Apparatus and method for discovering positioning reference user equipment on sidelink

Abstract

Example embodiments relate to apparatuses and methods for discovering positioning reference user equipment on a sidelink. The terminal device may be configured to transmit a positioning reference request on one or more sidelinks between the terminal device and one or more reference devices, receive a positioning reference reply from the one or more reference devices, and selecting at least one reference device from the one or more reference devices for positioning of the terminal device based at least in part on the received positioning reference reply. The positioning reference reply may include positioning reference measurement capabilities of one or more reference devices.

Description

Technical Field

[0001] The exemplary embodiments described herein relate generally to communication techniques, and more particularly to apparatus and methods for discovering a positioning reference user equipment (UE) on a sidelink. Background Art

[0002] Terrestrial network-based positioning techniques include trilateration, in which the user equipment (UE) measures the positioning reference signal (PRS) from multiple transmit and receive points (TRPs), and the UE's position can be calculated based on the PRS measurement results and the position coordinates of multiple TRPs. Obviously, accurate PRS measurements are critical to positioning accuracy. Double differential measurements can be used to mitigate PRS time / phase uncertainties in TRPs and UEs, thereby improving positioning accuracy. Summary of the invention

[0003] The following provides a brief summary of exemplary embodiments to provide a basic understanding of some aspects of various embodiments. It should be noted that this summary is not intended to identify key features of essential elements or to limit the scope of the embodiments, and its sole purpose is to introduce some concepts in a simplified form as a prelude to a more detailed description provided below.

[0004] In a first aspect, an example embodiment of a terminal device is provided. The terminal device may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, together with the at least one processor, cause the terminal device to at least: transmit a positioning reference request on one or more side links between the terminal device and one or more reference devices, receive a positioning reference reply from the one or more reference devices, and select at least one reference device from the one or more reference devices for positioning of the terminal device based at least in part on the received positioning reference reply. The positioning reference reply may include the positioning reference measurement capabilities of the one or more reference devices.

[0005] In a second aspect, an example embodiment of a reference device is provided. The reference device may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured, together with the at least one processor, to cause the reference device to at least: receive a positioning reference request on a side link between the terminal device and the reference device from a terminal device, and transmit a positioning reference reply to the terminal device in response to the positioning reference request, the positioning reference reply including the positioning reference measurement capability of the reference device.

[0006] Example embodiments of methods, apparatus, and computer program products are also provided. These example embodiments generally correspond to the example embodiments described above, and for convenience, repeated descriptions thereof are omitted herein.

[0007] Other features and advantages of example embodiments of the present application will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of example embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Some example embodiments will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

[0009] Figure 1 is a schematic diagram illustrating a communication network in which an example embodiment of the present application can be implemented.

[0010] Figure 2 is a schematic diagram illustrating an example scenario to which example embodiments of the present application may be applied.

[0011] Figure 3 is a schematic interaction diagram illustrating a process for selecting a positioning reference UE according to an exemplary embodiment of the present application.

[0012] Figure 4A It is a schematic diagram of interaction of UE-assisted positioning according to an embodiment of the present invention.

[0013] Figure 4B It is an interactive schematic diagram of UE-assisted positioning according to another preferred embodiment of the present invention.

[0014] Figure 5 is a schematic interaction diagram illustrating UE-based positioning according to an exemplary embodiment of the present application.

[0015] Figure 6 The figure shows a schematic block diagram of a device according to an exemplary embodiment of the present application.

[0016] Throughout the drawings, the same or similar reference numerals denote the same or similar elements, and repeated description of the same elements will be omitted. DETAILED DESCRIPTION

[0017] Hereinafter, some example embodiments will be described in detail with reference to the accompanying drawings. The following description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known circuits, techniques, and components are shown in block diagram form to avoid obscuring the concepts and features described.

[0018] As used herein, the term "network device" refers to any suitable device or entity capable of providing a cell or coverage, through which a terminal device can access a network or receive services. The network device can provide positioning services for UEs residing in a cell served by the network device or a neighboring network device by transmitting a downlink positioning reference signal (DL PRS) to the UE and / or receiving and measuring an uplink sounding reference signal (UL SRS) from the UE. Network devices may generally be referred to as base stations. The term "base station" used herein may represent a node B (NodeB or NB), an evolved node B (eNodeB or eNB), a gNB, an access point, a transmitting and receiving point (TRP), etc. A base station may be embodied as a macro base station, a relay node, or a low-power node such as a micro base station or a femto base station. A base station may be composed of several distributed network units, for example, a central unit (CU), one or more distributed units (DU), one or more remote radio heads (RRH). RRH may also be referred to as or implemented as a transmitting point (TP), a transmitting and receiving point (TRP), a radio unit (RU), a remote radio unit (RRU), an active antenna unit (AAU), etc. The number and functionality of these distributed units depends on the chosen split RAN architecture.

[0019] As used herein, the term "terminal device" or "user equipment" (UE) refers to any entity or device capable of wirelessly communicating with network devices or each other. The terminal device can perform a network positioning process by receiving and measuring DL PRS from a serving network device and an adjacent network device and / or transmitting UL SRS to the serving network device and the adjacent network device. Examples of terminal devices may include mobile phones, mobile terminals (MTs), mobile stations (MSs), subscriber stations (SSs), portable subscriber stations (PSSs), access terminals (ATs), computers, wearable devices, vehicle-mounted communication devices, machine type communication (MTC) devices, D2D communication devices, V2X communication devices, sensors, etc. The term "terminal device" may be used interchangeably with UE, user terminal, mobile terminal, mobile station, or wireless device.

[0020] Figure 1 An example communication network 100 is illustrated in which example embodiments of the present application may be implemented. Figure 1 , the communication network 100 may include a plurality of UEs 110a-b (each also individually referred to as UE 110 or collectively referred to as UE 110) in wireless communication with a plurality of TRPs 120a-b (each also individually referred to as TRP 120 or collectively referred to as TRP 120). It should be understood that the communication network 100 may include more UEs and more TRPs, although Figure 1Two UEs and two TRPs are shown in FIG. As described above, the TRP 120 may be implemented as a base station, such as a macro base station, a pico base station, and a femto base station, or as a remote radio head (RRH) of a base station. The location of the TRP 120 is known and is generally fixed.

[0021] The TRP 120 may broadcast a positioning reference signal (PRS) to surrounding UEs. The UE 110 may measure the arrival time or phase of the PRSs from multiple TRPs 120 to estimate the position of the UE relative to the TRP 120. In UE-assisted positioning, the UE 110 may transmit the PRS measurement result to the location server 130, where the PRS measurement result is processed to obtain the position of the UE 110. The location server 130 may be implemented as a location management function (LMF) in a core network, or as a location management component (LMC) in a radio access network (RAN), such as in a serving base station of the UE 110. In UE-based positioning, the UE 110 may include a location management component (LMC) that is implemented to calculate the position of the UE 110 based on the PRS measurement. Throughout this application, the term "positioning reference signal" may refer to any downlink reference signal that can be used to perform positioning measurements, examples of which may include, for example, a synchronization signal block (SSB), a cell-specific reference signal, a sounding reference signal (SRS), a phase tracking reference signal (PT-RS), and a positioning reference signal defined in the 3GPP specification.

[0022] In the double differential measurement scheme, two UEs including a target UE 110a whose location is unknown and a reference UE 110b whose location is known can synchronously measure the PRS from a pair of TRPs 120a, 120b, and a double differential measurement can be obtained by subtracting the PRS measurements between the TRPs and between the UEs. Figure 1 , the target UE 110a measures the arrival time or phase of the PRS from TRP 120a, 120b, and obtains PRS measurement values ​​M1, M2, respectively. Similarly, the reference UE 110b measures the arrival time or phase of the PRS from TRP 120a, 120b, and obtains PRS measurement values ​​M3, M4, respectively. The double differential measurement Mdd can be calculated by Mdd = (M1-M2)-(M3-M4). In order to determine the position of the target UE 110a, three independent double differential measurements are required, which can be obtained by observing at least four TRPs by the target and reference UEs. Since the double differential measurement Mdd can eliminate the PRS time / phase uncertainty in the TRP and UE, the positioning accuracy can be improved.

[0023] To apply the double differential measurement scheme for high-precision positioning, the target UE must discover at least one reference UE with a known position. Figure 2 An example scenario of discovering a reference UE for a target UE is illustrated. Figure 2 , multiple TRPs 120 and multiple reference UEs 110b can be deployed in, for example, a factory hall. For each target UE 110a, one or more reference UEs 110b need to be selected from all available reference UE sets and assigned to the target UE 110a for double differential measurement. However, since the location of the target UE 110a is unknown, the target UE 110a does not know which reference UEs 110b are suitable for it and how to select the reference UE 110b. In addition, in the case of UE-based positioning, measurement results need to be reported from the reference UE 110b to the target UE 110a. If the reference UE 110b transmits the measurement report to the target UE 110a via the RAN, the reporting delay is high, which is particularly undesirable for positioning based on carrier phase because the carrier phase changes very quickly.

[0024] The example embodiments described herein provide a reference UE discovery mechanism that can find one or more reference UEs with radio channels similar to the target UE. The mechanism can select a reference UE near the target UE without knowing the location of the target UE. It can be performed via side link communication and does not incur additional network signaling overhead. By selecting a suitable reference UE, the mechanism can also improve the positioning accuracy of the target UE. In some example embodiments, the reference UE can transmit a measurement report directly to the target UE via side link communication, which can minimize reporting delays and speed up the positioning process. This is particularly beneficial for positioning based on carrier phase because the carrier phase changes very quickly.

[0025] Figure 3 The process of selecting a positioning reference UE for a target UE according to an exemplary embodiment of the present application is illustrated. The reference UE selection process can be implemented by the target UE and one or more reference UEs. Figure 1-2 The described target UE 110a and reference UE 110b may be configured to perform a reference UE selection process. The target UE 110a and reference UE 110b may each include multiple components, modules, devices, or elements to perform the operations discussed below, and these components, modules, devices, and elements may be implemented in various ways, including but not limited to, for example, software, hardware, firmware, or any combination thereof.

[0026] refer to Figure 3, at operation 210, the target UE 110b may optionally receive a positioning reference advertisement from the reference UE 110b. The positioning reference advertisement may include an identifier or address of the reference UE 110b. From the positioning reference advertisement, the target UE 110b may know which UEs are providing the positioning reference service. In one example, the positioning reference advertisement may also include the location coordinates of the reference UE 110b. The reference UE 110b may transmit the positioning reference advertisement via a broadcast or multicast on a side link. For example, a multicast may be transmitted to, for example, a group "positioning reference service", and UEs that need to receive the service for purposes such as high-precision positioning may join the group. In some example embodiments, operation 210 may be omitted.

[0027] At operation 211, the target UE 110b may also optionally receive a positioning reference trigger indication from a location server 130 serving the target UE 110b or from a base station to which the target UE 110b is connected. The positioning reference trigger indication may be transmitted by a new message or by extending an existing message with a new information element. Through the positioning reference trigger indication, the location server 130 or the serving base station may instruct the target UE 110b to initiate a process of discovering a reference UE on a side link. The location server 130 may transmit the positioning reference trigger indication to the target UE 110b via the LTE positioning protocol (LPP), or may first transmit it to the serving base station of the target UE 110b via the NR positioning protocol (NRPPa), and then the serving base station may send the positioning reference trigger indication to the target UE 110b.

[0028] At operation 212, the target UE 110a may transmit a positioning reference request to the reference UE 110b on the side link between the target UE 110a and the reference UE 110b. In one example, the target UE 110a may transmit the positioning reference request in response to the positioning reference trigger indication received at operation 211. The positioning reference request may be transmitted to nearby UEs via broadcast communication, or to a group of reference UEs 110b via multicast communication. For example, a side link group "positioning reference UEs" including all reference UEs may be defined / configured, and the information of the group may be notified to the target UE 110a via positioning reference advertisements or on a side link broadcast channel.

[0029] The positioning reference request may include information of the target UE 110a and a positioning reference requirement of the target UE 110a. For example, the information of the target UE 110a may include an identifier or address of the target UE 110a, and optionally, a state of the target UE 110a. The state of the target UE 110a may indicate whether the target UE 110a is in an RRC connected, inactive, or idle state. The positioning reference requirement of the target UE 110a may include, for example, a first list of TRPs 120 measurable for the target UE 110a. That is, the target UE 110a may measure the PRS transmitted from the TRPs 120 of the first list. For the purpose of double differential measurement, it is expected that the reference UE of the target UE 110a may measure as many TRPs as possible in the first list. The positioning reference requirement may also include signal level information of the TRPs 120 of the first list measured at the target UE 110a. The signal level information may be represented by, for example, the measured SSB power from the TRPs 120. Since the signal level is generally inversely proportional to the distance from the target UE 110a to the TRP, the signal level can reflect which TRPs are close to the target UE 110a, and the reference UE for the target UE 110a is expected to be close to these TRPs. In one example, the first list of TRPs 120 can be arranged in descending order of signal level. In one example, the positioning reference requirement can also include beam direction information of the TRP 120, which indicates the strongest beam of the target UE 110a. The beam direction information can be represented by a beam index (e.g., the SSB index of the strongest beam). In addition, it is expected that the reference UE for the target UE 110a can measure the same beam of the TRP 120.

[0030] Based on the positioning reference request, the reference UE 110b may determine at operation 214 whether they can provide positioning reference services to the target UE 110a. In order to be able to provide positioning reference services, the reference UE 110b may be required to know its own location, perform positioning measurements, and report its location and positioning measurements to the network or neighboring UEs. Or the reference UE 110b may simply be configured to know that it is able and intended to be used as a reference UE to provide positioning reference services to other UEs. Typically, the reference UE 110b may have fixed and accurately calibrated location coordinates. In an example, the location server 130 may know the location coordinates of the reference UE 110b, and the reference UE 110b does not need to report their location to the location server 130. In operation 214, the reference UE 110b may evaluate whether they can provide positioning reference services to the target UE 110a by determining, for example, whether they can measure PRSs from at least a threshold number of TRPs listed in the positioning reference request, whether the signal level measured from the TRPs at the reference UE is close to the signal level of the TRPs indicated in the positioning reference request, and whether the reference UE measures the same strongest beam from the TRPs as the target UE 110a. In some example embodiments, the reference UE 110b also determines whether they can provide positioning reference services to the target UE 110b based on the state of the target UE 110b. For example, some reference UEs may only provide positioning reference services to target UEs in an RRC connected state, while some other reference UEs may also provide positioning reference services to target UEs in an RRC inactive and / or idle state. The reference UE 110b may run an algorithm to determine to what extent it meets the positioning reference requirements indicated in the positioning reference request, and determine whether the reference UE 110b can serve as a reference UE for the target UE 110a.

[0031] If one or more reference UEs 110b determine at operation 214 that they can be used as reference UEs for target 110a, they can send a positioning reference reply to target UE 110a at operation 216. By sending the positioning reference reply, reference UE 110b indicates to target UE 110a that they are able to provide positioning reference services to target UE 110a. The positioning reference reply may include explicit or implicit information about the positioning reference measurement capability of the reference UE, which means that the reference UE is able to be used as a reference UE and will provide positioning reference measurements. The positioning reference measurement capability may, for example, include a second list of TRPs, signal level information and beam direction information of the TRPs, and the location coordinates of the reference UE. In one example, the second list of TRPs may include TRPs that can be measured at both target UE 110a and reference UE 110b, i.e., the second list of TRPs may be selected from the first list of TRPs indicated in the positioning reference request. In another example, the TRPs of the second list may include TRPs that can be measured at the reference UE 110b, and the target UE 110a or the location server 130 may determine whether the target UE 110a and the reference UE 110b can receive PRS from the same TRP based on the first list of TRPs and the second list of TRPs. The signal level information of these TRPs may be represented by the SSB power measured from the TRPs. In one example, the second list of TRPs may be arranged in descending order of signal level. The beam direction information of the TRP may indicate the strongest beam of the reference UE and may be represented by a beam index (e.g., the SSB index of the strongest beam). The positioning reference reply may also include information about the reference UE, such as an identifier or address, status of the reference UE.

[0032] At operation 218, optionally, the target UE 110a may perform channel measurement on the reference UE 110b from which the positioning reference reply is received. For example, the target UE 110a may measure the side link SSB power of the reference UE 110b. The greater the measured SSB power, the closer the reference UE 110b is to the target UE 110a. In another example, the target UE 110a may measure the round trip time between the target UE and the reference UE 110b by exchanging messages, and the round trip time is proportional to the distance between the target UE 110a and the reference UE 110b. In some example embodiments, operation 218 may be omitted because the positioning reference measurement capability indicated in the positioning reference reply may also reflect the location area of ​​the reference UE 110b at least to some extent.

[0033] The target UE 110a may then select at least one reference UE 110b based on the positioning reference reply received at operation 216 and, optionally, the channel measurement performed at operation 218. The target UE 110a may select one or more best reference UEs 110b that receive PRS on the same or similar beams of the same TRP and measure the same or similar signal level from the TRP as the target UE 110a. Optionally, the channel measurement value of the reference UE 110b will also be considered, because the reference UE with a higher channel measurement value will be closer to the target UE 110a and therefore have a similar radio channel to the target UE 110a. The target UE 110a may run an algorithm to compare the positioning reference requirement of the target UE 110a and the positioning reference measurement capability of the reference UEs, and rank the reference UEs according to the similarity between the positioning reference requirement and the positioning reference measurement capability. The target UE 110a may then select a predetermined number of best reference UEs with a similarity above a threshold. If all reference UEs have a similarity below the threshold, no reference UE 110b may be used as the target UE 110a, and the target UE 110a may re-perform the process until a reference UE with a similarity above the threshold is found.

[0034] pass Figure 3 The target UE 110a can select one or more reference UEs close to the target UE without knowing the location of the target UE. The process can be performed when the target UE 110a is in RRC connection, inactive or idle state, and since the process can be performed on the side link communication, it does not increase the network signaling overhead.

[0035] Figure 4A FIG. 1 illustrates a UE assisted positioning process according to an exemplary embodiment of the present application. When the target UE 110a has selected one or more reference UEs 110b, the target UE 110a may select one or more reference UEs 110b. Figure 3 The process executes the process.

[0036] refer to Figure 4AAt operation 310, the target UE 110a may transmit a positioning reference report indicating the selection of one or more reference UEs 110b to the location server 130. In one example, the positioning reference report may be transmitted from the target UE 110a to the location server 130 via an LTE positioning protocol (LPP) message. In another example, the target UE 110a may send the positioning reference report to a base station to which the target UE 110a is connected, and the base station may then send the report to the location server 130 via an NR positioning protocol (NRPPa) message. The positioning reference report may include an identifier or address of the reference UE 110b selected for the target UE 110a. Optionally, the positioning reference report may also include the location coordinates of the selected reference UE 110b.

[0037] At operation 311, the network may configure a positioning reference signal (PRS) for the target UE 110a and the reference UE 110b. For example, the location server 130 may provide the PRS configuration to the target UE 110a and the reference UE 110b via LPP. The PRS configuration may include information of the PRS transmitted at the TRP 120 near the target UE 110a or the reference UE 110b.

[0038] Then, the target UE 110a and the reference UE 110b may receive and measure the PRS transmitted from the TRP 120 based on the PRS configuration received from the location server 130 at operations 312 and 314, respectively. The target UE 110a may transmit a measurement report to the location server 130 at operation 316, and the reference UE 110b may transmit a measurement report to the location server 130 at operation 318. The measurement report may include time / phase values ​​or time / phase differences of the PRS measured from multiple TRPs 120. It will be appreciated that the reported time / phase values ​​or time / phase differences from the reference UE may include the same impairments as the target UE (i.e., time and phase errors caused by unknown delays in the transmit chain of the TRP 120). The location server 130 may combine the measurement report of the target UE 110a with the measurement report of the reference UE 110b selected for the target UE 110a to calculate the PRS as described above with respect to FIG. Figure 1The double difference measurement discussed. By calculating the double difference, the impairments included in the reported time / phase value or time / phase difference can be offset. The location server 130 can calculate the position of the target UE 110a based on the double difference measurement, the position coordinates of the relevant TRP 120, and the position coordinates of the relevant reference UE 110b, and send the calculated position to the target UE 110a, for example, via LTE Positioning Protocol (LPP) signaling. Since the impairments included in the reported time / phase value or time / phase difference are offset when calculating the double difference, the position estimation accuracy of the target UE 110a is improved.

[0039] Figure 4B The UE assisted positioning process according to another exemplary embodiment of the present application is illustrated. Figure 4B In the process, similar to Figure 4A The operations are denoted by similar reference numerals, and repeated descriptions thereof are omitted here.

[0040] Reference Figure 4B At operation 310, the target UE 110a transmits a positioning reference report indicating the selected one or more reference UEs 110b to the location server 130. At operation 321, the network may configure an uplink sounding reference signal (UL SRS) for the target UE 110a and the reference UE 110b. For example, the serving base station of the UE (i.e., the target UE 110a or the reference UE 110B) may configure time and frequency resources for the UE to transmit the UL SRS. The serving base station may also send the SRS configuration to the location server 130. The location server 130 may transmit the SRS configuration of the UE to the neighboring base stations so that the serving base station and the neighboring base stations may receive and measure the SRS transmitted by the UE.

[0041] Based on the SRS configuration, target UE 110a may transmit a UL SRS to TRP 120 at operation 322, and reference UE 110b may transmit a UL SRS to TRP 120 at operation 324. TRP 120 may measure the arrival time or phase of the UL SRS transmitted from target UE 110a and reference UE 110b based on the positioning method used.

[0042] Then at operation 326, the TRP 120 may transmit the measurement results to the location server 130 via, for example, the NRPPa information. The location server 130 may combine the measurement results related to the target UE 110a with the measurement results related to the reference UE 110b selected for the target UE 110a to calculate the above-mentioned Figure 1The double difference measurement discussed. The location server 130 may calculate the location of the target UE 110a based on the double difference measurement, the location coordinates of the associated TRP 120, and the location coordinates of the associated reference UE 110b. Since the impairments included in the measured time / phase values ​​or time / phase differences are offset when calculating the double difference, the accuracy of the location estimate of the target UE 110a is improved. The location server 130 may send the calculated location coordinates to the target UE 110a, for example, via LTE Positioning Protocol (LPP) signaling.

[0043] Figure 5 FIG. 1 illustrates a UE-based positioning process according to an exemplary embodiment of the present application. When the target UE 110a has selected one or more reference UEs 110b, the target UE 110a may select one or more reference UEs 110b. Figure 3 The process executes the process.

[0044] refer to Figure 5 , at operation 410, the target UE 110a may establish a sidelink communication connection with the selected reference UE 110b, so that the selected reference UE 110b may report the measurement results to the target UE 110a over the connection. In one example, the established communication connection may be a unicast connection over which the reference UE 110b may transmit the measurement results to the target UE 110a. In another example, the communication connection may be a multicast connection, through which the reference UE 110b may transmit the measurement results to a group of target UEs including the target UE 110a. The multicast connection may be preferred when the reference UE may provide a positioning reference for multiple target UEs. A group may be defined / configured to include multiple target UEs served by the reference UE, and a target UE may be added to the group by transmitting a subscription message to the reference UE, or a target UE may be removed from the group by transmitting a cancellation subscription message to the reference UE. In yet another example, the communication connection may be a broadcast connection, and the reference UE may broadcast the measurement values ​​to all nearby UEs including the target UE 110a.

[0045] The target UE 110a may transmit a measurement request to the selected reference UE 110b at operation 412. The measurement request may specify the measurements required at the target UE 110a. For example, the measurement request may include a third list of TRPs 120 to be measured at the reference UE 110b (also at the target UE 110a), a measurement type (e.g., time or phase), a measurement period, and a number of measurements required at the target UE 110a. For double differential measurements, the measurement request may also specify a pairing relationship of the TRPs of the third list.

[0046] In an example embodiment, if the reference UE 110b is providing positioning reference services to other target UEs, the target UE 110a may transmit a registration request for the ongoing positioning reference service to the reference UE 110b. The registration request may include a third list of TRPs whose measurement results need to be transmitted to the target UE 110a. In an example, the reference UE 110b may respond with a positioning reference service confirmation / confirmation message (not shown) to confirm the successful registration of the target UE 110a. In an example embodiment, the reference UE 110b may treat the measurement request as a registration request to the positioning reference service, and operation 218 may be omitted.

[0047] Then, at operations 416a-n, the reference UE 110b may transmit a measurement report to the target UE 110a via the sidelink communication connection established at operation 410 in accordance with the measurement request. The measurement report may include PRS arrival time / phase values ​​measured relative to the corresponding TRP 120 or time / phase differences associated with the TRP 120 pair. As described above, the time / phase values ​​or time / phase differences measured at the reference UE 110b include the same impairments as measured at the target UE 110a, i.e., time and phase errors caused by unknown delays in the transmit chain of the TRP 120. The target UE 110a may combine the measurement results received from the reference UE 110b with the measurement results generated at the target UE 110a to calculate a double difference, as described above with respect to FIG. Figure 1 As discussed. By calculating the double difference, the impairments included in the measured time / phase value or the time / phase difference can be offset. The target UE 110a can calculate its position coordinates based on the double difference, the position coordinates of the relevant TRP 120, and the position coordinates of the relevant reference UE 110b. Since the impairments included in the measured time / phase value or the time / phase difference are offset when calculating the double difference, the position estimation accuracy of the target UE 110a is improved. In one example, the target UE 110a can send the position estimate to the location server 130, or to the base station to which the target UE 110a is connected, via LPP signaling.

[0048] exist Figure 5 During the process, the measurement report can be directly transmitted from the reference UE 110b to the target UE 110a via the sidelink communication. It can minimize the reporting delay and speed up the positioning process, which is especially beneficial for carrier phase-based positioning because the carrier phase changes quickly.

[0049] Figure 6 A schematic block diagram of a device 500 according to an exemplary embodiment of the present application is illustrated. The device 500 may be implemented as the target UE 110a and / or the reference UE 110b discussed above.

[0050] Reference Figure 6 , the device 500 may include one or more processors 511, one or more memories 512, and one or more transceivers 513 interconnected by one or more buses 514. The one or more buses 514 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fibers, optical devices, or other optical communication devices. Each of the one or more transceivers 513 may include a receiver and a transmitter connected to one or more antennas 516. The device 500 may communicate wirelessly with a network device or a terminal device via one or more antennas 516. The one or more memories 512 may include computer program code 515. The one or more memories 512 and the computer program code 515 may be configured to, when executed by the one or more processors 511, cause the device 500 to perform operations related to the target UE 110a and / or operations related to the reference UE 110b as described above.

[0051] The one or more processors 511 mentioned above may be of any appropriate type suitable for the local technical network, and may include a general-purpose processor, a dedicated processor, a microprocessor, a digital signal processor (DSP), one or more processors in a processor-based multi-core processor architecture, and one or more of dedicated processors such as those developed based on a field programmable gate array (FPGA) and an application-specific integrated circuit (ASIC). The one or more processors 511 may be configured to control other elements of the UE / network device and operate in cooperation with them to implement the processes discussed above.

[0052] The one or more memories 512 may include at least one storage medium in various forms, such as volatile memory and / or non-volatile memory. Volatile memory may include, but is not limited to, for example, random access memory (RAM) or cache. Non-volatile memory may include, but is not limited to, for example, read-only memory (ROM), hard disk, flash memory, etc. In addition, the one or more memories 512 may include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment or any combination thereof.

[0053] Some exemplary embodiments also provide computer program codes or instructions that, when executed by one or more processors, can cause a device or apparatus to perform the above-described processes. The computer program code for performing the processes of the exemplary embodiments can be written in any combination of one or more programming languages. The computer program code can be provided to one or more processors or controllers of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, causes the functions / operations to be specified in the flowchart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0054] Some exemplary embodiments also provide a computer program product or computer readable medium in which computer program code or instructions are stored. A computer readable medium may be any tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or apparatus. A machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. More specific examples of machine readable storage media would include an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0055] It should be understood that the blocks in the drawings can be implemented in various ways, including software, hardware, firmware, or any combination thereof. In some embodiments, one or more blocks can be implemented using software and / or firmware (e.g., machine executable instructions stored in a storage medium). In addition to or in place of machine executable instructions, some or all of the blocks in the drawings can be implemented at least in part by one or more hardware logic components. For example, but not limited to, illustrative types of hardware logic components that can be used include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), etc.

[0056] In addition, although the operation is described in a specific order, it should not be understood that it requires to perform these operations in the specific order shown or in a continuous order, or to perform all illustrated operations to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of the application, but rather descriptions of features that can be specific to a particular embodiment. Some of the features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0057] Although the subject matter has been described in language specific to structural features and / or methodological acts, it should be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims.

[0058] Certain abbreviations that may appear in the specification and / or drawings are defined as follows:

[0059] LMC Location Management Component

[0060] LMF Location Management Function

[0061] LPP LTE Positioning Protocol

[0062] NRPPa NR Positioning Protocol a

[0063] PRS Positioning Reference Signal

[0064] SSB Synchronous Signal Block

[0065] SRS Sounding Reference Signal

[0066] TRP Transmit and Receive Points

[0067] UE User Equipment

Claims

1. A terminal device, comprising: at least one processor; as well as at least one memory including computer program code, the at least one memory and the computer program code being configured, together with the at least one processor, to cause the terminal device to at least: transmitting a positioning reference request on one or more side links between the terminal device and one or more reference devices; receiving a positioning reference reply from the one or more reference devices, the positioning reference reply including positioning reference measurement capabilities of the one or more reference devices; as well as Based at least in part on the received positioning reference reply, at least one reference device is selected from the one or more reference devices for positioning of the terminal device.

2. The terminal device according to claim 1, wherein: The positioning reference request is transmitted via broadcast or multicast communication, and the multicast communication is directed to a group of reference devices.

3. The terminal device according to claim 1, wherein: The at least one memory and the computer program code are further configured to, together with the at least one processor, cause the terminal device to at least: Before transmitting the positioning reference request, a positioning reference advertisement is received, wherein the positioning reference advertisement includes information of the one or more reference devices.

4. The terminal device according to claim 1, wherein: The positioning reference request includes one or more of the following: a first list of network devices measurable by the terminal device; Signal level information of the network devices of the first list measured at the terminal device; and The beam direction information of the network devices in the first list relative to the terminal device.

5. The terminal device according to claim 1, wherein: The positioning reference measurement capability indicated in the positioning reference reply includes one or more of the following: a second list of network devices measurable by the reference device; signal level information of the network devices of the second list measured at the reference device; beam direction information of the network devices in the second list relative to the reference device; as well as The location coordinates of the reference device.

6. The terminal device according to claim 1, wherein: The at least one memory and the computer program code are further configured to, together with the at least one processor, cause the terminal device to at least: Channel measurements are performed on the one or more reference devices from which the positioning reference reply is received, wherein the at least one reference device is selected based at least in part on the channel measurements.

7. The terminal device according to claim 1, wherein: The at least one memory and the computer program code are further configured to, together with the at least one processor, cause the terminal device to at least: The selection of the at least one reference device is reported to a network device to which the terminal device is connected and / or a location server providing service for the terminal device.

8. The terminal device according to claim 1, wherein: The at least one memory and the computer program code are further configured to, together with the at least one processor, cause the terminal device to at least: establishing a communication connection with the at least one reference device; transmitting a measurement request to the at least one reference device; as well as A measurement report is received from the at least one reference device.

9. The terminal device according to claim 8, wherein: The measurement request includes one or more of the following: a third list of network devices to be measured; Network device pairing information; and Measurement type.

10. The terminal device according to claim 8, wherein: The at least one memory and the computer program code are further configured to, together with the at least one processor, cause the terminal device to at least: Prior to receiving the measurement report, a registration request for a positioning reference service is transmitted to the at least one reference device.

11. The terminal device according to claim 1, wherein: The positioning reference request is transmitted in response to a positioning reference trigger indication received from the location server or network device to which the terminal device is connected.

12. A reference device comprising: at least one processor; as well as at least one memory including computer program code, the at least one memory and the computer program code being configured, with the at least one processor, to cause the reference device to at least: receiving, from a terminal device, a positioning reference request on a side link between the terminal device and the reference device; as well as In response to the positioning reference request, a positioning reference reply is transmitted to the terminal device, wherein the positioning reference reply includes the positioning reference measurement capability of the reference device.

13. The reference device of claim 12, wherein: The positioning reference request is received on a broadcast or multicast communication, and the multicast is directed to a device group including a plurality of reference devices.

14. The reference device of claim 12, wherein: The at least one memory and the computer program code are further configured, with the at least one processor, to cause the reference device to at least: A location-based reference advertisement is transmitted, the location-based reference advertisement including information of one or more reference devices.

15. The reference device of claim 12, wherein: The positioning reference request includes one or more of the following: a first list of network devices measurable by the terminal device; Signal level information of the network devices of the first list measured at the terminal device, and The beam direction information of the network devices in the first list relative to the terminal device.

16. The reference device of claim 15, wherein: When the reference device determines from the positioning reference request that it can provide a positioning reference to the terminal device, the reference device transmits the positioning reference reply.

17. The reference device of claim 12, wherein: The positioning reference measurement capability indicated in the positioning reference reply includes one or more of the following: a second list of network devices measurable by the reference device; signal level information of the network devices of the second list measured at the reference device; beam direction information of the network devices in the second list relative to the reference device; as well as The location coordinates of the reference device.

18. The reference device of claim 12, wherein: The at least one memory and the computer program code are further configured, with the at least one processor, to cause the reference device to at least: Establishing a communication connection with the terminal device; receiving a measurement request from the terminal device; and In response to the measurement request, a measurement report is transmitted to the terminal device.

19. The reference device of claim 18, wherein: The measurement request includes one or more of the following: a third list of network devices to be measured; Network device pairing information; and Measurement type.

20. The reference device of claim 18, wherein: The at least one memory and the computer program code are further configured, with the at least one processor, to cause the reference device to at least: A registration request is received from the terminal device for a positioning reference service in which the measurement report is transmitted.

21. A method implemented at a terminal device, comprising: transmitting a positioning reference request on one or more side links between the terminal device and one or more reference devices; receiving a positioning reference reply from the one or more reference devices, the positioning reference reply including positioning reference measurement capabilities of the one or more reference devices; as well as Based at least in part on the received positioning reference reply, at least one reference device is selected from the one or more reference devices for positioning of the terminal device.

22. The method of claim 21, wherein: The positioning reference request is transmitted via broadcast or multicast communication, and the multicast communication is directed to a group of reference devices.

23. The method of claim 21, further comprising: Before transmitting the positioning reference request, a positioning reference advertisement is received, wherein the positioning reference advertisement includes information of the one or more reference devices.

24. The method of claim 21, wherein: The positioning reference request includes one or more of the following: a first list of network devices measurable by the terminal device; Signal level information of the network devices of the first list measured at the terminal device; and The beam direction information of the network devices in the first list relative to the terminal device.

25. The method of claim 21, wherein: The positioning reference measurement capability indicated in the positioning reference reply includes one or more of: a second list of network devices measurable by the reference device; signal level information of the network devices of the second list measured at the reference device; as well as The second list includes beam direction information of the network devices relative to the reference device.

26. The method of claim 21, further comprising: Channel measurements are performed on the one or more reference devices from which the positioning reference reply is received, wherein the at least one reference device is selected based at least in part on the channel measurements.

27. The method of claim 21, further comprising: The selection of the at least one reference device is reported to a network device to which the terminal device is connected and / or a location server providing service for the terminal device.

28. The method of claim 21, further comprising: establishing a communication connection with the at least one reference device; transmitting a measurement request to the at least one reference device; as well as A measurement report is received from the at least one reference device.

29. The method of claim 28, wherein: The measurement request includes one or more of the following: a third list of network devices to be measured; Network device pairing information; and Measurement type.

30. The method of claim 28, further comprising: Prior to receiving the measurement report, a registration request for a positioning reference service is transmitted to the at least one reference device.

31. The method of claim 21, wherein: The positioning reference request is transmitted in response to a positioning reference trigger indication received from the location server or network device to which the terminal device is connected.

32. A method implemented at a reference device, comprising: receiving, from a terminal device, a positioning reference request on a side link between the reference device and the terminal device; as well as In response to the positioning reference request, a positioning reference reply is transmitted to the terminal device, wherein the positioning reference reply includes the positioning reference measurement capability of the reference device.

33. The method of claim 32, wherein: The positioning reference request is received via broadcast or multicast communication, and the multicast communication is directed to a device group including a plurality of reference devices.

34. The method of claim 32, further comprising: A location reference advertisement is transmitted, wherein the location reference advertisement includes information of the one or more reference devices.

35. The method of claim 32, wherein: The positioning reference request includes one or more of the following: a first list of network devices measurable by the terminal device; Signal level information of the network devices of the first list measured at the terminal device, and The beam direction information of the network devices in the first list relative to the terminal device.

36. The method of claim 35, wherein: When the reference device determines from the positioning reference request that it can provide a positioning reference to the terminal device, the reference device transmits the positioning reference reply.

37. The method of claim 32, wherein: The positioning reference measurement capability indicated in the positioning reference reply includes one or more of the following: a second list of network devices measurable by the reference device; signal level information of the network devices of the second list measured at the reference device; beam direction information of the network devices in the second list relative to the reference device; as well as The location coordinates of the reference device.

38. The method of claim 32, further comprising: Establishing a communication connection with the terminal device; receiving a measurement request from the terminal device; as well as In response to the measurement request, a measurement report is transmitted to the terminal device.

39. The method of claim 38, wherein: The measurement request includes one or more of the following: a third list of network devices to be measured; Network device pairing information; and Measurement type.

40. The method of claim 38, wherein: The at least one memory and the computer program code are further configured, with the at least one processor, to cause the reference device to at least: A registration request is received from the terminal device for a positioning reference service in which the measurement report is transmitted.

41. An apparatus comprising: means for transmitting, by a terminal device, a positioning reference request on one or more side links between the terminal device and one or more reference devices; means for receiving a positioning reference reply from the one or more reference devices, the positioning reference reply comprising positioning reference measurement capabilities of the one or more reference devices; as well as Means for selecting at least one reference device from the one or more reference devices for positioning the terminal device based at least in part on the received positioning reference reply.

42. An apparatus comprising: means for receiving, at a reference device and from a terminal device, a positioning reference request on a side link between the reference device and the terminal device; as well as means for transmitting a positioning reference reply to the terminal device in response to a positioning reference request, the positioning reference reply comprising the positioning reference measurement capability of the reference device.

43. A computer program product, embodied in at least one computer-readable medium and comprising instructions which, when executed by at least one processor of a terminal device, cause the terminal device to at least: transmitting a positioning reference request on one or more side links between the terminal device and one or more reference devices; receiving a positioning reference reply from the one or more reference devices, the positioning reference reply including positioning reference measurement capabilities of the one or more reference devices; as well as Based at least in part on the received positioning reference reply, at least one reference device is selected from the one or more reference devices for positioning of the terminal device.

44. A computer program product, embodied in at least one computer-readable medium and comprising instructions which, when executed by at least one processor of a reference device, cause the reference device to at least: receiving, from a terminal device, a positioning reference request on a side link between the reference device and the terminal device; and In response to the positioning reference request, a positioning reference reply is transmitted to the terminal device, wherein the positioning reference reply includes the positioning reference measurement capability of the reference device.

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