signals 1504 that were just received prior to the UL UE association indicators 1506 with the identification of the UE 110 included in the UL UE association indicators 1506.

[0203] If the UEs 110 transmit the UL UE association indicators 1506 fast enough and with a wide enough frequency band, it is very likely that the UE association indicators 1506 arrive at the BS 170 between the two echo signals 1504, as Figure 15

[0204] Figure 16 The first curve 1500-1 of Figure 15 and the second curve 1600-2 of the received power of the BS 170 versus time is similar to Figure 15 the second curve 1500-2. Figure 15 The echo signal 1504 of the second curve 1500-2 is repeated in Figure 16 the second curve 1600-2. When the first UE 110A transmits the first UE association indication 1606-1, the first UE association indication 1606-1 is not wideband. Thus, Figure 16 The second curve 1600-2 shows that after the BS 170 receives the second echo signal 1504-2, the BS 170 can receive a time portion of the first UE association indicator 1606-1.

[0205] Even in the case shown in Figure 16 it can be seen that the first UE association indicator 1606-1 to help the LMF 190 filter out some of the association possibilities.

[0206] ​In view of this background, those UEs 100 detecting the presence of the sensing signal 1502 can immediately transmit a respective UL UE-associated indicator 1506 to the BS 170. Since the goal is to incorporate the UL UE-associated indicator 1506 into the association procedure, the UL UE-associated indicator 1506 transmitted by a UE 110 and received at the BS 170 can meet the expectation that the UL UE-associated indicator 1506 is received between receiving an echo signal 1504 backscattered from this UE 110 and an echo signal 1504 backscattered from the next nearest UE 110. Meeting such an expectation depends on the density of UEs 110 to the network, the average echo signal inter-arrival time period, and the processing delay at the UE 110. The processing delay at the UE 110 can be measured from the time the signature is detected in the reception pulse 1502 until the UL UE-associated indicator 1506 is transmitted.

[0207] Obviously, the UE 110 cannot wait for the network entity to pre-schedule an UL grant (e.g., by downlink control information or physical downlink control channel) in order that the UL UE-associated indicator 1506 can be transmitted, since scheduling a UE takes on average a few hundred microseconds in the most direct time slot, during which the echo signal 1504 of even the farthest UE 110 has already arrived at the BS 170. Instead, upon the UE 110 detecting the signature, the UE 110 is prompted to transmit the UL UE-associated indicator 1506. The UE 110 does not wait for the start of a frame / subframe / time slot boundary to initiate transmission of the UL UE-associated indicator 1506. As one example, a mechanism similar to carrier sense multiple access (without collision avoidance) in Wi-Fi can be a candidate mechanism. As another example, a code division multiple access based technique can be a candidate technique. As another example, the UE 110 can transmit the UL UE-associated indicator in the analog domain, while returning the received analog signal to the BS 170 on the fly (with slight modifications, leaving only the unique signature), without passing the received analog signal to the digital and / or baseband domain for decoding, etc.

[0208] Figure 17 Some signaling involved in implementing the mechanisms described above, in which the UE 110 is used to transmit the UL UE-associated indicator, is illustrated in a signal flow diagram. It is noted that each UE 110 can be assigned an orthogonal code for the UL UE-associated indicator transmission. Thus, the BS 170 can detect the code to implicitly understand the identity of the transmitting UE 110. Thus, in this case, it is unnecessary to transmit the UE ID in the UL UE-associated indicator. However, in the case where the UE beams share the same orthogonal code or the sensing signal is transmitted by multiple BSs 170, further information, such as the UE identity and BS identity, can be included in the UL UE-associated indicator.

[0209] Figure 17 As shown, the first base station 170A can transmit 1702A configuration instructions to the UE 110. In addition, the second base station 170B can also transmit 1702B configuration instructions to the UE 110. The configuration information can include orthogonal codes, frequencies, etc. UL UE association indicator transmission parameters.

[0210] The sensing round can then continue with the BSs 170 transmitting pulses and receiving echoes. The UE 110 can transmit 1704A an UL UE association indicator to the first BS 170A using the configuration instructions received from the first BS 170A. The UE 110 can also transmit 1704B an UL UE association indicator to the second BS 170B using the configuration instructions received from the second BS 170B. Upon receiving the UL UE association indicator, the first BS 170A can provide 1706A the LMF 190 with the sensing profile and information extracted from the UL UE association indicator based sensing. The LMF 190 can obtain 1707A the sensing profile and information extracted from the UL UE association indicator based sensing. Upon receiving the UL UE association indicator, the second BS 170B can provide 1706B the LMF 190 with the sensing profile and information extracted from the UL UE association indicator. The LMF 190 can obtain 1707B the sensing profile and information extracted from the UL UE association indicator based sensing.

[0211] A reference signal exchange round can then be performed between the BSs 170 and the UE 110, such that the BSs 170 can obtain 1708 RS based observations. The LMF 190 can obtain 1709A RS based observations from the first BS 170A, and can obtain 1709B further RS based observations from the second BS 170B.

[0212] The location management function 190 processes (step 1710) the sensing profile obtained in steps 1707A and 1707B as part of deriving multiple sensing based location hypothesis vectors. The processing (step 1710) of the sensing profile can include associating the sensing profile with the UE 110 based on information extracted from the UL UE association indicator.

[0213] The location management function 190 also processes (step 1710) the RS based observations obtained in steps 1709A and 1709B to determine UE identity information of the UE 110 and RS based location hypothesis vectors from the RS based observations.

[0214] Based on the same observation, with the help of information extracted from the UL UE association indicator, the processing (step 1710) of the location management function 190 can match a particular location hypothesis vector in the RS-based location hypothesis vector with a particular location hypothesis vector in the sensing-based location hypothesis vector. It is noted that since the sensing-based location hypothesis vector can be considered more accurate than the RS-based location hypothesis vector, and the RS-based location hypothesis vector is associated with UE identity information, the matching (step 1710) can be used to associate a UE sensing-based location hypothesis vector with UE identity information obtained from RS-based observation, and to associate a second UE sensing-based location hypothesis vector with second UE identity information obtained from RS-based observation.

[0215] Then, the location management function 190 can send (step 1711) an indication of the UE sensing-based location hypothesis vector to the UE 110 associated with the UE identity information.

[0216] As mentioned above, the angular related measurements (profile) obtained from the sensing round can be used to associate the identity with the unidentified sensing measurement. Assuming that the sending of the sensing signal and the reference signal is omnidirectional (i.e. without any beamforming), such that the angle-of-arrival (AoA) and the AoA measurement of the received UL RS respectively estimated for the echo allow the association between the identity and the unidentified sensing measurement to take place.

[0217] Generally, a sensing subsystem capable of estimating the AoA (at reception) is also capable of focusing the sensing signal in a given direction within a limited angular sector (at transmission) by means of analog or digital beamforming.

[0218] The transmission beamforming can be shown to allow reducing the ambiguity of the association procedure. The sensing signal can be transmitted within a narrow beam. Similarly, the DL reference signal can be transmitted within a narrow beam. By narrowing the transmission angle, the number of candidate location hypotheses is limited. It can be shown that one consequence of limiting the number of candidate location hypotheses is a reduction of the error probability in the step of associating the RS-based observation with the sensing observation.

[0219] It has been described above that the UE 110 can transmit a UL UE association indicator in response to detecting a sensing signal. This idea can be extended to the use of beamforming as described above. Consider a sensing signal transmitted within a narrow beam, and consider some features that the UE 110 can use to measure the received sensing signal. These features can include, for example, the received power of the sensing signal and the identity (ID) of the beam carrying the sensing signal. When formulating the UL UE association indication for transmission to the BS 170, the UE 110 can include an indication of the beam ID. Upon receiving the UL UE association indication, the BS 170 can interpret the ID of the beam as an indication of the angular sector of the space in which the UE 110 is located. The information that the BS 170 can glean from the UL UE association indicator can be shown to help the LMF 190 filter out some of the association possibilities.

[0220] In general, it can be stated that there are multiple practical ways to embed the beam ID into the sensing signal such that UEs 110 of different capabilities are able to detect the sensing signal and extract the beam ID from the sensing signal. Even if such extraction is not possible, there are still implicit ways to force the UE 110 to provide an indicator on the sensing signal to the LMF 190. The BS 170 can dwell in each beam for a long enough time such that not only the echoes from all UEs 110 within that spatial sector are received, but also the UE IDs. Based on the echoes returned within each beam, the BS 170 can estimate the angles-of-arrival (AoA) of the prominent peaks in the PAP and associate these estimated AoAs within a beam with the UEs reporting their ID in that beam.

[0221] In summary, the content presented in this embodiment differs from the directional radar in Figure 10 , Figure 11 and Figure 12 only in the way the UE identity is associated with the sensing-based AoA s . Here, the connection is through the beam ID (i.e. ), whereas in Figure 10 , Figure 11 and Figure 12 the connection is through the RS-based AoA p (i.e. ). It is noted that a trade-off between the two approaches can be considered. If the angular resolution that can be achieved from the RS-based perspective is finer than the analog beamwidth of the sensing system, the association problem benefits from the former approach (transmitting both sensing and RS signals). Otherwise, it is beneficial to continue with the latter approach. It can also be considered that there is another level of trade-off between the two systems. Beam sweeping requires transmitting sensing signals within many narrow beams that can be used by all UEs, while the RS-based approach involves transmitting UL reference signals by each UE 110.

[0222] The beam sweeping approach can be considered helpful when very narrow 3D (vertical and horizontal) sweeping can be performed, because the likelihood of multiple UEs falling in a single beam is small. When this is not the case, ambiguity occurs.

[0223] Figure 18 The base station 170B is shown as the source of four beams labeled B-2-1, B-2-2, B-2-3, and B-2-4. Two UEs 110 are shown, including a first UE 110A and a second UE 110B. Since both UEs exist in the same beam (the beam labeled beam ID B-2-2), both UEs 110 can be expected to report the same beam ID to the BS 170B along with their respective UE IDs. The BS 170 can provide the LMF 190 with the reports that the BS 170 has received from the two UEs 110. Unfortunately, the LMF 190 does not obtain unique information about the relative locations of the UEs from the reports of the same beam ID.

[0224] Figure 19 The original base station 170B and the UEs 110 in Figure 18 are shown, along with two additional base stations 170A, 170C. The first additional base station 170A is the source of four beams labeled A-2-1, A-2-2, A-2-3, and A-2-4. The second additional base station 170C is the source of four beams labeled C-2-1, C-2-2, C-2-3, and C-2-4. In Figure 19In the illustrated scenario, the first UE 110A can expect to report the beam ID B-2-2 to the original BS 170B along with the UE ID of the first UE 110A. Further, the first UE 110A can expect to report the beam ID A-2-1 to the first additional BS 170A along with the UE ID of the first UE 110A, and the first UE 110A can expect to report the beam ID C-2-4 to the second additional BS 170C along with the UE ID of the first UE 110A. Further, the second UE 110B can expect to report the beam ID B-2-2 to the original BS 170B along with the UE ID of the second UE 110B. Further, the second UE 110B can expect to report the beam ID A-2-2 to the first additional BS 170A along with the UE ID of the second UE 110B, and the first UE 110A can expect to report the beam ID C-2-3 to the second additional BS 170C along with the UE ID of the second UE 110B.

[0225] The three BSs 170 can provide the LMF 190 with information that the BSs 170 have received from the UEs 110. The LMF 190 obtains information indicating that the first UE 110A is in the beams IDS A-2-1, B-2-2, and C-2-4. The LMF 190 also obtains information indicating that the second UE 110B is in the beams IDS A-2-2, B-2-2, and C-2-3. Thus, the LMF 190 obtains information that allows for unambiguous positioning of both UEs 110.

[0226] According to various aspects of the application, the LMF 190 can coordinate the sensing signal scanning pattern of each BS 170 to minimize interference, allowing the UEs 110 to clearly detect the beam IDs.

[0227] According to various aspects of the application, the sensing signal and the reference signal are transmitted in a similar manner to the aspects described in the above disclosure. In this alternative, the sensing signal is transmitted first. From the returned echoes, an AoA measurement can be associated with each of the plurality of UEs 110. Then, when the beamformed DL reference signal is transmitted to the UEs 110, the information about the angle of arrival of the returned echoes can be used. Each UE 110 receives the DL reference signal and estimates an AoD p value. Then, each UE 110 transmits an UL reference signal to the BS 170, where the UL reference signal includes an indication of the estimated AoD p and the UE ID. Then, the LMF 190 can associate the AoA s with the received estimated AoDp are associated.

[0228] According to aspects of the present application, the LMF 190 can schedule reception of UL reference signals at the BS 170 by specifying UL grants to each UE 110.

[0229] It should be understood that one or more steps of the example methods provided herein can be performed by corresponding units or modules. For example, data can be transmitted by a transmitting unit or a transmitting 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 units / modules can be hardware-only implementations, software-only implementations, or combination thereof. For example, one or more units / modules can be an integrated circuit, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). It should be understood that if these modules are software, they can be retrieved from storage by a processor as needed, individually or collectively, for processing, as needed in one or more instances, and these modules themselves can include instructions for further deployment and instantiation.

[0230] While combinations of features are shown in the illustrated embodiments, not all combinations of features are required to practice the benefits of various embodiments of the application. In other words, not all features of the systems or methods designed in accordance with embodiments of the application are required, or even desirable, to realize the benefits of the various embodiments of the application. In addition, selected features of one example embodiment can be combined with selected features of another example embodiment.

[0231] While the application has been described with reference to the illustrative embodiments, the description is not intended to be limited to the embodiments described. Many modifications and variations of the illustrative embodiments and other embodiments of the application will be apparent to those of ordinary skill in the art from the description. Accordingly, it is intended that the scope of the application embrace any and all modifications and variations.

Claims

1. A method of indicating a location of a device to the device, characterized by, The method comprises: acquiring a sensing-based profile from a profile origin, the sensing-based profile comprising a sensing-based observation of the device; acquiring a reference-signal-based observation; transmitting an indication of the position hypothesis to a device associated with the device identification information based on an association between the position hypothesis and the device identification information; wherein the position hypothesis is derived from the sensing-based observation; wherein the device identification information of the device is determined from the reference-signal-based observation; wherein the reference-signal-based observation is processed in conjunction with the sensing-based observation to determine the association between the position hypothesis and the device identification information.

2. The method of claim 1, wherein, The sensing-based profile represents a geometric range measurement.

3. The method of claim 1, wherein, The sensing-based profile represents an angular measurement.

4. The method of claim 1, wherein, The sensing-based observation and the reference-signal-based observation represent a round-trip time from the profile origin to the device and back to the profile origin.

5. The method of claim 1, wherein, The sensing-based observation and the reference-signal-based observation represent an angle of arrival.

6. The method of claim 1, wherein, The reference-signal-based observation is processed in conjunction with the sensing-based observation by employing Doppler analysis to: identify echoes from the device and echoes from static clutter; decouple the echoes from the device and the echoes from the static clutter by determining a non-zero velocity of the device and determining a zero velocity of the clutter.

7. The method according to any one of claims 1 to 6, characterized in that, The acquiring the reference-signal-based observation comprises acquiring the reference-signal-based observation from the profile origin.

8. The method according to any one of claims 1 to 6, characterized in that, Further comprising selecting the device as a cluster head device among a plurality of devices.

9. The method of claim 8, wherein, Further comprising transmitting an indication of a sidelink communication schedule to each device of the plurality of devices and an indication of the selecting the cluster head device as the cluster head device.

10. The method of claim 9, wherein, Further comprising acquiring an indication of a cluster head identifier and inter-device measurements from the cluster head device.

11. The method of claim 10, wherein, Further comprising transmitting a respective position hypothesis for each device of the plurality of devices to the each device of the plurality of devices, wherein the respective position hypothesis is determined by processing the inter-device measurements in the context of the position hypothesis of the cluster head device derived from the sensing-based observation.

12. The method according to any one of claims 1 to 6, characterized in that, The method further comprises: acquiring a further sensing-based profile from each profile origin of a plurality of further profile origins; acquiring a further reference-signal-based observation from the each profile origin of the plurality of further profile origins.

13. The method of claim 12, wherein, The sensing-based profile represents an angular measurement and the further sensing-based profile represents an angular measurement, and the method further comprises: designating one transmission point of the plurality of transmission points as a spatial reference; reducing values of sensing-based observations received from each transmission point of the plurality of transmission points by sensing-based observations received from the spatial reference.

14. The method of claim 12, wherein, The sensing-based profile represents a geometric range measurement and the further sensing-based profile represents a geometric range measurement, and the method further comprises: designating one transmission point of the plurality of transmission points as a temporal reference; reduce a value of a sensing-based observation received from each of the plurality of transmission points based on a sensing-based observation received from the time reference.

15. The method according to any one of claims 1 to 6, characterized in that, The method further comprises: obtaining a further sensing-based observation from the profile origin; correct the position hypothesis based on the further sensing-based observation.

16. The method of any one of claims 1 to 6, wherein, Further comprising obtaining another signal from the profile origin, the another signal comprising an indication of an identity of the device.

17. The method of any one of claims 1 to 6, wherein, obtaining an indication of an identity of a particular beam in which the device receives a sensing signal from the profile origin.

18. The method of claim 17, wherein, Further comprising obtaining an indication of an identity of a particular beam in which the device receives another sensing signal from another profile origin.

19. An apparatus, comprising: comprising: a memory storing instructions; a processor, by executing the instructions, causes the processor to perform the method of any of claims 1-18.

20. A computer readable medium storing instructions, wherein: The instructions, when executed by a processor for indicating a position of a device to the device, cause the processor to perform the method of any of claims 1-18.

21. A method for a user equipment (UE), comprising: The method comprises: obtaining a reference signal-based observation of the user equipment; sending the reference signal-based observation to a network equipment; receiving an indication of a position hypothesis from the network equipment based on an association between the position hypothesis and device identity information of the user equipment; wherein the position hypothesis is derived from a sensing-based observation of the user equipment; wherein the device identity information of the device is determined from the reference signal-based observation; wherein the reference signal-based observation is processed in conjunction with the sensing-based observation to determine the association between the position hypothesis and the device identity information.

22. The method of claim 21, wherein, The sensing-based observation and the reference signal-based observation represent an angle of arrival.

23. The method of claim 21 or 22, wherein, Further comprising receiving an indication of a sidelink communication schedule and an indication of a cluster head device selected from a plurality of user equipment.

24. The method of claim 23, wherein, Further comprising sending an indication of a cluster head identifier and inter-user equipment measurements.

25. A user equipment, comprising: comprising: a memory storing instructions; a processor, by executing the instructions, causes the processor to perform the method of any of claims 21-24.

26. A computer readable medium characterized by The instructions, when executed by a processor for indicating a position of a device to the device, cause the processor to perform the method of any of claims 21-24.

27. A computer program product, characterised in that, The computer program product comprises a computer program which, when executed by a computer, causes the computer to perform the method of any of claims 1-18, 21-24.

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