Method and apparatus for reconfigurable smart surface assisted positioning

Abstract

Embodiments of the present disclosure relate to a method and apparatus for reconfigurable smart surface (RIS) assisted positioning. In accordance with an embodiment of the present disclosure, a location management function may include: a transceiver; and a processor coupled to the transceiver and configured to: transmit, via the transceiver and to a base station (BS), a request message requesting a positioning reference signal (PRS) configuration for RIS-assisted downlink positioning or a sounding reference signal (SRS) configuration for RIS-assisted uplink positioning; and receiving, via the transceiver, the PRS configuration or the SRS configuration from the BS.

Description

Technical Field

[0001] Embodiments of this application generally relate to wireless communication technology, and more specifically, to methods and apparatus for reconfigurable smart surface (RIS)-assisted positioning. Background Technology

[0002] RIS (Reflective Surface) is a promising technology for improving the positioning accuracy of wireless networks. Specifically, an RIS can be a planar surface containing numerous reflective elements and can be deployed on the surfaces of various objects, such as walls. The reflectivity of the RIS can be adjusted by changing the state of its elements. Deploying RIS is more flexible and less costly than deploying base stations (BS). With the help of RIS, wireless networks can achieve higher spatial resolution and positioning accuracy. Currently, details regarding RIS-assisted positioning have not been studied. Summary of the Invention

[0003] The embodiments of this application at least provide a technical solution for RIS-assisted positioning.

[0004] According to some embodiments of this application, a location management function (LMF) may include: a transceiver; and a processor coupled to the transceiver and configured to: transmit via the transceiver to a BS requesting a Positioning Reference Signal (PRS) configuration for RIS-assisted downlink (DL) positioning or a RIS-assisted uplink (UL) positioning detection reference signal (SRS) configuration; and receive the PRS configuration or the SRS configuration from the BS via the transceiver.

[0005] In some embodiments of this application, the processor is further configured to: determine whether to initiate RIS-assisted DL positioning or RIS-assisted UL positioning; transmit a request message via the transceiver to request an available RIS in response to determining whether to initiate RIS-assisted DL positioning or RIS-assisted UL positioning; and receive information about the available RIS via the transceiver, wherein the information about the available RIS includes at least one of the following: the location of the available RIS or the number of elements of each available RIS.

[0006] In some embodiments of this application, the processor is further configured to: transmit a transmit-receive point (TRP) information request message to the BS via the transceiver; receive from the BS via the transceiver an indication to initiate RIS-assisted DL positioning or RIS-assisted UL positioning, wherein the indication is a RIS-assisted positioning request message or received in a TRP information response message from the BS; and determine to initiate RIS-assisted DL positioning or RIS-assisted UL positioning in response to receiving the indication.

[0007] In some embodiments of this application, the processor is further configured to: receive, via the transceiver and from the BS, a TRP information response message indicating a minimum number of TRPs and a number of candidate TRPs; compare the number of candidate TRPs with the minimum number of TRPs; and determine to initiate RIS-assisted DL positioning or RIS-assisted UL positioning in response to the number of candidate TRPs being less than the minimum number of TRPs.

[0008] In some embodiments of this application, the processor is further configured to: determine to initiate RIS-assisted DL positioning in response to receiving an indication from the user equipment (UE) via the transceiver indicating to initiate RIS-assisted DL positioning, wherein the indication is a RIS-assisted positioning request message or received in a location information provision message from the UE.

[0009] In some embodiments of this application, the processor is further configured to transmit, via the transceiver and to the UE, a provision auxiliary data message indicating the minimum number of TRPs and the number of candidate TRPs configured by the BS.

[0010] In some embodiments of this application, the processor is further configured to: determine to initiate RIS-assisted UL positioning in response to receiving an indication from the BS via the transceiver indicating to initiate RIS-assisted UL positioning, wherein the indication is a RIS-assisted positioning request message or received in a measurement response message from the BS.

[0011] In some embodiments of this application, the processor is further configured to: transmit a RIS capability request message to the BS via the transceiver requesting capability information of the available RIS; and receive the capability information of the available RIS from the BS via the transceiver, wherein the capability information includes the ability to tune the coefficients and properties of RIS elements contained in each of the available RISs according to control information from the BS.

[0012] In some embodiments of this application, the processor is configured to: after receiving the capability information of the available RIS, transmit a request message requesting the PRS configuration to the BS via the transceiver, wherein the PRS configuration includes the PRS configuration of the direct link from the BS to the UE and the PRS configuration of the cascaded link including the link from the BS to the RIS and the link from the RIS to the UE; and receive the PRS configuration of the direct link and the PRS configuration of the cascaded link from the BS via the transceiver.

[0013] In some embodiments of this application, the processor is configured to: transmit the capability information of the available RIS to the UE via the transceiver; receive an on-demand PRS request message for RIS-assisted DL positioning from the UE via the transceiver; based on the on-demand PRS request message, transmit a request message via the transceiver requesting the PRS configuration, wherein the PRS configuration includes the PRS configuration of the direct link from the BS to the UE and the PRS configuration of the cascaded link including the link from the BS to the RIS and the link from the RIS to the UE; and receive the PRS configuration of the direct link and the PRS configuration of the cascaded link via the transceiver.

[0014] In some embodiments of this application, the processor is further configured to transmit the PRS configuration of the direct link and the PRS configuration of the cascaded link to the UE via the transceiver.

[0015] In some embodiments of this application, the PRS configuration of the cascaded link indicates a first list of DL PRS resource sets for each TRP in each frequency layer, and the DL PRS resource sets included in the first list are different from the DL PRS resource sets included in a second list of DL PRS resource sets in the configuration of each TRP in each frequency layer and included in the PRS configuration of the direct link from the BS to the UE.

[0016] In some embodiments of this application, each DL PRS resource set included in the first list is defined by a set of parameters including at least one of the following: a first parameter indicating the identifier (ID) of the DL PRS resource set; a second parameter indicating the periodicity and offset of the DL PRS resource set; a third parameter indicating how many times each DL PRS resource is repeated for a single instance of the DL PRS resource set; a fourth parameter indicating the offset between two repeated instances of the DL PRS resource; a fifth parameter indicating the number of symbols of the DL PRS resource within a time slot; a sixth parameter indicating the average energy of each resource element in the resource elements carrying the PRS; or a seventh parameter indicating a set of DL PRS resources.

[0017] In some embodiments of this application, the processor is further configured to: transmit a location information request message to the UE via the transceiver; receive PRS measurement results of the direct link and the cascaded link from the UE via the transceiver and in a location information provision message; and calculate the location result of the UE based at least in part on the PRS measurement results.

[0018] In some embodiments of this application, the request message requesting the SRS configuration is a location information request message, and the processor is configured to: after receiving the capability information of the available RIS, transmit the location information request message to the BS via the transceiver, wherein the SRS configuration includes the SRS configuration of the direct link from the UE to the BS and the SRS configuration of the cascaded link including the link from the UE to the RIS and the link from the RIS to the BS; and receive the SRS configuration of the direct link and the SRS configuration of the cascaded link from the BS via the transceiver in a location information response message.

[0019] In some embodiments of this application, the request message requesting the SRS configuration is a location activation request message, and the processor is configured to: after receiving the capability information of the available RIS, transmit the location activation request message via the transceiver to the BS, wherein the location activation request message activates SRS transmission of the direct link from the UE to the BS and SRS transmission of the cascaded link including the link from the UE to the RIS and the link from the RIS to the BS, and requests the SRS configuration of the direct link and the SRS configuration of the cascaded link; and receive the SRS configuration of the direct link and the SRS configuration of the cascaded link in a location activation response message from the BS via the transceiver.

[0020] In some embodiments of this application, the SRS configuration of the cascaded link indicates at least one of a first list of SRS location resource sets to be released or a second list of SRS location resource sets to be added or modified; and the SRS location resource sets included in the first list are different from the SRS location resource sets included in the third list of SRS location resource sets to be released configured for the direct link from the UE to the BS, or the SRS location resource sets included in the second list are different from the SRS location resource sets included in the fourth list of SRS location resource sets to be added or modified configured for the direct link.

[0021] In some embodiments of this application, each SRS location resource set included in the first list or the second list is defined by a set of parameters including at least one of the following: a first parameter indicating the ID of the SRS location resource set; a second parameter indicating the ID of the SRS location resource in the SRS location resource set; or a third parameter indicating whether the SRS location resource in the SRS location resource set is periodic, semi-persistent, or aperiodic.

[0022] In some embodiments of this application, the processor is further configured to: transmit a measurement request message to the BS via the transceiver; receive SRS measurement results of the direct link and the cascaded link from the BS via the transceiver and in a measurement response message; and calculate the positioning result of the UE based at least in part on the SRS measurement results.

[0023] According to some embodiments of this application, a BS may include: a transceiver; and a processor coupled to the transceiver and configured to: receive, via the transceiver and from an LMF, a request message for a PRS configuration for RIS-assisted DL positioning or an SRS configuration for RIS-assisted UL positioning; and transmit the PRS configuration or the SRS configuration to the LMF via the transceiver.

[0024] In some embodiments of this application, the processor is further configured to: receive a TRP information request message from the LMF via the transceiver; compare the number of candidate TRPs with the minimum number of TRPs configured by the BS; and, in response to the number of candidate TRPs being less than the minimum number of TRPs, transmit via the transceiver and to the LMF an indication to initiate RIS-assisted DL positioning or RIS-assisted UL positioning; wherein the indication is a RIS-assisted positioning request message or transmitted in a TRP information response message.

[0025] In some embodiments of this application, the processor is further configured to transmit a TRP information response message, indicating the minimum number of TRPs and the number of candidate TRPs, via the transceiver and to the LMF.

[0026] In some embodiments of this application, the processor is further configured to: compare a measured reference signal received power (RSRP) value with an RSRP threshold configured by the BS; and, in response to the measured RSRP value being less than the RSRP threshold, transmit an indication via the transceiver and to the LMF to initiate RIS-assisted UL positioning; wherein the indication is a RIS-assisted positioning request message or transmitted in a measurement response message.

[0027] In some embodiments of this application, the processor is further configured to receive, via the transceiver, information of available RISs for RIS-assisted DL positioning or RIS-assisted UL positioning, wherein the information of the available RISs includes at least one of the following: the location of the available RIS or the number of elements of each available RIS.

[0028] In some embodiments of this application, the processor is further configured to: receive, via the transceiver and from the LMF, a RIS capability request message requesting capability information of the available RIS; and, in response to receiving the RIS capability request message from the LMF, transmit, via the transceiver, the capability information of the available RIS, wherein the capability information includes the ability to tune the coefficients and properties of RIS elements contained in each of the available RIS according to control information from the BS.

[0029] In some embodiments of this application, the processor is configured to: after transmitting the capability information of the available RIS, receive, via the transceiver and from the LMF, a request message requesting the PRS configuration, wherein the PRS configuration includes the PRS configuration of a direct link from the BS to the UE and the PRS configuration of a cascaded link including a link from the BS to the RIS and a link from the RIS to the UE; configure the PRS configuration for the direct link and the PRS configuration for the cascaded link; and transmit the PRS configuration of the direct link and the PRS configuration of the cascaded link to the LMF via the transceiver.

[0030] In some embodiments of this application, the PRS configuration of the cascaded link indicates a first list of DL PRS resource sets for each TRP in each frequency layer, and the DL PRS resource sets included in the first list are different from the DL PRS resource sets included in a second list of DL PRS resource sets in the configuration of each TRP in each frequency layer and included in the PRS configuration of the direct link from the BS to the UE.

[0031] In some embodiments of this application, each DL PRS resource set included in the first list is defined by a set of parameters including at least one of the following: a first parameter indicating the ID of the DL PRS resource set; a second parameter indicating the periodicity and offset of the DL PRS resource set; a third parameter indicating how many times each DL PRS resource is repeated for a single instance of the DL PRS resource set; a fourth parameter indicating the offset between two repeated instances of the DL PRS resource; a fifth parameter indicating the number of symbols of the DL PRS resource within a time slot; a sixth parameter indicating the average energy of each resource element in the resource elements carrying the PRS; or a seventh parameter indicating a set of DL PRS resources.

[0032] In some embodiments of this application, the request message requesting the SRS configuration is a location information request message, and the processor is configured to: after transmitting the capability information of the available RIS, receive the location information request message via the transceiver and from the LMF, wherein the SRS configuration includes the SRS configuration of a direct link from the UE to the BS and the SRS configuration of a cascaded link including a link from the UE to the RIS and a link from the RIS to the BS; configure the SRS configuration for the direct link and the SRS configuration for the cascaded link; transmit the SRS configuration of the direct link and the SRS configuration of the cascaded link to the LMF via the transceiver and in a location information response message; and transmit the SRS configuration of the direct link and the SRS configuration of the cascaded link to the UE via the transceiver.

[0033] In some embodiments of this application, the request message requesting the SRS configuration is a location activation request message, and the processor is configured to: after transmitting the capability information of the available RIS, receive the location activation request message via the transceiver and from the LMF, wherein the location activation request message activates SRS transmission of the direct link from the UE to the BS and SRS transmission of the cascaded link including the link from the UE to the RIS and the link from the RIS to the BS, and requests SRS configuration of the direct link and the SRS configuration of the cascaded link; configure the SRS configuration for the direct link and the SRS configuration for the cascaded link; transmit the SRS configuration of the direct link and the SRS configuration of the cascaded link to the LMF via the transceiver in a location activation response message; transmit the SRS configuration of the direct link and the SRS configuration of the cascaded link to the UE via the transceiver; and activate the SRS transmission of the direct link and the SRS transmission of the cascaded link.

[0034] In some embodiments of this application, the SRS configuration of the cascaded link indicates at least one of a first list of SRS location resource sets to be released or a second list of SRS location resource sets to be added or modified; and the SRS location resource sets included in the first list are different from the SRS location resource sets included in the third list of SRS location resource sets to be released configured for the direct link from the UE to the BS, or the SRS location resource sets included in the second list are different from the SRS location resource sets included in the fourth list of SRS location resource sets to be added or modified configured for the direct link.

[0035] In some embodiments of this application, each SRS location resource set included in the first list or the second list is defined by a set of parameters including at least one of the following: a first parameter indicating the ID of the SRS location resource set; a second parameter indicating the ID of the SRS location resource in the SRS location resource set; or a third parameter indicating whether the SRS location resource in the SRS location resource set is periodic, semi-persistent, or aperiodic.

[0036] In some embodiments of this application, the processor is further configured to: receive a measurement request message from the LMF via the transceiver; measure the SRS on the direct link and the SRS on the cascaded link in response to receiving the measurement request message; and transmit the SRS measurement results of the direct link and the cascaded link to the LMF via the transceiver in a measurement response message.

[0037] In some embodiments of this application, the processor is further configured to: randomly select coefficients of elements in the available RIS; transmit a reference signal to the UE via the transceiver and via a cascaded link comprising a link from the BS to the available RIS and a link from the available RIS to the UE; receive channel state information (CSI) of the cascaded link from the UE via the transceiver; and tune the coefficients of the elements in the available RIS based on the CSI report.

[0038] According to some embodiments of this application, a UE may include: a transceiver; and a processor coupled to the transceiver and configured to: receive a RIS-assisted DL positioning PRS configuration or a RIS-assisted UL positioning SRS configuration via the transceiver; and receive a PRS based on the PRS configuration via the transceiver or transmit an SRS based on the SRS configuration via the transceiver.

[0039] In some embodiments of this application, the processor is configured to: receive, via the transceiver and from the LMF, a provide assistance data message indicating a minimum number of TRPs and a number of candidate TRPs configured by the BS; compare the number of candidate TRPs with the minimum number of TRPs; and, in response to the number of candidate TRPs being less than the minimum number of TRPs, transmit via the transceiver to the LMF a RIS-assisted positioning request message for initiating RIS-assisted DL positioning.

[0040] In some embodiments of this application, the processor is configured to: transmit an indication to the LMF via the transceiver to initiate RIS-assisted DL positioning in response to a measured reference signal received power (RSRP) value being less than an RSRP threshold configured by the UE or a calculated positioning result not meeting quality of service (QoS) requirements, wherein the indication is a RIS-assisted positioning request message or transmitted in a location information provision message.

[0041] In some embodiments of this application, the processor is further configured to: receive from the LMF via the transceiver the capability information of available RIS for RIS-assisted DL positioning; and transmit on-demand RPS request messages for the RIS-assisted DL positioning to the LMF via the transceiver.

[0042] In some embodiments of this application, the PRS configuration includes a PRS configuration for a direct link from the BS to the UE and a PRS configuration for cascaded links including a link from the BS to the RIS and a link from the RIS to the UE, wherein the PRS configuration for the cascaded links indicates a first list of DL PRS resource sets per TRP in each frequency layer, and the DL PRS resource sets included in the first list are different from the DL PRS resource sets included in a second list of DL PRS resource sets in the configuration of each TRP in each frequency layer and included in the PRS configuration of the direct link.

[0043] In some embodiments of this application, each DL PRS resource set included in the first list is defined by a set of parameters including at least one of the following: a first parameter indicating the ID of the DL PRS resource set; a second parameter indicating the periodicity and offset of the DL PRS resource set; a third parameter indicating how many times each DL PRS resource is repeated for a single instance of the DL PRS resource set; a fourth parameter indicating the offset between two repeated instances of the DL PRS resource; a fifth parameter indicating the number of symbols of the DL PRS resource within a time slot; a sixth parameter indicating the average energy of each resource element in the resource elements carrying the PRS; or a seventh parameter indicating a set of DL PRS resources.

[0044] In some embodiments of this application, the processor is further configured to: receive a location request message from the LMF via the transceiver; measure the PRS on the direct link from the BS to the UE and the PRS on the cascaded links including the link from the BS to the RIS and the link from the RIS to the UE in response to receiving the location request message; and calculate the location result of the UE based on the PRS measurement results of the direct link and the cascaded link or transmit the PRS measurement results of the direct link and the cascaded link to the LMF via the transceiver in a location information provision message.

[0045] In some embodiments of this application, the SRS configuration includes the SRS configuration of a direct link from the UE to the BS and the SRS configuration of a cascaded link including a link from the UE to the RIS and a link from the RIS to the BS; the SRS configuration of the cascaded link indicates at least one of a first list of SRS location resource sets to be released or a second list of SRS location resource sets to be added to or modified; and the SRS location resource sets included in the first list are different from the SRS location resource sets included in the third list of SRS location resource sets to be released for the direct link from the UE to the BS, or the SRS location resource sets included in the second list are different from the SRS location resource sets included in the fourth list of SRS location resource sets to be added to or modified for the direct link.

[0046] In some embodiments of this application, each SRS location resource set included in the first list or the second list is defined by a set of parameters including at least one of the following: a first parameter indicating the ID of the SRS location resource set; a second parameter indicating the ID of the SRS location resource in the SRS location resource set; or a third parameter indicating whether the SRS location resource in the SRS location resource set is periodic, semi-persistent, or aperiodic.

[0047] In some embodiments of this application, the processor is further configured to: receive a reference signal from the BS via the transceiver and via a cascaded link comprising a link from the BS to an available RIS and a link from the available RIS to the UE; and transmit a CSI report of the cascaded link to the BS via the transceiver.

[0048] According to some embodiments of this application, a method performed by an LMF may include: transmitting a request message to a BS requesting a RIS-assisted DL positioning PRS configuration or a RIS-assisted UL positioning SRS configuration; and receiving the PRS configuration or the SRS configuration from the BS.

[0049] According to some embodiments of this application, a method performed by a BS may include: receiving from an LMF a request message for a RIS-assisted DL positioning PRS configuration or a RIS-assisted UL positioning SRS configuration; and transmitting the PRS configuration or the SRS configuration to the LMF.

[0050] According to some embodiments of this application, a method performed by a UE may include: receiving a PRS configuration for RIS-assisted DL positioning or an SRS configuration for RIS-assisted UL positioning; and receiving a PRS based on the PRS configuration or an SRS based on the SRS configuration. Attached Figure Description

[0051] To illustrate the advantages and features of this application, the description of the application is presented with reference to specific embodiments of the application illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of the application and should therefore not be considered as limiting its scope.

[0052] Figure 1 This is a schematic diagram illustrating an exemplary wireless communication system according to some embodiments of this application;

[0053] Figures 2A to 2D This application describes an exemplary method for initiating RIS-assisted DL localization according to some embodiments;

[0054] Figure 3 This application describes exemplary procedures for determining a usable RIS according to some embodiments;

[0055] Figure 4 This application describes exemplary procedures for obtaining information about the capabilities of available RIS according to some embodiments;

[0056] Figure 5A and 5B This application describes exemplary procedures for transmitting PRS configuration according to some embodiments;

[0057] Figure 6 This application describes an exemplary procedure for calculating the positioning result of a UE using RIS-assisted DL positioning, according to some embodiments of the present application.

[0058] Figure 7 This application describes an exemplary method for initiating RIS-assisted UL positioning according to some embodiments;

[0059] Figure 8 This application describes exemplary procedures for transmitting SRS configuration according to some embodiments;

[0060] Figure 9Exemplary procedures for calculating UE positioning results using RIS-assisted UL positioning according to some embodiments of this application; and

[0061] Figure 10 A simplified block diagram illustrating an exemplary device for RIS-assisted positioning according to some embodiments of this application. Detailed Implementation

[0062] The detailed description of the accompanying drawings is intended to describe the presently preferred embodiments of this application and is not intended to represent the only form in which this application can be practiced. It should be understood that the same or equivalent functionality may be accomplished through different embodiments that are intended to be covered by the spirit and scope of this application.

[0063] Although operations are depicted in a specific order in the diagram, those skilled in the art will readily recognize that such operations need not be performed in the specific order shown or in a sequential manner, or that one or more operations may sometimes be skipped in order to achieve the desired result. Furthermore, the diagram may schematically depict one or more instance processes in the form of a flowchart. However, other operations not depicted may be incorporated into the schematically illustrated instance processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the illustrated operations. In some cases, multitasking and parallel processing may be advantageous.

[0064] Reference will now be made in detail to some embodiments of this application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architectures and new service scenarios (e.g., 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE), LTE Advanced, 5th Generation (5G) (i.e., New Radio (NR)), 5G Advanced, 6th Generation (6G), etc.). Those skilled in the art will readily recognize that the embodiments in this application are applicable to similar technical problems as network architectures and new service scenarios evolve; furthermore, the terminology cited in this application may be changed without affecting the principles of this application.

[0065] Figure 1 This is a schematic diagram illustrating an exemplary wireless communication system 100 according to some embodiments of this application.

[0066] like Figure 1 As shown, the wireless communication system 100 includes at least one BS 101, at least one UE (e.g., UE 102a and UE 102b), and at least one LMF 103. Although Figure 1 For illustrative purposes, one BS, two UEs and one LMF are depicted, but it is understood that any number of BS, UE and LMF may be included in the wireless communication system 100.

[0067] The wireless communication system 100 is compatible with any type of network capable of transmitting and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with wireless communication networks, cellular telephone networks, time division multiple access (TDMA) based networks, code division multiple access (CDMA) based networks, orthogonal frequency division multiple access (OFDMA) based networks, LTE networks, 3GPP based networks, 3GPP 5G networks, satellite communication networks, high-altitude platform networks, and / or other communication networks.

[0068] BS101 may be an access point, access terminal, radio access network (RAN) node, TRP, base station, next-generation (NG) RAN node, node B, enhanced node B (eNB), next-generation node B (gNB), home node B, relay node, or device, or may be described using other terms used in the field. BS101 is typically a portion of the RAN that may contain a controller communicatively coupled to BS101.

[0069] According to some embodiments of this application, UE 102a and UE 102b may include a vehicle UE (VUE) and / or an energy-efficient UE (also referred to as a power-sensitive UE). The energy-efficient UE may include a power-sensitive vulnerable road user (VRU), a public safety UE (PS-UE), and / or a commercial sidelink UE (CS-UE). In embodiments of this application, the VRU may include a pedestrian UE (P-UE), a cyclist UE, a wheelchair UE, or other UE that requires energy savings compared to the VUE. In embodiments of this application, UE 102a may be an energy-efficient UE and UE 102b may be a VUE. In another embodiment of this application, both UE 102a and UE 102b may be either a VUE or an energy-efficient UE.

[0070] According to some other embodiments of this application, UE 102a and UE 102b may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart TVs (e.g., TVs connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, and modems) or the like.

[0071] According to some other embodiments of this application, UE 102a and UE 102b may include a portable wireless communication device, a smartphone, a cellular phone, a flip phone, a device with a user identity module, a personal computer, a selective call receiver, or any other device capable of transmitting and receiving communication signals on a wireless network.

[0072] According to some other embodiments of this application, UE 102a and UE 102b may include wearable devices, such as smartwatches, fitness trackers, optical head-mounted displays, or the like.

[0073] In addition, the UE may be referred to as a user unit, mobile device, mobile station, user, terminal, mobile terminal, wireless terminal, fixed terminal, user station, user terminal, or apparatus, or other terms used in the field to describe it.

[0074] Figure 1 In the embodiments, both UE 102a and UE 102b are within the coverage area of ​​BS101 and can transmit information or data to BS101 and receive control information or data from BS101, for example, via LTE or NR Uu interfaces.

[0075] LMF 103 (also known as an LMF entity) can refer to a network element or network entity used to support location services, which can be deployed in the core network (CN) or the RAN of the wireless communication system 100. LMF 103 can communicate with BS101 via NR Location Protocol A (NRPPa) signaling and with UE 102a or UE 102b via LTE Location Protocol (LPP) signaling.

[0076] The wireless communication system can support both Radio Access Technology (RAT)-independent positioning and RAT-dependent positioning for the UE. RAT-independent positioning means that the positioning is independent of the reference signals in the Uu interface and can include WLAN positioning, Bluetooth positioning, Global Navigation Satellite System (GNSS) positioning, etc. RAT-dependent positioning means that the UE's position is calculated based on measurements of reference signals (such as SRS, PRS, and / or other reference signals) in the Uu interface. RAT-dependent positioning can include various positioning methods, such as Enhanced Cell Identifier (E-CID) positioning, Multiple Round Trip Time (Multiple RTT) positioning, DL Angle of Departure (AoD) positioning, DL Time Difference of Arrival (TDoA) positioning, UL-TDoA positioning, UL Angle of Arrival (AoA) positioning, etc.

[0077] RAT-dependent positioning can involve the UE (e.g., a target UE that needs to know its location), NG-RAN nodes (e.g., BS and TRP), and LMF. In some instances, the NG-RAN node and LMF can exchange location-related information via NRPPa signaling. The UE and LMF can exchange location-related information via LPP signaling. The UE can receive location-related configuration from the NG-RAN node via Radio Resource Control (RRC) signaling.

[0078] DL PRS is the master reference signal used to support DL-based positioning methods (such as DL-TDoA, DL-AoD, etc.), while SRS is the master reference signal used to support UL-based positioning methods (such as UL-TDoA, UL-AoA, etc.).

[0079] In some instances, when the LMF determines that a positioning method for the UE requires measurements from the UE, the LMF can interact with the UE to support the positioning method. The LMF can then request the BS to configure the PRS configuration for the UE, and the BS can respond to the LMF with the PRS configuration. The LMF can then send the PRS configuration to the UE via an auxiliary data transmission procedure. In some instances, to reduce signaling costs, an on-demand PRS transmission procedure can be initiated by the UE or the LMF to allow the LMF to control and decide whether to transmit PRS and to modify the characteristics of ongoing PRS transmissions.

[0080] In some instances, when the LMF determines that a positioning method for the UE requires measurements from the BS, the LMF can interact with the BS to support the positioning method. The LMF can then request the BS to configure the SRS configuration for the UE, and the BS can respond to the LMF with the SRS configuration. In some instances, when the SRS configuration changes, the BS can provide the LMF with the updated SRS configuration. In some instances, if a semi-persistent or non-periodic SRS is configured for the UE, the LMF can activate or deactivate SRS transmission. When SRS is transmitted by the UE, the LMF can request multiple TRPs to perform UL measurements and report the measurement results. In such instances, the BS can serve several TRPs, including, for example, remote radio heads, UL-SRS-only receiver points (RPs), DL-SRS-only transmitter points (TPs), etc.

[0081] Both PRS and SRS can be designed to cover the entire bandwidth, with resource elements distributed across different symbols to cover all subcarriers. Additionally, SRS is also designed with a comb-based mode, similar to PRS. The configuration and transmission of PRS and SRS are very similar, and therefore, for illustrative purposes, the following examples describe the configuration and transmission of PRS. For instance, PRS can be transmitted by different BSs (e.g., the serving BS and one or more neighboring BSs) using narrow beams in frequency range 1 (FR1, 450MHz to 6,000MHz) and frequency range 1 (FR2, 24,250MHz to 52,600MHz), and can be transmitted across the entire cell. PRS can be associated with the PRS resource set ID and resource ID of the BS for each TRP. In the example, UE positioning measurements (e.g., Reference Signal Time Difference (RSTD)) and PRS RSRP measurements can be performed between beams (e.g., between a pair of different DL PRS resources or a pair of different DL PRS resource sets).

[0082] The adoption of millimeter-wave (mmWave) and terahertz technologies ensures higher available bandwidth, which can lead to higher positioning accuracy. However, it also brings new challenges in terms of coverage and reliability, because signals may be blocked by obstacles and multipath propagation may not be sufficient to guarantee adequate coverage under non-line-of-sight (NLoS) channel conditions. Furthermore, positioning accuracy can also be limited by the location of the base station (BS), the number of BSs, and the availability of line-of-sight (LoS).

[0083] One promising technology for addressing the aforementioned problems is Reflection Components (RIS), which proactively customizes the radio environment for wireless systems such as Beyond 5G (B5G) or 6G systems. Specifically, an RIS can be a planar surface containing numerous reflective elements (referred to herein as RIS elements) and can be deployed on the surfaces of various objects, such as walls. The reflection coefficient of the RIS can be adjusted by changing the state of its elements. Deploying RIS is more flexible and less costly than deploying Base Stations (BS). With the help of RIS, wireless networks can achieve higher spatial resolution and positioning accuracy.

[0084] While RIS is a promising technology for improving the positioning accuracy of wireless networks, the procedures for RIS-assisted positioning have not yet been discussed. For example, during traditional RAT-dependent positioning procedures (e.g., positioning without RIS assistance), when there is a limited TRP, limited known positioning information for the TRP, weak signal quality, or the calculated positioning result fails to meet QoS requirements, further research is needed on how RIS can assist in completing the positioning procedure and improve the accuracy of the calculated positioning result.

[0085] In view of the above, embodiments of this application propose solutions for RIS-assisted positioning (e.g., RIS-assisted RAT-dependent positioning). For example, embodiments of this application propose solutions regarding the triggering conditions for RIS-assisted positioning, the determination of available RIS for RIS-assisted positioning, the PRS configuration and corresponding delivery procedure for RIS-assisted positioning, or the SRS configuration and corresponding delivery procedure for RIS-assisted positioning. Further details regarding embodiments of this application will be described below in conjunction with the accompanying drawings.

[0086] According to some embodiments of this application, the RIS can be deployed in the RAN to enhance the link between the BS and the UE.

[0087] In some embodiments, the RIS may be deployed as a radio node or a new radio node in a network similar to a BS or a UE.

[0088] In some embodiments, the air interface between the BS and the RIS may be a known interface, such as the Uu interface if the RIS is deployed as a radio node similar to a UE, or the Xn interface if the RIS is deployed as a radio node similar to a BS. In some embodiments, if the RIS is deployed as a completely new radio node in the network, then the air interface between the BS and the RIS may be a newly defined interface.

[0089] In some embodiments, the air interface between the UE and the RIS may be a known interface, such as the PC5 interface if the RIS is deployed as a radio node similar to the UE, or the Uu interface if the RIS is deployed as a radio node similar to the BS. In some embodiments, if the RIS is deployed as a completely new radio node in the network, the air interface between the UE and the RIS may be a newly defined interface.

[0090] In some embodiments, the air interface between the Access and Mobility Management Function (AMF) and the RIS may be a known interface, such as an NG interface if the RIS is deployed as a radio node similar to a BS. In some embodiments, if the RIS is deployed as a completely new radio node in the network, the air interface between the AMF and the RIS may be a newly defined interface.

[0091] In some embodiments, the RIS can be fully controlled by the BS or UE via the aforementioned air interface.

[0092] In some embodiments, the BS or UE may transmit control information of the RIS to the RIS. The control information may instruct the RIS to tune the coefficients and properties of the RIS elements, instruct the RIS to receive information from the network, or reconfigure the coefficients of the RIS elements, etc.

[0093] RIS-assisted positioning can include RIS-assisted DL positioning and RIS-assisted UL positioning. Example 1 below provides solutions for triggering conditions, determining available RIS for RIS-assisted DL positioning, PRS configuration for RIS-assisted DL positioning, and corresponding transmission procedures. Example 2 below provides solutions for triggering conditions, determining available RIS for RIS-assisted UL positioning, SRS configuration for RIS-assisted UL positioning, and corresponding transmission procedures.

[0094] Example 1

[0095] According to some embodiments of this application, before initiating RIS-assisted DL positioning, the positioning system can perform a RAT-dependent DL positioning procedure without RIS assistance. For example, when a positioning service request exists from the UE (e.g., a mobile-initiated positioning request (MO-LR)) or from the network (e.g., a mobile-terminated positioning request (MT-LR)), the AMF can determine whether an available RIS exists in the positioning system. If no available RIS exists, the LMF, BS, and UE can continue the capability information transmission procedure specified in the 3GPP standard document and the subsequent DL positioning procedure without RIS assistance. If an available RIS exists, the LMF, BS, and UE can also continue the capability information transmission procedure, but when certain conditions occur, the LMF can initiate RIS-assisted DL positioning.

[0096] In Example 1, the LMF can determine the DL positioning that initiates RIS assistance based on at least one of the auxiliary data or measurement results from at least one of the BS or UE. Figures 2A to 2D This application describes an exemplary method for initiating RIS-assisted DL localization according to some embodiments of the present application.

[0097] Figure 2A The methods described herein can be performed by at least two network entities (e.g., BS (or TRP) and LMF). Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0098] refer to Figure 2A In step 2a-1, the LMF may transmit a TRP information request message (e.g., an NRPPa message) to the BS. Before, after, or simultaneously with step 2a-1, the BS may configure (or pre-configure) a minimum number of TRPs (e.g., a threshold) based on the QoS requirements of the location service. In response to receiving the TRP information request message, in step 2a-2, the BS may compare the number of candidate TRPs with the minimum number of TRPs. In response to the number of candidate TRPs being less than the minimum number of TRPs, in step 2a-3, the BS may transmit an indication to the LMF indicating the initiation of RIS-assisted DL positioning. In one embodiment, the indication may be a RIS-assisted positioning request message (e.g., an NRPPa message). In another embodiment, the indication (e.g., a flag) may be transmitted from the BS to the LMF in a TRP information response message (e.g., an NRPPa message). For example, the indication may be a 1-bit indication with a value indicating the initiation of RIS-assisted DL positioning. Therefore, in step 2a-3, the LMF may receive the indication from the BS. The LMF may then determine the initiation of RIS-assisted DL positioning in response to receiving the indication.

[0099] Figure 2B The methods described herein can be performed by at least two network entities (e.g., BS (or TRP) and LMF). Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0100] refer to Figure 2B In step 2b-1, the LMF may send a TRP information request message (e.g., an NRPPa message) to the BS. Before, after, or simultaneously with step 2a-1, the BS may configure (or pre-configure) a minimum number of TRPs (e.g., a threshold) based on the QoS requirements of the location service. In response to receiving the TRP information request message, in step 2b-2, the BS may send a TRP information response message (e.g., an NRPPa message) to the LMF indicating the minimum number of TRPs and the number of candidate TRPs. In response to receiving the TRP information response message, in step 2b-3, the LMF may compare the number of candidate TRPs with the minimum number of TRPs. In response to the number of candidate TRPs being less than the minimum number of TRPs, the LMF may determine to initiate RIS-assisted DL positioning.

[0101] Figure 2C The methods described herein can be performed by at least three network entities (e.g., UE, BS (or TRP), and LMF). The UE can be the target UE that needs to know its location. Although the methods are described at the system level, those skilled in the art will understand that methods implemented in three network entities can be implemented individually and combined in other devices with similar functionality.

[0102] refer to Figure 2C In step 2c-1, the LMF may send a TRP Information Request message (e.g., an NRPPa message) to the BS. Before, after, or simultaneously with step 2c-1, the BS may configure (or pre-configure) a minimum number of TRPs (e.g., a threshold) based on the QoS requirements of the location service. In response to receiving the TRP Information Request message, in step 2c-2, the BS may send a TRP Information Response message (e.g., an NRPPa message) to the LMF indicating the minimum number of TRPs and the number of candidate TRPs.

[0103] In response to receiving a TRP information response message, in step 2c-3, the LMF may transmit a provision assistance data message (e.g., an LPP message) to the UE indicating a minimum number of TRPs and a number of candidate TRPs configured or pre-configured by the BS. In response to receiving the provision assistance data message, in step 2c-4, the UE may compare the number of candidate TRPs with the minimum number of TRPs. In response to the number of candidate TRPs being less than the minimum number of TRPs, in step 2c-5, the UE may transmit an indication to the LMF indicating the initiation of RIS-assisted DL positioning. In one embodiment, the indication may be a RIS-assisted positioning request message (e.g., an LPP message). In another embodiment, the indication (e.g., a flag) may be transmitted from the UE to the LMF in a location information provision message (e.g., an LPP message). For example, the indication may be a 1-bit indication with a value indicating the initiation of RIS-assisted DL positioning. Therefore, in step 2c-5, the LMF may receive the indication from the UE. The LMF may then determine the initiation of RIS-assisted DL positioning in response to receiving the indication.

[0104] Figure 2D The methods described herein can be performed by at least two network entities (e.g., UE and LMF). The UE can be a target UE that needs to know its location. Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0105] In some instances, the UE can configure (or pre-configure) the RSRP threshold. (See reference) Figure 2D In step 2d-1, the UE may compare the measured RSRP value with the RSRP threshold or compare the calculated location result with the QoS requirements. Step 2d-1 is optional and may not be performed by the UE.

[0106] In response to a measured RSRP value being less than the RSRP threshold or a calculated positioning result not meeting QoS requirements, in step 2d-2, the UE may transmit an indication to the LMF to initiate RIS-assisted DL positioning. In one embodiment, the indication may be a RIS-assisted positioning request message (e.g., an LPP message). In another embodiment, the indication (e.g., a flag) may be transmitted from the UE to the LMF in a location information provision message (e.g., an LPP message). For example, the indication may be a 1-bit indication with a value indicating the initiation of RIS-assisted DL positioning. Therefore, in step 2d-2, the LMF may receive the indication from the UE. The LMF may then determine to initiate RIS-assisted DL positioning in response to receiving the indication.

[0107] After consideration, it is feasible. Figures 2A to 2D Any one or any combination of the methods described herein may be used to initiate RIS-assisted DL localization.

[0108] After the LMF determines the DL location for RIS-assisted RAID, the available RIS for RIS-assisted RAID location can be determined. Figure 3 This application describes exemplary procedures for determining available RIS according to some embodiments. Figure 3 The procedures described herein can be executed by at least three network entities (e.g., BS (or TRP), LMF, and AMF). Although the methods are described at the system level, those skilled in the art will understand that the methods implemented in the three network entities can be implemented individually and combined in other devices with similar functionality.

[0109] refer to Figure 3 In response to determining the DL location for RIS-assisted initiation, in step 301, the LMF may send a request message to the AMF to request an available RIS. Upon receiving the request message, the AMF may select (or determine) an available RIS for RIS-assisted DL location. Then, in step 302, the AMF may send information about the available RIS to the BS and the LMF. In some embodiments, the information about the available RIS includes at least one of the following: the location of the available RIS or the number of elements in each available RIS.

[0110] After identifying the available RISs for RIS-assisted DL positioning, the LMF can obtain capability information for the available RISs. Figure 4 This application describes exemplary procedures for obtaining information about the capabilities of available RIS according to some embodiments. Figure 4 The methods described herein can be performed by at least two network entities (e.g., BS (or TRP) and LMF). Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0111] refer to Figure 4 In response to receiving information about available RIS from the AMF, in step 401, the LMF may transmit a RIS capability request message to the BS requesting capability information of the available RIS. In response to receiving the RIS capability request message, in step 402, the BS may transmit capability information of the available RIS to the LMF. In some embodiments, the capability information includes the ability to tune the coefficients and properties of the RIS elements contained in each of the available RIS according to control information from the BS.

[0112] In some embodiments, after receiving information about available RIS from the AMF, the BS may transmit information about available RIS to the LMF without a request from the LMF.

[0113] After identifying an available RIS, the BS can configure PRS for RIS-assisted DL positioning. When configuring PRS, it is necessary to address how to distinguish the PRS of the direct link from the BS to the UE (e.g., the target UE) and the cascaded links containing links from the BS to the RIS and from the RIS to the UE, when they use the same resource set and resource ID at the same layer. The following embodiments provide a solution for PRS configuration and a corresponding PRS configuration delivery procedure to address the above problems.

[0114] Figure 5A and 5B This application describes an exemplary PRS configuration delivery procedure according to some embodiments of the present application.

[0115] Figure 5A and 5B The methods described herein can be performed by at least three network entities (e.g., UE, BS (or TRP), and LMF). The UE can be the target UE that needs to know its location. Although the methods are described at the system level, those skilled in the art will understand that methods implemented in three network entities can be implemented individually and combined in other devices with similar functionality.

[0116] refer to Figure 5A After receiving the available RIS capability information, in step 5a-1, the LMF may send a request message (e.g., an NRPPa message) to the BS requesting PRS configuration. The PRS configuration may include PRS configuration for the direct link from the BS to the UE (e.g., denoted as DL-PRS configuration) and PRS configuration for cascaded links including the link from the BS to the RIS and the link from the RIS to the UE (e.g., DL-PRS-RIS configuration). In response to receiving the request message, the BS may configure the PRS configuration, such as the DL-PRS configuration and the DL-PRS-RIS configuration. Next, in step 5a-2, the BS may send the DL-PRS configuration and the DL-PRS-RIS configuration to the LMF, for example, via an NRPPa message. For example, the PRS configuration may be a successfully configured or updated PRS configuration. In step 5a-3, the LMF may send the PRS configuration (e.g., DL-PRS configuration and DL-PRS-RIS configuration) to the UE, for example, via a Provide Auxiliary Data message to the UE (e.g., an LPP message).

[0117] refer to Figure 5BAfter receiving the available RIS capability information, in step 5b-1, the LMF may, for example, transmit the available RIS capability information to the UE via an LPP message. In step 5b-2, the UE may transmit an on-demand PRS request message for RIS-assisted DL positioning (e.g., an LPP message) to the LMF. Based on the on-demand PRS request message, in step 5b-3, the LMF may transmit a request message to the BS requesting PRS configuration (e.g., an NRPPa message). The PRS configuration may include DL-PRS configuration for the direct link from the BS to the UE and DL-PRS-RIS configuration for cascaded links including the link from the BS to the RIS and the link from the RIS to the UE. In response to receiving the request message, the BS may configure the PRS configuration, such as the DL-PRS configuration and the DL-PRS-RIS configuration. Then, in step 5b-4, the BS may, for example, transmit the DL-PRS configuration and the DL-PRS-RIS configuration to the LMF via an NRPPa message. For example, the PRS configuration may be a successfully configured or updated PRS configuration. In steps 5b-5, the LMF may transmit PRS configurations (e.g., DL-PRS configuration and DL-PRS-RIS configuration) to the UE, for example, via a Provide Assistance Data message to the UE (e.g., an LPP message).

[0118] In some embodiments, the DL-PRS-RIS configuration of a cascaded link may indicate (e.g., include) a first list (e.g., defined by an Information Element (IE) nr-DL-PRS-RIS-ResourceSetList) of DL PRS resource sets configured for each TRP in each frequency layer. The DL-PRS configuration of a direct link may indicate (e.g., include) a second list (e.g., defined by an IE nr-DL-PRS-ResourceSetList) of DL PRS resource sets configured for each TRP in each frequency layer. In such embodiments, the DL PRS resource sets included in the first list are different from those included in the second list. For example, the DL PRS resource sets included in the second list may be defined by an IE NR-DL-PRS-ResourceSet specified in a 3GPP standard document, while the DL PRS resource sets included in the first list may be defined by an IE NR-DL-PRS-RIS-ResourceSet.

[0119] For example, assuming the maximum number of DL PRS resource sets configured per TRP in each frequency layer is represented as nrMaxSetsPerTrpPerFreqLayer, then:

[0120] nr-DL-PRS-RIS-ResourceSetList can be defined as a sequence (size (1…N1)) of nr-DL-PRS-RIS-ResourceSetList::= NR-DL-PRS-RIS-ResourceSet; and

[0121] nr-DL-PRS-ResourceSetList can be defined as: nr-DL-PRS-ResourceSetList::= a sequence of NR-DL-PRS-ResourceSet (size (N1+1…nrMaxSetsPerTrpPerFreqLayer));

[0122] Where N1 is the number of DL PRS resource sets included in the first list, and 1 ≤ N1 ≤ nrMaxSetsPerTrpPerFreqLayer. The above example means that the first list contains the first N1 DL PRS resource sets included in the maximum number of DL PRS resource sets, and the second list contains the remaining (nrMaxSetsPerTrpPerFreqLayer-N1) DL PRS resource sets included in the maximum number of DL PRS resource sets.

[0123] In some embodiments, NR-DL-PRS-RIS-ResourceSet may include parameters (also known as IEs) that are defined similarly to those defined in NR-DL-PRS-ResourceSet as specified in the 3GPP standard archive.

[0124] For example, each DL PRS resource set included in the first list can be defined by a set of parameters that includes at least one of the following:

[0125] • The first parameter (e.g., represented as nr-DL-PRS-RIS-ResourceSetID) indicates the ID of the DL PRS resource set;

[0126] • The second parameter (e.g., dl-PRS-RIS-Periodicity-and-ResourceSetSlotOffset) indicates the periodicity and offset of the DL PRS resource set;

[0127] • The third parameter (e.g., dl-PRS-RIS-ResourceRepetitionFactor) indicates how many times each DLPRS resource is repeated for a single instance of the DL PRS resource set;

[0128] • The fourth parameter (e.g., dl-PRS-RIS-ResourceTimeGap) indicates the offset between two repeating instances of the DL PRS resource;

[0129] • The fifth parameter (e.g., dl-PRS-RIS-NumSymbols) indicates the number of symbols for the DL PRS resource within a time slot;

[0130] • The sixth parameter (e.g., denoted as dl-PRS-RIS-ResourcePower) indicates the average energy per resource element in the resource elements carrying the PRS; or

[0131] • The seventh parameter (e.g., dl-PRS-RIS-ResourceList) indicates a set of DL PRS resources.

[0132] In other words, NR-DL-PRS-RIS-ResourceSet may contain at least one of the parameters mentioned above. In addition to the parameters mentioned above, NR-DL-PRS-RIS-ResourceSet may contain other parameters that are similar to those defined in NR-DL-PRS-ResourceSet specified in the 3GPP standard documentation.

[0133] In some embodiments of this application, after the PRS configuration transmission procedure, the BS can adjust the coefficients of elements in the available RIS. For example, first, the BS can randomly select the coefficients of elements in the available RIS. Then, the BS can transmit a reference signal to the UE via a cascaded link including a link from the BS to the available RIS and a link from the available RIS to the UE (e.g., a target UE that needs to know its location). Based on the reference signal, the UE can determine a CSI report and transmit a CSI report of the cascaded link to the BS. The BS can then tune the coefficients of elements in the available RIS based on the CSI report. In some instances, once the available RIS is enabled, the cascaded link can be estimated to derive the optimal reflection coefficients of elements in the available RIS for the UE.

[0134] In some embodiments of this application, for RIS-assisted DL positioning, the UE or LMF can calculate the UE's positioning result.

[0135] Figure 6 This application describes an exemplary procedure for calculating the positioning result of a UE using RIS-assisted DL positioning, according to some embodiments of the present application. Figure 6 The methods described herein can be performed by at least two network entities (e.g., UE and LMF). Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0136] exist Figure 6 In this embodiment, the UE may receive a PRS transmitted by the BS. The PRS may be transmitted by the BS and received by the UE based on a PRS configuration configured by the BS as described above (e.g., DL-PRS configuration and DL-PRS-RIS configuration).

[0137] refer to Figure 6 In step 601, the LMF may transmit a location information request message (e.g., an LPP message) to the UE. In response to receiving the location information request message, in step 602, the UE may measure the PRS on the direct link from the BS to the UE and the PRS on cascaded links including the link from the BS to the RIS and the link from the RIS to the UE. Next, for UE-based positioning (i.e., the positioning result is calculated by the UE), step 603 may be performed. In step 603, the UE may calculate the UE's positioning result based on the PRS measurement results of the direct and cascaded links. Alternatively, for LMF-based positioning (i.e., the positioning result is calculated by the LMF), steps 604a and 604b may be performed. In step 604a, the UE may transmit the PRS measurement results of the direct and cascaded links to the LMF in a location information provision message (e.g., an LPP message). Next, in step 604b, the LMF may calculate the UE's positioning result based at least partially on the PRS measurement results.

[0138] Example 2

[0139] According to some embodiments of this application, before initiating RIS-assisted UL positioning, the positioning system can perform a RAT-dependent UL positioning procedure without RIS assistance. For example, when a positioning service request exists from the UE (e.g., a mobile-initiated positioning request (MO-LR)) or from the network (e.g., a mobile-terminated positioning request (MT-LR)), the AMF can determine whether an available RIS exists in the positioning system. If no available RIS exists, the LMF, BS, and UE can continue the capability information transmission procedure specified in the 3GPP standard document and the subsequent UL positioning procedure without RIS assistance. If an available RIS exists, the LMF, BS, and UE can also continue the capability information transmission procedure, but when certain conditions occur, the LMF can initiate RIS-assisted UL positioning.

[0140] In Embodiment 2, the LMF can determine the UL positioning for initiating RIS assistance based on auxiliary data from the BS. In some embodiments, Figure 2A and 2B The method for initiating RIS-assisted DL positioning described herein can also be applied to LMF-initiated RIS-assisted UL positioning, and for simplicity, its details are omitted here.

[0141] Figure 7 This application describes another exemplary method for initiating RIS-assisted UL positioning according to some embodiments of the present application. Figure 7 The methods described herein can be performed by at least two network entities (e.g., BS (or TRP) and LMF). Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0142] In some instances, the BS can configure (or pre-configure) the RSRP threshold. (See reference) Figure 7 In step 701, the BS can compare the measured RSRP value with an RSRP threshold. In response to the measured RSRP value being less than the RSRP threshold, in step 702, the BS can transmit an indication to the LMF to initiate RIS-assisted UL positioning. In one embodiment, the indication can be a RIS-assisted positioning request message (e.g., an NRPPa message). In another embodiment, the indication (e.g., a flag) can be transmitted from the BS to the LMF in a measurement response message (e.g., an NRPPa message). For example, the indication can be a 1-bit indication with a value indicating the initiation of RIS-assisted UL positioning. Therefore, in step 702, the LMF can receive the indication from the BS. The LMF can then determine to initiate RIS-assisted UL positioning in response to receiving the indication.

[0143] After consideration, it is feasible. Figure 2A , 2B Any one or any combination of the methods described in section 7 to initiate RIS-assisted UL positioning.

[0144] After the LMF determines the UL location for RIS-assisted activation, the available RIS for RIS-assisted UL location can be determined. Figure 3 The method shown in the diagram can also be adapted to identify available RIS for RIS-assisted UL positioning, and for simplicity, the details are omitted here.

[0145] After identifying the available RIS for RIS-assisted UL positioning, the LMF obtains capability information for the available RIS. Figure 4 The method shown in the diagram can also be adapted to obtain information on the capabilities of available RIS for RIS-assisted UL positioning, and for simplicity, the details are omitted here.

[0146] After identifying an available RIS, the BS can configure SRS for RIS-assisted UL positioning. When configuring SRS, it is necessary to address how to distinguish between the SRS of the direct link and the SRS of the cascaded link when the direct link from the UE (e.g., the target UE) to the BS and cascaded links containing links from the UE to the RIS and from the RIS to the BS use the same resource set and resource ID at the same layer. The following embodiments provide a solution for SRS configuration and a corresponding SRS configuration transmission procedure to address the above problems.

[0147] Figure 8 This application describes an exemplary SRS configuration transmission procedure according to some embodiments.

[0148] Figure 8 The methods described herein can be performed by at least three network entities (e.g., UE, BS (or TRP), and LMF). The UE can be the target UE that needs to know its location. Although the methods are described at the system level, those skilled in the art will understand that methods implemented in three network entities can be implemented individually and combined in other devices with similar functionality.

[0149] refer to Figure 8 After receiving the available RIS capability information, in step 801, the LMF may send a request message to the BS requesting SRS configuration (e.g., an NRPPa message).

[0150] exist Figure 8 In some embodiments, the request message for SRS configuration may be a location information request message, and the SRS configuration may include the SRS configuration of the direct link from UE to BS (e.g., denoted as UL-SRS configuration) and the SRS configuration of the cascaded link including the link from UE to RIS and the link from RIS to BS (e.g., UL-SRS-RIS configuration).

[0151] In response to receiving the request message in step 801, the BS can configure the UL-SRS configuration and the UL-SRS-RIS configuration. Next, in step 802, the BS can transmit the SRS configuration (e.g., the UL-SRS configuration and the UL-SRS-RIS configuration) to the LMF in a location information response message (e.g., an NRPPa message). In step 803, the BS can also transmit the SRS configuration (e.g., the UL-SRS configuration and the UL-SRS-RIS configuration) to the UE, for example, via an RRC message. Step 803 can occur before, after, or simultaneously with step 802.

[0152] exist Figure 8In some other embodiments, a semi-persistent or non-periodic SRS is configured. In such embodiments, the request message requesting SRS configuration may be a location activation request message, and the SRS configuration may include a UL-SRS configuration for a direct link from the UE to the BS and a UL-SRS-RIS configuration for cascaded links including a link from the UE to the RIS and a link from the RIS to the BS.

[0153] In such embodiments, the location activation request message can activate SRS transmission on the direct link and SRS transmission on the cascaded link, and request UL-SRS configuration and UL-SRS-RIS configuration.

[0154] In response to receiving the location activation request message in step 801, the BS can configure the UL-SRS configuration and the UL-SRS-RIS configuration. Next, in step 802, the BS can transmit the SRS configuration (e.g., the UL-SRS configuration and the UL-SRS-RIS configuration) to the LMF in a location information response message (e.g., an NRPPa message). In step 803, the BS can transmit the SRS configuration (e.g., the UL-SRS configuration and the UL-SRS-RIS configuration) to the UE, for example, via an RRC message. In step 803, the BS can also activate SRS transmission for direct links and SRS transmission for cascaded links. Step 803 can occur before, after, or simultaneously with step 802.

[0155] In some embodiments, the UL-SRS-RIS configuration of a cascaded link may indicate (e.g., include) at least one of a first list of SRS location resource sets to be released (e.g., defined by IE srs-RIS-PosResourceSetToReleaseList) or a second list of SRS location resource sets to be added to or modified (e.g., defined by IE srs-RIS-PosResourceSetToAddModList). The UL-SRS configuration of a direct link may indicate (e.g., include) at least one of a third list of SRS location resource sets to be released (e.g., defined by IE srs-PosResourceSetToReleaseList) or a fourth list of SRS location resource sets to be added to or modified (e.g., defined by srs-PosResourceSetToAddModList). The SRS location resource sets included in the first list are different from those included in the third list. The SRS location resource sets included in the second list are different from those included in the fourth list. For example, the SRS location resource set included in the third or fourth list can be defined by the IE srs-PosResourceSet specified in the 3GPP standard document, and the SRS location resource set included in the first or second list can be defined by the IE srs-RIS-PosResourceSet.

[0156] As an example, assuming the maximum number of SRS location resource sets configured per UL bandwidth portion (BWP) is denoted as maxNrofSRS-PosResourceSets, then:

[0157] srs-RIS-PosResourceSetToReleaseList can be defined as a sequence of srs-RIS-PosResourceSetToReleaseList::= srs-RIS-PosResourceSet (size (1…N2)); and

[0158] srs-PosResourceSetToReleaseList can be defined as:

[0159] srs-PosResourceSetToReleaseList::=Sequence of srs-PosResourceSet (size (N2+1...maxNrofSRS-PosResourceSets));

[0160] Where N2 is the number of SRS location resource sets included in the first list and 1 ≤ N2 ≤ maxNrofSRS-PosResourceSets. The above example means that the first list contains the first N2 SRS location resource sets included in the maximum number of SRS location resource sets, and the third list contains the remaining (maxNrofSRS-PosResourceSets-N2) SRS location resource sets included in the maximum number of SRS location resource sets.

[0161] As another example, assuming the maximum number of SRS location resource sets configured per UL BWP is represented as maxNrofSRS-PosResourceSets, then:

[0162] srs-RIS-PosResourceSetToAddModList can be defined as a sequence (size (1…N3)) of srs-RIS-PosResourceSetToAddModList::= srs-RIS-PosResourceSet; and

[0163] srs-PosResourceSetToAddModList can be defined as:

[0164] srs-PosResourceSetToAddModList::=Sequence of srs-PosResourceSet (size (N3+1...maxNrofSRS-PosResourceSets);

[0165] Where N3 is the number of SRS location resource sets included in the second list, 1 ≤ N3 ≤ maxNrofSRS-PosResourceSets, and N3 may or may not be equal to N2. The above example means that the second list contains the first N3 SRS location resource sets included in the maximum number of SRS location resource sets, and the fourth list contains the remaining (maxNrofSRS-PosResourceSets-N3) SRS location resource sets included in the maximum number of SRS location resource sets.

[0166] In some embodiments, srs-RIS-PosResourceSet may include parameters (also known as IEs) that are defined similarly to those defined in srs-PosResourceSet as specified in the 3GPP standard archive.

[0167] For example, each SRS location resource set included in the first list or the second list may be defined by a set of parameters including at least one of the following:

[0168] • The first parameter (e.g., srs-RIS-PosResourceSetId) indicates the ID of the SRS location resource set;

[0169] The second parameter (e.g., srs-RIS-PosResourceIdList) indicates the ID of the SRS location resource in the SRS location resource set; or

[0170] • The third parameter (e.g., denoted as RIS-resourceType) indicates whether the SRS location resources in the SRS location resource set are periodic (e.g., indicated by RIS-periodic), semi-persistent (e.g., indicated by RIS-semi-persistent), or aperiodic (e.g., indicated by RIS-periodic).

[0171] In other words, srs-RIS-PosResourceSet may contain at least one of the parameters mentioned above. In addition to the parameters mentioned above, srs-RIS-PosResourceSet may contain other parameters that are similar in definition to those defined in srs-PosResourceSet specified in the 3GPP standard documentation.

[0172] In some embodiments of this application, after the SRS configuration transmission procedure, the BS can adjust the coefficients of elements in the available RIS. For example, first, the BS can randomly select the coefficients of elements in the available RIS. Then, the BS can transmit a reference signal to the UE via a cascaded link including a link from the BS to the available RIS and a link from the available RIS to the UE (e.g., a target UE that needs to know its location). Based on the reference signal, the UE can determine a CSI report and transmit a CSI report of the cascaded link to the BS. The BS can then tune the coefficients of elements in the available RIS based on the CSI report. In some instances, once the available RIS is enabled, the cascaded link can be estimated to derive the optimal reflection coefficients of elements in the available RIS for the UE.

[0173] In some embodiments of this application, for RIS-assisted UL positioning, the LMF can calculate the positioning result of the UE.

[0174] Figure 9 This application describes an exemplary procedure for calculating the positioning result of a UE using RIS-assisted UL positioning, according to some embodiments of the present application. Figure 9 The methods described herein can be performed by at least two network entities (e.g., BS (or TRP) and LMF). Although the methods are described at the system level, those skilled in the art will understand that methods implemented in two network entities can be implemented individually and combined in other devices with similar functionality.

[0175] exist Figure 9 In this embodiment, the BS can receive SRS transmitted by the UE. The SRS can be transmitted by the UE and received by the BS based on an SRS configuration configured by the BS as described above (e.g., UL-PRS configuration and UL-PRS-RIS configuration).

[0176] refer to Figure 9 In step 901, the LMF may transmit a measurement request message (e.g., an NRPPa message) to the BS. In response to receiving the measurement request message, in step 902, the BS may measure the SRS on the direct link from the UE to the BS and the SRS on cascaded links including the link from the UE to the RIS and the link from the RIS to the BS. Next, in step 903, the BS may transmit the SRS measurement results of the direct and cascaded links to the LMF in a measurement response message (e.g., an NRPPa message). After receiving the SRS measurement results of the direct and cascaded links, in step 904, the LMF may calculate the UE's positioning result based at least partially on the SRS measurement results.

[0177] Figure 10 A simplified block diagram illustrating an exemplary device 1000 for RIS-assisted positioning according to some embodiments of this application is provided. In some embodiments, device 1000 may be or include a UE (e.g., Figure 1 At least a portion of UE 102a or UE 102b in the embodiment. In some other embodiments, device 1000 may be or include a BS (e.g., Figure 1 At least a portion of BS101 in the above. In some other embodiments, device 1000 may be or include LMF (e.g., Figure 1 At least a portion of the LMF (103) in the device. In some other embodiments, the device 1000 may be or include at least a portion of the AMF.

[0178] refer to Figure 10 The device 1000 may include at least one transceiver 1002 and at least one processor 1006. At least one transceiver 1002 is coupled to at least one processor 1006.

[0179] Although elements such as transceiver 1002 and processor 1006 are illustrated in the singular form in this figure, the plural form is considered unless explicitly stated to be limited to the singular. In some embodiments of this application, transceiver 1002 may be divided into two devices, such as a receiving circuitry system (or receiver) and a transmitting circuitry system (or transmitter). In some embodiments of this application, device 1000 may further include input devices, memory, and / or other components. Transceiver 1002 and processor 1006 may be configured to perform any of the methods described herein (e.g., regarding...). Figures 2A to 9(The methods described herein or other methods described in the embodiments of this application).

[0180] According to some embodiments of this application, device 1000 may be an LMF (Low-Level Function), and transceiver 1002 and processor 1006 may be configured to perform operations related to... Figures 2A to 9 The operation of the LMF described herein or other methods described in the embodiments of this application. For example, the processor 1006 is configured to: transmit a request message via transceiver 1002 to the BS requesting a RIS-assisted DL positioning PRS configuration or a RIS-assisted UL positioning SRS configuration; and receive the PRS configuration or SRS configuration from the BS via transceiver 1002.

[0181] According to some embodiments of this application, device 1000 may be a BS, and transceiver 1002 and processor 1006 may be configured to perform operations related to... Figures 2A to 2C The operation of the BS described in 3 to 5 and 7 to 9, or other methods described in the embodiments of this application. For example, the processor 1006 is configured to: receive, via transceiver 1002 and from the LMF, a request message for a RIS-assisted DL positioning PRS configuration or a RIS-assisted UL positioning SRS configuration; and transmit the PRS configuration or SRS configuration to the LMF via the transceiver.

[0182] According to some embodiments of this application, device 1000 may be a UE (e.g., a target UE that needs to know its location), and transceiver 1002 and processor 1006 may be configured to perform operations related to... Figure 2C , 2D The operation of the UE described in 5A, 5B, 6, and 8, or other methods described in the embodiments of this application. For example, the processor 1006 is configured to: receive a RIS-assisted DL-location PRS configuration or a RIS-assisted UL-location SRS configuration via transceiver 1002; and receive a PRS based on the PRS configuration or transmit an SRS based on the SRS configuration via transceiver 1002.

[0183] In some embodiments of this application, device 1000 may further include at least one non-transitory computer-readable medium. In some embodiments of this disclosure, the non-transitory computer-readable medium may store computer-executable instructions that cause processor 1006 to perform any of the methods described above. For example, the computer-executable instructions, when executed, may cause processor 1006 to interact with transceiver 1002 to perform, for example, actions related to... Figures 2A to 9 The operation of the described method or other methods described in the embodiments of this application.

[0184] The methods described in any of the embodiments of this application can also be implemented on a programmable processor. However, controllers, flowcharts, and modules can also be implemented on general-purpose or special-purpose computers, programmable microprocessors or microcontrollers and peripheral integrated circuit elements, integrated circuits, hardware electronic or logic circuits (e.g., discrete element circuits), programmable logic devices, or the like. Generally, any device residing on a finite state machine capable of implementing the flowcharts shown in the figures can be used to implement the processor functions of this application. For example, an embodiment of this application provides an apparatus for RIS-assisted positioning, comprising a processor and a memory. Computer-programmable instructions for implementing a method for RIS-assisted positioning are stored in the memory, and the processor is configured to execute the computer-programmable instructions for implementing the method for RIS-assisted positioning. The method for RIS-assisted positioning can be any method described in this application.

[0185] Alternative embodiments preferably implement the methods of embodiments of this application in a non-transitory computer-readable storage medium storing computer-programmable instructions. The instructions are preferably executed by a computer-executable component preferably integrated with a network security system. The non-transitory computer-readable storage medium can be stored on any suitable computer-readable medium, such as RAM, ROM, flash memory, EEPROM, optical storage devices (CD or DVD), hard disk drives, floppy disk drives, or any suitable device. The computer-executable component is preferably a processor, but the instructions may alternatively or additionally be executed by any suitable dedicated hardware device. For example, embodiments of this application provide a non-transitory computer-readable storage medium in which computer-programmable instructions are stored. The computer-programmable instructions are configured to implement a RIS-assisted positioning method according to any embodiment of this application.

[0186] Although this application has been described with reference to specific embodiments thereof, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be readily apparent. For example, various components of an embodiment may be interchanged, added, or substituted in other embodiments. Moreover, not all elements of each figure are essential to the operation of the disclosed embodiments. For example, the teachings of this application will enable those of ordinary skill in the art to make and use them by simply employing the elements of the independent claims. Therefore, the embodiments of this application set forth herein are intended to be illustrative rather than restrictive. Various changes may be made without departing from the spirit and scope of this application.

[0187] In this disclosure, relational terms such as “first,” “second,” and similar terms may be used only to distinguish one entity or action from another and do not necessarily require or imply any actual such relationship or order between such entities or actions. The term “comprises / comprising” or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but may also include other elements not expressly listed or inherent to the process, method, article, or apparatus. Elements beginning with “a / an” or similar terms do not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element, without further constraints. Furthermore, the term “another” is defined as at least a second or more. As used herein, the terms “comprising,” “having,” and similar terms are defined as “including.”

Claims

1. A location management function (LMF), comprising: transceiver; and A processor, coupled to the transceiver and configured to: The transceiver transmits a request message to the base station BS requesting reconfiguration of the positioning reference signal PRS for RIS-assisted downlink DL positioning or the detection reference signal SRS for RIS-assisted uplink UL positioning; and The PRS configuration or the SRS configuration is received from the BS via the transceiver.

2. The LMF of claim 1, wherein the processor is further configured to: The transceiver receives a TRP information response message indicating the minimum number of TRPs and the number of candidate TRPs from the BS. Compare the number of candidate TRPs with the minimum number of TRPs; and In response to the number of candidate TRPs being less than the minimum number of TRPs, the RIS-assisted DL positioning or the RIS-assisted UL positioning is initiated.

3. A base station (BS), comprising: transceiver; and A processor, coupled to the transceiver and configured to: The transceiver receives, via the location management function (LMF), a request message requesting reconfiguration of the positioning reference signal (PRS) for RIS-assisted downlink DL positioning or the detection reference signal (SRS) for RIS-assisted uplink UL positioning; and The PRS configuration or the SRS configuration is transmitted to the LMF via the transceiver.

4. The BS of claim 3, wherein the processor is further configured to: The transceiver receives a Transmit-Receive Point (TRP) Information Request message from the LMF, compares the number of candidate TRPs with the minimum number of TRPs configured by the BS, and, in response to the number of candidate TRPs being less than the minimum number of TRPs, transmits an indication via the transceiver to the LMF to initiate RIS-assisted DL positioning or RIS-assisted UL positioning, wherein the indication is either a RIS-assisted positioning request message or transmitted in a TRP Information Response message; or The measured reference signal received power (RSRP) value is compared with an RSRP threshold configured by the BS, and in response to the measured RSRP value being less than the RSRP threshold, an indication to initiate RIS-assisted UL positioning is transmitted via the transceiver to the LMF, wherein the indication is either a RIS-assisted positioning request message or transmitted in a measurement response message.

5. The BS of claim 3, wherein the processor is further configured to: receive via the transceiver information of available RIS for RIS-assisted DL positioning or RIS-assisted UL positioning, wherein the information of available RIS includes at least one of: the location of the available RIS or the number of elements of each available RIS.

6. The BS of claim 5, wherein the processor is further configured to: Receives a RIS capability request message requesting the available RIS capability information via the transceiver and from the LMF; and In response to receiving the RIS capability request message from the LMF, the transceiver transmits the capability information of the available RIS, wherein the capability information includes the ability to tune the coefficients and properties of the RIS elements contained in each of the available RIS according to control information from the BS.

7. The BS of claim 6, wherein the processor is configured to: After transmitting the capability information of the available RIS, a request message requesting the PRS configuration is received via the transceiver and from the LMF, wherein the PRS configuration includes the PRS configuration of the direct link from the BS to the UE and the PRS configuration of the cascaded link including the link from the BS to the RIS and the link from the RIS to the UE. Configure the PRS configuration for the direct link and configure the PRS configuration for the cascaded link; and The PRS configuration of the direct link and the PRS configuration of the cascaded link are transmitted to the LMF via the transceiver.

8. The BS of claim 7, wherein the PRS configuration of the cascaded link indicates a first list of DL PRS resource sets for each TRP in each frequency layer, and the DL PRS resource sets included in the first list are different from the DL PRS resource sets included in a second list of DL PRS resource sets for each TRP configuration in each frequency layer and included in the PRS configuration of the direct link from the BS to the UE.

9. The BS of claim 8, wherein each DL PRS resource set included in the first list is defined by a set of parameters comprising at least one of the following: The first parameter indicates the identifier ID of the DL PRS resource set; The second parameter indicates the periodicity and offset of the DL PRS resource set; The third parameter indicates how many times each DL PRS resource is repeated for a single instance of the DL PRS resource set. The fourth parameter indicates the offset between two duplicate instances of the DL PRS resource; The fifth parameter indicates the number of symbols for the DL PRS resources within a time slot; The sixth parameter indicates the average energy of each resource element in the resource elements carrying the PRS; or The seventh parameter indicates a set of DL PRS resources.

10. The BS of claim 6, wherein the request message requesting the SRS configuration is a location information request message, and the processor is configured to: After transmitting the capability information of the available RIS, the location information request message is received via the transceiver and from the LMF, wherein the SRS configuration includes the SRS configuration of the direct link from the UE to the BS and the SRS configuration of the cascaded link including the link from the UE to the RIS and the link from the RIS to the BS. Configure the SRS configuration for the direct link and configure the SRS configuration for the cascaded link; Transmit the SRS configuration of the direct link and the SRS configuration of the cascaded link to the LMF via the transceiver and in a location information response message; and The transceiver transmits the SRS configuration of the direct link and the SRS configuration of the cascaded link to the UE.

11. The BS of claim 6, wherein the request message requesting the SRS configuration is a location activation request message, and the processor is configured to: After transmitting the capability information of the available RIS, the location activation request message is received via the transceiver and from the LMF, wherein the location activation request message activates the SRS transmission of the direct link from the UE to the BS and the SRS transmission of the cascaded link including the link from the UE to the RIS and the link from the RIS to the BS, and requests the SRS configuration of the direct link and the SRS configuration of the cascaded link. Configure the SRS configuration for the direct link and configure the SRS configuration for the cascaded link; The transceiver transmits the SRS configuration of the direct link and the SRS configuration of the cascaded link to the LMF in the location activation response message. Transmit the SRS configuration of the direct link and the SRS configuration of the cascaded link to the UE via the transceiver; and Activate the SRS transmission of the direct link and the SRS transmission of the cascaded link.

12. The BS according to claim 10 or 11, wherein: The SRS configuration indication of the cascaded link is at least one of a first list of SRS location resource sets to be released or a second list of SRS location resource sets to be added to or modified; and The SRS location resource set included in the first list is different from the SRS location resource set included in the third list of SRS location resource sets to be released configured for the direct link from the UE to the BS, or the SRS location resource set included in the second list is different from the SRS location resource set included in the fourth list of SRS location resource sets to be added or modified configured for the direct link.

13. The BS of claim 12, wherein each SRS location resource set included in the first list or the second list is defined by a set of parameters including at least one of the following: The first parameter indicates the ID of the SRS location resource set; The second parameter indicates the ID of the SRS location resource in the SRS location resource set; or The third parameter indicates whether the SRS positioning resources in the SRS positioning resource set are periodic, semi-persistent, or aperiodic.

14. A user equipment (UE) comprising: transceiver; and A processor, coupled to the transceiver and configured to: The transceiver receives a reconfigurable positioning reference signal (PRS) for downlink DL positioning assisted by a smart surface (RIS) or a detection reference signal (SRS) for uplink UL positioning assisted by a RIS. and Receive PRS based on the PRS configuration via the transceiver or transmit SRS based on the SRS configuration via the transceiver.

15. The UE of claim 14, wherein the processor is configured to: The transceiver receives, via the transceiver and from the location management function (LMF), a provision assistance data message indicating the minimum number of TRPs and the number of candidate TRPs configured by the BS; compares the number of candidate TRPs with the minimum number of TRPs; and in response to the number of candidate TRPs being less than the minimum number of TRPs, transmits a RIS-assisted positioning request message via the transceiver to the LMF to initiate RIS-assisted DL positioning; or In response to a measured reference signal received power (RSRP) value being less than the RSRP threshold configured by the UE or a calculated location result not meeting the Quality of Service (QoS) requirements, an indication is transmitted via the transceiver to the LMF to initiate RIS-assisted DL positioning, wherein the indication is either a RIS-assisted positioning request message or transmitted in a location information provision message.

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