Backscatter-based localization

Abstract

This disclosure provides systems, methods, and devices for wireless communication supporting backscatter-based positioning. In a first aspect, a method of wireless communication includes transmitting a tag configuration message indicating a first tag configuration and a second tag configuration. The method also includes transmitting a positioning reference signal (PRS). The method also includes receiving a first backscatter signal based on the PRS from a first tag device, and receiving a second backscatter signal based on the PRS from a second tag device. The method includes sending a measurement report indicating a first round trip time (RTT) of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Patent Application No. 18 / 073,496, entitled "BACKSCATTER - BASED POSITIONING", filed on December 1, 2022, which is hereby incorporated by reference in its entirety. Technical Field

[0003] Aspects of the present disclosure generally relate to wireless communication systems, and more particularly, to backscatter - based positioning. Some features can enable and provide improved communication, including reduced control overhead, efficient resource utilization, improved network access, improved ranging measurements, position determination, TRP selection, reduced interference, or combinations thereof. Background Art

[0004] Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcasting, etc. These wireless networks can be multi - access networks capable of supporting multiple users by sharing available network resources. Such networks can be multi - access networks that support communication for multiple users by sharing available network resources.

[0005] A wireless communication network may include some components. These components may include wireless communication devices, such as a base station (or Node B) that can support the communication of several user equipments (UEs). The UEs can communicate with the base station via the downlink and the uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

[0006] The base station can send data and control information to the UE on the downlink, or receive data and control information from the UE on the uplink. On the downlink, the transmission from the base station may encounter interference caused by transmissions from neighboring base stations or other radio frequency (RF) transmitters. On the uplink, the transmission from the UE may encounter interference from other UEs communicating with neighboring base stations or from uplink transmissions of other wireless RF transmitters. Such interference may degrade the performance on both the downlink and the uplink.

[0007] Due to the continuous growth of the demand for mobile broadband access, with more UEs accessing remote wireless communication networks and more short - range wireless systems deployed in the community, the likelihood of interference and congested networks is also growing. Research and development continue to advance wireless technologies to not only meet the growing demand for mobile broadband access, but also enhance and improve the user experience of mobile communication.

[0008] Radio Frequency Identification (RFID) systems and devices typically include a reader device, referred to as a reader, and one or more tag devices, such as RFID tag devices. Tag devices typically include a wireless microchip for tagging an object for automatic identification. However, the use of tag devices has not been applied to current 3GPP technologies and Internet of Things (IoT) implementations, which may include identification, monitoring, positioning, and tracking (as illustrative non-limiting examples). Additionally, the individual capacities and components of tag devices can vary. Accordingly, the use of tag devices for current 3GPP technologies (such as coexistence with User Equipment (UE)) and the infrastructure for current 3GPP technology bands have not been established. Given the low power and limited processing capabilities of different types of tag devices, the integration of tag devices with 3GPP technologies presents various complex technical challenges, such as limiting network congestion, overhead, and interference associated with the use of tag devices with 3GPP technologies. SUMMARY

[0009] Some aspects of the present disclosure are summarized below to provide a basic understanding of the technologies discussed. This Summary is not an exhaustive overview of all contemplated features of the present disclosure, and is neither intended to identify key or critical elements of all aspects of the present disclosure nor to delineate the scope of any or all aspects of the present disclosure. The sole purpose of this Summary is to present some concepts of one or more aspects of the present disclosure in a generalized form as a prelude to the more detailed description that is presented later.

[0010] In one aspect of the present disclosure, a method for wireless communication is performed by a network entity. The method includes transmitting a tag configuration message indicating a first tag configuration and a second tag configuration. The method further includes transmitting a positioning reference signal (PRS). The method further includes receiving a first backscatter signal based on the PRS from a first tag device and receiving a second backscatter signal based on the PRS from a second tag device. The method includes transmitting a measurement report indicating a first round-trip time (RTT) of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal.

[0011] In an additional aspect of the present disclosure, an apparatus includes at least one processor and a memory coupled to the at least one processor. The at least one processor is configured to send a tag configuration message indicating a first tag configuration and a second tag configuration. The at least one processor is further configured to send a PRS. The at least one processor is further configured to receive a first backscatter signal based on the PRS from a first tag device and a second backscatter signal based on the PRS from a second tag device. The at least one processor is configured to send a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal.

[0012] In an additional aspect of the present disclosure, an apparatus includes a communication interface configured to send a tag configuration message indicating a first tag configuration and a second tag configuration. The communication interface is further configured to send a PRS. The communication interface is further configured to receive a first backscatter signal based on the PRS from a first tag device and a second backscatter signal based on the PRS from a second tag device. The apparatus further includes at least one processor coupled to a memory storing processor-readable code, the at least one processor being configured to execute the processor-readable code to cause the at least one processor to generate a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal.

[0013] In an additional aspect of the present disclosure, an apparatus includes means for sending a tag configuration message indicating a first tag configuration and a second tag configuration. The apparatus further includes means for sending a PRS. The apparatus further includes means for receiving a first backscatter signal based on the PRS from a first tag device and means for receiving a second backscatter signal based on the PRS from a second tag device. The apparatus includes means for sending a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal.

[0014] In an additional aspect of the present disclosure, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations. The operations include sending a tag configuration message indicating a first tag configuration and a second tag configuration. The operations also include sending a PRS. The operations further include receiving a first backscatter signal based on the PRS from a first tag device and receiving a second backscatter signal based on the PRS from a second tag device. The operations include sending a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal.

[0015] In an additional aspect of the present disclosure, a method for wireless communication is performed by a network entity. The method includes sending a transmit / receive point (TRP) configuration indicating first information associated with a first tag device and second information associated with a second tag device. The first information indicates a first location of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. The second information indicates a second location of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof. The method further includes receiving, from the TRP, a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first information and the first backscatter signal, and the second RTT is based on the second information and the second backscatter signal.

[0016] In an additional aspect of the present disclosure, an apparatus includes at least one processor and a memory coupled to the at least one processor. The at least one processor is configured to send a TRP configuration indicating first information associated with a first tag device and second information associated with a second tag device. The first information indicates a first location of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. The second information indicates a second location of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof. The at least one processor is further configured to receive, from the TRP, a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first information and the first backscatter signal, and the second RTT is based on the second information and the second backscatter signal.

[0017] In an additional aspect of the present disclosure, an apparatus includes at least one processor coupled to a memory storing processor-readable code. The at least one processor is configured to execute the processor-readable code to cause the at least one processor to generate a TRP configuration indicating first information associated with a first tag device and second information associated with a second tag device. The first information indicates a first positioning of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. The second information indicates a second positioning of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof. The apparatus further includes a communication interface configured to send the TRP configuration and receive, from the TRP, a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first information and a first backscatter signal, and the second RTT is based on the second information and a second backscatter signal.

[0018] In an additional aspect of the present disclosure, an apparatus includes means for sending a TRP configuration indicating first information associated with a first tag device and second information associated with a second tag device. The first information indicates a first positioning of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. The second information indicates a second positioning of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof. The apparatus further includes means for receiving, from the TRP, a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first information and a first backscatter signal, and the second RTT is based on the second information and a second backscatter signal.

[0019] In an additional aspect of the present disclosure, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations. The operations include sending a TRP configuration indicating first information associated with a first tag device and second information associated with a second tag device. The first information indicates a first positioning of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. The second information indicates a second positioning of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof. The operations further include receiving, from the TRP, a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first information and a first backscatter signal, and the second RTT is based on the second information and a second backscatter signal.

[0020] In an additional aspect of the present disclosure, a method for wireless communication is performed by a tag device. The method includes receiving a tag configuration message indicating a plurality of tag configurations and receiving a PRS. The method further includes transmitting a backscatter signal based on the PRS and a first tag configuration among the plurality of tag configurations. The first tag configuration indicates a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0021] In an additional aspect of the present disclosure, an apparatus includes at least one processor and a memory coupled to the at least one processor. The at least one processor is configured to receive a tag configuration message indicating a plurality of tag configurations and receive a PRS. The at least one processor is further configured to transmit a backscatter signal based on the PRS and a first tag configuration among the plurality of tag configurations. The first tag configuration indicates a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0022] In an additional aspect of the present disclosure, an apparatus includes at least one processor coupled to a memory storing processor-readable code. The at least one processor is configured to execute the processor-readable code to cause the at least one processor to identify a first tag configuration among the plurality of tag configurations indicated by a tag configuration message. The apparatus further includes a communication interface configured to receive a PRS and transmit a backscatter signal based on the PRS and the first tag configuration. The first tag configuration indicates a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0023] In an additional aspect of the present disclosure, an apparatus includes means for receiving a tag configuration message indicating a plurality of tag configurations and means for receiving a PRS. The apparatus further includes means for transmitting a backscatter signal based on the PRS and a first tag configuration among the plurality of tag configurations. The first tag configuration indicates a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0024] In an additional aspect of the present disclosure, a non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to perform operations. The operations include receiving a tag configuration message indicating a plurality of tag configurations and receiving a PRS. The operations further include transmitting a backscatter signal based on the PRS and a first tag configuration among the plurality of tag configurations. The first tag configuration indicates a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0025] The features and technical advantages of examples in accordance with the present disclosure have been outlined above rather extensively in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein (both as to their organization and method of operation) as well as associated advantages will be better understood when considered in conjunction with the accompanying drawings. Each of the drawings provided in the figures is for purposes of illustration and description and not as a definition of the limits of the claims.

[0026] While aspects and specific implementations are described herein by way of illustration of some examples, those skilled in the art will appreciate that additional specific implementations and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, packaging arrangements. For example, aspects and / or uses can be implemented via integrated chips and other non-module-component-based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchase devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). Although some examples may or may not be specifically directed to a use case or application, a wide variety of applicability of the innovations described may arise. The scope of specific implementations can range from chip-level or modular components to non-modular, non-chip-level implementations and further to the scope of aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the innovations described. In some practical environments, devices incorporating the aspects and features described may also necessarily include additional components and features for implementing and practicing the aspects claimed and described. For example, the transmission and reception of wireless signals necessarily includes multiple components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The innovations described herein are intended to be practiced in a variety of devices, chip-level components, systems, distributed arrangements, end-user devices, etc. having different sizes, shapes, and configurations. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] A further understanding of the nature and advantages of the present disclosure can be realized by reference to the following drawings. In the drawings, like components or features may have the same reference numeral. Additionally, various components of the same type can be distinguished by following the reference numeral with a dash and a second numeral used to differentiate between like components. If only the first reference numeral is used in the specification, the description applies to any one of the like components having the same first reference numeral regardless of the second reference numeral.

[0028] Figure 1 is a block diagram illustrating details of an example wireless communication system in accordance with one or more aspects.

[0029] Figure 2 is a block diagram illustrating examples of a base station and a user equipment (UE) in accordance with one or more aspects.

[0030] Figure 3 is a block diagram illustrating an example wireless communication system supporting backscatter-based positioning in accordance with one or more aspects.

[0031] Figure 4 is a ladder diagram illustrating an example supporting backscatter-based positioning in accordance with one or more aspects.

[0032] Figure 5 is a conceptual timing diagram illustrating another example of a system supporting backscatter-based positioning in accordance with one or more aspects.

[0033] Figure 6 is a block diagram illustrating another example of a system supporting backscatter-based positioning in accordance with one or more aspects.

[0034] Figure 7 is a timing diagram illustrating another example of a system supporting backscatter-based positioning in accordance with one or more aspects.

[0035] Figure 8 is a timing diagram illustrating another example of a system supporting backscatter-based positioning in accordance with one or more aspects.

[0036] Figure 9 is a flowchart illustrating an example process supporting backscatter-based positioning in accordance with one or more aspects.

[0037] Figure 10 is a flowchart illustrating an example process supporting backscatter-based positioning in accordance with one or more aspects.

[0038] Figure 11 is a block diagram of an example network entity supporting backscatter-based positioning in accordance with one or more aspects.

[0039] Figure 12 is a flowchart illustrating an example process supporting backscatter-based positioning in accordance with one or more aspects.

[0040] Figure 13 is a block diagram of an example tag device supporting backscatter-based positioning in accordance with one or more aspects.

[0041] Like reference numerals and names in different figures indicate like elements. Detailed implementation manners

[0042] The detailed implementation manners described below in conjunction with the accompanying drawings are intended as a description of various configurations and are not intended to limit the scope of the present disclosure. On the contrary, the detailed implementation manners include specific details for providing a thorough understanding of the subject matter of the present invention. It will be apparent to those skilled in the art that these specific details are not required in every case, and in some instances, well-known structures and components are shown in block diagram form for the sake of clarity of presentation.

[0043] The present disclosure provides systems, devices, methods, and computer-readable media that support backscatter-based. For example, the present disclosure describes positioning a tag device, such as a passive Internet of Things (IoT) device or, via backscatter transmission. The location management function (LMF) of the core network may be configured to determine the positioning of the tag device, such as two-dimensional positioning or three-dimensional positioning, based on one or more measurement reports received from one or more transmit / receive points (TRPs). By way of illustration, the LMF may identify a tag device for positioning, such as a passive tag device or a semi-passive tag device, and configure multiple TRPs for a tag device positioning session. For example, the LMF may configure one or more TRPs to transmit corresponding positioning reference signals (PRSs) and receive corresponding backscatter signals. In some specific implementations, each of the one or more TRPs may be configured for full-duplex operation, be asynchronous, or a combination thereof.

[0044] In some specific implementations, the LMF sends a TRP configuration to the TRP, and the TRP configuration indicates first information associated with a first tag device and second information associated with a second tag device. For example, the first information may include or indicate a first location (e.g., a first estimated location) of the first tag device, and the second information may include or indicate a second location (e.g., a second estimated location) of the second tag device. Additionally or alternatively, the first information may include or indicate a first training sequence or a first backscatter time frame window for the first tag device, and the second information may include or indicate a second training sequence or a second backscatter time frame window for the second tag device. The TRP receives the TRP configuration and generates a tag configuration message indicating a first tag configuration and a second tag configuration. For example, the first tag configuration may indicate a tag address, a frequency shift parameter, a phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. The TRP sends a PRS, and in response to the PRS, receives a first backscatter signal from the first tag device and a second backscatter signal from the second tag device. For example, the first tag device may send the first backscatter signal based on the PRS and the first tag configuration. The TRP generates and sends a measurement report to the LMF, and the measurement report indicates a first RTT of the first tag device and a second RTT of the second tag device. The first RTT is based on the first tag configuration and the first backscatter signal, and the second RTT is based on the second tag configuration and the second backscatter signal. The LMF may determine the location of the first tag device or the second tag device based on the measurement report.

[0045] Specific embodiments of the subject matter described in this disclosure may be implemented to achieve one or more of the following potential advantages or benefits. In some aspects, this disclosure provides techniques for supporting backscatter-based positioning. The described techniques facilitate determining the location of tag devices (such as passive tag devices or semi-passive tag devices) with limited on-board power and computational resources, such as two-dimensional or three-dimensional positioning.

[0046] Specifically, the present disclosure facilitates determining the location of one or more tag devices subject to the computational and power constraints of passive and semi-passive tag devices, such as two-dimensional or three-dimensional positioning. For example, by providing tag configuration messages indicating a first tag configuration and a second tag configuration, the TRP configures each of the plurality of tag devices such that in response to a PRS transmitted by the TRP, the tag device generates and transmits a backscatter signal having a pattern (such as a preamble sequence, a training sequence, a backscatter time frame window, or a combination thereof) to distinguish the backscatter signals received from the plurality of tag devices at the TRP. Additionally, the TRP can be configured to apply different techniques based on the distance of the tag device from the TRP to distinguish the backscatter signals received from the plurality of tag devices. For example, if a group of tag devices is approximately equidistant from the TRP, the TRP may receive backscatter signals from these tag devices approximately simultaneously. Thus, the TRP can distinguish the received backscatter signals by configuring the tag devices to include in the backscatter signal a training sequence pattern unique to each tag device. Alternatively, if one or more of the tag devices in a group of tag devices are at different distances from the TRP, the TRP can configure these tag devices to provide backscatter signals on different backscatter time frame windows. For example, the TRP can configure a first tag device that is at a greater distance from the TRP compared to a second tag device to transmit a backscatter signal on a longer backscatter time frame window than the second tag device that is closer to the TRP to account for the possible attenuation of the backscatter signal due to the greater distance. Additionally or alternatively, the disclosed techniques can handle backscatter signals from tag devices in a first group where the tag devices are within a target range to the TRP and a second group where the distance of each tag device to the TRP can be different. Thus, in this manner, these techniques facilitate the TRP in determining the RTT to and from the plurality of tag devices, thereby facilitating determining the location of the plurality of tag devices.

[0047] The present disclosure generally relates to providing or participating in authorized shared access between two or more wireless devices in one or more wireless communication systems (also referred to as wireless communication networks). In various embodiments, the techniques and apparatus can be used in wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, fifth-generation (5G) or new radio (NR) networks (sometimes referred to as "5G NR" networks, systems, or devices), and other communication networks. As described herein, the terms "network" and "system" can be used interchangeably.

[0048] A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (W-CDMA) and Low Chip Rate (LCR). Cdma2000 covers the IS-2000, IS-95, and IS-856 standards.

[0049] For example, a TDMA network can implement radio technologies such as the Global System for Mobile Communications (GSM). The 3rd Generation Partnership Project (3GPP) defines the standards for the GSM EDGE (Enhanced Data Rates for GSM Evolution) Radio Access Network (RAN) (also known as GERAN). GERAN is the radio component of the network that consists of GSM / EDGE together with the networks connecting the base stations (such as the Ater and Abis interfaces) and the base station controller (the A interface, etc.). The radio access network represents the components of the GSM network through which telephone calls and packet data are routed from the Public Switched Telephone Network (PSTN) and the Internet to the subscriber's mobile phone (also known as the user terminal or user equipment (UE)) and from the subscriber's mobile phone to the PSTN and the Internet. The network of a mobile phone operator can include one or more GERANs, which can be coupled to the UTRAN in the case of a UMTS / GSM network. Additionally, the operator's network can also include one or more LTE networks, or one or more other networks. Various different network types can use different Radio Access Technologies (RATs) and RANs.

[0050] OFDMA networks can implement radio technologies such as evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM, etc. UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunications System (UMTS). Specifically, Long-Term Evolution (LTE) is a UMTS version that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents provided by an organization called the "3rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization called the "3rd Generation Partnership Project 2" (3GPP2). These radio technologies and standards are known or under development. For example, 3GPP is a cooperation among telecommunication society groups aimed at defining globally applicable third-generation (3G) mobile phone specifications. 3GPP LTE is a 3GPP program aimed at improving the UMTS mobile phone standard. 3GPP can define the specifications for next-generation mobile networks, mobile systems, and mobile devices. Certain aspects of this disclosure may be described with reference to LTE, 4G, or 5G NR technologies; however, this description is not intended to be limited to a specific technology or application, and one or more aspects described with reference to one technology may be understood to apply to another technology. Additionally, one or more aspects of this disclosure may relate to shared access to the radio spectrum between networks using different radio access technologies or radio air interfaces.

[0051] 5G networks are expected to have diverse deployments, diverse spectrums, and diverse services and devices that can be achieved using an OFDM-based unified air interface. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to scale to provide coverage (1) for massive Internet of Things (IoT) with ultra-high density (e.g., about 1M nodes / km 2 ), ultra-low complexity (e.g., about 10s bits per second), ultra-low power consumption (e.g., about 10+ years of battery life), and deep coverage with the ability to reach challenging locations; (2) including mission-critical control with strong security to protect sensitive personal, financial, or classified information, ultra-high reliability (e.g., about 99.9999% reliability), ultra-low latency (e.g., about 1 millisecond (ms)), and users with a wide range of mobility or lack of mobility; and (3) providing enhanced mobile broadband with enhanced coverage including extremely high capacity (e.g., about 10 Tbps / km 2 ), extremely high data rates (e.g., multi-Gbps rates, 100+ Mbps user experience rate), and deep awareness with advanced discovery and optimization.

[0052] Devices, networks, and systems can be configured to communicate via one or more portions of the electromagnetic spectrum. The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz to 7.125 GHz) and FR2 (24.25 GHz to 52.6 GHz). The frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, in various documents and articles, FR1 is typically (interchangeably) referred to as the "sub-6 GHz" band. A similar naming issue sometimes occurs for FR2, where in documents and articles, FR2 is typically (interchangeably) referred to as the "millimeter wave" (mmWave) band, although it is different from the extremely high frequency (EHF) band (30 GHz to 300 GHz) identified by the International Telecommunication Union (ITU) as the "mmWave" band.

[0053] Taking the above aspects into account, unless otherwise specifically stated, it should be understood that if used herein, terms such as "sub-6 GHz" can broadly represent frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. Additionally, unless otherwise specifically stated, it should be understood that if used herein, terms such as "mmWave" can broadly represent frequencies that can include mid-band frequencies, can be within FR2, or can be within the EHF band.

[0054] 5G NR devices, networks, and systems can be implemented to use waveform features based on optimized OFDM. These features can include a scalable parameter set and transmission time interval (TTI); a common flexible framework that effectively multiplexes services and features using dynamic, low-latency time division duplex (TDD) designs or frequency division duplex (FDD) designs; and advanced radio technologies such as massive multiple input multiple output (MIMO), robust mmWave transmission, advanced channel decoding, and device-centric mobility. The scalability of the parameter set in 5G NR and the scaling of the subcarrier spacing can efficiently address the operation of various services across different spectrums and different deployments. For example, in various outdoor and macro coverage deployments with less than 3 GHz FDD or TDD implementations, the subcarrier spacing may occur at 15 kHz, such as over bandwidths of 1 MHz, 5 MHz, 10 MHz, 20 MHz, etc. For other various outdoor and small cell coverage deployments with TDD greater than 3 GHz, the subcarrier spacing may occur at 30 kHz over an 80 MHz / 100 MHz bandwidth. For other various indoor broadband implementations, using TDD in the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur at 60 kHz over a 160 MHz bandwidth. Finally, for various deployments with transmission via mmWave components under TDD at 28 GHz, the subcarrier spacing can occur at 120 kHz over a 500 MHz bandwidth.

[0055] The scalable parameter set of 5G NR contributes to scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs allows transmissions to start at symbol boundaries. 5G NR also anticipates self-contained integrated subframe designs, where uplink or downlink scheduling information, data, and acknowledgments are in the same subframe. Self-contained integrated subframes support communication in unlicensed or contention-based shared spectrums, and the adaptive uplink or downlink can be flexibly configured on a per-cell basis to dynamically switch between the uplink and downlink to meet current traffic demands.

[0056] For clarity, certain aspects of the devices and technologies may be described below with reference to example 5G NR implementations or in a 5G-centric manner, and 5G terminology may be used as an illustrative example in parts of the description below; however, the description is not intended to be limited to 5G applications.

[0057] In addition, it should be understood that in operation, a wireless communication network adapted according to the concepts herein can operate using any combination of licensed spectrum or unlicensed spectrum depending on load and availability. Accordingly, it will be apparent to those of ordinary skill in the art that the systems, apparatuses, and methods described herein can be applied to other communication systems and applications in addition to the specific examples provided.

[0058] Although aspects and specific implementations are described by way of some examples in this application, those skilled in the art will understand that additional specific implementations and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, a specific implementation or use can be implemented via an integrated chip or other non-module-component-based device (e.g., an end-user device, a vehicle, a communication device, a computing device, an industrial device, a retail device or a purchasing device, a medical device, an AI-enabled device, etc.). Although some examples may or may not specifically refer to a use case or application, a wide variety of applicability of the described innovations can occur. The scope of specific implementations can range from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems that incorporate one or more of the described aspects. In some practical environments, a device incorporating the described aspects and features may also necessarily include additional components and features for implementing and practicing the claimed and described aspects. It is intended that the innovations described herein can be implemented in a wide variety of specific implementations of different sizes, shapes, and configurations, including both large and small devices, chip-level components, multi-component systems (e.g., radio frequency (RF) chains, communication interfaces, processors), distributed arrangements, end-user devices, etc.

[0059] Figure 1 is a block diagram illustrating details of an example wireless communication system according to one or more aspects. The wireless communication system can include a wireless network 100. The wireless network 100 can include, for example, a 5G wireless network. As recognized by those skilled in the art, Figure 1 the components that appear in are likely to have related corresponding components in other network arrangements, including, for example, cellular-style network arrangements and non-cellular-style network arrangements (e.g., device-to-device or peer-to-peer or ad-hoc network arrangements, etc.).

[0060] Figure 1The illustrated wireless network 100 includes a number of base stations 105 and other network entities. A base station can be a station that communicates with a UE and can also be referred to as an evolved Node B (eNB), a next-generation eNB (gNB), an access point, etc. Each base station 105 can provide communication coverage for a specific geographical area. In 3GPP, the term "cell" can refer to the specific geographical coverage area of a base station or the base station subsystem serving that coverage area, depending on the context in which the term is used. In a particular implementation of the wireless network 100 herein, the base stations 105 can be associated with the same operator or different operators (e.g., the wireless network 100 can include multiple operator wireless networks). Additionally, in a particular implementation of the wireless network 100 herein, the base stations 105 can use one or more frequencies in the same frequency as an adjacent cell (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) to provide wireless communication. In some examples, a separate base station 105 or UE 115 can be operated by more than one network operation entity. In some other examples, each base station 105 and UE 115 can be operated by a single network operation entity.

[0061] A base station can provide communication coverage for a macro cell or a small cell (such as a pico cell or a femto cell) or other types of cells. A macro cell generally covers a relatively large geographical area (e.g., with a radius of several kilometers) and can allow unrestricted access by UEs having a service subscription with the network provider. A small cell (such as a pico cell) generally covers a relatively small geographical area and can allow unrestricted access by UEs having a service subscription with the network provider. A small cell (such as a femto cell) generally also covers a relatively small geographical area (e.g., a home) and can provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.) in addition to unrestricted access. A base station for a macro cell can be referred to as a macro base station. A base station for a small cell can be referred to as a small cell base station, a pico base station, a femto base station, or a home base station. In Figure 1 the example shown, base stations 105d and 105e are conventional macro base stations, while base stations 105a to 105c are macro base stations implemented using one of 3-dimensional (3D), full-dimensional (FD), or massive MIMO. Base stations 105a to 105c utilize their higher-dimensional MIMO capabilities to employ 3D beamforming in elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station, which can be a home node or a portable access point. A base station can support one or more (e.g., two, three, four, etc.) cells.

[0062] Wireless network 100 may support synchronous or asynchronous operations. For synchronous operations, base stations may have similar frame timings, and transmissions from different base stations may be approximately aligned in time. For asynchronous operations, base stations may have different frame timings, and transmissions from different base stations may not be aligned in time. In some cases, the network may be enabled or configured to handle dynamic switching between synchronous and asynchronous operations.

[0063] UEs 115 are scattered throughout wireless network 100, and each UE can be stationary or mobile. It should be understood that although in the standards and specifications promulgated by 3GPP, mobile devices are typically referred to as UEs, such devices may additionally or otherwise be referred to by those skilled in the art as mobile stations (MSs), subscriber stations, mobile units, subscriber units, radio units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals (ATs), mobile terminals, wireless terminals, remote terminals, cell phones, terminals, user agents, mobile clients, clients, gaming devices, augmented reality devices, vehicle components, vehicle devices, or vehicle modules, or some other suitable term. In this document, a "mobile" device or UE does not necessarily have the ability to move and can be stationary. Some non-limiting examples of mobile devices may include specific implementations such as one or more UEs 115, including mobile phones, cellular phones, smartphones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, laptop computers, personal computers (PCs), notebooks, netbooks, smartbooks, tablets, and personal digital assistants (PDAs). Mobile devices can additionally be IoT or "Internet of Everything" (IoE) devices, such as cars or other transportation vehicles, satellite radios, global positioning system (GPS) devices, global navigation satellite system (GNSS) devices, logistics controllers, drones, multi-rotor helicopters, quad-rotor helicopters, smart energy or security devices, solar panels or solar cell arrays, city lighting, water supply, or other infrastructure; industrial automation and enterprise equipment; consumer and wearable devices, such as glasses, wearable cameras, smartwatches, health or fitness trackers, mammalian implantable devices, gesture tracking devices, medical devices, digital audio players (e.g., MP3 players), cameras, gaming consoles, etc.; and digital home or smart home devices, such as home audio, video, and multimedia devices, appliances, sensors, vending machines, smart lighting, home security systems, smart meters, etc. In one aspect, a UE can be a device that includes a universal integrated circuit card (UICC). In another aspect, a UE can be a device that does not include a UICC. In some aspects, a UE that does not include a UICC can also be referred to as an IoE device. Figure 1The illustrated specific implementations of UEs 115a through 115d are examples of mobile smart phone-type devices that access the wireless network 100. A UE can also be a machine specifically configured for connectivity communications, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc. Figure 1 The illustrated UEs 115e through 115k are examples of various machines that access the wireless network 100 and are configured for communication.

[0064] A mobile device such as UE 115 may be capable of communicating with any type of base station, whether it is a macro base station, a pico base station, a femto base station, a relay station, etc. In Figure 1 it, the communication link (represented as lightning) indicates a wireless transmission between the UE and the serving base station (which is the base station designated to serve the UE on the downlink or uplink), a desired transmission between base stations, and a backhaul transmission between base stations. The UE can operate as a base station or other network node in some scenarios. The backhaul communication between the base stations of the wireless network 100 can be carried out using wired or wireless communication links.

[0065] In operation, at the wireless network 100, base stations 105a through 105c use 3D beamforming and cooperative spatial techniques such as coordinated multipoint (CoMP) or multi-connectivity to serve UEs 115a and 115b. Macro base station 105d performs backhaul communication with base stations 105a through 105c and the small cell (base station 105f). Macro base station 105d also transmits multicast services subscribed to and received by UEs 115c and 115d. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or Gray alerts.

[0066] The specifically implemented wireless network 100 supports mission-critical communications with ultra-reliable and redundant links for mission-critical devices such as this UE 115e acting as a drone. The redundant communication links with the UE 115e include links from macro base stations 105d and 105e and small cell base station 105f. Other machine type devices such as UE 115f (thermometer), UE 115g (smart meter), and UE 115h (wearable device) can communicate directly with base stations such as small cell base station 105f and macro base station 105e via the wireless network 100, or in a multi-hop configuration by communicating with another user equipment that relays its information to the network, such as UE 115f communicating temperature measurement information to smart meter UE 115g, which then reports it to the network via small cell base station 105f. The wireless network 100 can also provide additional network efficiency via dynamic, low-latency TDD communication or low-latency FDD communication (such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i to 115k communicating with macro base station 105e).

[0067] The base stations 105 can communicate with the core network 130 and with each other. For example, the base stations 105 can interface with the core network 130 via a backhaul link 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 can communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via the core network 130) via a backhaul link (e.g., via X2, Xn, or other interfaces).

[0068] The core network 130 can provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 can be an evolved packet core (EPC), which can include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME can manage non-access stratum (e.g., control plane) functions such as the mobility, authentication, and bearer management of UEs 115 served by base stations 105 associated with the EPC. User IP packets can be relayed through the S-GW, which itself can be connected to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to the network operator IP services. The operator IP services can include access to the Internet, intranet, IP multimedia subsystem (IMS), or packet switched (PS) streaming services.

[0069] In some specific implementations, the core network 130 includes or is coupled to a Location Management Function (LMF) 131, which is an entity in the 5G core network (5GC) that supports various functionalities such as managing the support for different location services for one or more UEs. For example, the LMF 131 may include one or more servers, such as multiple distributed servers. The base station 105 may forward location messages to the LMF 131 and may communicate with the LMF via the NR Positioning Protocol A (NRPPa). The LMF 131 is configured to control the positioning parameters of the UE 115, and the LMF 131 may provide information to the base station 105 and the UE 115 such that actions can be taken at the UE 115. In some specific implementations, the UE 115 and the base station 105 are configured to communicate with the LMF 131 via the Access and Mobility Management Function (AMF).

[0070] A tag device system generally includes a tag device 120 and a reader device 121. The tag device 120 includes a Radio Frequency Identification (RFID) device or tag, which includes a wireless microchip for tagging an object for automatic object identification. The reader device 121 (such as an RFID reader) may be configured to send electromagnetic signals to other devices (such as the tag device 120). The reader device 121 may include one or more processors and memories and is generally capable of processing data. Additionally, the reader device 121 generally includes one or more transmitters and receivers. During typical operation, the reader device 121 may be configured to send signals that can be received by the tag device 120 and is configured to receive and process signals from the tag device 120 in response to the sent signals.

[0071] Tag devices such as the tag device 120 are classified based on functionality or capabilities. For example, depending on the functionality or capabilities of the tag device 120, the tag device 120 may be classified as one of a passive tag, a semi-passive tag, and an active tag. Thus, the tag device 120 may correspond to a passive tag, a semi-passive tag, or an active tag.

[0072] Passive tags typically lack a power source, harvest energy from ambient electromagnetic signals, and have limited computing capabilities, often lacking components such as analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) for signal processing. Since passive tags generally lack signal processing capabilities, passive tags typically include simple circuits to reflect the received electromagnetic signals back into the environment in the form of backscatter transmissions. For example, a reader device 121 may transmit an electromagnetic signal, and a passive tag such as a tag device 120 may receive the electromagnetic signal and at least partially reflect the electromagnetic signal in the form of a backscattered signal. Specifically, if the tag device 120 is a passive tag, the tag device 120 may include a circuit to at least partially reflect the unabsorbed portion of the electromagnetic signal received from the surrounding environment, such as the electromagnetic signal transmitted by the reader device 121, in the form of a backscatter transmission.

[0073] Semi-passive tags typically include an on-board power source to power the on-board electronic components. Generally speaking, semi-passive tags typically have greater computing capabilities than passive tags. Additionally, semi-passive tags may have a limited on-board power source; however, semi-passive tags typically transmit signals via backscatter transmission, as explained above in the context of passive tags.

[0074] Active tags typically include an on-board power source and greater computing capabilities than passive or semi-passive tags. In addition, unlike passive and semi-passive tags that generally cannot transmit unless a reader device such as a reader device 121 is in close proximity to them, active tags are capable of transmitting regardless of the proximity of the reader device. Active tag devices typically include signal processing functions such as ADCs, DACs, etc. In addition, active tags typically include a power source and are capable of transmitting actively. Specifically, unlike passive and semi-passive tags that generate a backscattered signal by at least partially reflecting a transmission received from a reader device (e.g., reader device 121), active tags are capable of transmitting independently of signals received from another device such as a reader device 121.

[0075] Additionally, a tagging device (such as tagging device 120) typically includes a tag identifier to uniquely identify the tagging device. Thus, a tagging device (such as tagging device 120) can include its unique tag identifier in response to a transmission received from a reader device 121 at the tagging device. If tagging device 120 corresponds to a passive tag or a semi-passive tag, then tagging device 120 can be configured to at least partially reflect a transmission received from reader device 121 in the form of a backscatter signal that can be read by reader device 121. Although an active tag is capable of processing a transmission signal received from reader device 121, in some embodiments, the active tagging device can also partially reflect the received signal as a backscatter signal, or can independently transmit a signal to reader device 121 in response to a signal received from reader device 121.

[0076] A tagging device system including tagging device 120 and reader device 121 can be deployed to locate an object associated with tagging device 120. For example, tagging device 120 can be attached to an object, and reader device 121 can be configured to identify the location (e.g., two-dimensional location, three-dimensional location) of the object to which tagging device 120 is attached by using backscatter-based positioning. Thus, the tagging device system can be deployed in a wide range of applications where precise and accurate object location is achieved. As illustrative non-limiting examples, these applications can include self-checkout, medical applications such as monitoring a patient's compliance with medical instructions, and law enforcement and security applications.

[0077] Figure 2 is a block diagram illustrating examples of a base station 105 and a UE 115 in accordance with one or more aspects. The base station 105 and the UE 115 can be Figure 1 any one of the base stations and one of the UEs among the base stations in. For a restricted association scenario (as described above), the base station 105 can be Figure 1 the small cell base station 105f in, and the UE 115 can be the UE 115c or 115d operating in the service area of the small cell base station 105f, which will be included in the list of accessible UEs of the small cell base station 105f for accessing the small cell base station 105f. The base station 105 can also be some other type of base station. As Figure 2 shown, the base station 105 can be equipped with antennas 234a to 234t, and the UE 115 can be equipped with antennas 252a to 252r for facilitating wireless communication.

[0078] At base station 105, transmit processor 220 may receive data from data source 212 and control information from controller 240, such as a processor. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ (automatic repeat request) indicator channel (PHICH), a physical downlink control channel (PDCCH), an enhanced physical downlink control channel (EPDCCH), an MTC physical downlink control channel (MPDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. Additionally, transmit processor 220 may process (e.g., encode and symbol map) the data and control information respectively to obtain data symbols and control symbols. Transmit processor 220 may also generate reference symbols, such as for a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), and cell-specific reference signals. Transmit (TX) MIMO processor 230 may perform spatial processing (e.g., precoding), if applicable, on the data symbols, control symbols, or reference symbols, and may provide an output symbol stream to modulators (MOD) 232a through 232t. For example, the spatial processing performed on the data symbols, control symbols, or reference symbols may include precoding. Each modulator 232 may process the respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Additionally or alternatively, each modulator 232 may process the output sample stream (e.g., perform analog-to-digital conversion, amplification, filtering, and upconversion on it) to obtain a downlink signal. The downlink signals from modulators 232a through 232t may be transmitted via antennas 234a through 234t respectively.

[0079] At UE 115, antennas 252a through 252r may receive the downlink signals from base station 105 and may provide the received signals to demodulators (DEMOD) 254a through 254r respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) the respective received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 may obtain the received symbols from demodulators 254a through 254r, perform MIMO detection on the received symbols when needed, and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide the decoded data for UE 115 to data sink 260, and provide the decoded control information to controller 280, such as a processor.

[0080] On the uplink, at the UE 115, the transmit processor 264 may receive and process data from the data source 262 (e.g., for the physical uplink shared channel (PUSCH)) and control information from the controller 280 (e.g., for the physical uplink control channel (PUCCH)). Additionally, the transmit processor 264 may also generate reference symbols for reference signals. Symbols from the transmit processor 264 may be pre-coded by the TX MIMO processor 266 when needed, further processed by the modulators 254a to 254r (e.g., for SC-FDM, etc.), and transmitted to the base station 105. At the base station 105, the uplink signals from the UE 115 may be received by the antenna 234, processed by the demodulator 232, detected by the MIMO detector 236 when needed, and further processed by the receive processor 238 to obtain the decoded data and control information transmitted by the UE 115. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller 240.

[0081] The controllers 240 and 280 may direct operations at the base station 105 and the UE 115, respectively. The controller 240 or other processors and modules at the base station 105 or the controller 280 or other processors and modules at the UE 115 may execute or direct the execution of various processes for the techniques described herein to, for example, execute or direct Figure 9 , Figure 10 or Figure 12 the execution illustrated in

[0082] In some cases, UE 115 and base station 105 may operate in a shared radio spectrum band, which may include licensed or unlicensed (e.g., contention-based) spectrum. In the unlicensed frequency portion of the shared radio spectrum band, UE 115 or base station 105 may traditionally perform a medium sensing process to compete for access to the spectrum. For example, UE 115 or base station 105 may perform a listen-before-talk or listen-before-transmit (LBT) process (such as clear channel assessment (CCA)) before communication to determine whether the shared channel is available. In some implementations, CCA may include an energy detection process to determine whether there is any other active transmission. For example, a device may infer that a change in the received signal strength indicator (RSSI) of a power meter indicates that the channel is occupied. Specifically, signal power concentrated in a certain bandwidth and exceeding a predetermined noise floor may indicate another wireless transmitter. CCA may also include detection of a specific sequence indicating the use of the channel. For example, another device may transmit a specific preamble before transmitting a data sequence. In some cases, the LBT process may include a wireless node adjusting its own backoff window based on the amount of energy detected on the channel or acknowledgment / negative acknowledgment (ACK / NACK) feedback (as an indication of a collision) for its own transmitted packets.

[0083] Figure 3 is a block diagram of an example wireless communication system 300 that supports backscatter-based positioning in accordance with one or more aspects. In some examples, wireless communication system 300 may implement aspects of wireless network 100. Wireless communication system 300 includes a core network 130, a TRP 340, a first tag device 120, a second tag device 322, a third tag device 323, a fourth tag device 324, and a fifth tag device 325. Although five tag devices are illustrated, in some other implementations, wireless communication system 300 may generally include fewer or more than five TRPs.

[0084] As an illustrative, non-limiting example, tag device 120 may be an RFID tag device. Additionally or alternatively, tag device 120 may be a passive tag that does not have a power source and has limited computing capabilities, a semi-passive tag that has a limited power source and computing capabilities equal to or greater than those of the passive tag device, or an active tag that has a power source and computing capabilities equal to or greater than those of the semi-passive tag device.

[0085] The tag device 120 may include a plurality of components (such as structural hardware components) for performing one or more functions described herein. For example, these components may include a circuit 351, a transmitter 356, and a receiver 358. As a non-limiting example, the circuit 351 may include or correspond to an energy harvesting circuit, a microcontroller, one or more processors, a memory, an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), or any combination thereof. The circuit 351 may depend on whether the tag device 120 is a passive tag, a semi-passive tag, or an active tag.

[0086] The transmitter 356 is configured to send one or more signals to one or more other devices (e.g., one or more TRPs or reader devices 121), and the receiver 358 is configured to receive one or more signals from one or more other devices (e.g., one or more TRPs, reader devices 121, core network 130). For example, the transmitter 356 may send a backscatter signal 376 to one or more TRPs, and the receiver 358 may receive a PRS 374 from one or more TRPs. In some embodiments, the transmitter 356 and the receiver 358 may be integrated in one or more transceivers. Additionally or alternatively, the transmitter 356 or the receiver 358 may include or correspond to one or more components of the tag device 120.

[0087] The tag device 120 may have a tag delay. The tag delay, such as a radio frequency (RF) group delay or other delay, may include or be based on one or more components of the tag device (e.g., the circuit 351, the transmitter 356, the receiver 358, or a combination thereof). The one or more components are configured to: receive a positioning reference signal, generate a backscatter signal based on the positioning reference signal, and send the backscatter signal. In some embodiments, the tag delay is the amount of time between the tag device 120 receiving a positioning reference signal and sending a backscatter signal based on the received positioning reference signal.

[0088] The tag device 120 may include one or more components as described herein with reference to the tag device 120. In some embodiments, the tag device 120 is a tag device with 3GPP capabilities, a tag device with LTE capabilities, a tag device with 5G capabilities, a tag device with 6G capabilities, or a combination thereof.

[0089] The tagging devices 322 to 325 may include components similar to or different from those of the tagging device 120. Additionally, although five tagging devices are depicted, the system 300 may include fewer or more tagging devices. Further, the tagging devices 120 and 322 to 325 may be equidistant from the TRP 340 or within the same range from the TRP. In some specific implementations, the tagging devices 120 and 322 to 325 may be at different distances from the TRP 340 or within different ranges from the TRP. In some specific implementations, a first group of tagging devices (such as the tagging devices 120, 322, and 323) may each be equidistant from the TRP 340 or within the same range from the TRP, while a second group of tagging devices (such as the tagging devices 324, 325) may each be at a different distance from the TRP 340.

[0090] The TRP 340 may include various components (such as structures, hardware components) for performing one or more functions described herein. For example, these components may include one or more processors 302 (collectively referred to hereinafter as "processors 302"), one or more memory devices 304 (collectively referred to hereinafter as "memory 304"), one or more transmitters 316 (collectively referred to hereinafter as "transmitters 316"), and one or more receivers 318 (collectively referred to hereinafter as "receivers 318"). In some specific implementations, the TRP 340 may include an interface (e.g., a communication interface) that includes a transmitter 316, a receiver 318, or a combination thereof. The processor 302 may be configured to execute instructions 305 stored in the memory 304 to perform the operations described herein. In some specific implementations, the processor 302 includes or corresponds to one or more of the receiving processor 238, the transmitting processor 220, and the controller 240, and the memory 304 includes or corresponds to the memory 242 as described for the base station 105 with reference to Figure 2 the base station 105.

[0091] The memory 304 includes or is configured to store instructions 305 and information 306. The information 306 may include PRS information 307, measurement gap information 308, tagging device information 309, and measurement information 310.

[0092] The PRS information 307 includes information used by the TRP 340 to generate a positioning reference signal (PRS) 374. For example, the PRS information 307 may include one or more parameters, such as a repetition rate, a bandwidth configuration, a comb pattern configuration, or any combination thereof. The repetition rate may include or indicate the number of times the PRS is transmitted within a period of time. The comb pattern may include or indicate a configurable resource block allocation. In some specific implementations, the PRS information 307 may be generated or stored based on a TRP configuration (e.g., 372) or a PRS configuration (e.g., 381).

[0093] The measurement gap information 308 indicates one or more time periods associated with the positioning session of the tag device 120. For example, the measurement gap information 308 indicates one or more time periods during which one or more TRPs are configured to monitor the PRS 374, the backscatter signal 376, or a combination thereof. Additionally or alternatively, the measurement gap information 308 may indicate a time period for one or more TRPs to generate a measurement report (e.g., 378), send a measurement report, or a combination thereof. In some embodiments, the measurement gap information 308 may indicate a time period during which one or more TRPs suppress sending signals (such as the PRS 374). For example, the measurement gap information 308 may indicate a time period during which the first TRP 340 suppresses scheduling one or more transmissions from occurring. The measurement gap information 308 may be based on the TRP configuration (e.g., 372) or the measurement gap (MG) configuration 382.

[0094] The tag device information 309 includes or corresponds to information or characteristics about one or more tag devices (such as the tag device 120). For example, the tag device information 309 may include information about the distance (such as approximate distance, estimated distance, previously calculated distance) of one or more tag devices (such as the tag device 120 and the tag devices 322 to 325) from the TRP 340. For example, for a tag device, the tag device information 309 may include the tag type, bandwidth, PRS slot periodicity, sensitivity, tag latency (e.g., group delay), or a combination thereof. The tag type may correspond to whether the tag device (e.g., the tag device 120) is a passive tag, a semi-passive tag, or an active tag. The bandwidth may correspond to the bandwidth on which the tag device 120 is capable of communicating. The PRS slot periodicity may correspond to the time frame of the period or frequency during which the tag device 120 expects to receive the PRS 374. The sensitivity may correspond to the sensitivity of the tag device 120 to the PRS 374, such as the transmit power of the PRS, the distance from the TRP at which the tag device 120 can successfully receive the signal, or a combination thereof. The tag latency may correspond to the amount of time for the tag device 120 to process the PRS 374 and generate the backscatter signal 376 in response to the reception or the PRS 374 at the tag device 120.

[0095] The measurement information 310 includes or corresponds to the propagation time associated with a positioning reference signal (e.g., 374), a backscattered signal (e.g., 376), or a combination thereof. For example, when the TRP 340 is configured as a Tx TRP, the measurement information 310 may include the transmission time of the PRS 374, the reception time of the backscattered signal 376, the amount of time elapsed from the transmission of the PRS 374 to the reception of the backscattered signal 376, or a combination thereof. In some specific implementations, when the TRP is configured as an Rx TRP, the measurement information 310 may include the reception time of the PRS 374, the reception time of the backscattered signal 376, the amount of time elapsed from the reception of the PRS 374 to the reception of the backscattered signal 376, or a combination thereof. In some specific implementations, the measurement information 310 may include or indicate the reception time of a backscattered signal (e.g., 376), the transmission time of a positioning reference signal (e.g., 374) transmitted after the reception of the backscattered signal, the amount of time elapsed from the reception of the backscattered signal to the transmission of the positioning reference signal, or a combination thereof. The TRP 340 may be configured to generate a measurement report based on the measurement information 310.

[0096] The transmitter 316 is configured to send reference signals, control information, and data to one or more other devices, and the receiver 318 is configured to receive reference signals, synchronization signals, control information, and data from one or more other devices. For example, the transmitter 316 may send signaling, control information, and data to the core network 130, another TRP, or a network entity, while the receiver 318 may receive signaling, control information, and data from the core network, another TRP, or a network entity. Additionally or alternatively, the transmitter 316 may send a first signal such as a positioning reference signal (e.g., 374), and the receiver 318 may receive a second signal such as a backscattered signal (e.g., 376). In some specific implementations, the transmitter 316 and the receiver 318 may be integrated in one or more transceivers. Additionally or alternatively, the transmitter 316 or the receiver 318 may include or correspond to one or more components as described for the UE115 or the base station 105 in the reference Figure 2 In some specific implementations, the transmitter 316 or the receiver 318 may be configured to operate in a full-duplex mode. For example, the TRP 340 may include a first panel for the transmitter 316 and a second panel for the receiver 318. In some other specific implementations, the TRP 340 may not be configurable in a full-duplex mode.

[0097] In some specific implementations, the TRP 340 may include one or more antenna arrays. The antenna array may include a plurality of antenna elements configured to perform wireless communication with other devices (such as with the core network 130, another TRP, or the tag device 120). In some specific implementations, the antenna array may be configured to perform wireless communication using different beams (also referred to as antenna beams). The beams may include TX beams and RX beams. For illustration, the antenna array may include a plurality of independent sets (or subsets) of antenna elements (or a plurality of independent antenna arrays), and each set of antenna elements of the antenna array may be configured to communicate using a different corresponding beam, which may have a corresponding direction different from other beams. For example, the first set of antenna elements of the antenna array may be configured to communicate via a first beam having a first direction, and the second set of antenna elements of the antenna array may be configured to communicate via a second beam having a second direction. In other specific implementations, the antenna array may be configured to communicate via more than two beams. Alternatively, one or more sets of antenna elements of the antenna array may be configured to concurrently generate multiple beams, such as using multiple RF chains. Each individual set (or subset) of antenna elements may include a plurality of antenna elements, such as two antenna elements, four antenna elements, ten antenna elements, twenty antenna elements, or any other number greater than two. Although described as an antenna array, in other specific implementations, the antenna array may include or correspond to a plurality of antenna panels, and each antenna panel may be configured to communicate using a different corresponding beam. In some specific implementations, the TRP 340 may be configured as or include a reader device (e.g., 120), such as an RFID reader device.

[0098] The core network 130 may include a 3GPP core network, a 4G core network, a 5G core, or an evolved packet core (EPC). The core network 130 may be coupled (such as communicatively coupled) to one or more network entities, such as the TRP 340. The core network 130 may include or correspond to the LMF 131.

[0099] Although shown and described as being included in the core network 130, in some embodiments, the LMF 131 can be different from the core network 130. For example, the LMF 131 can include one or more servers, such as multiple distributed servers. The LMF 131 can be configured to support various functionalities, such as managing support for different location services for one or more UEs, one or more tag devices, or one or more network entities. For example, the LMF can provide information to the TRP 340, the tag device 120, or the tag devices 322 to 325, such that actions or operations can be taken or performed at the TRP 340, the tag devices 121 and 322 - 235, or a combination thereof. Communication with the LMF 131 can be implemented via a protocol such as the NR Positioning Protocol A (NRPPa). In some embodiments, the TRP 340, the tag devices 120 and 322 to 325, or a combination thereof are configured to communicate with the LMF 131 via the Access and Mobility Management Function (AMF).

[0100] In some embodiments, the LMF 131 is configured to support backscatter - based positioning. Thus, the LMF 131 can include one or more processors 362 (collectively referred to hereinafter as "processor 362") and one or more memory devices 364 (collectively referred to hereinafter as "memory 364") storing instructions executable by the processor 362 to perform the operations described herein. Additionally, the memory 364 can be configured to store tag device information 366. The tag device information 366 can include tag latency 368 and positioning 369.

[0101] To support backscatter - based positioning, the LMF 131 can be configured to perform one or more operations. These functions can include generating a TRP configuration 372 and sending the TRP configuration 372 to the TRP 340. Additionally, the LMF 131 can be configured to generate a PRS configuration 381, a Measurement Gap (MG) configuration 382, or a combination thereof. In some embodiments, the LMF 131 can be configured to receive one or more measurement reports (collectively referred to hereinafter as "measurement reports 378") generated by the TRP 340 or other TRPs (e.g., Figure 3 not depicted in the figure). In some embodiments, the LMF 131 is configured to determine the positioning 369 of the tag device 120 based on the measurement reports 378. For example, the LMF 131 is configured to determine the positioning 369 of the tag device 120 without knowing the tag latency 368.

[0102] The LMF 131 can be configured to determine the location of the tag device 120 based on multiple measurement reports (collectively referred to as "measurement reports 378") without knowing the tag latency 368 corresponding to the tag device 120. Determining the location 369 of the tag device 120 can include calculating the location based on TDoA technology. The location can be 2D location or 3D location. Additionally, the LMF 131 can be configured to use the location 369 for one or more operations, or send a location indicator indicating the location 369 of the tag device 120 and / or any one of the tag devices 322 to 325.

[0103] In some specific implementations, the wireless communication system 300 implements a 5G NR network. For example, the wireless communication system 300 can include multiple 5G-capable devices, such as UEs and base stations configured to operate according to 5G NR network protocols (such as those defined by 3GPP). In some other specific implementations, the wireless communication system 300 implements a 6G network.

[0104] During the operation of the wireless communication system 300, the LMF 131 can send a TRP configuration (e.g., 372) to the TRP 340, which indicates the first information associated with the first tag device 120 and the second information associated with the second tag device 322. For example, the first information can include or indicate the first location (e.g., the first estimated location) of the first tag device 120, and the second information can include or indicate the second location (e.g., the second estimated location) of the second tag device 322. In some specific implementations, the first location is the first distance from the TRP 340, and the second location is the second distance from the TRP 340. Additionally or alternatively, the first information can include or indicate a tag address, a first training sequence, or a first backscatter time frame window for the first tag device 120, and the second information can include or indicate a second training sequence or a second backscatter time frame window for the second tag device 322. The tag address can be a tag ID or a group ID associated with, corresponding to, or indicating at least one of the tag devices 120, 322 to 325.

[0105] The TRP 340 receives a TRP configuration (e.g., 372) and generates a tag configuration message (e.g., 380) indicating a first tag configuration and a second tag configuration. For example, the first tag configuration may indicate a tag address, a frequency shift parameter, a phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. In some specific implementations, the first tag configuration indicates a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. Additionally or alternatively, the second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof.

[0106] In some specific implementations, the first preamble sequence and the second preamble sequence are the same sequence or different sequences. Additionally or alternatively, the first training sequence may be different from the second training sequence, or may be the same as the second training sequence. In some specific implementations, the TRP 340 may generate the first tag configuration based on an RSSI / RSPR indicator associated with the first tag device 120.

[0107] The TRP 340 transmits a PRS (e.g., 374), and in response to the PRS, receives a first backscatter signal (e.g., 376) from the first tag device 120 and a second backscatter signal (e.g., 384) from the second tag device 322. For example, the first tag device 120 may transmit the first backscatter signal based on the PRS and the first tag configuration.

[0108] The TRP 340 may determine a first backscatter signal gain associated with the first tag device based on the first training sequence, the first preamble sequence, the first backscatter signal, or a combination thereof. Additionally or alternatively, the TRP 340 may determine a second backscatter signal gain associated with the second tag device based on the second training sequence, the second preamble sequence, the second backscatter signal, or a combination thereof. For example, by configuring the tag device to include a preamble sequence in its backscatter signal, the TRP 340 may identify the backscatter signal received from the tag device as being associated with a tag device within a threshold range to the TRP 340. In this way, the TRP 340 may estimate the first backscatter channel gain and the second backscatter channel gain by searching for the preamble sequence in the backscatter signal. As another example, by configuring one or more of the plurality of tag devices to include different training sequences in their reflected backscatter signals, the TRP 340 may eliminate the ambiguity of the backscatter signals received from each of these tag devices, thereby estimating the backscatter channel gain of each of the plurality of tag devices.

[0109] The TRP 340 generates and sends a measurement report to the LMF 131, which indicates a first RTT of the first tag device 120 and a second RTT of the second tag device 322. The measurement report may include or correspond to the measurement report 378. The first RTT may be based on the first tag configuration and the first backscatter signal, and the second RTT may be based on the second tag configuration and the second backscatter signal. The LMF 131 may determine the location of the first tag device 120 or the second tag device 322 based on the measurement report.

[0110] In some embodiments, the tag configuration message 380 indicates a third tag configuration for the third tag device 323, a fourth tag configuration for the fourth tag device 324, or a combination thereof. The TRP 340 may receive a third backscatter signal based on the PRS 374 from the third tag device 323. Additionally or alternatively, the TRP 340 may receive a fourth backscatter signal based on the PRS 340 from the fourth tag device. The third tag device 323 may be at a third distance from the TRP 340, and the fourth tag device 324 may be at a fourth distance from the TRP 340.

[0111] In some embodiments, the TRP 340 may assign the first tag device 120 and the third tag device 323 to a first group based on the first distance and the third distance. The assignment of the tag devices 120 and 323 to the first group may be indicated by or associated with the tag configuration message 380. The TRP 340 may assign the second tag device 322 and the fourth tag device 324 to a second group based on the second distance and the fourth distance. The assignment of the tag devices 322 and 324 to the second group may be indicated by or associated with the tag configuration message 380. In some embodiments, the first distance and the third distance are within a first threshold range of the TRP 340. Additionally or alternatively, the second distance and the fourth distance are within a second threshold range of the TRP 340 that is different from and non-overlapping with the first threshold range.

[0112] In some embodiments, the tag configuration message 380 includes or indicates a third tag configuration (which indicates a third training sequence different from the first training sequence), a fourth tag configuration (which indicates a fourth training sequence different from the second training sequence); or a combination thereof. The TRP 340 may determine a first backscatter signal gain associated with the first tag device 120 based on the first training sequence, the first preamble sequence, and the first backscatter signal 376. Additionally or alternatively, determine a third backscatter signal gain associated with the third tag device 323 based on the third training sequence, the third preamble sequence, and the third backscatter signal. In some embodiments, the first preamble sequence and the third preamble sequence are the same preamble sequence.

[0113] As referencedFigure 3 As described, the present disclosure provides techniques for supporting backscatter-based positioning. The described techniques facilitate determining the positioning 369 of a tag device (such as tag device 120) having limited on-board power and computational resources (e.g., passive or semi-passive tags), such as two-dimensional or three-dimensional positioning. By way of illustration, the LMF 131 is capable of providing a TRP configuration 372 (e.g., a PRS configuration 381) to one or more TRPs, such as TRPs 340 to 348, which takes into account the specific characteristics of the tag device, such as the limited on-board power or computational resources of the tag device. Additionally, when the tag latency of the tag device 120 is unknown or unavailable, the LMF 131 is capable of determining the positioning of the tag device 120 based on one or more measurement reports 378. For example, when the tag latency 368 of the tag device is unknown or unavailable to the device calculating the positioning 369 of the tag device 120, the LMF 131 may perform measurements of TDoA-based backscatter-based positioning of multiple TRPs 340 to 349.

[0114] The present disclosure facilitates determining the location of one or more tag devices subject to computational and power constraints of passive and semi - passive tag devices, such as two - dimensional or three - dimensional location. For example, by providing a tag configuration message 380 indicating a first tag configuration and a second tag configuration, the TRP 340 can configure each of the one or more tag devices such that in response to a PRS 374 transmitted by the TRP 340, the tag devices 120, 322 to 325 can generate and transmit a backscatter signal having a pattern (such as a preamble sequence, a training sequence, a backscatter time - frame window, or a combination thereof) to distinguish the backscatter signal received from another tag device at the TRP 340. Additionally, the TRP 340 can be configured to apply different techniques based on the distance of one or more tag devices from the TRP 340 to distinguish the backscatter signals received from the one or more tag devices. For example, if a set of tag devices is within a threshold range from the TRP 340, the TRP 340 can receive backscatter signals from these tag devices concurrently or substantially concurrently. Thus, the TRP 340 can distinguish the received backscatter signals by configuring one or more tag devices to include in the backscatter signal a training - sequence pattern unique to each tag device. In contrast, if at least one tag device is at a different distance from the TRP 340 compared to one or more tag devices, the TRP 340 can configure the at least one tag device to provide a backscatter signal on a different backscatter time - frame window. For example, the TRP 340 can configure a first tag device that is at a greater distance from the TRP 340 compared to a second tag device to transmit a backscatter signal on a longer backscatter time - frame window than the second tag device that is closer to the TRP 340 to account for the possible attenuation of the backscatter signal due to the greater distance. Further, the disclosed techniques can handle backscatter signals from one or more tag devices in a first group at a first threshold distance from the TRP 340 and in a second group at a second threshold distance from the TRP 340. Thus, in this manner, these techniques facilitate the TRP 340 in determining the RTT to and from one or more tag devices, thereby facilitating determining the location of one or more tag devices.

[0115] Figure 4 is a ladder diagram illustrating an example of backscatter - based location in accordance with aspects of the present disclosure. As Figure 4 shown, Figure 4 the wireless communication system 400 of the ladder diagram includes a first tag device 120, an LMF 131, a second tag device 322, and a TRP 340. The wireless communication system 400 can include or correspond to the wireless communication system 100 or 300. Although Figure 4Depicts a single TRP 340, but the wireless communication system 400 may include TRPs. Additionally or alternatively, although the wireless communication system 400 includes two tag devices, in other embodiments, the wireless communication system 400 may include fewer or more than two tag devices.

[0116] During operation of the system 400, at 402, the LMF 131 sends a TRP configuration to the TRP 340. For example, the TRP configuration may include or correspond to the TRP configuration 372, the PRS configuration 381, the MG configuration 382, the PRS information 307, the measurement gap information 308, the tag device information 366 or 309, or a combination thereof.

[0117] At 404, the TRP 340 sends a tag configuration message. For example, the tag configuration message may include or correspond to the tag configuration message 380 or the tag device information 309 or 366. The tag configuration message may be received by the first tag device 120 and the second tag device 322.

[0118] At 404, the TRP 340 sends a PRS. For example, the PRS may include or correspond to the positioning reference signal 374. The PRS message may be received by the first tag device 120 and the second tag device 322.

[0119] At 410, the first tag device 120 sends a first backscatter signal in response to the PRS. For example, the first tag device 120 may reflect the PRS to generate the first backscatter signal. The first backscatter signal may include or correspond to the backscatter signal 376. The first backscatter signal may be received by the TRP 340.

[0120] At 412, the second tag device 322 sends a second backscatter signal in response to the PRS. For example, the second tag device 322 may reflect the PRS to generate the second backscatter signal. The second backscatter signal may include or correspond to the backscatter signal 384. The second backscatter signal may be received by the TRP 340.

[0121] In some specific implementations, the first tag device is at a first distance from the TRP, and the second tag device is at a second distance from the TRP. The first distance and the second distance can be estimated distances. The first distance can be substantially equal to the second distance—for example, both the first distance and the second distance are within a threshold range of the TRP 340. In some such specific implementations, the first backscatter signal and the second backscatter signal can have different phase shifts, different phase scramblings, different modulations (e.g., training sequences), or combinations thereof. Alternatively, the first distance can be less than the second distance. In some such specific implementations, the first backscatter signal and the second backscatter signal can have different phase shifts, different phase scramblings, different modulations (e.g., training sequences), different backscatter time frame windows, or combinations thereof. In the specific implementation where the first tag device is closer to the TRP than the second tag device, the first backscatter signal can be shorter (e.g., in the time domain) compared to the second backscatter signal, the first backscatter signal and the second backscatter signal can have the same training sequence, or combinations thereof.

[0122] In some specific implementations, the LMF 131 sends a TRP configuration (e.g., 372) to the TRP 340, and the TRP configuration indicates the first information associated with the first tag device 120 and the second information associated with the second tag device 322. For example, the first information may include or indicate the first positioning (e.g., the first estimated positioning) of the first tag device 120, and the second information may include or indicate the second positioning (e.g., the second estimated positioning) of the second tag device 322. Additionally or alternatively, the first information may include or indicate the first training sequence or the first backscatter time frame window for the first tag device 120, and the second information may include or indicate the second training sequence or the second backscatter time frame window for the second tag device 322. The TRP 340 receives the TRP configuration (e.g., 372) and generates a tag configuration message (e.g., 380) indicating the first tag configuration and the second tag configuration. For example, the first tag configuration may indicate the tag address, the frequency shift parameter, the phase scrambling parameter, the first preamble sequence, the first training sequence, the first backscatter time frame window, or a combination thereof. The TRP 340 sends a PRS (e.g., 374), and in response to the PRS, receives the first backscatter signal (e.g., 376) from the first tag device 120 and the second backscatter signal (e.g., 384) from the second tag device 322. For example, the first tag device 120 may send the first backscatter signal based on the PRS and the first tag configuration. The TRP 340 generates and sends a measurement report to the LMF 131, and the measurement report indicates the first RTT of the first tag device 120 and the second RTT of the second tag device 322. The measurement report may include or correspond to the measurement report 378. The first RTT may be based on the first tag configuration and the first backscatter signal, and the second RTT may be based on the second tag configuration and the second backscatter signal. The LMF 131 may determine the positioning of the first tag device 120 or the second tag device 322 based on the measurement report.

[0123] Figure 5is a conceptual diagram supporting backscatter-based positioning according to one or more aspects. At 502, a TRP (such as TRP 340) transmits a configuration message X (e.g., a configuration signal). The configuration message may include or correspond to a tag configuration message 380. The configuration message may include or indicate a tag address of a tag device (e.g., the first tag device 120), a modulation scheme of the tag device for generating a backscatter signal 376, or a combination thereof. The tag address may indicate a tag identifier of the first tag device 120, a group identifier associated with the first tag device 120, or a combination thereof. The modulation scheme may indicate a frequency shift parameter, a phase scrambling parameter, an on / off mode, modulation data, or a combination thereof. In some embodiments, the configuration message X is a bipartite signal including a first component and a second component, the first component corresponding to an energy signal and configured to provide energy to the first tag device 120, and the second component corresponding to tag configuration data. In some embodiments, the first component or the configuration message X may operate as a wake-up signal for the first tag device 120.

[0124] After the transmission of the configuration message, the TRP transmits a PRS 374. The PRS 374 may include or correspond to a broadband signal c(t). For example, c(t) may be a code division multiple access pseudo-random (CDMA-PN) signal having a chip rate equal to the frequency of the Tx TRP (denoted as f TxTRp ). In some embodiments, c(t) may be selected to have a robust autocorrelation with c(t - t c )(corresponding to a time-shifted component of the PRS included in the backscatter signal that may be received at the Rx TRP).

[0125] The start of the PRS 374 may have a time-of-flight (ToF) 512 from the TRP 340 to the first tag device 120. At 503, the first tag device 120 may be configured to modulate a signal b(t) over the PRS c(t) and may reflect the combined c(t)b(t) as a backscatter signal to the TRP 340. Note that the first tag device 120 may experience a processing delay starting from the reception of the configuration message X to the start of the backscatter scrambling operation. Thus, the start of the backscatter scrambling operation may not be at the start of the PRS 340 as received by the first tag device 120.

[0126] In some embodiments, the backscatter signal may be frequency-shifted such that the backscatter signal (e.g., the backscatter signal 376) corresponds mathematically at the tag device 120 to c(t - t c )b(frequency-shifted signal). As an example, when the frequency shift parameter includes a frequency shift waveform having a backscatter frequency offset value f b , the frequency-shifted signal may correspond to when In some specific implementations, the backscattered signal can be phase scrambled such that the backscattered signal (e.g., backscattered signal 376) mathematically corresponds to h at the tag device 120 b c(t - t c )b(t - t b ), where t c corresponds to the PRS time offset value, and t b corresponds to the backscattered signal time offset value. As another example, when generating a phase-scrambled backscattered signal, the tag device 120 can be configured to convert the frequency of the backscattered signal to the following: f tagdevice = f TRP / K, where K is a scaling factor included in the phase scrambling parameter.

[0127] At 506, the TRP 340 receives the backscattered signal 376. Note that ToF 514 occurs from the transmission of the backscattered signal 376 to the reception of the backscattered signal 376 by the TRP 340 (e.g., the reader). Also note that there can be a tag delay between ToF 512 and ToF 514. Since the received backscattered signal has been contaminated by interference, the backscattered signal received at the TRP 340 can be mathematically represented as r(t) = h c c(t)+bh b c(t - t c )(frequency-shifted waveform)+∑ i h i c(t - t i )(when the backscattered signal has been frequency-shifted at the tag device 120), and as r(t) = h c c(t)+h b c(t - t c )b(t - t b )+∑ i h i c(t - t i )(when the backscattered signal has been phase-scrambled). Note that for a multi-tag scenario, the detection problem becomes r(t) = h c c(t)+∑ i h b,i c(t - t c,i )b i (t - t b,i )+∑ i h i c(t - t i ).

[0128] Additionally, at 506, the TRP 340 can perform operations on the received backscattered signal to extract, cancel, or eliminate interference in the received backscattered signal. In some specific implementations, in response to receiving a frequency-shifted backscattered signal, the TRP 340 can remove one or more components of the frequency-shift parameter included in the received backscattered signal, apply a low-pass filter to the backscattered signal to remove interference-related components of the received backscattered signal, and by selecting an appropriate PRS time offset value t c to associate PRSc(t) with the time-shifted component c(t - t c ) of the PRS included in the received backscattered signal.

[0129] In some specific implementations, in response to receiving a frequency-shifted backscattered signal, the TRP 340 can remove one or more components of the frequency-shift parameter included in the received backscattered signal, apply a low-pass filter to the backscattered signal to remove interference-related components of the received backscattered signal, and by selecting an appropriate PRS time offset value t c to associate the transmitted PRSc(t) with the time-shifted component c(t - t c ) of the PRS included in the received backscattered signal.

[0130] In some specific implementations, in response to receiving a phase-scrambled backscattered signal, the TRP 340 can remove one or more components of the received backscattered signal that are not phase-scrambled. For example, the TRP 340 can perform double-correlation by first correlating the received backscattered signal with b(t - t b ) using an appropriate t b and then by selecting an appropriate PRS time offset value t c to associate the transmitted PRs c(t) with the time-shifted component c(t - t c ) of the PRS included in the received backscattered signal.

[0131] In some specific implementations, the TRP 340 receives a modulated portion of the backscattered signal at time t2. The TRP 340 can associate the modulated portion (e.g., symbol or chip) with a portion of the PRS 374 transmitted at time t1. Thus, the TRP 340 can determine the RTT of the first tag 120 based on time t2, time t2, the tag delay of the first tag device 120, or a combination thereof.

[0132] Figure 6FIG. is a block diagram illustrating another example of a system 600 that supports backscatter-based positioning in accordance with one or more aspects. In some examples, system 600 (e.g., a wireless communication system) may include or correspond to wireless communication systems 100, 300, 400, or 500. System 600 includes a TRP 340 and tag devices 120 and 322-325.

[0133] As shown, each of tag devices 120 and 322-325 is within a range 606 (e.g., a threshold range). For example, the range may be based on a first distance 602 and a second distance 604. In some implementations, range 606 is based on the speed of light and a unit of time such as the duration of a symbol (e.g., 10 ms, as an illustrative non-limiting example). The TRP 340 may transmit a PRS 374 and may receive one or more backscatter signals, such as a first backscatter signal 376 from the first tag device 120. In some implementations, the TRP 304 may receive backscatter signals from one or more of tag devices 120, 322-325.

[0134] In some implementations, the TRP 340 sends a tag configuration message including a preamble sequence to tag devices 322-325, which may be the same in some implementations. Thus, each of tag devices 322-325 is configured to generate a backscatter signal encoded with the preamble sequence. Since tag devices 322-325 are within the same threshold range from the TRP 340, the TRP 340 will receive backscatter signals from each of tag devices 322-325 at approximately the same time (e.g., concurrently). By encoding the preamble sequence in the backscatter signals, the TRP 340 can more easily identify the backscatter signals, thereby distinguishing the backscatter signals from other signals (such as interference).

[0135] In some implementations, the TRP 340 sends a tag configuration including a unique training sequence to tag devices 322-325 such that each of tag devices 322-325 may receive the unique training sequence in the tag configuration message. In this way, each of tag devices 322-325 is configured to generate and transmit a backscatter signal encoded with the unique training sequence. Thus, the TRP 340 can distinguish the backscatter signals received from each of tag devices 322-325 based on the training sequence included in each backscatter signal and attributable to a particular tag device 322-325.

[0136] In some specific implementations, the TRP 340 is configured to determine the RTT associated with the transmission of a PRS such as PRS 374 to tag devices that are within a threshold range (e.g., approximately equidistant) from the TRP 340, such that the travel times of the backscattered signals are substantially equal, as follows: t c,tag120 = t c,tag322 = … = t c,tag325 = t c . Specifically, if the distances of tag devices (such as tag devices 120, 322 to 325) from the RTP 340 are within a distance within the threshold range, which corresponds to the duration of the symbol of the PRS (e.g., PRS 374) multiplied by the speed of light (e.g., in air), as depicted by range 606, they can be considered to be approximately equidistant from the TRP 340.

[0137] Mathematically, the backscattered signals received at the TRP 340 from each of the tag devices 120, 322 to 325 can be modeled as r(t) = h c c(t) + c(t - t c ) ∑ i h b,i b i (t - t b,i ) + ∑ i h i c(t - t i ). In the foregoing equation, r(t) can include or correspond to the backscattered signals received at the TRP 340 from multiple tags 120, 322 to 325; h c c(t) can include or correspond to the self-interference attributable to the PRS c(t); c(t - t c ) ∑ i h b,i b i (t - t b,i ) can include or correspond to the manipulated backscattered signal b c (t - t i ) modulated onto the PRS 374 c(t - t b,i ), where the backscattering coefficient h b,i corresponds to the backscattering channel gain; and ∑ i h i c(t - t i ) can include or correspond to interference from environmental sources (such as objects near the tag devices 120, 322 to 325). Specifically, each of the tag devices 120, 322 to 325 can be configured to transmit a data-manipulated signal that has been included in a tag configuration message (such as tag configuration message 380) to the TRP 340. For example, the manipulated backscattered signal b i (t - t b,i)The message based on the tag configuration may be frequency-shifted, phase-scrambled, include a preamble sequence, include a training sequence, or any combination thereof.

[0138] To achieve the RTT of the tag devices 120, 322 to 325, the TRP 340 may estimate the time offset t c . Thus, to estimate the time offset t c , the TRP 340 may estimate the backscatter coefficient h b,i , to determine the superposition ∑ i h b,i b i (t - t b,i ). For example, the TRP 340 may configure the tag devices 120, 322 to 325 to include a preamble sequence, such as [1 - 1 1 - 1], in the backscattered signal b i (t - t b,i ), such that when the TRP 340 simultaneously receives the backscattered signals from the tag devices 120, 322 to 325, the TRP 340 can determine the backscatter channel gain corresponding to ∑ i h b,i . As another example, the TRP 340 may configure the tag devices 120, 322 to 325 to include a unique training sequence for each tag device in addition to the phase sequence, such that the backscatter channel gain corresponding to each tag device can be determined. For example, the TRP 340 may configure the tag device 120 with the first training sequence [1 1], and configure the tag device 323 with the second tag training sequence [1, - 1]. In some specific implementations, each tag device in a group of tag devices within a threshold range may have a different training sequence. In other specific implementations, two tag devices in the same group may have the same training sequence, but can be distinguished in different ways, such as having different frequency shifts.

[0139] Figure 7 is a block diagram illustrating another example of a system 700 that supports backscatter-based positioning according to one or more aspects. In some examples, the system 700 (e.g., a wireless communication system) may include or correspond to the wireless communication systems 100, 300, 400, 500, or 600. The system 700 includes the TRP 340 and the tag devices 120 and 322.

[0140] The TRP 340 may send a configuration message 702. The configuration message 702 may include or correspond to Figure 5Configuration message X. Based on configuration 702, each of the first tag device 120 and the second tag device 322 may be ready (e.g., 710 and 712 respectively) to receive PRS 374. For example, the first tag device 120 and / or the second tag device 322 may wake up, determine or select a corresponding tag configuration, configure one or more components, or a combination thereof. In some specific implementations, to select a tag configuration, the first tag device 120 and / or the second tag device 322 may determine the corresponding RSSI / RSRP based on configuration message 702 or based on PRS 374.

[0141] The TRP 340 may send PRS 374. The first tag device 120 may perform a backscatter operation 722 on the PRS 374, and the second tag device 322 may perform a backscatter operation 724 on the PRS 374. Based on the backscatter operation 722 performed by the first tag device 120, the first tag device 120 may generate a first backscatter signal 376, which is received by the TRP 340. Based on the backscatter operation 724 performed by the second tag device 322, the second tag device 322 may generate a second backscatter signal 384, which is received by the TRP 340.

[0142] Note that the second tag device 322 may be positioned farther from the TRP 340 than the first tag device 120. For example, the first tag device 120 is at a first distance from the TRP 340, and the second tag device 322 is at a second distance from the TRP 340. The first distance may be less than the second distance. For illustration, the first distance may be within a first threshold range of the TRP 340, and the second distance is within a second threshold range of the TRP 340, which is different from and does not overlap with the first threshold range - for example, the second threshold range is farther from the TRP 340 than the first threshold range. The configuration message 702 may assign the first tag device 120 to a first group based on the first distance, and may assign the second tag device 322 to a second group based on the second distance. The first group may be associated with a first tag configuration that includes or indicates a first backscatter time frame window. The second group is associated with a second configuration that includes or indicates a second backscatter time frame window. The second backscatter time frame window is longer than the first backscatter time frame window, such that the first duration of the first backscatter signal is less than (e.g., shorter than) the second duration of the second backscatter signal. In such a case, the TRP 340 may have a longer second backscatter 382 sequence (compared to the first backscatter 376) for correlation. Additionally, the shorter time period of the first backscatter window and the farther distance of the second tag device 322 help the first backscatter signal 376 and the second backscatter signal 384 not to overlap in time (e.g., not to interfere with each other).

[0143] In some embodiments, tag devices such as the first tag device 120 and the second tag device 322 are at different distances from the TRP 340, such that the time offset t associated with the first tag device 120 c,tagdevice120 << the time offset t associated with the second tag device 322 c,tag322 . This different time offset can be attributed to the fact that the first distance separating the first tag device 120 from the TRP 340 is shorter than the second distance separating the second tag device 322 from the TRP 340, as Figure 7 depicted in the example of. Thus, the backscatter signal 376 associated with the first tag device 120 may be attenuated less than the backscatter signal 384 associated with the second tag device 322. Thus, different from the second backscatter signal 384, less processing time may be necessary for processing the first backscatter signal 376. Thus, the TRP 340 may configure the second tag device 322 to have a longer backscatter time frame window than the first tag device 120.

[0144] Figure 8 is a block diagram illustrating another example of a system 800 that supports backscatter-based positioning in accordance with one or more aspects. In some examples, the system 800 (e.g., a wireless communication system) may include or correspond to the wireless communication systems 100, 300, 400, 500, 600, or 700. The system 800 includes the TRP 340 and the tag devices 120 and 322 to 325.

[0145] The TRP 340 may send a configuration message 702. The configuration message 702 may include or correspond to Figure 5 configuration message X. Based on the configuration 702, each of the tag devices 120, 322 to 325 may be ready to receive the PRS 374. For example, the tag devices 120, 322 to 325 may wake up, determine or select corresponding tag configurations, configure one or more components, or a combination thereof. In some embodiments, to select a tag configuration, the tag devices 120, 322 to 325 may determine the corresponding RSSI / RSRP based on the configuration message 702 or based on the PRS 374.

[0146] TRP 340 can send PRS 374. Each of the tag devices 120, 322 to 325 can perform a backscattering operation on PRS 374 to generate a corresponding backscattering signal based on the tag configuration of the tag device. For example, the first tag device 120 generates a first backscattering signal 376, the second tag device 322 generates a second backscattering signal 384, the third tag device 323 generates a third backscattering signal 876, the fourth tag device 324 generates a fourth backscattering signal 887, and the fifth tag device 325 generates a fifth backscattering signal 888.

[0147] Note that the second tag device 322, the fourth tag device 324, and the fifth tag device 325 can be positioned farther from the TRP 340 than the first tag device 120 and the third tag device 323. For example, the tag devices 120 and 323 can be at a first distance (e.g., within a first range) from the TRP 340, and the tag devices 322, 324, 325 can be at a second distance (e.g., within a second range) from the TRP 340. The first distance can be less than the second distance. For illustration, the first distance can be within a first threshold range of the TRP 340, and the second distance is within a second threshold range of the TRP 340, where the second threshold range is different from and does not overlap with the first threshold range - for example, the second threshold range is farther from the TRP 340 than the first threshold range. The configuration message 702 can assign the tag devices 120, 323 to a first group based on the first distance, and can assign the tag devices 322, 324, 325 to a second group based on the second distance. The first group can be associated with a first backscattering time frame window. The second group can be associated with a second backscattering time frame window. The second backscattering time frame window is longer than the first backscattering time frame window, such that the first duration of the first backscattering signal is less than (e.g., shorter than) the second duration of the second backscattering signal. In such a case, the TRP 340 can have a longer second backscattering 382 sequence (compared to the first backscattering 376) for correlation. Additionally, the shorter time period of the first backscattering window and the farther distance of the second tag device 322 help the first backscattering signal 376 and the second backscattering signal 384 not to overlap in time (e.g., not to interfere with each other).

[0148] For each of the first group and the second group, the tag devices within the corresponding group can have different modulations - for example, different training sequences or different phase shifts. The different modulations are applied to the backscattering signals and enable the TRP 340 to identify or recover the backscattering signals from different tag devices included in the same group.

[0149] In some specific implementations, the first plurality of tag devices may be within a first threshold range (e.g., approximately equidistant) from a TRP (such as TRP 340), while the second plurality of tag devices may each have a different distance to TRP 340. The second plurality of tag devices may be within a second threshold range. The first threshold range and the second threshold range may at least partially overlap or may not overlap at all. The LMF (such as LMF 131) may group the tag devices based on the estimated distance of the tag devices to TRP 340. For example, LMF 131 may group the first plurality of tag devices into a first group, and LMF 131 may group the second plurality of tag devices into a second group. Thereafter, LMF 131 may notify TRP 340 which tag devices are assigned to each group. Alternatively, LMF 131 may provide relative and estimated distance information of the tag devices to TRP 340, and then TRP 340 may use this estimated distance information to group the tag devices into a first group (corresponding to the tag devices within the same first threshold range from TRP 340), and into a second group (corresponding to the tag devices having different distances from TRP 340 (e.g., within the same second threshold range)). Once the tag devices are grouped, TRP 340 may apply the algorithms and techniques described herein to determine the RTT of the tag devices in each group.

[0150] Figure 9 is a flowchart illustrating an example process 900 that supports backscatter-based positioning according to one or more aspects. The operations of process 900 may be performed by a network entity, such as base station 105, UE 115, LMF 131, reader device 121, TRP 340, or a network entity as described in reference Figure 11 and enables a network entity to support backscatter-based positioning.

[0151] At block 902, the network entity transmits a label configuration message indicating a first label configuration for a first label device and a second label configuration for a second label device. For example, the label configuration message may include or correspond to label configuration message 380, the first label device may include or correspond to first label device 120, and the second label device may include or correspond to second label device 322. It should be understood that either the first label device, the second label device, or both may include or correspond to any one of third label device 323, fourth label device 324, or fifth label device 325. In some specific implementations, the first label configuration for the first label device may indicate a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. Additionally or alternatively, the second label configuration for the second label device may indicate a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof; or a combination of them.

[0152] At block 904, the network entity transmits a PRS. For example, the PRS may include or correspond to PRS 374.

[0153] At block 906, the network entity receives a first backscatter signal based on the PRS from the first label device. The first backscatter signal may include or correspond to backscatter signal 376.

[0154] At block 908, the network entity receives a second backscatter signal based on the PRS from the second label device. The second backscatter signal may include or correspond to second backscatter signal 384.

[0155] At block 910, the network entity transmits a measurement report. The measurement report may include or correspond to measurement report 378. The measurement report may include or indicate a first RTT of the first label device. The first RRT may be based on the first configuration and the first backscatter signal. Additionally or alternatively, the measurement report may include or indicate a second RTT of the second label device. The second RTT may be based on the second configuration and the second backscatter signal.

[0156] In some specific implementations, the label configuration message indicates a label address, a frequency shift parameter, a phase scrambling parameter, a preamble sequence, a training sequence, a backscatter time frame window, or a combination thereof. In some specific implementations, the first label configuration indicates a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. Additionally, in some specific implementations, the second label configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof.

[0157] In some specific implementations, the first preamble sequence and the second preamble sequence are the same sequence. Additionally or alternatively, the first training sequence and the second training sequence can be the same training sequence. Alternatively, the first training sequence can be different from the second training sequence.

[0158] In some specific implementations, the first tag device is at a first distance from the TRP, the second tag device is at a second distance from the TRP, or a combination thereof. In some specific implementations, the first distance is a first estimated distance, the second tag distance is a second estimated distance, or a combination thereof. In some specific implementations, the network entity receives a TRP configuration indicating the first distance, the second distance, or a combination thereof. For example, the TRP configuration can include or correspond to TRP configuration 372, PRS configuration 381, MG configuration 382, PRS information 307, measurement gap information 308, tag device information 366 or 309, or a combination thereof. The network entity can determine the first distance based on a first RSSI / RSRP indicator corresponding to the first backscatter signal. Additionally or alternatively, the network entity can determine the second distance based on a second RSSI / RSPR indicator corresponding to the second backscatter signal. In some specific implementations, the first distance is greater than the second estimated distance, and the first backscatter time frame window is greater than (e.g., longer than) the second backscatter time frame window. For example, the first duration of the first backscatter signal can be greater than the second duration of the second backscatter signal.

[0159] In some specific implementations, the first distance and the second distance are within a threshold range from the network entity, and the first preamble sequence and the second preamble sequence are the same sequence. Additionally, the network entity can determine the backscatter channel gain of the first tag device based on a first portion of the first backscatter signal and the first preamble sequence.

[0160] In some specific implementations, the network entity determines a first backscatter signal gain associated with the first tag device based on the first training sequence, the first preamble sequence, the first backscatter signal, or a combination thereof. Additionally or alternatively, the network entity can determine a second backscatter signal gain associated with the second tag device based on the second training sequence, the second preamble sequence, the second backscatter signal, or a combination thereof.

[0161] In some specific implementations, the tag configuration message indicates a third tag configuration for a third tag device (e.g., the third tag device 323), a fourth tag configuration for a fourth tag device (e.g., the fourth tag device 324), or a combination thereof. In some specific implementations, the network entity receives a third backscatter signal based on PRS from the third tag device and a fourth backscatter signal based on PRS from the fourth tag device. The third tag device may be at a third distance from the network entity, and the fourth tag device may be at a fourth distance from the TRP.

[0162] In some specific implementations, the network entity assigns the first tag device and the third tag device to a first group based on the first distance and the third distance. Additionally or alternatively, the network entity assigns the second tag device and the fourth tag device to a second group based on the second distance and the fourth distance. In some specific implementations, the first distance and the third distance are within a first threshold range of the network entity. Additionally or alternatively, the second distance and the fourth distance are within a second threshold range of the network entity, and the second threshold range is different from and does not overlap with the first threshold range.

[0163] In some specific implementations, the third tag configuration indicates a third training sequence different from the first training sequence, the fourth tag configuration indicates a fourth training sequence different from the second training sequence, or a combination thereof. In some specific implementations, the network entity determines a first backscatter signal gain associated with the first tag device based on the first training sequence, the first preamble sequence, and the first backscatter signal. Additionally or alternatively, the network entity may determine a third backscatter signal gain associated with the third tag device based on the third training sequence, the third preamble sequence, and the third backscatter signal. In some specific implementations, the first preamble sequence and the third preamble sequence are the same preamble sequence.

[0164] Figure 10 is a flowchart illustrating an example process 1000 that supports backscatter-based positioning according to one or more aspects. The operations of process 1000 may be performed by a network entity, such as base station 105, UE 115, LMF 131, reader device 121, TRP 340, or a network entity as described in reference Figure 11 For example, the example operations of process 1000 may enable the network entity to support backscatter-based positioning.

[0165] At block 1002, the network entity transmits a TRP configuration. For example, the TRP configuration may include or correspond to a TRP configuration 372, a PRS configuration 381, an MG configuration 382, PRS information 307, measurement gap information 308, tag device information 366 or 309, or a combination thereof. The TRP configuration may include or indicate first information associated with a first tag device such as tag device 120. The first information may include or indicate a first localization of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. Additionally or alternatively, the TRP configuration may include or indicate second information associated with a second tag device such as second tag device 322. The second information may include or indicate a second localization of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof. In some embodiments, the first localization, the second localization, or both are estimated localizations.

[0166] In some embodiments, the first information includes or indicates a first preamble sequence, and the second information includes or indicates a second preamble sequence. For example, the first preamble sequence and the second preamble sequence may be the same preamble sequence. In some embodiments, the first information further includes or indicates a tag ID, a frequency shift parameter, a phase scrambling parameter, or a combination thereof.

[0167] At block 1004, the network entity receives a measurement report from the TRP. For example, the TRP may include or correspond to TRP 340. The measurement report may include or correspond to a measurement report 378 or measurement information 310. The measurement report may include or indicate a first RTT of the first tag device, a second RTT of the second tag device, or a combination thereof. The first RTT may be based on the first information and a first backscatter signal from the first tag device, and the second RTT may be based on the second information and a second backscatter signal from the second tag device. The first backscatter signal may include or correspond to a first backscatter signal 376. The second backscatter signal may include or correspond to a second backscatter signal 384.

[0168] In some embodiments, the TRP configuration indicates a first configuration for the first tag device and a second configuration for the second tag device. For example, the first configuration may include the first information, and the second configuration may include the second information.

[0169] In some embodiments, the network entity determines an RSSI or an RSRP associated with the first tag device. Additionally, the network entity may generate the first information based on the RSSI or the RSRP. In some embodiments, the first localization includes an estimated localization of the first tag device. In some embodiments, the network entity determines an updated localization of the first tag device based on the first measurement report.

[0170] Figure 11 is a block diagram of an example network entity 1100 that supports backscatter-based positioning according to one or more aspects. The network entity 1100 may be configured to perform operations including referring to the blocks of process 1100 described in Figure 9 and Figure 10 In some specific implementations, the network entity 1100 includes the structures, hardware, and components shown and described with reference to base station 105, UE 115, LMF 131, reader device 121, or TRP 340. For example, the network entity 1100 may include a controller 240 that operates to execute logic or computer instructions stored in a memory 242 and controls components that provide the features and functionality of the network entity 1100. The network entity 1100 is configured to transmit and receive signals via radio components 1101a-t and antennas 234a-t under the control of the controller 240. The radio components 1101a-t include various components and hardware as illustrated for base station 105 in Figure 2 including modulators and demodulators 232a-t, transmit processor 220, TX MIMO processor 230, MIMO detector 236, and receive processor 238.

[0171] As shown, the memory 242 may include tag information 1102, configuration logic 1103, positioning logic 1104, and communication logic 1105. The tag information 1102 may include or correspond to tag device information 309. The configuration information 1102 may be configured to generate one or more configurations or configuration data, such as TRP configuration 372, PRS configuration 381, MG configuration 382, tag device configuration, or combinations thereof. The positioning logic 1104 may be configured to determine the positioning of the tag device, such as the positioning 369 of tag device 120. The communication logic 1105 may be configured to enable communication between the network entity 1100 and one or more other devices. The network entity 1100 may receive signals from or send signals to one or more other devices, such as UE 115, base station 105, tag devices 120 or 322 to 325, reader device 121, core network 130, LMF 131, TRP 340, or tag devices as described in reference to Figure 13

[0172] Figure 12 is a flowchart illustrating an example process 1200 that supports backscatter-based positioning according to one or more aspects. The operations of process 1200 may be performed by a tag device, such as tag device 120 or 322 to 325 or reference Figure 13 ​The described tag device. For example, an example operation (also referred to as a "block") of process 1200 can enable the tag device to support backscatter-based positioning.

[0173] At block 1202, the tag device receives a tag configuration message indicating multiple tag configurations. For example, the tag configuration message can include or correspond to tag configuration message 380 or tag device information 309 or 366.

[0174] At block 1204, the tag device receives a PRS. For example, the PRS can include or correspond to PRS 374 or PRS information 307.

[0175] At block 1206, the tag device transmits a backscatter signal based on the PRS and a first tag configuration among the multiple tag configurations. The backscatter signal can include or correspond to backscatter signal 376 or measurement information 310. The first tag configuration can include or indicate a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0176] In some specific embodiments, the first tag configuration indicates a tag ID, a frequency shift parameter, a phase scrambling parameter, or a combination thereof. In some specific embodiments, the tag device determines that the tag ID of the first tag configuration indicates a first tag device. Additionally, the tag device can select the first tag configuration among the multiple tag configurations based on the tag ID.

[0177] In some specific embodiments, the tag device determines the RSSI or RSRP of the PRS. Additionally, the tag device can select a backscatter time frame window from the multiple backscatter time frame windows indicated by the tag configuration message based on the RSSI or RSRP. Further, the tag device backscatters the PRS based on the first backscatter time frame window.

[0178] In some specific embodiments, the multiple tag configurations include a first tag configuration for a first tag device and a second tag configuration for a second tag device. For example, the first tag configuration can indicate a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. As another example, the second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof.

[0179] In some specific implementations, the first preamble sequence and the second preamble sequence are the same sequence, and the first training sequence is different from the second training sequence. In some specific implementations, the first tag device and the second tag device are within the threshold range of the TRP (e.g., 606). In some specific implementations, the first tag device is within the first threshold range of the TRP, the second tag device is within the second threshold range of the TRP, and the first threshold range is different from and does not overlap with the second threshold range.

[0180] Figure 13 is a block diagram of an example tag device 1300 that supports backscatter-based positioning according to one or more aspects. The tag device 1300 may include or correspond to the tag device 130, the tag devices 322 to 325, or a combination thereof. For example, the tag device 1300 may include an RFID or IoT device. Additionally or alternatively, the tag device may include a passive device, a semi-passive device, or an active device.

[0181] The tag device 1300 may be configured to perform operations including referring to Figure 12 the blocks of the processes described. In some specific implementations, the tag device 1300 includes the structures, hardware, and components shown and described with reference to the tag device 130. For example, the tag device 1300 includes a controller 1380 that operates to execute logic or computer instructions stored in a memory 1382 and controls components that provide the features and functionality of the tag device 1300. The controller 1380 and the memory 1382 may include or correspond to the circuit 351. The tag device 1300 is configured to transmit and receive signals via a wireless radio component 1301 and an antenna 1352 under the control of the controller 1380. In some specific implementations, the wireless radio component 1301 and the antenna 1352 may include or correspond to a transmitter 356, a receiver 358, or a combination thereof. The wireless radio component 1301 includes various components and hardware. As an illustrative non-limiting example, as described with reference to Figure 2 the tag device 1300 may include modulators and demodulators 254a to 254r, a MIMO detector 256, a receive processor 258, a transmit processor 264, and a TX MIMO processor 266.

[0182] The tag device 1300 further includes an energy harvesting circuit 1390. The energy harvesting circuit 1390 may include or correspond to circuit 351. The energy harvesting circuit 1390 may include hardware (e.g., circuitry), software, or a combination thereof configured to harvest energy from an energy source of the tag device 1300. For example, as an illustrative non-limiting example, the energy source may include a solar energy source, a vibration energy source, a thermal energy source, or an RF energy source. The energy harvesting circuit 1390 may be coupled to circuitry such as the controller 1380, the memory 1382, the wireless radio component 1301, the power supply of the tag device 1300, or a combination thereof. In some embodiments, the harvested energy may be used to charge a power supply (such as a battery or a capacitor). The power supply may be coupled to the controller 1380, the memory 1382, the wireless radio component 1301, or a combination thereof. Additionally or alternatively, the harvested energy may be configured to power one or more components of the tag device 1300.

[0183] As shown, the memory 1382 may include tag capability information 1302, tag configuration information 1303, and communication logic 1304. The tag capability information 1302 may include or correspond to tag device information 309. The tag configuration information 1303 may correspond to the tag configuration. The communication logic 1304 may be configured to enable communication between the tag device 1300 and one or more other devices. The tag device 1300 may be configured to receive signals from or transmit signals to one or more network entities (base station 105, UE 115, reader device 121, core network 130, LMF 131, TRP 340, or network entities as Figure 11 illustrated therein).

[0184] Note that the tag device 1300 may include fewer or more components than those described with respect to Figure 13 . For example, in some embodiments, the tag device 1300 may include a power storage device. As another example, the tag device 1300 may not include the controller 1380.

[0185] Note that one or more of the blocks (or operations) described with reference to Figure 9 , Figure 10 , or Figure 12 may be combined with one or more of the blocks (or operations) described with reference to another figure. For example, Figure 9 one or more of the blocks (or operations) of Figure 10 may be combined with one or more of the blocks (or operations) of Figure 9 . As another example, one or more of the blocks of Figure 12 may be combined with one or more of the blocks (or operations) of Figure 10 . As yet another example, one or more of the blocks of Figure 12One or more combinations of boxes (or operations). For another example, Figure 9 , Figure 10 or Figure 12 One or more boxes of may be combined with Figures 4 to 7 One or more boxes (or operations). For another example, with Figure 9 , Figure 10 or Figure 12 One or more boxes (or operations) associated with may be combined with one or more boxes associated with the same Figures 1 to 3 . Additionally or alternatively, one or more operations described above with reference to Figures 1 to 7 may be combined with one or more operations described with reference to Figure 11 or Figure 13 .

[0186] In one or more aspects, techniques for supporting backscatter-based positioning may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes or devices described elsewhere herein. In a first aspect, techniques for supporting backscatter-based positioning may include sending a tag configuration message indicating a first tag configuration for a first tag device and a second tag configuration for a second tag device, and sending a PRS. These techniques may also include receiving a first backscatter signal based on the PRS from the first tag device, and receiving a second backscatter signal based on the PRS from the second tag device. These techniques may further include sending a measurement report indicating a first RTT of the first tag device and a second RTT of the second tag device. The first RTT may be based on the first configuration and the first backscatter signal, and the second RTT may be based on the second configuration and the second backscatter signal. In some examples, the techniques in the first aspect may be implemented in a method or process. In some other examples, the techniques of the first aspect may be implemented in a wireless communication device (such as a TRP, which may include a network entity, a base station, a reader device, a UE, or components thereof). In some examples, the wireless communication device may include at least one processing unit or system (which may include an application processor, a modem, or other components) and at least one memory device coupled to the processing unit. The processing unit may be configured to perform the operations described herein with respect to the wireless communication device. In some examples, the memory device includes a non-transitory computer-readable medium having program code stored thereon, the program code being configured to cause the wireless communication device to perform the operations described herein when executed by the processing unit. Additionally or alternatively, the wireless communication device may include an interface (e.g., a wireless communication interface) including a transmitter, a receiver, or a combination thereof. Additionally or alternatively, the wireless communication device may include one or more components configured to perform the operations described herein.

[0187] In a second aspect, in combination with the first aspect, the tag configuration message indicates a tag address, a frequency shift parameter, a phase scrambling parameter, a preamble sequence, a training sequence, a backscatter time frame window, or a combination thereof.

[0188] In a third aspect, in combination with the first aspect, the first tag configuration indicates a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

[0189] In a fourth aspect, in combination with the third aspect, the second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof.

[0190] In a fifth aspect, in combination with the fourth aspect, the first preamble sequence and the second preamble sequence are the same sequence, and the first training sequence is different from the second training sequence.

[0191] In a sixth aspect, in combination with the fourth aspect, the first preamble sequence and the second preamble sequence are the same sequence.

[0192] In a seventh aspect, in combination with the fourth aspect, the first training sequence and the second training sequence are the same training sequence.

[0193] In an eighth aspect, in combination with the fourth aspect, the first tag device is at a first estimated distance from the TRP, the second tag device is at a second estimated distance from the TRP, or a combination thereof.

[0194] In a ninth aspect, in combination with the eighth aspect, the first distance is the first estimated distance, the second tag distance is the second estimated distance, or a combination thereof.

[0195] In a tenth aspect, in combination with the eighth aspect, the techniques further include receiving a TRP configuration indicating the first distance, the second distance, or a combination thereof.

[0196] In an eleventh aspect, in combination with the eighth aspect, the first distance is determined based on a first RSSI / RSRP indicator corresponding to the first backscatter signal.

[0197] In a twelfth aspect, in combination with the eleventh aspect, the techniques further include determining the second distance based on a second RSSI / RSPR indicator corresponding to the second backscatter signal.

[0198] In a thirteenth aspect, in combination with the eighth aspect, the first distance is greater than the second estimated distance.

[0199] In a fourteenth aspect, in combination with the thirteenth aspect, the first backscatter time frame window is greater than the second backscatter time frame window.

[0200] In a fifteenth aspect, in combination with the eighth aspect, the first distance and the estimated distance are within a threshold range from the TRP.

[0201] In a sixteenth aspect, in combination with the sixteenth aspect, the first preamble sequence and the second preamble sequence are the same sequence.

[0202] In a seventeenth aspect, in combination with the sixteenth aspect, the techniques further include determining a backscatter channel gain of the first tag device based on a first portion of the first backscatter signal and the first preamble sequence.

[0203] In an eighteenth aspect, in combination with the sixteenth aspect, the first training sequence is different from the second training sequence.

[0204] In a nineteenth aspect, in combination with the eighteenth aspect, the techniques further include determining a first backscatter signal gain associated with the first tag device based on the first training sequence, the first preamble sequence, the first backscatter signal, or a combination thereof.

[0205] In a twentieth aspect, in combination with the nineteenth aspect, the techniques further include determining a second backscatter signal gain associated with the second tag device based on the second training sequence, the second preamble sequence, the second backscatter signal, or a combination thereof.

[0206] In a twenty - first aspect, in combination with the eighth aspect, the tag configuration message indicates a third tag configuration for a third tag device, a fourth tag configuration for a fourth tag device, or a combination thereof.

[0207] In a twenty - second aspect, in combination with one or more of the first aspect to the twenty - first aspect, the techniques further include receiving a third backscatter signal based on PRS from the third tag device.

[0208] In a twenty - third aspect, in combination with the twenty - second aspect, the techniques further include receiving a fourth backscatter signal based on PRS from the fourth tag device.

[0209] In a twenty - fourth aspect, in combination with the twenty - third aspect, the third tag device is at a third distance from the TRP, and the fourth tag device is at a fourth distance from the TRP.

[0210] In a twenty - fifth aspect, in combination with the twenty - fourth aspect, the techniques further include assigning the first tag device and the third tag device to a first group based on the first distance and the third distance.

[0211] In a twenty - sixth aspect, in combination with the twenty - fifth aspect, the techniques further include assigning the second tag device and the fourth tag device to a second group based on the second distance and the fourth distance.

[0212] In a twenty-seventh aspect, in combination with the twenty-fourth aspect, the first distance and the third distance are within a first threshold range of the TRP.

[0213] In a twenty-eighth aspect, in combination with the twenty-seventh aspect, the second distance and the fourth distance are within a second threshold range of the TRP, the second threshold range being different from and non-overlapping with the first threshold range.

[0214] In a twenty-ninth aspect, in combination with the twenty-eighth aspect, the third tag configuration indicates a third training sequence different from the first training sequence; the fourth tag configuration indicates a fourth training sequence different from the second training sequence; or a combination thereof.

[0215] In a thirtieth aspect, in combination with the twenty-eighth aspect, the techniques further include determining a first backscatter signal gain associated with the first tag device based on the first training sequence, the first preamble sequence, and the first backscatter signal.

[0216] In a thirty-first aspect, in combination with the thirtieth aspect, the techniques further include determining a third backscatter signal gain associated with the third tag device based on the third training sequence, the third preamble sequence, and the third backscatter signal.

[0217] In a thirty-second aspect, in combination with the thirty-first aspect, the first preamble sequence and the third preamble sequence are the same preamble sequence.

[0218] In one or more aspects, techniques for supporting backscatter-based positioning may include additional aspects, such as any individual aspect or any combination of aspects described below or in combination with one or more other processes or devices described elsewhere herein. In a thirty-third aspect, techniques for supporting backscatter-based positioning may include transmitting a TRP configuration that indicates first information associated with a first tag device and second information associated with a second tag device. The first information includes or indicates a first positioning of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. The second information includes or indicates a second positioning of the second tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof. These techniques may also include receiving, from the TRP, a measurement report indicating a first RTT and a second RTT. The first RTT is based on the first information and a first backscatter signal, and the second RTT is based on the second information and a second backscatter signal. In some examples, the techniques in the thirty-third aspect may be implemented in a method or process. In some other examples, the techniques in the thirty-third aspect may be implemented in a communication device or a communication system. For example, the communication device may include a wireless communication device, such as a network entity, a core network, an LMF, a UE, a base station, a reader device, a TRP, or a component thereof. In some examples, the wireless communication device may include at least one processing unit or system (which may include an application processor, a modem, or other components) and at least one memory device coupled to the processing unit. The processing unit may be configured to perform the operations described herein with respect to the wireless communication device. In some examples, the memory device includes a non-transitory computer-readable medium having program code stored thereon that, when executed by the processing unit, is configured to cause the wireless communication device to perform the operations described herein. Additionally or alternatively, the wireless communication device may include an interface (e.g., a wireless communication interface) that includes a transmitter, a receiver, or a combination thereof. Additionally or alternatively, the wireless communication device may include one or more components configured to perform the operations described herein.

[0219] In a thirty-fourth aspect, in combination with the thirty-third aspect, the first information indicates a first preamble sequence, and the second preamble indicates a second preamble sequence.

[0220] In a thirty-fifth aspect, in combination with the thirty-third through thirty-fourth aspects, the first preamble sequence and the second preamble sequence are the same preamble sequence.

[0221] In a thirty-sixth aspect, in combination with one or more of the thirty-third through thirty-fifth aspects, the first information further indicates a tag ID, a frequency shift parameter, a phase scrambling parameter, or a combination thereof.

[0222] In a thirty-seventh aspect, in combination with one or more of the thirty-third to thirty-sixth aspects, the TRP configuration indicates a first configuration for a first tag device and a second configuration for a second tag device.

[0223] In a thirty-eighth aspect, in combination with the thirty-seventh aspect, the first configuration includes first information and the second configuration includes second information.

[0224] In a thirty-ninth aspect, in combination with one or more of the thirty-third to thirty-eighth aspects, the techniques further include determining an RSSI or an RSRP associated with the first tag device and generating first information based on the RSSI or the RSRP.

[0225] In a fortieth aspect, in combination with one or more of the thirty-third to thirty-ninth aspects, the first positioning includes an estimated positioning of the first tag device.

[0226] In a forty-first aspect, in combination with one or more of the thirty-third to fortieth aspects, the techniques further include determining an updated positioning of the first tag device based on a first measurement report.

[0227] In one or more aspects, techniques for supporting backscatter-based positioning may include additional aspects, such as any individual aspect or any combination of aspects described below or in combination with one or more other processes or devices described elsewhere herein. In a forty-second aspect, techniques for supporting backscatter-based positioning may include receiving a tag configuration message that includes or indicates a plurality of tag configurations, and receiving a PRS. These techniques may also include transmitting a backscatter signal based on the PRS and a first tag configuration among the plurality of tag configurations. The first tag configuration includes or indicates a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof. In some examples, the techniques in the forty-second aspect may be implemented in a method or process. In some other examples, the techniques in the forty-second aspect may be implemented in a wireless communication device (such as a tag device or an IoT device), which may include a passive tag, a semi-passive tag, an active tag, a UE, an RFID, or components thereof. In some examples, the wireless communication device may include circuitry such as at least one processing unit or system (which may include an application processor, a modem, or other components) and at least one memory device coupled to the processing unit, as illustrated by non-limiting examples. The processing unit may be configured to perform the operations described herein with respect to the wireless communication device. In some examples, the memory device includes a non-transitory computer-readable medium having program code stored thereon, which when executed by the processing unit is configured to cause the wireless communication device to perform the operations described herein. Additionally or alternatively, the wireless communication device may include an interface (e.g., a wireless communication interface) that includes a transmitter, a receiver, or a combination thereof. Additionally or alternatively, the wireless communication device may include one or more components configured to perform the operations described herein.

[0228] In a forty-third aspect, in combination with the forty-second aspect, the first tag configuration indicates a tag ID, a frequency shift parameter, a phase scrambling parameter, or a combination thereof.

[0229] In a forty-fourth aspect, in combination with the forty-third aspect, these techniques also include determining that the tag ID of the first tag configuration indicates a first tag device.

[0230] In a forty-fifth aspect, in combination with the forty-fourth aspect, these techniques also include selecting the first tag configuration among the plurality of tag configurations based on the tag ID.

[0231] In a forty-sixth aspect, in combination with the forty-third aspect, these techniques also include determining the RSSI or RSRP of the PRS.

[0232] In a forty-seventh aspect, in combination with the forty-sixth aspect, these techniques also include selecting a backscatter time frame window from the plurality of backscatter time frame windows indicated by the tag configuration message based on the RSSI or the RSRP.

[0233] In a forty-eighth aspect, in combination with the forty-seventh aspect, these techniques further include backscattering PRS based on a first backscattering time frame window.

[0234] In a forty-ninth aspect, in combination with the forty-second aspect, the plurality of tag configurations includes a first tag configuration for a first tag device and a second tag configuration for a second tag device.

[0235] In a fiftieth aspect, in combination with the forty-ninth aspect, the first tag configuration indicates a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscattering time frame window, or a combination thereof.

[0236] In a fifty-first aspect, in combination with the fiftieth aspect, the second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscattering time frame window, or a combination thereof.

[0237] In a fifty-second aspect, in combination with the fifty-first aspect, the first preamble sequence and the second preamble sequence are the same sequence, and the first training sequence is different from the second training sequence.

[0238] In a fifty-third aspect, in combination with the forty-ninth aspect, the first tag device and the second tag device are within a threshold range of the TRP.

[0239] In a fifty-fourth aspect, in combination with the forty-ninth aspect, the first tag device is within a first threshold range of the TRP.

[0240] In a fifty-fifth aspect, in combination with the fifty-fourth aspect, the second tag device is within a second threshold range of the TRP.

[0241] In a fifty-sixth aspect, in combination with the fifty-fifth aspect, the first threshold range is different from and does not overlap with the second threshold range.

[0242] Those skilled in the art should understand that any one of a variety of different techniques and arts can be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0243] This article regarding Figures 1 to 13The described components, functional blocks, and modules include processors, electronic devices, hardware devices, electronic components, logic circuits, memories, software code, firmware code, and so on, or any combination thereof. Software should be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and / or functions, etc., regardless of whether it is referred to as software, firmware, middleware, microcode, hardware description language, or other terms. Additionally, the features discussed herein can be implemented via dedicated processor circuitry, via executable instructions, or a combination thereof.

[0244] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and the design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such specific implementation decisions should not be interpreted as causing a departure from the scope of the disclosure. Skilled artisans will also readily recognize that the order or combination of the components, methods, or interactions described herein are merely examples, and that the components, methods, or interactions of the various aspects of the disclosure can be combined or performed in ways other than those illustrated and described herein.

[0245] The various illustrative logical components, logical blocks, modules, circuits, and algorithmic processes described in connection with the specific implementations disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. The interchangeability of hardware and software has been generally described in terms of functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented as hardware or software depends upon the particular application and the design constraints imposed on the overall system.

[0246] The hardware and data processing apparatus for implementing or performing the various illustrative logics, logic blocks, modules, and circuits described in connection with the aspects disclosed herein can be implemented or performed using a general single-chip or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof that are designed to perform the functions described herein. The general processor can be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. In some particular implementations, the processor can be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. In some particular implementations, specific processes and methods can be performed by circuitry specific to a given function.

[0247] In one or more aspects, the described functions can be implemented in hardware, digital electronic circuits, computer software, firmware, including the structures disclosed in this specification and their structural equivalents, or any combination thereof. The particular implementations of the subject matter described in this specification can also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by, or to control the operation of, a data processing apparatus.

[0248] If implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. The processes of the methods or algorithms disclosed herein may be implemented in a processor-executable software module that may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be implemented to transfer a computer program from one place to another. The storage media may be any available media accessible by a computer. By way of example and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and that can be accessed by a computer. Additionally, any connection may be properly termed a computer-readable medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. Additionally, operations of a method or algorithm may reside as one or any combination of code and instruction sets on a machine-readable medium and a computer-readable medium, which may be incorporated into a computer program product.

[0249] Various modifications to the specific embodiments described in this disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to some other specific embodiments without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the specific embodiments shown herein but are to be accorded the broadest scope consistent with this disclosure, the principles disclosed herein, and the novel features.

[0250] Additionally, those of ordinary skill in the art will readily recognize that the terms “upper” and “lower” are sometimes used for ease of description of the figures and indicate relative positions corresponding to the orientation of the figures on a properly oriented page and may not reflect the correct orientation of any device as implemented.

[0251] Certain features that are described in the context of separate embodiments in this specification can also be implemented in a single embodiment in combination. Conversely, the various features that are described in the context of a single embodiment can also be implemented separately or in any suitable sub-combination in multiple embodiments. Additionally, although features may have been described above as acting in certain combinations and even initially claimed as such, one or more features from the claimed combination can in some cases be removed from the combination, and the claimed combination can be directed to a sub-combination or variations of the sub-combination.

[0252] Similarly, although operations are depicted in the figures in a particular order, this should not be construed as requiring that such operations be performed in the particular order shown or in a sequential order, or that all of the illustrated operations be performed to achieve the desired result. Additionally, the figures may schematically depict one or more example processes in the form of a flowchart. However, other operations not depicted can be incorporated into the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously with, or between any of the illustrated operations. In certain environments, multitasking and parallel processing are advantageous. Further, the separation of the various system components in the embodiments described above should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, some other embodiments also fall within the scope of the appended claims. In some cases, the acts recited in the claims can be performed in a different order and still achieve the desired result.

[0253] As used herein (including in the claims), the term "or" as used in a list of two or more items means that any one of the listed items can be employed individually, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, or C, the composition can contain A alone; B alone; C alone; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C. Further, as used herein (including in the claims), "or" as used in a list of items beginning with "at least one" indicates a disjunctive list such that, for example, a list of "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any combination of any of these items. The term "substantially" is defined as being largely but not necessarily wholly that which is specified (and includes that which is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by one of ordinary skill in the art. In any of the particular embodiments disclosed, the term "substantially" can be replaced by "[percentage] within" the specified content, where the percentage includes 0.1%, 1%, 5%, or 10%.

[0254] The foregoing description of the disclosure has been provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of wireless communication performed by a transmit / receive point (TRP), the method comprising: Sending a tag configuration message indicating a first tag configuration and a second tag configuration; Sending a positioning reference signal (PRS); Receiving a first backscatter signal based on the PRS from a first tag device; Receiving a second backscatter signal based on the PRS from a second tag device; And Sending a measurement report indicating: A first round-trip time (RTT) of the first tag device based on the first tag configuration and the first backscatter signal, and A second RTT of the second tag device based on the second tag configuration and the second backscatter signal.

2. The method according to claim 1, wherein the tag configuration message indicates a tag address, a frequency shift parameter, a phase scrambling parameter, a preamble sequence, a training sequence, a backscatter time frame window, or a combination thereof.

3. The method according to claim 1, wherein: The tag configuration message includes a threshold such that the first tag device can select one of the first tag configuration or the second tag configuration based on a first received signal strength indicator (RSSI) / reference signal received power (RSRP) indicator of the PRS.

4. The method according to claim 1, wherein: The first tag configuration indicates a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof; The second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof; or A combination thereof.

5. The method according to claim 4, wherein: The first tag device is at a first distance from the TRP; The second tag device is at a second distance from the TRP; The first distance is greater than the second distance; The first backscatter time frame window is longer than the second backscatter time frame window; and A first duration of the first backscatter signal is greater than a second duration of the second backscatter signal.

6. The method according to claim 4, wherein: The first preamble sequence and the second preamble sequence are the same sequence, and The first training sequence is different from the second training sequence.

7. The method according to claim 6, further comprising: Determining a first backscatter channel gain of the first tag device based on a first portion of the first backscatter signal, the first preamble sequence, and the first training sequence; Determining the first RTT based on the first backscatter channel gain and the first backscatter signal; Determining a second backscatter channel gain associated with the second tag device based on the second training sequence, the second preamble sequence, the second backscatter signal, or a combination thereof; and Determining the second RTT based on the second backscatter channel gain and the second backscatter signal.

8. The method according to claim 1, further comprising: Receive a TRP configuration indicating a first distance, a second distance, or a combination thereof, and wherein: The first tag device is at a first distance from the TRP, or The second tag device is at a second distance from the TRP.

9. The method according to claim 8, wherein: The first distance is a first estimated distance; The second distance is a second estimated distance; or A combination thereof.

10. The method according to claim 1, wherein: The first tag device is at a first distance from the TRP; The second tag device is at a second distance from the TRP; A third tag device is at a third distance from the TRP; A fourth tag device is at a fourth distance from the TRP; The first distance and the third distance are within a first threshold range of the TRP; and The second distance and the fourth distance are within a second threshold range of the TRP, the second threshold range being different from and non-overlapping with the first threshold range.

11. The method according to claim 10, further comprising: Assigning the first tag device and the third tag device to a first group based on the first distance and the third distance, the first group being associated with a first backscatter time frame window; And Assigning the second tag device and the fourth tag device to a second group based on the second distance and the fourth distance, the second group being associated with a second backscatter time frame window; Receiving a third backscatter signal based on the PRS from the third tag device; And Receiving a second backscatter signal based on the PRS from the fourth tag device.

12. A transmit / receive point (TRP), comprising: A memory that stores processor-readable code; And At least one processor coupled to the memory, the at least one processor being configured to execute the processor-readable code to cause the at least one processor to: Send a tag configuration message indicating a first tag configuration and a second tag configuration; Send a positioning reference signal (PRS); Receive a first backscatter signal based on the PRS from a first tag device; Receive a second backscatter signal based on the PRS from a second tag device; And Send a measurement report indicating: A first round-trip time (RTT) of the first tag device based on the first tag configuration and the first backscatter signal, and A second RTT of the second tag device based on the second tag configuration and the second backscatter signal.

13. The TRP according to claim 12, wherein the tag configuration message indicates a tag address, a frequency shift parameter, a phase scrambling parameter, a preamble sequence, a training sequence, a backscatter time frame window, or a combination thereof.

14. The TRP according to claim 12, wherein the tag configuration message includes a threshold such that the first tag device can select one of the first tag configuration or the second tag configuration based on a first received signal strength indicator (RSSI) or a reference signal received power (RSRP) determined based on the PRS.

15. The TRP according to claim 12, wherein: the at least one processor is further configured to execute the processor-readable code to cause the at least one processor to receive a TRP configuration indicating a first distance, a second distance, or a combination thereof; and the first tag device is at a first distance from the TRP; or the second tag device is at a second distance from the TRP.

16. The TRP according to claim 12, wherein: the first tag configuration indicates a first frequency shift parameter, a first phase scrambling parameter, a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof; the second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof; or a combination thereof.

17. The TRP according to claim 16, wherein: the at least one processor is further configured to execute the processor-readable code to cause the at least one processor to: determine a first backscatter channel gain of the first tag device based on a first portion of the first backscatter signal, the first preamble sequence, and the first training sequence; determine the first RTT based on the first backscatter channel gain and the first backscatter signal; determine a second backscatter channel gain associated with the second tag device based on the second training sequence, the second preamble sequence, the second backscatter signal, or a combination thereof; and determine the second RTT based on the second backscatter channel gain and the second backscatter signal; the first preamble sequence and the second preamble sequence are the same sequence; and the first training sequence is different from the second training sequence.

18. The TRP according to claim 16, wherein: the first tag device is at a first distance from the TRP; the second tag device is at a second distance from the TRP; the first distance is greater than the second distance; the first backscatter time frame window is longer than the second backscatter time frame window; and a first duration of the first backscatter signal is greater than a second duration of the second backscatter signal.

19. A method for wireless communication performed by a network entity, the method comprising: sending a transmit / receive point (TRP) configuration, the transmit / receive point (TRP) configuration indicating: first information associated with a first tag device, the first information indicating a first location of the first tag device, a first training sequence for the first tag device, a first backscatter time frame window for the first tag device, or a combination thereof, and second information associated with a second tag device, the second information indicating a second location of the second tag device, a second training sequence for the second tag device, a second backscatter time frame window for the second tag device, or a combination thereof; and receiving a measurement report from the TRP, the measurement report indicating: The first round-trip time (RTT) of the first tag device based on the first information and the first backscatter signal, and the second RTT of the second tag device based on the second information and the second backscatter signal.

20. The method according to claim 19, wherein: the first information indicates a first preamble sequence, and the second information indicates a second preamble sequence, or the first information further indicates a tag ID, a frequency shift parameter, a phase scrambling parameter, or a combination thereof.

21. The method according to claim 20, wherein the first preamble sequence and the second preamble sequence are the same preamble sequence.

22. The method according to claim 19, wherein: the TRP configuration indicates a first configuration for the first tag device and a second configuration for the second tag device; and the first configuration includes the first information, and the second configuration includes the second information.

23. The method according to claim 19, further comprising: determining a received signal strength indicator (RSSI) or a reference signal received power (RSRP) associated with the first tag device; and generating the first information based on the RSSI or the RSRP.

24. The method according to claim 19, further comprising: determining an updated location of the first tag device based on the measurement report, and wherein the first location includes an estimated location of the first tag device.

25. A method of wireless communication performed by a first tag device, the method comprising: receiving a tag configuration message indicating a plurality of tag configurations; receiving a positioning reference signal (PRS); and transmitting a backscatter signal based on the PRS and a first tag configuration among the plurality of tag configurations, the first tag configuration indicating a first preamble sequence, a first training sequence, a first backscatter time frame window, or a combination thereof.

26. The method according to claim 25, wherein the first tag configuration indicates a tag ID, a frequency shift parameter, a phase scrambling parameter, or a combination thereof.

27. The method according to claim 26, further comprising: determining that the tag ID of the first tag configuration indicates the first tag device; and selecting the first tag configuration among the plurality of tag configurations based on the tag ID.

28. The method according to claim 25, further comprising: determining a received signal strength indicator (RSSI) or a reference signal received power (RSRP) of the PRS; selecting the first backscatter time frame window from a plurality of backscatter time frame windows indicated by the tag configuration message based on the RSSI or the RSRP; and backscattering the PRS based on the first backscatter time frame window.

29. The method according to claim 25, wherein: the plurality of tag configurations includes the first tag configuration for the first tag device and a second tag configuration for a second tag device; The first tag configuration indicates a first frequency shift parameter, a first phase scrambling parameter, the first preamble sequence, the first training sequence, the first backscatter time frame window, or a combination thereof; The second tag configuration indicates a second frequency shift parameter, a second phase scrambling parameter, a second preamble sequence, a second training sequence, a second backscatter time frame window, or a combination thereof; or A combination thereof.

30. The method according to claim 25, wherein: The plurality of tag configurations includes the first tag configuration for the first tag device and a second tag configuration for a second tag device; The first tag device is within a first threshold range of a transmit / receive point (TRP); The second tag device is within a second threshold range of the TRP; and The first threshold range is different from and does not overlap with the second threshold range.

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