Sidelink positioning reference signal configuration

Abstract

Disclosed is a method comprising the steps of: transmitting to one or more user devices a message comprising a first reference signal and a first set of masks; receiving from the one or more user devices first mask channel information for each mask of the first set of masks or at least one of a preferred sidelink positioning reference signal configuration based on the first mask channel information; receiving the at least one of the first mask channel information or the preferred sidelink positioning reference signal configuration based on the first mask channel information; and determining a first sidelink positioning reference signal configuration based on the first mask channel information or the preferred sidelink positioning reference signal configuration based on the first mask channel information.

Description

[Technical Field]

[0001] The following exemplary embodiments relate to wireless communication and positioning. [Background technology]

[0002] Positioning techniques can be used to estimate the physical location of a device. A challenge is how to select an appropriate positioning reference signal configuration to provide high positioning accuracy and low latency. Summary of the Invention [Problem to be solved by the invention]

[0003] The scope of protection sought for various exemplary embodiments is defined by the claims. The exemplary embodiments and features described herein that do not fall within the scope of the independent claims should, in some cases, be construed as useful examples for understanding various embodiments. [Means for solving the problem]

[0004] According to an aspect, there is provided an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: transmit a message comprising a first reference signal and a first set of masks to one or more user devices; receive from the one or more user devices first mask channel information for each mask of the first set of masks or at least one of a preferred sidelink positioning reference signal configuration based on the first mask channel information; and determine a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0005] According to another aspect, there is provided an apparatus comprising: means for transmitting a message comprising a first reference signal and a first set of masks to one or more user devices; means for receiving from the one or more user devices first mask channel information for each mask of the first set of masks or at least one of preferred sidelink positioning reference signal configurations based on the first mask channel information; and means for determining a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0006] According to another aspect, there is provided a method comprising the steps of: transmitting to one or more user devices a message comprising a first reference signal and a first set of masks; receiving from the one or more user devices at least one of first mask channel information for each mask of the first set of masks or a preferred sidelink positioning reference signal configuration based on the first mask channel information; and determining a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0007] According to another aspect, there is provided a computer program comprising instructions that, when executed by an apparatus, cause the apparatus to at least: transmit a message comprising a first reference signal and a first set of masks to one or more user devices; receive from the one or more user devices first mask channel information for each mask of the first set of masks or a preferred sidelink positioning reference signal configuration based on the first mask channel information; and determine the first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0008] According to another aspect, there is provided a computer-readable medium comprising program instructions that, when executed by the apparatus, cause an apparatus to: send a message to one or more user devices, the message including a first reference signal and a first set of masks; receive from the one or more user devices first mask channel information for each mask of the first set of masks or a preferred sidelink positioning reference signal configuration based on the first mask channel information; and determine a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0009] According to another aspect, there is provided a non-transitory computer-readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to at least: transmit a message comprising a first reference signal and a first set of masks to one or more user devices; receive from the one or more user devices first mask channel information for each mask of the first set of masks or at least one of a preferred sidelink positioning reference signal configuration based on the first mask channel information; and determine a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0010] According to another aspect, there is provided an apparatus comprising: at least one processor; and at least one memory that stores instructions that, when executed by the at least one processor, cause the apparatus to at least perform the following steps: apply a first set of masks to a first reference signal; measure first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; and transmit at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information to a user device.

[0011] According to another aspect, there is provided an apparatus comprising: means for applying a first set of masks to a first reference signal; means for measuring first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; and means for transmitting at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information to a user device.

[0012] According to another aspect, there is provided a method comprising: applying a first set of masks to a first reference signal; measuring first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; and transmitting at least one of the first mask channel information or a first sidelink positioning reference signal based on the first mask channel information to a user device.

[0013] According to another aspect, there is provided a computer program comprising instructions that, when executed by the apparatus, cause the apparatus to at least: apply a first set of masks to a first reference signal; measure first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; and transmit at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information to a user device.

[0014] According to another aspect, there is provided a computer-readable medium comprising program instructions that, when executed by the apparatus, cause an apparatus to at least: apply a first set of masks to a first reference signal; measure first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; and transmit at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information to a user device.

[0015] According to another aspect, there is provided a non-transitory computer-readable medium comprising program instructions that, when executed by the apparatus, cause an apparatus to at least: apply a first set of masks to a first reference signal; measure first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; and transmit at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information to a user device.

[0016] Various exemplary embodiments will now be described in more detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 illustrates an example of a cellular communication network. [Figure 2] FIG. 1 illustrates an example of a sidelink positioning scenario. [Figure 3] FIG. 1 is a signaling diagram according to an exemplary embodiment. [Figure 4] FIG. 1 is a signaling diagram according to an exemplary embodiment. [Figure 5] FIG. 1 is a signaling diagram according to an exemplary embodiment. [Figure 6] FIG. 1 illustrates a flowchart in accordance with an exemplary embodiment. [Figure 7]FIG. 1 illustrates a flowchart in accordance with an exemplary embodiment. [Figure 8] FIG. 10 is a diagram illustrating an example of a reference signal in a slot. [Figure 9] FIG. 10 is a diagram illustrating an example of a message. [Figure 10] FIG. 1 is a diagram illustrating an example of an apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0018] The following embodiments are illustrative. Although the specification may refer to "an," "one," or "some" embodiments in several places throughout the document, this does not necessarily mean that each reference is to the same embodiment or that a particular feature applies only to a single embodiment. Single features of various embodiments may also be combined to provide other embodiments.

[0019] In the following, various exemplary embodiments are described using radio access architectures based on Long Term Evolution Advanced (LTE-Advanced, LTE-A), New Radio (NR, 5G), Beyond 5G, or Sixth Generation (6G) as examples of access architectures to which the exemplary embodiments can be applied, but the exemplary embodiments are not limited to such architectures. It will be apparent to those skilled in the art that the exemplary embodiments can also be applied to other types of communication networks having appropriate means by appropriately adjusting parameters and procedures. Some examples of alternatives to a suitable system may be Universal Mobile Telecommunications System (UMTS) Radio Access Networks (UTRAN or E-UTRAN), Long Term Evolution (LTE, similar to E-UTRA), Wireless Local Area Networks (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth, Personal Communications Services (PCS), ZigBee, Wideband Code Division Multiple Access (WCDMA), systems using Ultra Wideband (UWB) technology, sensor networks, Mobile Ad Hoc Networks (MANETs), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0020] 1 shows an example of a simplified system architecture showing several elements and functional entities, all of which are logical units, but whose implementation may differ from those shown. The connections shown in FIG. 1 are logical connections, and the actual physical connections may differ. It will be apparent to one skilled in the art that the system may have other functions and structures other than those shown in FIG. 1.

[0021] However, the illustrated embodiment is not limited to the system given as an example, and a person skilled in the art can apply the solution to other communication systems with the required characteristics.

[0022] The embodiment of FIG. 1 illustrates a portion of an exemplary radio access network.

[0023] FIG. 1 illustrates user devices 100 and 102 configured to wirelessly connect to one or more communication channels in a radio cell with an access node (AN) 104, such as an evolved Node B (eNB or abbreviated as eNodeB) or next generation Node B (gNB or abbreviated as gNodeB), that provides the radio cell. The physical link from the user device to the access node can be referred to as an uplink (UL) or reverse link, and the physical link from the access node to the user device can be referred to as a downlink (DL) or forward link. A user device can also communicate directly with another user device via sidelink (SL) communication. It should be understood that the access node or this functionality can be implemented using any node, host, server, access point, or other entity suitable for such use.

[0024] A communication system may include two or more access nodes, in which case the access nodes may also be configured to communicate with each other via wired or wireless links designed for this purpose. These links may be used for signaling purposes and for data routing from one access node to another. An access node may be a computing device configured to control the radio resources of the communication system to which it is coupled. An access node may be referred to as a base station, a base transceiver station (BTS), an access point, or any other type of interfacing device, including a relay station, capable of operating in a wireless environment. An access node may include or be coupled to a transceiver. Connection may be provided from the transceiver of the access node to an antenna unit that establishes a bidirectional wireless link to a user device. The antenna unit may include multiple antennas or antenna elements. An access node may further be connected to a core network 110 (CN or Next Generation Core NGC). Depending on the equipment technology, the counterpart to which the access node can be connected on the CN side can be a Serving Gateway (S-GW, routing and forwarding user data packets), a Packet Data Network Gateway (P-GW) for providing connectivity of user devices to external packet data networks, a User Plane Function (UPF), a Mobility Management Entity (MME), or an Access and Mobility Management Function (AMF).

[0025] Regarding positioning, the service-based architecture (core network) may comprise an AMF 111 and a Location Management Function (LMF) 112. The AMF may provide location information for call processing, policy, and charging to other network functions and other entities in the core network that request terminal device positioning. The AMF may receive and manage location requests from multiple sources, i.e., mobile-originated location requests (MO-LR) from user devices and mobile-terminated location requests (MT-LR) from other functions or network elements in the core network. The AMF may select an LMF for a given request and trigger a positioning session using its positioning service. Upon receiving such a request from the AMF, the LMF may perform positioning. The LMF may manage resources and timing of positioning activities. The LMF may request user device positioning from one or more access nodes using the Namf_Communication service of the NL1 interface, or may communicate with the user device via N1 for UE-based or UE-assisted positioning. Positioning can include estimating the location, and if requested, the LMF can estimate the movement or accuracy of the location information. In terms of connectivity, the AMF is between the access node and the LMF and therefore can be closer to the access node than the LMF.

[0026] A user device illustrates one type of device that can allocate and assign resources over the air interface, and therefore any features described herein in connection with a user device can be implemented in connection with a corresponding device, such as a relay node.

[0027] An example of such a relay node may be a Layer 3 relay (self-backhauling relay) towards an access node. A self-backhauling relay node may also be called an integrated access and backhaul (IAB) node. An IAB node may comprise two logical parts: a mobile termination (MT) part comprising the backhaul link (i.e., the link between the IAB node and a donor node (also known as a parent node)), and a distributed unit (DU) part handling the access link, i.e., the child link between the IAB node and a user device and / or between the IAB node and other IAB nodes (multi-hop scenario).

[0028] Another example of such a relay node may be a Layer 1 relay, called a repeater, which may amplify signals received from an access node and forward them to user devices and / or amplify signals received from user devices and forward them to the access node.

[0029] A user device may also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, or user equipment (UE), to name but a few of the names or devices. A user device may also refer to portable computing devices, including, but not limited to, the following types of devices: mobile stations (cell phones), smartphones, personal digital assistants (PDAs), handsets, devices that use wireless modems (such as alarm devices or measurement devices), laptops and / or touchscreen computers, tablets, gaming consoles, notebooks, multimedia devices, reduced capability (RedCap) devices, wireless sensor devices, or wireless mobile communication devices that operate with or without a subscriber identity module (SIM), including any device embedded in a vehicle.

[0030] It should be understood that a user device can also be an almost exclusively uplink-only device, an example of which can be a camera or video camera that loads images or video clips onto the network. A user device can also be a device capable of operating in an Internet of Things (IoT) network, a scenario in which objects can be provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. A user device can also utilize the cloud. In some applications, a user device can include a small portable or wearable device (watch, earphones, or glasses) with a radio portion, and computations can be performed in the cloud or another user device. A user device (or in some exemplary embodiments, a Layer 3 relay node) can be configured to perform one or more of the user equipment functions.

[0031] The various techniques described herein can also be applied to cyber-physical systems (CPS), systems of cooperating computational elements that control physical entities. CPS can enable the implementation and exploitation of a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects in various locations. Mobile cyber-physical systems, in which such physical systems can have inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices carried by humans or animals.

[0032] In addition, although the device has been shown as a single entity, it may be implemented with various units, processors and / or memory units (not all of which are shown in FIG. 1).

[0033] 5G is enabled by the use of many more base stations or nodes than LTE (the so-called small cell concept), including multiple-input, multiple-output (MIMO) antennas and macro sites that utilize a variety of radio technologies in cooperation with smaller base stations depending on service needs, use cases, and / or available spectrum. 5G mobile communications can support a wide range of use cases and related applications, including video streaming, augmented reality, various methods of data sharing, and various forms of machine-type applications (e.g., (massive) machine-type communications (mMTC)) including vehicle safety, various sensors, and real-time control. 5G can have multiple air interfaces, i.e., below 6 GHz, cm-wave, and mm-wave, and can be integrated with existing legacy radio access technologies such as LTE. Integration with LTE can occur, at least in the early stages, and as a system, macro coverage can be provided by LTE, with 5G air interface access occurring from small cells via aggregation to LTE. In other words, 5G can support both inter-RAT operability (e.g., LTE-5G) and inter-RI operability (operability between air interfaces below 6 GHz, e.g., cm-wave-mm-wave). One concept that may be used in 5G networks may be network slicing, where multiple independent and dedicated virtual sub-networks (network instances) may be created within substantially the same infrastructure to run services with different requirements regarding latency, reliability, throughput, and mobility.

[0034] The current architecture in LTE networks can be fully distributed across radios or fully centralized in the core network. Low latency applications and services in 5G may require bringing content closer to the radios, resulting in local breakout and multi-access edge computing (MEC). 5G can enable analytics and knowledge generation to occur at the source of the data. This approach may require utilizing resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC can provide a distributed computing environment for a host of applications and services. MEC may also have the ability to store and process content closer to the cellular subscriber for faster response times. Edge computing can cover a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad-hoc networking and processing which can also be categorized as local cloud / fog computing and grid / mesh computing, due computing, mobile edge computing, cloudlets, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications), etc.

[0035] The communications system may also communicate with, or use services provided by, one or more other networks 113, such as the public switched telephone network or the Internet. The communications network may also support the use of cloud services, e.g., perform at least a portion of the core network operations as cloud services (this is illustrated in FIG. 1 by "cloud" 114). The communications system may also include a central control entity, etc., and may provide facilities for cooperation between networks of various operators, e.g., in spectrum sharing.

[0036] An edge cloud can participate in a radio access network (RAN) by utilizing network function virtualization (NFV) and software-defined networking (SDN). Using an edge cloud can mean that access node operations are performed, at least in part, on a server, host, or node operatively coupled to a remote radio head (RRH) or radio unit (RU), or an access node including a radio portion. Node operations can also be distributed among multiple servers, nodes, or hosts. The application of the cloudRAN architecture allows RAN real-time functions to be performed on the RAN side (in the distributed unit DU 105) and non-real-time functions to be performed centrally (in the centralized unit CU 108).

[0037] It should also be understood that the division of functions between core network operations and access node operations may be different from LTE or may not exist. Some other technological advances that may be used include big data and all-IP, which may change the way networks are built and managed. 5G (or New Radio, NR) networks may be designed to support multiple tiers, where MEC servers may be located between the core and access nodes. It should be understood that MEC may be applied to 4G networks as well.

[0038] 5G can also utilize non-terrestrial communications, such as satellite communications, to extend or complement 5G service coverage, for example, by providing backhaul. Possible use cases include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices, or passengers on vehicles, or ensuring service availability for critical communications and future rail, maritime, and aviation communications. Satellite communications can utilize geostationary Earth orbit (GEO) satellite systems as well as low Earth orbit (LEO) satellite systems, especially megaconstellations (systems in which hundreds of (nano)satellites are deployed). A given satellite 106 in a megaconstellation can cover several satellite-enabled network entities, generating on-ground cells. The on-ground cells can be generated via on-ground relay nodes 104 or by on-ground-located access nodes 104 or on the satellite.

[0039] 6G networks are expected to employ flexible decentralized and / or distributed computing systems and architectures and ubiquitous computing with intelligent automated management, artificial intelligence, short packet communication, and blackchain technologies underpinned by local spectrum licensing, spectrum sharing, infrastructure sharing, and mobile edge computing. Key features of 6G include intelligent connection management and control capabilities, programmability, integrated sensing and communication, reduced energy footprint, reliable infrastructure, scalability, and affordability. In addition, 6G also targets new use cases covering the integration of localization and sensor capabilities into system definitions that unify user experiences across the physical and digital worlds.

[0040] It will be apparent to those skilled in the art that the illustrated system is only some examples of a wireless access system, and that in practice the system may include multiple access nodes, a user device may have access to multiple radio cells, and the system may also include other devices such as physical layer relay nodes or other network elements, at least one of the access nodes may be a Home eNodeB or a Home gNodeB.

[0041] Furthermore, an access node can be divided into a radio unit (RU) including a radio transceiver (TRX), i.e., a transmitter (Tx) and a receiver (Rx), one or more distributed units (DUs) that can be used for so-called Layer 1 (L1) processing and real-time Layer 2 (L2) processing, and a central unit (CU) (also known as a centralized unit) that can be used for non-real-time L2 and Layer 3 (L3) processing. The CU can be connected to one or more DUs, for example, by using an F1 interface. Such a division can allow for centralization of the CU to the cell site and the DU, but the DU can be further distributed and even reside at the cell site. The CU and DU together can be referred to as baseband or baseband unit (BBU). The CU and DU can also be included in a wireless access point (RAP).

[0042] A CU may be defined as a logical node that hosts higher layer protocols, such as the Radio Resource Control (PRC), Service Data Adaptation Protocol (SDAP), and / or Packet Data Convergence Protocol (PDCP) of an access node. A DU may be defined as a logical node that hosts the Radio Link Control (RLC), Medium Access Control (MAC), and / or Physical (PHY) layers of an access node. The operation of the DU may be controlled, at least in part, by the CU. The CU may include a control plane (CU-CP), which may be defined as a logical node that hosts the RRC of the CU toward the access node and the control plane portion of the PDCP protocol of the CU. The CU may further include a user plane (CU-UP), which may be defined as a logical node that hosts the user plane portion of the PDCP protocol and SDAP protocol of the CU toward the access node.

[0043] A cloud computing platform can also be used to execute the CU and / or DU. The CU can execute on the cloud computing platform and can be referred to as a virtualized CU (vCU). In addition to the vCU, there can also be a virtualized DU (vDU) executing on the cloud computing platform. Furthermore, combinations can also exist, where the DU can use a so-called bare metal solution, such as an application specific integrated circuit (ASIC) or a customer specific standard product (CSSP) system-on-chip (SoC) solution. It should also be understood that the distribution of functionality between the above-mentioned access node units, or various core network operations and access node operations, can vary.

[0044] In addition, several different types of radio cells as well as several radio cells can be provided in the geographical area of ​​a wireless communication system. The radio cells can be macrocells (or umbrella cells), large cells with diameters up to tens of kilometers, or small cells such as micro, femto, or picocells. The access node of FIG. 1 can provide any of these cell types. A cellular wireless system can be implemented as a multi-layer network including several types of radio cells. In a multi-layer network, one access node can provide one or more radio cells of one type, and therefore multiple access nodes are required to provide such a network structure.

[0045] To satisfy the need for improved deployment and performance of communication systems, the concept of "plug and play" access nodes can be introduced. Networks that can use "plug and play" access nodes can include a Home Node B Gateway, or HNB-GW (not shown in Figure 1), in addition to Home eNodeBs or Home gNodeBs. The HNB-GW, which can be installed within an operator's network, can aggregate traffic from multiple Home eNodeBs or Home gNodeBs back to the core network.

[0046] Positioning techniques can be used to estimate the physical location of a user device. A positioned user device is referred to herein as a target UE or target user device. For example, positioning techniques used in NR can be based on at least one of time difference of arrival (TDoA), round trip time (RTT), angle of departure (AoD), and / or angle of arrival (AoA).

[0047] In wireless positioning, multiple positioning anchors at known locations can transmit and / or receive one or more positioning reference signals (PRS) to and from a target UE. In the uplink, a sounding reference signal (SRS) can be used as a positioning reference signal. For example, a multilateration technique can be used to localize (i.e., position) the target UE relative to the positioning anchors. A positioning anchor may also be referred to herein as an anchor, anchor node, multilateration anchor, or reference point. A positioning anchor may be, for example, a radio access node (e.g., gNB) or a transmit / receive point (TRP) (in the case of uplink / downlink positioning), or another UE (in the case of sidelink positioning).

[0048] Sidelink (SL) positioning refers to a positioning method in which a target UE uses the sidelink (i.e., a direct device-to-device link) to locate itself, either in an absolute manner (in the case of absolute positioning) or a relative manner (in the case of relative positioning). Sidelink (SL) positioning refers to a positioning technique in which a target UE determines its location using the sidelink (i.e., a direct device-to-device link) either in an absolute manner (in the case of absolute positioning) or a relative manner (in the case of relative positioning). In the case of UE-assisted positioning, the target UE can obtain positioning measurements using the sidelink and report the measurements to a network entity such as a Location Management Function (LMF). Sidelink positioning can also be used to obtain ranging information.

[0049] Ranging refers to determining the distance between two UEs and / or the direction of one UE to another UE via a direct device connection.

[0050] Absolute positioning refers to estimating the location of a target UE in two-dimensional or three-dimensional geographic coordinates (eg, latitude, longitude, and / or altitude) within a coordinate system.

[0051] Relative positioning refers to estimating the location of a target UE relative to other network elements or other UEs.

[0052] SL positioning may be based on the transmission of sidelink positioning reference signals (SL PRS) by multiple anchor UEs, which are received and measured by the target UE to enable localization of the target UE within the precise latency and accuracy requirements of the corresponding SL positioning session. Alternatively or additionally, the target UE may transmit SL PRS that are received and measured by the anchor UE.

[0053] An anchor UE can be defined as a UE that supports the positioning of a target UE, for example, by transmitting and / or receiving reference signals for positioning (e.g., SL PRS) over the SL interface. This is similar to UL / DL-based positioning, where a gNB can function as an anchor that transmits and / or receives reference signals to and from a target UE for positioning.

[0054] SL PRS refers to the reference signal transmitted over SL for positioning purposes.

[0055] 2 shows an example of a sidelink positioning scenario, in which a target UE 200 is conducting a sidelink positioning session, i.e., exchanging SL PRS with two anchor UEs 201, 202, to determine its position. Here, the anchor UEs 201, 202 are said to provide SL PRS assistance (including SL PRS) to the target UE 200.

[0056] Some example use cases for sidelink positioning can include, but are not limited to, vehicle-to-everything (V2X), public safety, commercial, and industrial Internet of Things (IIoT).

[0057] One of the advantages of sidelink positioning is when a target UE needs to be located outside of network coverage or in scenarios where the number of radio access nodes or TRPs used as positioning anchors is limited. That is, sidelink positioning can be considered as a solution to improve positioning availability when, for example, Uu positioning is unavailable (e.g., when the target UE is out of coverage) and when Global Navigation Satellite System (GNSS) signals are unavailable (e.g., in places like tunnels, dense urban scenarios, etc.).

[0058] Using sidelink positioning, the target UE can utilize other UEs (or roadside units with SL interface, etc.) that act as positioning anchors via SL. Using SL, the target UE can perform positioning in limited coverage or out-of-coverage scenarios. The roadside unit (RSU) can be defined as a stationary infrastructure entity of UE or gNB type, for example, supporting V2X applications.

[0059] When at least two UEs are involved in sidelink positioning, three network coverage scenarios can be considered: in-coverage, partial coverage, and out-of-coverage. Taking the case of two UEs as an example, the in-coverage scenario means that both UEs are in network coverage. Partial coverage means that one UE is in network coverage while the other UE is out of network coverage. The out-of-coverage scenario means that both UEs are out of network coverage. UEs can transition between in-coverage, partial coverage, and out-of-coverage scenarios. For example, there may be V2X and public safety use cases that may require positioning when there is no network coverage and no GNSS coverage.

[0060] For example, for IIoT use cases in out-of-coverage scenarios, there may be several positioning accuracy requirements. The positioning requirements can be implemented through key performance indicators (KPIs), such as horizontal and vertical accuracy, availability of positioning services, latency of positioning services, time to first fix (TTFF), update rate, energy consumption, etc.

[0061] Vertical accuracy can refer to altitude accuracy, determining the floor in indoor use cases and distinguishing between overlapping tracks in road and rail use cases (e.g., bridges).

[0062] The availability of a positioning service can be defined as a percentage value that is the amount of time that the positioning service is delivering the required location-related data within performance requirements divided by the amount of time that the system is expected to deliver the positioning service according to specifications in the target service area.

[0063] The latency of a positioning service may be defined as the time elapsed between an event that triggers the determination of location-related data and the availability of the location-related data at the system interface.

[0064] The TTFF may be defined as the time elapsed between an event that first triggers the determination of location-related data and the availability of the location-related data at the positioning system interface.

[0065] Performance requirements can be defined for different positioning service levels: Positioning service levels 4 (99.9% availability, 15ms latency) and 6 (99.9% availability, 10ms latency) can have very stringent requirements on positioning service availability and positioning service latency, along with requirements on horizontal and vertical accuracy.

[0066] Example scenarios or use cases for Positioning Service Levels 4 and 6 can include V2X, Set 2, and Set 3 use cases, which can correspond to lane-level positioning requirement use cases such as vehicle platooning, cooperative lane merging, lane change warning, emergency exit warning, and intersection maneuver assistance, as well as sub-meter positioning requirement use cases such as high-definition sensor sharing, traffic vulnerability (VRU)-collision risk warning, cooperative operation in emergency situations, real-time situational awareness, and high-definition maps.

[0067] For IIoT, examples of scenarios or use cases for positioning of service levels 4 and 6 include "Factories of the Future" scenarios such as augmented reality in smart factories, mobile control panels with safety functions in smart factories (in danger zones of factories), and inbound logistics for manufacturing (for driving trajectories when supported by additional sensors such as cameras, GNSS, and inertial measurement units in indoor autonomous driving systems).

[0068] The SL PRS can be configured with various parameters, for example, (pre-)configuration of the SL PRS can refer to (pre-)configured parameters of the SL PRS such as its time-frequency resources including its bandwidth and periodicity, directivity-related parameters (e.g., beam direction), beam width, number of beams, and transmit power.

[0069] In an in-coverage or partial coverage scenario, the SL PRS (pre-)configuration may be determined by the network (e.g., LMF or gNB). In an out-of-coverage scenario, the SL PRS (pre-)configuration may be pre-configured and / or determined autonomously by the UE.

[0070] A Resource Pool (RP) is a set of resources allocated for SL procedures. There are two types of RPs: Receive Resource Pool (RxRP) and Transmit Resource Pool (TxRP). These can be signaled by the gNB for the in-coverage case or pre-configured for the out-of-coverage case.

[0071] To send and receive data or control signaling over SL, a UE can utilize one of the following resource allocation modes: NR SL Mode 1 (Network Controlled Mode) or NR SL Mode 2 (UE Autonomous Mode). In NR SL Mode 1, the network allocates SL resources to the UE. In NR SL Mode 2, the UE autonomously selects SL resources based on a sensing mechanism.

[0072] For NR SL Mode 1, the UE may be required to be in the RRC_CONNECTED state. For NR SL Mode 2, the UE may also be in the RRC_INACTIVE or RRC_IDLE state (e.g., when out of coverage) in addition to possibly operating in the RRC_CONNECTED state.

[0073] NR SL transmissions utilize a demodulation reference signal (DMRS) to enable a receiver UE to decode the associated SL physical channel, i.e., the physical sidelink control channel (PSCCH), the physical sidelink shared channel (PSSCH), or the physical sidelink broadcast channel (PSBCH), where the DMRS is transmitted within the associated sidelink physical channel.

[0074] To demodulate the PSCCH, the DMRS can be transmitted within the PSCCH. The PSCCH DMRS can follow the design of the DMRS associated with the PDCCH in Rel.15 NR Uu. The PSCCH DMRS can reuse the same pseudo-random sequence used for the PDCCH DMRS in Rel.15 NR Uu, and the initialization of the PSCCH DMRS sequence is based on a value configured (pre-configured) for each resource pool. Furthermore, every PSCCH symbol can contain the PSCCH DMRS. The pattern of the PSCCH DMRS in the frequency domain can also reuse the DMRS frequency pattern adopted for the PDCCH in Rel.15 NR Uu.

[0075] To demodulate the PSSCH, the DMRS can be transmitted within the PSSCH. The design of the PSSCH DMRS can follow the aspects of the DMRS associated with the Rel.15 NR Uu Physical Uplink Shared Channel (PUSCH) and other aspects of the PDSCH DMRS. The PSSCH DMRS can reuse the pseudo-random sequence used for the PUSCH DMRS in Rel.15, with the sequence initialization based on a (pre)configured value for each resource pool. In the frequency domain, the Type 1 pattern configuration of the PDSCH DMRS can be adopted for the PSSCH DMRS.

[0076] To support different channel conditions, the DMRS associated with the PSSCH can be carried in different symbols within a PSSCH slot, i.e., 2, 3, or 4 SL symbols, i.e., in different time patterns. The different time patterns of the PSSCH DMRS can depend on the number of PSCCH symbols, the number of PSSCH DMRS symbols, and the number of PSSCH symbols within the slot. The currently supported time patterns for the PSSCH DMRS in NR SL are listed in Table 1 below, where the positioning of the DMRS symbols is given by l, where l_'d' is the duration of the scheduled resources for the transmission of the PSSCH and associated PSCCH, including the overlap of orthogonal frequency division multiplexing (OFDM) symbols. One or more time patterns for the PSSCH DMRS can be configured (pre-configured) for a resource pool. If multiple patterns are configured (pre-configured), the DMRS time pattern used for the PSSCH can be indicated in the associated first-stage sidelink control information (SCI). TIFF2025529681000002.tif104142 Table 1.

[0077] As mentioned above, SL positioning can enable target UE localization within the precise latency and accuracy requirements of the corresponding SL positioning session based on the exchange of SL PRS between the target UE and anchor UE (e.g., in an RTT-based positioning technique) or the transmission of SL PRS by multiple anchor UEs to be received by the target UE (e.g., in a TDoA-based positioning technique). Here, the SL PRS reception quality at the anchor UE (in an RTT-based technique) and / or at the target UE can be an important factor determining the achievable latency and accuracy performance in an SL positioning use case. Therefore, the configuration of resources for SL PRS transmission needs to guarantee the desired SL PRS reception quality. In the following, an RTT-based SL positioning technique is considered as an example.

[0078] Note that in Uu positioning, the LMF selects, for example, the bandwidth (BW), the comb (frequency pattern) of that bandwidth, and the repetition (number of consecutive symbols) based on a coarse location estimate of the target UE. In other words, the LMF knows the worst case the target UE may experience and can dimension the PRS accordingly, e.g., a tighter time allocation in poor signal-to-interference-plus-noise ratio (SINR) conditions, a comb proportional to the coherence bandwidth, etc.

[0079] Unlike Uu positioning, in SL positioning, there may be no central entity (e.g., LMF) that is aware of SL channel conditions and has control over the SL PRS configuration. Therefore, the target UE and / or anchor UE may need to autonomously select an SL PRS configuration for SL PRS transmission (e.g., in an RTT-based or TDoA-based manner). In this regard, a challenge arises: how does the target UE select an appropriate SL PRS configuration for a given anchor UE, especially when the target UE is unaware of the channel toward the anchor UE (e.g., early in the SL positioning session)? The target UE may select the most conservative SL PRS configuration to ensure high SL PRS reception quality, but this may be resource inefficient and therefore may not scale well, for example, in denser UE deployment scenarios.

[0080] In some exemplary embodiments, a method may be provided for a target UE to select or adapt an SL PRS configuration to link conditions between itself and a given anchor UE, which may implement a closed-loop type approach to tailoring the SL PRS configuration to propagation and interference conditions specific to a given radio link between the target UE and the anchor UE.

[0081] In some exemplary embodiments, improved SL resource utilization (since it is not necessary to apply the most conservative SL PRS configuration to ensure high SL PRS reception quality), low latency (since high SL PRS reception quality can be ensured even in the early stages of an SL positioning session), and high accuracy SL positioning can be provided.

[0082] For example, for some exemplary embodiments, an RTT-based SL positioning scheme can be considered, in which SL PRSs are exchanged between the target UE and the anchor UE, and the target UE determines the SL PRS configuration. However, it should be noted that this problem and solution are applicable to any SL positioning technique, in which the anchor UE, the target UE, and / or a third UE (if a neighboring third UE is provided with IUC-like information) need to select an SL PRS configuration (either for its own SL PRS transmission or for providing IUC-like information to other UEs transmitting SL PRS). IUC stands for inter-UE cooperation. Masked channel information (MCI)-based SL PRS configuration determination can be utilized to determine an appropriate SL PRS configuration suited to the radio link conditions between the target UE and a given anchor UE. Here, a set of RS masks can be defined for a set of reference signals (RSs) transmitted between the target UE and the anchor UE, and the given RS mask is designed to emulate the SL PRS. Thus, the RS mask emulates the effect of transmitting multiple differently configured SL PRSs, i.e., SL PRSs with different time / frequency / spatial patterns and densities.

[0083] However, without limiting the example embodiments to 5G communication systems, some example embodiments using principles and terminology of 5G technology are described below.

[0084] 3 shows a signaling diagram of an exemplary embodiment. In this exemplary embodiment, a target UE selects an SL PRS configuration for its own SL PRS transmission. During (re)establishment of an SL positioning session, the target UE transmits a message containing a set of reference signals (RSs) and RS masks to the anchor candidate UE. The candidate anchor UE then applies the masks to the RSs, calculates an MCI for each mask, and responds with the MCI to the target UE. This MCI is used by the target UE to select an SL PRS configuration for its own SL PRS transmission.

[0085] 3, in block 301, an SL positioning session initiation is triggered at the target UE. This may be due to a localization requirement of the relevant use case (e.g., V2X). For example, an RTT-based SL positioning technique may be considered by the target UE.

[0086] In block 302, the target UE determines an RS mask configuration comprising at least a first set of masks (RS masks) that, when applied to a first reference signal at the candidate anchor UE, emulate a sidelink positioning reference signal (SL PRS) using multiple different SL PRS configurations. In other words, the RS masks are defined to emulate SL PRS when applied to the first reference signal, and the different RS maskings emulate the effect of transmitting different configurations of SL PRS, i.e., SL PRS with different time, frequency, and spatial patterns and densities. The masking helps the target UE predict how a given SL PRS configuration will affect the accuracy of subsequent SL positioning measurements / estimations.

[0087] For example, the target UE may determine a first set of masks based on coarse ranging information to the candidate anchor UEs (if previous SL communication has occurred). Otherwise, the target UE may select a mask by incrementally muting resources from a minimum muting pattern to a maximum muting pattern, where the minimum and maximum may be established based on a minimum or maximum coherence time and bandwidth. For example, for a minimum coherence bandwidth (denoted as minB), minFreq comb=minB. Similarly, for a minimum coherence time (denoted as minTcoh), minTime comb=minTcoh. A comb may refer to a pattern defined in one or more of a time domain (e.g., symbols), a frequency domain (e.g., subcarriers), and / or one or more spatial domains (e.g., beams).

[0088] Here, an SL PRS configuration can refer to a set of parameters that establish an RS pattern in at least the following domains: frequency, time, and space (eg, transmit beam and / or receive beam).

[0089] A given mask of the first set of masks may comprise a binary (Boolean) matrix that, when applied to the matrix of the first reference signal (RS sample matrix), mutes one or more entries (i.e., some entries) of the matrix of the first reference signal. The binary matrix (mask) may be a two-dimensional matrix or a multidimensional matrix. That is, the binary matrix (mask) may have two or more dimensions.

[0090] Let M denote the first set of masks determined by the target UE, where the ith entry M(i) describes how the ith mask is generated and applied to the first reference signal. For example, a given mask M(i) of the first set of masks can be defined by a combination of at least a time-domain comb, a frequency-domain comb, and a spatial-domain comb. The time-domain comb can refer to, for example, a time pattern for selecting every xth symbol of the first reference signal. The frequency-domain comb can refer to, for example, a frequency pattern for selecting every xth subcarrier of the first reference signal for symbol (x). The spatial-domain comb can refer to, for example, a spatial pattern for selecting transmit beams b1, b2, ... and receive beams r1, r3, ... for symbol (x).

[0091] In other words, if the entry of the mask is 1, i.e., If JPEG2025529681000003.jpg16153=1, then the RS samples of frequency f, symbol x, transmit beam b, and receive beam r are used to calculate MCI(i). Conversely, if an entry is 0, the corresponding RS sample is not used in calculating MCI(i). Here, the term "symbol" may refer to an OFDM symbol.

[0092] Non-limiting examples of applying a mask are provided below. Mask = JPEG2025529681000004.jpg21153 is RS sample matrix RS= When applied to JPEG2025529681000005.jpg21153, output = mask x RS = JPEG2025529681000006.jpg22153 is generated, where f1 and f2 may indicate subcarrier number indices, and t1 and t2 may indicate OFDM symbol number or sample number indices.

[0093] In block 303, the target UE transmits a message including a first reference signal and a first set of masks to one or more candidate anchor UEs (FIG. 3 shows only one anchor UE; other UEs are not shown, but may be present). Here, the term "candidate anchor UE" may refer to a UE that is not yet active in the target UE's SL positioning session. In other words, the one or more candidate anchor UEs may not have transmitted SL PRS to the target UE or may not have measured SL PRS transmitted by the target UE. For example, the first reference signal may comprise a DMRS.

[0094] The message may also comprise a request to measure and report MCI using the first set of masks. The MCI measured by using the first set of masks may also be referred to herein as first mask channel information.

[0095] The message can be sent as an SL broadcast message on an SL slot with a configuration in which some symbols are used for RS transmission and other symbols carry data. The data symbol payload can comprise an SL positioning request (and session KPIs such as latency targets), the type of positioning technology (e.g., TDoA, RTT, etc.) used in the SL positioning session, a first set of masks M (where the i-th entry M(i) describes how the i-th mask should be generated and applied to the RS portion of the SL signal), and a request to measure MCI using a mask in the first set of masks M.

[0096] For example, to initiate the RTT-based SL positioning technique, the target UE can send an anchor discovery request message, denoted as Msg-A, to find / discover suitable nearby anchor UEs. To provide RS mask configurations (first set of masks) to one or more candidate anchor UEs, the target UE can include the mask configuration in Msg-A. SL PRSs (which can be used to obtain different SL PRS configurations) can also be embedded in Msg-A. Furthermore, the target UE can embed a request for anchor candidate UEs to respond to MCI in Msg-A. In other words, a message including the first reference signal and the first set of masks (and the request) can be referred to as an anchor discovery request message (Msg-A). An example of the structure of Msg-A is shown in FIG. 9.

[0097] In block 304, one or more candidate anchor UEs receive the request, decode the payload, and evaluate the request. If a positive result is obtained (i.e., if the given candidate anchor UE determines that it supports the SL positioning session of the target UE), the candidate anchor UE applies the first set of masks to the first reference signal according to the indicated mask configuration, and measures or calculates first mask channel information for each mask in the first set of masks from the first reference signal to which the first set of masks has been applied.

[0098] The first mask channel information may include at least one of a reference signal received power (RSRP), a received signal strength indicator (RSSI), a channel frequency response (CFR), or a channel impulse response (CIR) measured from a first reference signal to which the first set of masks has been applied (i.e., combined).

[0099] Applying the first set of masks to the first reference signal may include applying a binary matrix for each mask to the matrix of the first reference signal, for example, by multiplying the binary matrix (mask) with the matrix of the first reference signal. That is, the indicated mask, i.e., binary (Boolean) matrix, is concatenated onto the RS sample matrix of the first reference signal, for example, as described above for block 302. An example of RSs to which masks are applied is shown in FIG. 8. On the masked RS samples (having applied mask M to the RS as indicated), the candidate anchor UE measures or calculates a mask M(i) for each MCI.

[0100] For example, a given anchor candidate UE may sample a first reference signal and arrange the samples in a matrix Mrs, where Mrs(f,t,s,r) denotes the RS sample at time t, subcarrier f, transmit beam s, and receive beam r. For a given mask "i", the anchor candidate UE may compute the mask RS matrix Mmrs=Mrs×M(i) and use Mmrs to extract MCI(i).

[0101] In block 305, (if the evaluation yields a positive result) one or more candidate anchor UEs transmit first mask channel information to the target UE. A given candidate anchor UE may respond to the request with an SL unicast message, the payload of which is encoded with at least the candidate anchor UE's location and location certainty, and the first mask channel information MCI(i) for each mask M(i).

[0102] For example, a given anchor candidate UE may respond to the request in Msg-A by sending (e.g., in a unicast manner) an anchor discovery response message, denoted Msg-B, to the target UE. In Msg-B, the anchor candidate UE may include at least its own location and location certainty, and first mask channel information MCI(i) for each mask M(i).

[0103] Alternatively, or additionally, the one or more candidate anchor UEs may determine a preferred SL PRS configuration based on the first mask channel information and transmit the preferred SL PRS configuration to the target UE instead of or in addition to the first mask channel information.

[0104] In other words, one or more candidate anchor UEs may transmit to the target UE at least one of the first mask channel information or a preferred sidelink positioning reference signal configuration based on the first mask channel information. The preferred sidelink positioning reference signal configuration may also be referred to as the first sidelink positioning reference signal configuration.

[0105] In block 306, the target UE performs anchor UE selection, for example, based on the received Msg-B. In other words, the target UE can select at least one anchor UE from one or more candidate anchor UEs to support its SL positioning session.

[0106] In block 307, the target UE determines or selects a first sidelink positioning reference signal configuration based at least in part on first mask channel information (e.g., RSRP, RSSI, CFR and / or CIR, etc.) received from the at least one selected anchor UE or based on a preferred sidelink positioning reference signal configuration received from the at least one selected anchor UE. In this way, the target UE can determine or select a suitable SL PRS configuration for the radio link between the target UE and the at least one selected anchor UE.

[0107] The first sidelink positioning reference signal configuration may further be determined, at least in part, based on a mapping between the first mask channel information and one or more sidelink positioning reference signal parameter settings. In other words, the target UE may select a suitable SL PRS configuration for the anchor UE using the received MCI list and an internal mapping between the MCI and SL PRS parameter settings. For example, the mapping may be provided in a tabular form as shown in Table 2 below. In Table 2, the positioning requirement level (e.g., Pos_Req_1, Pos_Req_2, etc.) captures the requirements of the associated positioning use case (e.g., positioning accuracy requirements). For a given MCI range (e.g., Range 1, Range 2, etc.), different accuracy requirements may be mapped to different SL PRS parameter settings (i.e., SL PRS configurations), such as frequency and time patterns.

[0108] Such a table may be populated autonomously by the target UE or may be provided by the network or another UE (e.g., anchor UE or neighbor UE). Depending on the type of session, the number of responding anchor candidate UEs, and their availability, the target UE may further refine the SL PRS parameter settings output by the table lookup. The table may be known by both the target UE and one or more candidate anchor UEs. In this case, one or more anchor candidate UEs may indicate preferred SL PRS settings in block 305 instead of or in addition to the MCI. TIFF2025529681000007.tif67136 Table 2

[0109] In block 308, the target UE transmits a first sidelink positioning reference signal to at least one selected anchor UE based on the first sidelink positioning reference signal configuration. In other words, the target UE applies the selected SL PRS configuration to its own SL PRS transmissions. The at least one selected anchor UE receives and measures the first sidelink positioning reference signal to support the target UE's SL positioning session.

[0110] 4 shows a signaling diagram of an exemplary embodiment. In this exemplary embodiment, an SL PRS configuration is selected in a target UE for an SL PRS transmission of the anchor UE. Here, the target UE is provided with the RS configuration in a response message from the anchor UE. The anchor UE then responds with a reference signal according to the indicated RS configuration. The target UE then applies an RS mask to the RS transmitted from the anchor UE to calculate an MCI. This MCI is used to select an appropriate SL PRS configuration for the anchor UE's SL PRS transmission. The target UE then indicates the selected SL PRS configuration to the anchor UE, allowing the anchor UE to use the appropriate SL PRS configuration for its SL PRS transmission.

[0111] 4, initiation of an SL positioning session is triggered at the target UE in block 401. This may be due to a localization requirement of a related use case (e.g., V2X). For example, an RTT-based SL positioning technique may be considered by the target UE.

[0112] In block 402, the target UE determines a reference signal configuration, which may be referred to as a first reference signal configuration, where configuration may refer to a set of parameters that establish an RS pattern in at least the following domains: frequency, time, and space (e.g., transmit beam and / or receive beam).

[0113] In block 403, the target UE transmits a configuration for a first reference signal to one or more candidate UEs. For example, to initiate RTT-based SL positioning, the target UE may transmit an anchor discovery request message (denoted as Msg-A) to find / discover a suitable nearby anchor UE. In Msg-A, the target UE may include the reference signal configuration determined in block 402. Msg-A may also comprise a request to respond with a first reference signal.

[0114] In block 404, one or more candidate anchor UEs receive Msg-A, decode the payload, and evaluate the request. If a positive result is obtained (i.e., if a given candidate anchor UE determines that it supports the SL positioning session for the target UE), the candidate anchor UE applies the reference signal configuration to its response message.

[0115] In block 405, (if the evaluation yields a positive result) one or more candidate anchor UEs respond to the target UE by transmitting a first reference signal to the target UE according to the reference signal configuration received from the target UE. For example, a given candidate anchor UE may respond to the request by transmitting (e.g., in a unicast manner) an anchor discovery response message (denoted Msg-B) to the target UE, where Msg-B also comprises the first reference signal. For example, the first reference signal may be a DMRS.

[0116] In block 406, the target UE performs anchor UE selection, for example, based on the received Msg-B. In other words, the target UE can select at least one anchor UE from one or more candidate anchor UEs to support its SL positioning session.

[0117] In block 407, the target UE determines and applies a first set of masks to a first reference signal received from the selected at least one anchor UE, and measures first mask channel information for each mask in the first set of masks from the first reference signal to which the first set of masks has been applied.

[0118] The first masked channel information may include at least one of a reference signal received power (RSRP), a received signal strength indicator (RSSI), a channel frequency response (CFR), or a channel impulse response (CIR) measured from a first reference signal having a first set of masks applied.

[0119] A given mask of the first set of masks may comprise a binary (Boolean) matrix that, when applied to the matrix of the first reference signal (RS sample matrix), mutes one or more entries (i.e., some entries) of the matrix of the first reference signal. The binary matrix (mask) may be a two-dimensional matrix or a multidimensional matrix. That is, the binary matrix (mask) may have two or more dimensions.

[0120] If M represents a first set of masks, the ith entry M(i) describes how the ith mask should be generated and applied to the first reference signal. For example, a given mask M(i) of the first set of masks can be defined by at least the following combinations: a time domain comb, a frequency domain comb, and a spatial domain comb. The time domain comb can refer to, for example, a time pattern for selecting every xth symbol of the first reference signal. The frequency domain comb can refer to, for example, a frequency pattern for selecting every yth subcarrier of the first reference signal for symbol (x). The spatial domain comb can refer to, for example, a spatial pattern for selecting transmit beams b1, b2, ... and receive beams r1, r3, ... for symbol (x).

[0121] On the masked RS samples (i.e., the RS resulting from applying the mask M to the received DMRS), the target UE calculates the MCI for each mask M(i). In other words, if the entry of the mask is 1, i.e., If JPEG2025529681000008.jpg16153=1, then the RS samples of frequency f, symbol x, transmit beam b, and receive beam r are used to calculate MCI(i). Conversely, if an entry is 0, the corresponding RS sample is not used in calculating MCI(i). Here, the term "symbol" may refer to an OFDM symbol.

[0122] Non-limiting examples of applying a mask are provided below. Mask = JPEG2025529681000009.jpg21153 is RS sample matrix RS= When applied to JPEG2025529681000010.jpg21153, output = mask x RS = JPEG2025529681000011.jpg21153 is generated, where f_1 and f_2 may indicate subcarrier number indices, and t_1 and t_2 may indicate OFDM symbol number or sample number indices.

[0123] In block 408, the target UE determines or selects a first sidelink positioning reference signal positioning based at least in part on first mask channel information (e.g., RSRP, RSSI, CFR and / or CIR, etc.) measured by the target UE. In this way, the target UE can determine or select a suitable SL PRS configuration for the radio link between the target UE and the selected at least one anchor UE.

[0124] In block 409, the target UE transmits the first sidelink positioning reference signal configuration to the selected at least one anchor UE so that the selected at least one anchor UE can use an appropriate SL PRS configuration for its SL PRS transmissions.

[0125] In block 410, the selected at least one anchor UE transmits a sidelink positioning reference signal to the target UE based on the first sidelink positioning reference signal configuration, and the target UE receives and measures the first sidelink positioning reference signal from the selected at least one anchor UE for the target UE's SL positioning session.

[0126] FIG. 5 shows a signaling diagram of an exemplary embodiment. In this exemplary embodiment, the target UE selects an SL PRS configuration for its own SL PRS transmission and an SL PRS configuration for the anchor UE's SL PRS transmission. Here, during (re)establishment of an SL positioning session, the target UE transmits a message to the anchor candidate UE, including the RS, a first set of RS masks, and an RS configuration for the response message. The candidate anchor UE applies the masks to the RSs, calculates a first MCI for each mask, and responds to the target UE with the first MCI. The response includes the indicated RS configuration. The target UE uses the received first MCI to select an appropriate SL PRS configuration for its own SL PRS transmission. Furthermore, the target UE applies a second set of RS masks to the RSs transmitted from the anchor UE to calculate a second MCI. This second MCI is used to select an appropriate SL PRS configuration for the anchor UE's SL PRS transmission. The target UE then indicates the selected SL PRS configuration to the anchor UE, enabling the anchor UE to use the appropriate SL PRS configuration for its SL PRS transmission.

[0127] 5, in block 501, the initiation of a SL positioning session is triggered at the target UE. This may be for a positioning request of a related use case (e.g., V2X). For example, an RTT-based SL positioning technique may be considered by the target UE.

[0128] In block 502, the target UE determines a first RS mask configuration comprising at least a first set of masks (RS masks) that, when applied to a first reference signal at the candidate anchor UE, emulate sidelink positioning reference signals (SL PRS) using a plurality of different SL PRS configurations. In other words, the RS masks are defined to emulate SL PRS when applied to the first reference signal, where the different RS maskings emulate the effect of transmitting different configurations of SL PRS, i.e., SL PRS with different time, frequency, and spatial patterns and densities.

[0129] Here, an SL PRS configuration can refer to a set of parameters that establish an RS pattern in at least the following domains: frequency, time, and space (eg, transmit beam and / or receive beam).

[0130] A predetermined mask of the first set of masks may comprise a binary (Boolean) matrix that, when applied to the matrix of the first reference signal (RS sample matrix), mutes one or more entries (i.e., some entries) of the matrix of the first reference signal. The binary matrix (mask) may be a two-dimensional matrix or a multidimensional matrix. That is, the binary matrix (mask) may have two or more dimensions.

[0131] In block 503, the target UE determines a reference signal configuration, which may be referred to as a second reference signal configuration.

[0132] In block 504, the target UE transmits a message to one or more candidate UEs, including a first reference signal, a first set of masks, and a configuration for a second reference signal. For example, to initiate RTT-based SL positioning, the target UE may transmit an anchor discovery request message (denoted as Msg-A) to search for / discover a suitable nearby anchor UE. Msg-A may include the first reference signal, the first set of masks, and the second reference signal configuration. Msg-A may also include a request to respond with a first MCI measured using the second reference signal and the first set of masks. An example configuration of Msg-A is shown in FIG. 9. Alternatively, the first reference signal, the first set of masks, the second reference signal configuration, and the request may be transmitted separately rather than in a single message.

[0133] In block 505, one or more candidate anchor UEs receive Msg-A, decode the payload, and evaluate the request. If a positive result is obtained (i.e., if the candidate anchor UE determines that it supports the SL positioning session for the target UE), the candidate anchor UE applies the first set of masks to the first reference signal and measures or calculates first mask channel information for each mask in the first set of masks from the first reference signal to which the first set of masks has been applied.

[0134] The first mask channel information may include at least one of a reference signal received power (RSRP), a received signal strength indicator (RSSI), a channel frequency response (CFR), or a channel impulse response (CIR) measured from a first reference signal applied using the first set of masks.

[0135] Applying the first set of masks to the first reference signal may include applying a binary matrix for each mask to the matrix of the first reference signal. That is, the indicated mask, i.e., binary (Boolean) matrix, is applied onto the matrix of RS samples of the first reference signal. An example of RSs with masks applied is shown in FIG. 8. On the masked RS samples (upon applying mask M on RSs according to the instruction), the candidate anchor UE measures or calculates MCI for each mask M(i).

[0136] For example, a given anchor candidate UE may sample a first reference signal and arrange the samples in a matrix Mrs, where Mrs(f,t,s,r) denotes the RS sample at time t, subcarrier f, transmit beam s, and receive beam r. For a given mask "i", the candidate anchor UE may compute the masked RS matrix Mmrs=Mrs×M(i) and use Mmrs to extract MCI(i).

[0137] In block 506, if the evaluation yields a positive result (i.e., if the given anchor UE is determined to support the SL positioning session for the target UE), the candidate anchor UE applies the reference signal configuration to its response message.

[0138] In block 507, (if the evaluation yields a positive result), one or more candidate anchor UEs respond to the target UE by transmitting a second reference signal (e.g., DMRS) according to the first mask channel information and the reference signal configuration received from the target UE. For example, a given anchor candidate UE may respond to the request by transmitting an anchor discovery response message (denoted as Msg-B) to the target UE (e.g., in a unicast manner), where Msg-B may include the first MCI and the second reference signal. Alternatively, the first MCI and the second reference signal may be transmitted separately rather than in a single message.

[0139] In block 508, the target UE performs anchor UE selection, for example, based on the received Msg-B. In other words, the target UE can select at least one anchor UE from one or more candidate anchor UEs to support its SL positioning session.

[0140] In block 509, the target UE determines or selects a first sidelink positioning reference signal positioning for the specific SL PRS transmission based at least in part on the first mask channel information (e.g., RSRP, RSSI, CFR and / or CIR, etc.) received from the selected at least one anchor UE.

[0141] In block 510, the target UE applies a second set of masks to a second reference signal received from the selected at least one anchor UE, and measures second mask channel information for each mask in the second set of masks from the second reference signal to which the second set of masks has been applied.

[0142] The second mask channel information may include at least one of a reference signal received power (RSRP), a received signal strength indicator (RSSI), a channel frequency response (CFR), or a channel impulse response (CIR) measured from a second reference signal to which the second set of masks has been applied.

[0143] A given mask of the second set of masks may comprise a binary (Boolean) matrix that, when applied to the matrix of the second reference signal (RS sample matrix), mutes one or more entries (i.e., some entries) of the matrix of the second reference signal. The binary matrix (mask) may be a two-dimensional matrix or a multidimensional matrix. That is, the binary matrix (mask) may have two or more dimensions.

[0144] In block 511, the target UE determines or selects a second sidelink positioning reference signal configuration for the anchor UE's SL PRS transmission based at least in part on second masked channel information (e.g., RSRP, RSSI, CFR and / or CIR, etc.) measured by the target UE.

[0145] In block 512, the target UE transmits a first sidelink positioning reference signal to at least one selected anchor UE based on the first sidelink positioning reference signal configuration. In other words, the target UE applies the first SL PRS configuration to its own SL PRS transmissions. The at least one selected anchor UE receives and measures the first sidelink positioning reference signal to support the target UE's SL positioning session.

[0146] In block 513, the target UE transmits the second sidelink positioning reference signal configuration to the selected at least one anchor UE, and the selected at least one anchor UE can use the second SL PRS configuration for its SL PRS transmissions.

[0147] In block 514, the selected at least one anchor UE transmits a second sidelink positioning reference signal to the target UE based on the second sidelink positioning reference signal configuration received from the target UE. The target UE receives and measures the second sidelink positioning reference signal from the selected at least one anchor UE for the target UE's SL positioning session.

[0148] Here, the terms "first sidelink positioning reference signal" and "second sidelink positioning reference signal" are used to distinguish between sidelink positioning reference signals and do not necessarily imply a particular order of sidelink positioning reference signals. Similarly, the terms "first sidelink positioning reference signal configuration" and "second sidelink positioning reference signal configuration" are used to distinguish between SL PRS configurations and do not necessarily imply a particular order of determining the SL PRS configurations.

[0149] 6 shows a flowchart of an exemplary embodiment of a method performed by an apparatus such as, comprising, or consisting of a user device. The user device may also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, user equipment (UE), target UE, or target user device. The user device may correspond to one of the user devices 100, 102 of FIG. 1 or the target UE 200 of FIG. 2.

[0150] 6, in block 601, a message including a first reference signal and a first set of masks is transmitted to one or more user devices. The one or more user devices may comprise one or more anchor UEs or one or more candidate anchor UEs.

[0151] In block 602, at least one of first mask channel information for each mask of a first set of masks or a preferred sidelink positioning reference signal configuration based on the first mask channel information is received from one or more user devices.

[0152] In block 603, a first sidelink positioning reference signal configuration is determined based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration.

[0153] 7 shows a flowchart of an exemplary embodiment of a method performed by, provided by, or configured in an apparatus such as a user device. The user equipment may also be referred to as a subscriber unit, a mobile station, a remote terminal, an access terminal, a user terminal, a terminal device, user equipment (UE), an anchor UE, a candidate anchor UE, a target UE, or a target user device. The user device may correspond to one of the user devices 100, 102 of FIG. 1, the target UE 200 of FIG. 2, or one of the anchor UEs 201, 202 of FIG. 2.

[0154] 7, a first set of masks is applied to a first reference signal in block 701. Here, applying the first set of masks to the first reference signal may mean combining the first reference signal with a predetermined mask of the first set of masks.

[0155] In block 702, first mask channel information is measured for each mask in the first set of masks from a first reference signal applied with the first set of masks.

[0156] In block 703, at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information is transmitted to a user device (e.g., to a target UE or an anchor UE).

[0157] The blocks, associated functions, and information exchanges (messages) described above with reference to Figures 3-7 are not in absolute chronological order; some of them may be performed simultaneously or in a different order than described. Other functions may also be performed between or within them, other information may be transmitted, and / or other rules may apply. Some of the blocks or portions of blocks or one or more pieces of information may also be omitted or replaced by a corresponding block or portion of a block or one or more pieces of information.

[0158] As used herein, "at least one of: " and "at least one of " and similar expressions (where a list of two or more elements is joined by "and" or "or") mean at least one of the elements, or at least two or more of the elements, or at least all of the elements.

[0159] Figure 8 shows examples of RS patterns of an SL signal to which a mask can be applied to obtain masked RS samples that emulate different configurations of SL PRS. In Figure 8, a given black box 801 represents a resource element (RE) that carries an RS.

[0160] FIG. 9 shows an example of a structure 900 of Msg-A, in which PSSCH-DMRS is used as the SL PRS, with a PSCCH duration of two symbols, four PSSCH DMRSs, and a guard period of symbol 13 ((l_"d")) in Table 1 above. In FIG. 9, the PSSCH symbol carrying the DMRS is indicated as DMRS. In Msg-A, the payload transmitted in the PSSCH symbol along with the anchor discovery request message may include, for example, at least: an RS mask configuration (set M of masks) and a measurement request for MCI using a mask in set M. MCI may refer to any combination of RSRP, RSSI, CFR, CIR, etc. In FIG. 9, AGC stands for automatic gain control, and AGC is used to adjust signal strength. The numbers 0 to 13 in FIG. 9 refer to symbols in the time domain.

[0161] Figure 10 illustrates an example of an apparatus 1000 comprising means for performing any of the methods of Figures 3 through 7 or other exemplary embodiments described above. For example, the apparatus 1000 may be an apparatus such as a user device, or an apparatus comprising or configured as a user device. The user device may correspond to one of the user devices 100, 102 of Figure 1 or one of the user devices 200, 201, 202 of Figure 2. The user equipment may be referred to as a subscriber unit, a mobile station, a remote terminal, an access terminal, a user terminal, a terminal device, user equipment (UE), an anchor UE, a candidate anchor UE, a target UE, or a target user device.

[0162] The device 1000 includes at least one processor 1010. The at least one processor 1010 interprets instructions (or computer program instructions) and processes data. The at least one processor 1010 may include one or more programmable processors. The at least one processor 1010 may include programmable hardware with embedded firmware, and alternatively or additionally may include one or more application-specific integrated circuits (ASICs).

[0163] The at least one processor 1010 is coupled to at least one memory 1020. The at least one processor is configured to read and write data from and to the at least one memory 1020. The at least one memory 1020 may include one or more memory units. The memory units may be volatile or nonvolatile. It should be noted that there may be one or more units of nonvolatile memory and one or more units of volatile memory, or alternatively, one or more units of nonvolatile memory, or alternatively, one or more units of volatile memory. The volatile memory may be, for example, random access memory (RAM), dynamic random access memory (DRAM), or synchronous dynamic random access memory (SDRAM). The nonvolatile memory may be, for example, read-only memory (ROM), programmable read-only memory (PROM), electronically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. Generally, memory may refer to a non-transitory computer-readable medium. As used herein, the term "non-transitory" refers to a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation of the permanence of data storage (e.g., RAM vs. ROM). The at least one memory 1020 stores computer-readable instructions that are executed by the at least one processor 1010 to implement one or more of the exemplary embodiments described above. For example, a non-volatile memory stores the computer-readable instructions, and the at least one processor 1010 executes the instructions using a volatile memory for temporary storage of data and / or instructions. Computer-readable instructions may refer to computer program code.

[0164] The computer-readable instructions may be pre-stored in at least one memory 1020, or alternatively or additionally, the computer-readable instructions may be received by the device via an electromagnetic carrier signal and / or may be reproduced from a physical entity such as a computer program product. Execution of the computer-readable instructions by the at least one processor 1010 causes the device 1000 to perform one or more of the exemplary embodiments described above. That is, the at least one processor and at least one memory storing instructions may provide a means for providing or causing the performance of any of the methods and / or blocks described above.

[0165] In the context of this document, "memory" or "computer-readable medium" or "computer-readable mediums" can be any one or more non-transitory media or means capable of containing, storing, transmitting, propagating or transferring instructions used by or in connection with an instruction execution system, apparatus, or device such as a computer. As used herein, the term "non-transitory" is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation of the permanence of data storage (e.g., RAM vs. ROM).

[0166] The device 1000 may further include or be connected to an input unit 1030. The input unit 1030 may include one or more interfaces for receiving input. The one or more interfaces may include, for example, one or more temperature, motion, and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons, and / or one or more touch detection units. Furthermore, the input unit 1030 may include interfaces to which external devices may be connected.

[0167] The device 1000 may also include an output unit 1040. The output unit may include or be connected to one or more displays capable of rendering visual content, such as a light-emitting diode (LED) display, a liquid crystal display (LCD) and / or a liquid crystal on silicon (LCoS) display. The output unit 1040 may further include one or more audio outputs. The one or more audio outputs may be, for example, loudspeakers.

[0168] The device 1000 further includes a connection unit 1050. The connection unit 1050 enables wireless connection with one or more external devices. The connection unit 1050 includes at least one transmitter and at least one receiver, which may be integrated into the device 1000 or connected to the device 1000. The at least one transmitter includes at least one transmitting antenna, and the at least one receiver includes at least one receiving antenna. The connection unit 1050 may include an integrated circuit or a set of integrated circuits that provide wireless communication functionality for the device 1000. Alternatively, the wireless connection may be a hardwired application-specific integrated circuit (ASIC). The connection unit 1050 may also provide means for implementing at least some of the blocks for one or more exemplary embodiments described above. The connection unit 1050 may include one or more components, such as a power amplifier, a digital front end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a (de)modulator, and / or an encoder / decoder circuit, controlled by a corresponding control unit.

[0169] It should be noted that the device 1000 may further include various components not shown in Figure 10. The various components may be hardware and / or software components.

[0170] The term "circuit" as used in this application may refer to one or more or all of the following: a) hardware-only circuit implementations (e.g., analog and / or digital-only circuit implementations); b) combinations of hardware circuitry and software (where applicable), such as i) combinations of analog and / or digital hardware circuitry with software / firmware, and ii) any portion of a hardware processor with software (including digital signal processors, software, and memory that work together to cause a device such as a mobile phone to perform various functions); and c) hardware circuits and / or processors, such as microprocessors or portions of microprocessors, that require software (e.g., firmware) to operate; However, software does not have to be present when it is not required for operation.

[0171] This definition of circuit applies to all uses of the term in this application, including any claims. As a further example, the term circuit as used in this application covers merely a hardware circuit or processor (or processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware implementations. The term circuit also covers, for example, and where applicable to certain claim elements, a baseband or processor integrated circuit in a mobile device or similar integrated circuit in a server, cellular network device, or other computing or network device.

[0172] The techniques and methods described herein may be implemented by various means. For example, these techniques may be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. In a hardware implementation, an apparatus of an exemplary embodiment may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. In firmware or software, the implementation may be via modules (e.g., procedures, functions, etc.) of at least one chipset that performs the functions described herein. Software code may be stored in a memory unit and executed by a processor. The memory unit may be implemented within the processor or external to the processor. In the latter case, the memory unit may be communicatively coupled to the processor via various means, as is well known in the art. Additionally, the components of the systems described herein may be reconfigured and / or completed with additional components to facilitate, for example, the accomplishment of the various aspects described therewith, and are not limited to the configurations depicted in the given drawings, as will be understood by those skilled in the art.

[0173] It will be obvious to those skilled in the art that as technology advances, the concept of the present invention can be implemented in various ways. The embodiments are not limited to the exemplary embodiments described above, but can be varied within the scope of the claims. Therefore, all terms and expressions should be interpreted broadly, and they are intended to illustrate exemplary embodiments, not to limit them. [Explanation of symbols]

[0174] 301 SL positioning triggered 302 Determine the mask set 303 Signals including a set of reference signals and masks 304 Apply a set of masks to the reference signal and measure MCI 306 Select another UE Determine SL PRS configuration based on 307 MCI

Claims

1. 1. An apparatus comprising at least one processor and at least one memory that stores instructions, The instructions, when executed by the at least one processor, transmitting a message including a first reference signal and a first set of masks to one or more user devices; receiving from the one or more user devices at least one of first mask channel information for each mask of the first set of masks or a preferred sidelink positioning reference signal configuration based on the first mask channel information; determining a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration; The apparatus causes the apparatus to perform at least the following.

2. 2. The apparatus of claim 1, further comprising: determining the first set of masks that, when applied to the first reference signal, emulate sidelink positioning reference signals having a plurality of different configurations.

3. a mask of the first set of masks comprising a binary matrix that, when applied to a matrix of the first reference signal, mutes one or more entries of the matrix of the first reference signal; 3. The device according to claim 1 or 2.

4. The apparatus of claim 3 , wherein the mask is defined by a combination of at least a comb shape in the time domain, a comb shape in the frequency domain, and a comb shape in the spatial domain.

5. The apparatus of any of claims 1 to 4, further causing the one or more user devices to send a request to measure the first mask channel information using the first set of masks.

6. 6. The apparatus of claim 1, wherein the first mask channel information comprises at least one of a reference signal received power, a received signal strength indicator, a channel frequency response, or a channel impulse response measured from the first reference signal applied using the first set of masks.

7. 7. The apparatus of claim 1, wherein the first sidelink positioning reference signal configuration is determined based at least in part on a mapping between the first mask channel information and one or more sidelink positioning reference signal parameter settings.

8. 8. The apparatus of claim 1, further configured to transmit the first sidelink positioning reference signal based on the first sidelink positioning reference signal configuration.

9. transmitting a configuration for a second reference signal to the one or more user devices; receiving the second reference signal from the one or more user devices; applying a second set of masks to the second reference signal; measuring second mask channel information for each mask of the second set of masks from the second reference signal to which the second set of masks has been applied; determining a second sidelink positioning reference signal configuration based at least in part on the second mask channel information; and transmitting the second sidelink positioning reference signal configuration to the one or more user devices; receiving, from the one or more user devices, a second sidelink positioning reference signal based on the second sidelink positioning reference signal configuration; The apparatus according to any one of claims 1 to 3, further comprising:

10. 1. An apparatus comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, applying a first set of masks to a first reference signal; measuring first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; transmitting, to a user device, at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information; The apparatus causes the apparatus to perform at least the following.

11. 11. The apparatus of claim 10, wherein the masks of the first set of masks comprise binary matrices, and wherein applying the first set of masks to the first reference signal comprises applying a binary matrix for each mask to a matrix of the first reference signal.

12. receiving a message from the user device, the message including the first reference signal and the first set of masks; receiving, from the user device, the first sidelink positioning reference signal based on the first mask channel information or the first sidelink positioning reference signal configuration; The apparatus according to any one of claims 10 to 11, further comprising:

13. receiving a configuration for a second reference signal from the user device; transmitting the second reference signal to the user device based on the configuration; receiving a second sidelink positioning reference signal configuration from the user device; transmitting, to the user device, a second sidelink positioning reference signal based on the second sidelink positioning reference signal configuration; The apparatus according to any one of claims 10 to 12, further comprising:

14. transmitting a configuration for the first reference signal to the user device; receiving the first reference signal from the user device; determining the first sidelink positioning reference signal configuration based at least in part on the first mask channel information measured for each mask of the first set of masks; The apparatus according to any one of claims 10 to 11, further comprising:

15. 1. A method comprising: transmitting a message including a first reference signal and a first set of masks to one or more user devices; receiving, from the one or more user devices, first mask channel information for each mask of the first set of masks or at least one of a preferred sidelink positioning reference signal configuration based on the first mask channel information; determining a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration; A method comprising:

16. 1. A method comprising: applying a first set of masks to a first reference signal; measuring first mask channel information for each mask of the first set of masks from the first reference signal to which the first set of masks has been applied; transmitting, to a user device, at least one of the first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information; A method comprising:

17. A non-transitory computer-readable medium containing program instructions that, when executed by a device, transmitting a message including a first reference signal and a first set of masks to one or more user devices; receiving, from the one or more user devices, at least one of first mask channel information for each mask of a first set of masks or a preferred sidelink positioning reference signal configuration based on the first mask channel information; determining a first sidelink positioning reference signal configuration based at least in part on the first mask channel information or the preferred sidelink positioning reference signal configuration; a non-transitory computer-readable medium that causes the device to perform at least the steps of:

18. A non-transitory computer-readable medium containing program instructions that, when executed by a device, applying a first set of masks to a first reference signal; measuring first mask channel information for each mask of the first set of masks from a first reference signal to which the first set of masks has been applied; transmitting, to a user device, at least one of first mask channel information or a first sidelink positioning reference signal configuration based on the first mask channel information; a non-transitory computer-readable medium that causes the device to perform at least the steps of:

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