Surface acoustic wave (SAW) 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 receiving a plurality of measurement reports associated with a surface acoustic wave (SAW) tag device. For each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports includes a measurement report for the TRPs. The method also includes determining a location of the SAW tag device based on the plurality of measurement reports. Other aspects and features are also claimed and described.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Patent Application No. 18 / 073,488, filed on December 1, 2022, entitled "SURFACE ACOUSTIC WAVE (SAW) BACKSCATTER - BASED POSITIONING", 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, such as backscatter - based positioning of surface acoustic wave (SAW) devices. Some features may enable and provide improved communication, including reduced control overhead, efficient resource utilization, improved network access, improved ranging measurements, position determination, transmit / receive point (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 UE 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 radio 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 communities, the likelihood of interference and congested networks is also increasing. 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 generally include a reader device, referred to as a reader, and one or more tag devices, such as RFID tag devices. The reader typically suffers from self-interference or interference caused by signals reflected in the environment near the reader, such as reflections from static or moving objects. Self-interference can be a particularly severe problem when the reader operates in full-duplex mode. The tag device generally includes 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). Thus, the use of tag devices applied to current 3GPP technologies (such as coexistence with User Equipment (UE)) and the infrastructure in the frequency bands for current 3GPP technologies 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 OF THE INVENTION

[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 the expected features of the present disclosure and is neither intended to identify the key or important elements of all aspects of the present disclosure nor to depict 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 general form as a prelude to the more detailed embodiments that are presented later.

[0010] In one aspect of the present disclosure, a method for wireless communication is performed by a Transmit / Receive Point (TRP). The method includes transmitting a tag configuration indicator indicating a first tag configuration for a first tag device. The first tag configuration indicates a reflector configuration. The method further includes receiving, in response to a Positioning Reference Signal (PRS), a first backscatter signal from the first tag device. The first backscatter signal is based on the first tag configuration.

[0011] In an additional aspect of the present disclosure, a device 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 indicator indicating a first tag configuration for a first tag device. The first tag configuration indicates a reflector configuration. The at least one processor is further configured to receive a first backscatter signal from the first tag device in response to PRS. The first backscatter signal is based on the first tag configuration.

[0012] In an additional aspect of the present disclosure, a device 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 tag configuration indicator indicating a first tag configuration for a first tag device. The first tag configuration indicates a reflector configuration. The device further includes a communication interface configured to send the tag configuration indicator and to receive a first backscatter signal from the first tag device in response to PRS. The first backscatter signal is based on the first tag configuration.

[0013] In an additional aspect of the present disclosure, a device includes means for sending a tag configuration indicator indicating a first tag configuration for a first tag device. The first tag configuration indicates a reflector configuration. The device further includes means for receiving a first backscatter signal from the first tag device in response to PRS. The first backscatter signal is based on the first tag configuration.

[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 indicator indicating a first tag configuration for a first tag device. The first tag configuration indicates a reflector configuration. The operations further include receiving a first backscatter signal from the first tag device in response to PRS. The first backscatter signal is based on the first tag configuration.

[0015] 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 indicator indicating a tag configuration for the tag device. The tag configuration indicates a reflector configuration. The method further includes sending a backscatter signal in response to PRS based on the tag configuration.

[0016] In an additional aspect of the present disclosure, a device 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 indicator indicating a tag configuration for the tag device. The tag configuration indicates a reflector configuration. The at least one processor is further configured to send a backscatter signal in response to PRS based on the tag configuration.

[0017] In an additional aspect of the present disclosure, a device includes a communication interface configured to receive a tag configuration indicator indicative of a tag configuration for the tag device. The tag configuration indicates a reflector configuration. The device 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 backscatter signal in response to a PRS based on the tag configuration.

[0018] In an additional aspect of the present disclosure, a device includes means for receiving a tag configuration indicator indicative of a tag configuration for the tag device. The tag configuration indicates a reflector configuration. The device further includes means for transmitting a backscatter signal in response to a PRS based on the tag configuration.

[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 receiving a tag configuration indicator indicative of a tag configuration for the tag device. The tag configuration indicates a reflector configuration. The operations further include transmitting a backscatter signal in response to a PRS based on the tag configuration.

[0020] In an additional aspect of the present disclosure, a method for wireless communication is performed by a network entity. The method includes receiving a plurality of measurement reports associated with a surface acoustic wave (SAW) tag device. For each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports includes a measurement report for the TRP. The method further includes determining a location of the SAW tag device based on the plurality of measurement reports.

[0021] In an additional aspect of the present disclosure, a device 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 plurality of measurement reports associated with a SAW tag device. For each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports includes a measurement report for the TRP. The at least one processor is further configured to determine a location of the SAW tag device based on the plurality of measurement reports.

[0022] In an additional aspect of the present disclosure, a device includes a communication interface configured to receive a plurality of measurement reports associated with a SAW tag device. For each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports includes a measurement report for the TRP. The device 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 determine a location of the SAW tag device based on the plurality of measurement reports.

[0023] In an additional aspect of the present disclosure, an apparatus includes means for receiving a plurality of measurement reports associated with a SAW tag device. For each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports includes a measurement report for that TRP. The apparatus further includes means for determining a location of the SAW tag device based on the plurality of measurement reports.

[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 plurality of measurement reports associated with a SAW tag device. For each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports includes a measurement report for that TRP. The operations further include determining a location of the SAW tag device based on the plurality of measurement reports.

[0025] The features and technical advantages of examples in accordance with the present disclosure have been outlined rather broadly above so 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. When considered in conjunction with the accompanying drawings, the characteristics (both the organization and method of operation) of the concepts disclosed herein, as well as the associated advantages, will be better understood. Each of the drawings provided is for the purpose of illustration and description only and is not a definition of the limits of the claims.

[0026] While aspects and specific implementations are described herein by way of some examples, 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, packaging arrangements. For example, aspects and / or uses can be implemented via integrated chips and other devices based on non-module components (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 specifically refer to use cases or applications, 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 the scope of aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical environments, devices incorporating the described aspects and features may also necessarily include additional components and features for implementing and practicing the claimed and described aspects. 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 label. Additionally, various components of the same type can be distinguished by adding a dash and a second label used to differentiate between like components after the reference label. If only the first reference label is used in the specification, the description applies to any one of the like components having the same first reference label, regardless of the second reference label.

[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 4Is a diagram illustrating an example surface acoustic wave (SAW) tag device that supports backscatter-based positioning according to one or more aspects.

[0032] Figure 5 Is a graph of a positioning reference signal and a backscatter signal that supports backscatter-based positioning according to one or more aspects.

[0033] Figure 6 Is a diagram illustrating another example SAW tag device that supports backscatter-based positioning according to one or more aspects.

[0034] Figure 7 Is a block diagram of another example of a system that supports backscatter-based positioning according to one or more aspects.

[0035] Figure 8 Is a block diagram of another example of a system that supports backscatter-based positioning according to one or more aspects.

[0036] Figure 9 Is a block diagram of another example of a system that supports backscatter-based positioning according to one or more aspects.

[0037] Figure 10 Is a block diagram of another example of a system that supports backscatter-based positioning according to one or more aspects.

[0038] Figure 11 Is a flowchart illustrating an example process that supports backscatter-based positioning according to one or more aspects.

[0039] Figure 12 Is a block diagram of an example tag device that supports backscatter-based positioning according to one or more aspects.

[0040] Figure 13 Is a flowchart illustrating an example process that supports backscatter-based positioning according to one or more aspects.

[0041] Figure 14 Is a flowchart illustrating an example process that supports backscatter-based positioning according to one or more aspects.

[0042] Figure 15 Is a block diagram of an example network entity that supports backscatter-based positioning according to one or more aspects.

[0043] Identical reference numerals and names in different figures indicate the same elements. Detailed Description

[0044] The following detailed description, presented in conjunction with the accompanying drawings, is intended as a description of various configurations and is not intended to limit the scope of the present disclosure. On the contrary, the detailed description includes 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 instance, and in some examples, well-known structures and components are shown in block diagram form for the sake of clarity of presentation.

[0045] The present disclosure provides systems, devices, methods, and computer-readable media that support backscatter-based positioning. For example, the present disclosure describes positioning a tag device, such as a passive Internet of Things (IoT) device or a surface acoustic wave (SAW) device, via backscatter transmission. A location management function (LMF) of a 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).

[0046] The present disclosure describes techniques for reducing or eliminating the detrimental effects of these types of interference. By way of illustration, the LMF may determine a tag configuration for the tag device, such as a surface acoustic wave (SAW) tag device that includes multiple reflectors, interdigital transducers, a controller, or a combination thereof. The tag configuration may include or indicate a reflector configuration, such as a first set of reflectors among the multiple reflectors of the tag device will be activated, a second set of reflectors among the multiple reflectors will be deactivated, or a combination thereof. Additionally or alternatively, the tag configuration may indicate one reflector among the multiple reflectors of the first tag device to be configured as an initial reflector, the configuration of the multiple reflectors, or frequency response parameters. The frequency response parameters may include or indicate an up-chirp or a down-chirp, a frequency offset, or a combination thereof. In some embodiments, the tag configuration may additionally or alternatively include or indicate an amplitude, a phase shift, or a frequency associated with the first backscatter signal. In some embodiments, the tag configuration further indicates a tag address of the tag device or a tag address associated with the tag device. The tag address may include or indicate an active state of at least one reflector of the first tag device. In some embodiments, the tag device may receive the tag configuration and determine whether the first tag configuration is for the tag device based on the tag address (e.g., tag ID or group ID) included in or indicated by the tag configuration.

[0047] In some aspects, the tag configuration indicates another tag configuration for a second tag device among multiple tag devices. By way of illustration, the multiple tag devices may include a beacon device and a second tag device. The another tag configuration may indicate that the second tag device deactivates a set of reflectors of the second tag device. In some embodiments, the another tag configuration indicates that the second tag deactivates all of its reflectors. Additionally or alternatively, the TRP may receive a second backscatter signal from the second tag device in response to the PRS. The second backscatter signal may be based on other tag configurations.

[0048] In some embodiments, the LMF may identify a tag device for positioning, such as a SAW tag device, and configure multiple TRPs for a tag device positioning session. For example, the LMF may configure one or more TRPs to transmit respective positioning reference signals (PRSs) and receive respective backscatter signals. In some embodiments, a first TRP may be configured to monitor or detect a first reflection of a backscatter signal from the SAW tag device, and a second TRP may be configured to monitor or detect a second reflection of the backscatter signal from the SAW tag device. Additionally or alternatively, each of the one or more TRPs may be configurable for full-duplex operation, asynchronous, or a combination thereof. The LMF may receive multiple measurement reports associated with the tag device. For example, for each of the multiple TRPs, the multiple measurement reports may include a measurement report of that TRP. The LMF may determine the positioning of a tag device having a tag delay that is unknown to the LMF based on the multiple measurement reports. The tag delay may include radio frequency group delays of one or more components of the tag device. To determine the positioning, the LMF may determine a set of time differences based on the multiple measurement reports. By way of illustration, the multiple TRPs include a reference TRP and a set of TRPs, and the LMF may determine a measurement value for each of the multiple TRPs based on the measurement report of that TRP. To determine the set of time differences, the LMF may, for each of the set of TRPs, subtract the measurement value of the reference TRP from the measurement value of that TRP to determine a difference, and divide the difference by two to determine a quotient that includes a time difference in the set of time differences. The LMF may calculate the positioning of the tag device using the time difference of arrival technique based on the set of time differences.

[0049] Specific embodiments that can implement the subject matter described in this disclosure can 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 positioning of tag devices (such as SAW tag devices) with limited on-board power and computing resources, such as two-dimensional or three-dimensional positioning. In some specific embodiments, one or more tag devices (such as SAW tag devices) can be configured to enable a TRP-identifiable backscatter signal. For example, the configuration indicates one reflector among a plurality of reflectors of a first tag device to be configured as an initial reflector, the configuration of the plurality of reflectors, frequency response parameters, or amplitude, phase shift, or frequency associated with the backscatter signal. Additionally, when the tag delay of the tag device is unknown or unavailable, the LMF can determine the positioning of the SAW tag device based on one or more measurement reports. For example, when the tag delay of the tag device is unknown or unavailable to the LMF (e.g., unknown or unavailable to the device for calculating the positioning of the tag device), the LMF can perform measurements for TRP-based TDoA backscatter-based positioning of multiple TRPs.

[0050] This 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 specific embodiments, the techniques and devices 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.

[0051] CDMA networks 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.

[0052] For example, a TDMA network may implement radio technologies such as 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 GSM / EDGE together with the network connecting base stations (such as the Ater and Abis interfaces) and base station controllers (the A interface, etc.). The radio access network represents the component 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 may include one or more GERANs, which may be coupled to the UTRAN in the case of a UMTS / GSM network. Additionally, the operator network may also include one or more LTE networks, or one or more other networks. Various different network types may use different Radio Access Technologies (RATs) and RANs.

[0053] An OFDMA network may 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 named "3rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These radio technologies and standards are known or under development. For example, 3GPP is a cooperation among telecommunication association groups aimed at defining globally applicable third-generation (3G) mobile phone specifications. 3GPP LTE is a 3GPP plan aimed at improving the UMTS mobile phone standard. 3GPP may define the specifications for next-generation mobile networks, mobile systems, and mobile devices. Certain aspects of the present disclosure may be described with reference to LTE, 4G, or 5G NR technologies; however, the 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 be applicable to another technology. Additionally, one or more aspects of the present disclosure may relate to shared access to the radio spectrum between networks using different radio access technologies or radio air interfaces.

[0054] The 5G network is expected to have diverse deployments, diverse spectrums, and diverse services and devices enabled by a unified OFDM-based air interface. To achieve these goals, in addition to developing new radio technologies for the 5G NR network, 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+ year 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 10Tbps / km 2 ), extremely high data rates (e.g., multi-Gbps rates, 100+ Mbps user experience rates), and deep awareness with advanced discovery and optimization.

[0055] 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, frequency bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating frequency bands have been identified as Frequency Range Designation 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.

[0056] Taking the above aspects into account, unless otherwise specifically stated, it should be understood that if used in this document, terms such as "sub-6 GHz" can generally 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 in this document, 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.

[0057] 5G NR devices, networks, and systems can be implemented to use waveform features based on optimized OFDM. These features can include scalable parameter sets and transmission time intervals (TTIs); 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 parameter sets in 5G NR and the scaling of 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 FDD or TDD below 3 GHz, the subcarrier spacing may occur at 15 kHz, such as for bandwidths exceeding 1 MHz, 5 MHz, 10 MHz, 20 MHz, etc. For other various outdoor and small cell coverage deployments with TDD above 3 GHz, the subcarrier spacing may occur at 30 kHz for 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 for 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 for a 500 MHz bandwidth.

[0058] The scalable parameter sets of 5G NR contribute to scalable TTIs 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 adaptive uplink or downlink can be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet current traffic demands.

[0059] 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 illustrative examples in parts of the description below; however, the description is not intended to be limited to 5G applications.

[0060] 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.

[0061] While aspects and specific implementations are described in this application by way of illustration of some examples, 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, 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 or point-of-purchase device, a medical device, an AI-enabled device, etc.). While 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, devices that incorporate the described aspects and features may also necessarily include additional components and features for implementing and practicing the aspects claimed and described. It is intended that the innovations described herein 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.

[0062] 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 as well as non-cellular-style network arrangements (e.g., device-to-device or peer-to-peer or ad-hoc network arrangements, etc.).

[0063] 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 geographic area. In 3GPP, the term "cell" can refer to the specific geographic 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 operating entity. In some other examples, each base station 105 and UE 115 can be operated by a single network operating entity.

[0064] 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 geographic 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 will cover a relatively small geographic 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 will also cover a relatively small geographic area (e.g., a home), and in addition to unrestricted access, 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.). 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.

[0065] 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.

[0066] UEs 115 are scattered throughout the wireless network 100, and each UE may be stationary or mobile. It should be understood that although in the standards and specifications promulgated by 3GPP, mobile devices are generally 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 may 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, smart phones, 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 may 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, tap water, or other infrastructure; industrial automation and enterprise equipment; consumer and wearable devices, such as glasses, wearable cameras, smart watches, 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 may be a device that includes a universal integrated circuit card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, a UE that does not include a UICC may 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 accessing the wireless network 100. The UEs can also be machines specifically configured for connecting communications, including machine type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc. Figure 1 The illustrated UEs 115e through 115k are examples of various machines configured for communicating that access the wireless network 100.

[0067] A mobile device (such as UE 115) can 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 a wired or wireless communication link.

[0068] In operation, at the wireless network 100, base stations 105a through 105c use 3D beamforming and collaborative 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 can include mobile TV or streaming video, or can include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or Gray alerts.

[0069] 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 the 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 through 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).

[0070] 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 the base stations 105) or indirectly (e.g., via the core network 130) via a backhaul link (e.g., via X2, Xn, or other interfaces).

[0071] 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.

[0072] 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).

[0073] 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. Additionally, the tag device may include a SAW tag device. 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 typically 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.

[0074] In some specific implementations, the transmitter and receiver of the reader device 121 may be co-located (e.g., monostatic) or separately located (bistatic). For the monostatic case, self-interference may become the main interference for the receiver. For the bistatic case, the direct transmission from the transmitter may become the main interference received. However, in the bistatic case, if the location / distance between the transmitter and the receiver is known, the Line-of-Sight (LOS) signal can be used as a reference for TDoA measurement.

[0075] 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.

[0076] 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. Due to the typically lacking signal processing capabilities of passive tags, passive tags generally include simple circuits to reflect the received electromagnetic signals back into the environment in the form of backscatter transmission. For example, a reader device 121 may transmit an electromagnetic signal, and a passive tag such as tag device 120 may receive the electromagnetic signal and at least partially reflect the electromagnetic signal in the form of a backscatter signal. Specifically, if tag device 120 is a passive tag, tag device 120 may include circuitry to at least partially reflect, in the form of backscatter transmission, the unabsorbed portion of the electromagnetic signal received from the surrounding environment, such as the electromagnetic signal transmitted by reader device 121.

[0077] Semi-passive tags generally 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 generally transmit signals via backscatter transmission, as explained above in the context of passive tags.

[0078] Active tags generally include an on-board power source and greater computing capabilities than passive or semi-passive tags. Additionally, unlike passive and semi-passive tags that generally cannot transmit unless a reader device such as reader device 121 is in close proximity to them, active tags are capable of transmitting regardless of the proximity of a reader device. Active tag devices generally include signal processing functions such as ADCs, DACs, etc. Additionally, active tags generally include a power source and are capable of transmitting actively. Specifically, unlike passive and semi-passive tags that generate a backscatter 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 reader device 121.

[0079] 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 respond to a transmission received from a reader device 121 at the tagging device by including its unique tag identifier. 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 the transmission received from reader device 121 in the form of a backscatter signal that can be read by reader device 121. While 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 the signal received from reader device 121.

[0080] 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.

[0081] Figure 2 is a block diagram illustrating an example of a base station 105 and a UE 115 according to 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. For a restricted association scenario (as described above), the base station 105 can be Figure 1 the small cell base station 105f among them, 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.

[0082] 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, for example, reference symbols for a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), as well as cell-specific reference signals. Transmit (TX) MIMO processor 230 may perform spatial processing (e.g., precoding) on the data symbols, control symbols, or reference symbols (if applicable), 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 corresponding 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.

[0083] 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 corresponding received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain the 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 the 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).

[0084] 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. The 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 signal 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.

[0085] 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, such as executing or directing Figure 11 , Figure 13 or Figure 14 as illustrated in

[0086] 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 conventionally 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 a 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 the 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 the acknowledgment / negative acknowledgment (ACK / NACK) feedback (as an indication of a collision) for its own transmitted packets.

[0087] Figure 3 is a block diagram of an example wireless communication system 300 that supports backscatter-based positioning according to one or more aspects. In some examples, wireless communication system 300 may implement aspects of wireless network 100. Wireless communication system 300 includes a tag device 120, a first TRP 340, a second TRP 342, a third TRP 346, a fourth TRP 348, a fifth TRP 349, and a core network 130. Although five TRPs are illustrated, in some other implementations, wireless communication system 300 may generally include fewer or more than five TRPs.

[0088] Tag device 120 may be an RFID tag device. Additionally, 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 a passive tag device, or an active tag that has a power source and computing capabilities the same as or greater than those of a semi-passive tag device. In some implementations, tag device 120 includes a SAW tag device.

[0089] 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 SAW device 352, 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 a 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. In some specific embodiments, the circuit 351 includes a controller configured to control one or more components of the SAW device 352. For example, the controller may be configured to activate or deactivate one or more reflectors of the SAW device 352.

[0090] The SAW device 352 may include one or more reflectors, interdigital transducers, or a combination thereof. In some specific embodiments, the SAW device 352 may include a receiving antenna, a transmitting antenna, a transmitter 356, a receiver 358, or a combination thereof. Additional aspects of the SAW device 352 are described at least herein with reference to Figures 4 to 6 further.

[0091] The transmitter 356 is configured to send one or more signals (such as a backscatter signal 376 or data) to one or more other devices (e.g., one or more TRPs or a reader 121). The receiver 358 is configured to receive one or more signals (such as a positioning reference signal 374 or data) from one or more other devices (e.g., one or more TRPs, a reader 121, a core network 130). For example, the receiver 358 may receive a positioning reference signal 374 from one or more TRPs, and the transmitter 356 may send a backscatter signal 376 to one or more TRPs. In some specific 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 UE 115 described with reference to Figure 2 herein.

[0092] The tag device 120 may include one or more components as described herein with reference to the tag device 120. In some specific 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.

[0093] In some specific embodiments, the tag device 120 includes a SAW tag device and is configured as described at least herein with reference to Figures 4 to 6 further. With reference to Figure 4 , Figure 4FIG. 0 is a diagram illustrating an example SAW tag device that supports backscatter-based positioning according to one or more aspects. The SAW tag device may include or correspond to tag device 120 or SAW device 352. The SAW tag device includes an antenna 410 (e.g., a transmit antenna and a receive antenna), a coupling transducer 412 (e.g., an interdigital transducer), and a plurality of reflectors 414. The coupling transducer 412, the plurality of reflectors 414, or both may be formed on a substrate (such as a piezoelectric crystal). Note that arrow 416 indicates a signal path and is included for illustrative purposes only.

[0094] The SAW tag device is configured to receive a signal such as PRS 374 and output a backscatter signal (e.g., 376). For example, the coupling transducer 412 receives the signal and converts the signal from the RF domain to the acoustic domain. The acoustic signal propagates through the SAW tag device and is reflected by the reflectors 414. The reflected acoustic signal is converted back to the RF domain by the coupling transducer and output via the antenna 410. Note that the reflectors 414 include a first reflector 441 and a second reflector 442, each of which generates a reflection that is included as part of the backscatter signal. As shown, the backscatter signal includes a first reflection 461 corresponding to the first reflector 441 and a second reflection 462 corresponding to the second reflector 442.

[0095] Reference Figure 5 , Figure 5 FIG. 10 is a graph of a positioning reference signal and a backscatter signal that supports backscatter-based positioning according to one or more aspects. The Tx signal includes or corresponds to PRS 374, and the RF response corresponds to the backscatter signal 376. As shown, there is a time period between transmitting the Tx signal and transmitting the first reflection 461. Note that the tag delay of the SAW tag device may be unknown, while the time delay between different reflections may be known or easily determined.

[0096] Reference Figure 6 , Figure 6 FIG. 17 is a diagram illustrating another example SAW tag device that supports backscatter-based positioning according to one or more aspects. Figure 6 The SAW tag device of FIG. 19 may include or correspond to tag device 120, SAW device 352, or Figure 4 the SAW tag device of Figure 4 Compared with the SAW tag device of Figure 6 the SAW tag device of FIG. 25 includes a piezoelectric crystal 616 as a substrate. Additionally, compared with the SAW tag device of Figure 4 the SAW tag device of FIG. 27, the number of reflectors, the number of interdigital transducers 412, and the placement of one or more components are different. Further, Figure 6The SAW tag device is configured to output an RF response having a frequency response that is an upward chirp (e.g., 376). Other frequency responses are possible, such as a downward chirp or a frequency shift.

[0097] SAW tag devices such as tag device 120, SAW device 352, Figure 4 a SAW tag device of Figure 6 SAW tag devices such as a SAW tag device of

[0098] SAW tag devices can support TDM of backscattered signals relative to self-interference or other environmental reflections (e.g., echoes). The SAW tag device can be configured to receive an electromagnetic (EM) wave at an antenna and convert the EM wave into a mechanical wave such as a sound wave. Compared to the EM wave passing through air at the speed of light, the mechanical wave can propagate through a medium such as a substrate (e.g., a piezoelectric crystal) at a much slower propagation speed. One or more reflectors can be configured to reflect mechanically such that the mechanical wave is provided towards the antenna and converted back into an EM wave for transmission. Due to the slow propagation speed of the mechanical wave, a small distance to a reflector in the medium will be converted into a (relatively) large delay, large enough to be separated from the original input signal in the time domain. Thus, the backscattered signal can be TDM relative to self-interference and other reflectors (e.g., environmental reflections). Thus, the backscattered signal can avoid interference based on the propagation speed of the mechanical wave.

[0099]

[0100] ​The SAW tag device can be configured to use the position of the reflector to carry information, the load of the antenna. In other words, the information is carried when the reflected signal appears. Multiple reflectors can be designed in the SAW tag hardware to carry more complex information. For example, the information can be carried by the position of the multipath reflected signal. In some specific implementations, the delay introduced by the reflector separates the signals such that no additional scrambling of the signals is required.

[0101] If there are multiple SAW tags in the environment, they can all respond to an interrogation signal, such as PRS 374. Thus, a reader device (such as reader device 121 or TRP 340) can be configured to identify individual response signals (e.g., individual backscatter signals) from the combined reflected signals received at the reader device due to multiple tag devices (such as multiple SAW tag devices). To be able to identify individual response signals, the reader device can control or configure the individual tag devices. For example, the reader device can transmit a tag configuration (e.g., 390) to configure the SAW tag device. Additionally or alternatively, the reader device can control or configure one or more tag devices not to respond, e.g., deactivate the reflector, so that only the expected or desired SAW tag device provides a response signal.

[0102] In some specific implementations, the SAW tag device can have different types or categories. For example, a first category of SAW tag device can have a fixed reflector delay line such that the reflector is fixed and non-tunable. A first subtype of the first category can be a purely passive device that always provides a response. A second subtype of the first category can include an external circuit that is configured to control whether the SAW tag device reflects or not, e.g., connect the antenna to the SAW device or IDT or not connect to the SAW device or IDT. For the second subtype, the reader device can send a message, such as tag configuration 390, to activate or deactivate the reflection.

[0103] A second category of SAW tag device can include a programmable reflector. For example, one or more reflectors can be programmed or reprogrammed by an external circuit or controller. A first subtype of the second category can enable modulation to be programmed. By way of illustration, the reflector positioning is fixed, which determines the pulse symbol rate. However, the amplitude, phase, or frequency of the reflected signal can be controlled. A second subtype of the second category can enable the reflector positioning to be programmed (or reprogrammed). For example, one or more reflectors can be activated (e.g., reflect) or deactivated (e.g., not reflect). A third subtype of the second category can enable both modulation and reflector positioning to be programmed (or reprogrammed).

[0104] In some specific implementations, the SAW tag device may report reprogramming latency, such as the amount of time required for the SAW tag device to be reprogrammed (e.g., changed from a first configuration to a second configuration). Additionally or alternatively, the reader device may send a configuration message (e.g., 390) to request or control the SAW tag device to apply a configuration, such as using a specific reflection setting.

[0105] In some specific implementations, one or more SAW tag devices may be controlled (e.g., configured) to use a specific configuration or reflection setting such that multiple tags can be multiplexed. For example, one or more SAW tag devices may be TDM. By way of illustration, the positioning of the first reflector (i.e., the initial reflector) determines the first reflection time. The SAW tag device may be controlled to use different first reflector positions such that the responses of different SAW tag devices are separated in the time domain. It should be noted that based on the tag latency of the SAW tag device, the response of the SAW tag device can be naturally separated in time from other backscatter signals (such as RFID tag devices) of (other tag devices).

[0106] As another example, one or more SAW tag devices may be CDM. By way of illustration, multiple reflectors may send a reflection chain that constitutes a code. Different low-correlation codes may be assigned to different SAW tag devices. In some specific implementations, the code sequence may be mapped to different SAW tag devices based on the SAW tag ID.

[0107] As another example, one or more SAW tag devices may be chirp-based controlled. By way of illustration, quasi-orthogonal codes may be used, such as up chirps, down chirps with different frequency offsets.

[0108] Return reference Figure 3 , the first TRP 340 may include multiple components (such as structural hardware components) for performing one or more functions described herein. For example, these components may include one or more processors 302 (collectively referred to as "processors 302" hereinafter), one or more memory devices 304 (collectively referred to as "memory 304" hereinafter), one or more transmitters 316 (collectively referred to as "transmitters 316" hereinafter), and one or more receivers 318 (collectively referred to as "receivers 318" hereinafter). In some specific implementations, the first 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 receive processor 238, the transmit processor 220, and the controller 240, and the memory 304 includes or corresponds to the memory 242.

[0109] 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, tag device information 309, and measurement information 310.

[0110] The PRS information 307 includes information for the first TRP 340 to generate positioning reference signal (PRS) 374. For example, the PRS information 307 may include one or more parameters, such as repetition rate, bandwidth configuration, comb pattern configuration, or a combination thereof. The repetition rate may include or indicate the number of times the PRS is sent within a period of time. The comb pattern may include or indicate configurable resource block allocation. Additionally or alternatively, the PRS information 307 may include frequency shift parameters, phase scrambling parameters, or a combination thereof. In some specific embodiments, the PRS information 307 may include or indicate the waveform corresponding to the PRS 374, such as a phase shift keying (PSK) waveform (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK)), amplitude shift keying (ASK) waveform (e.g., on-off keying), chirp waveform (e.g., up-chirp, down-chirp that scans frequencies over the available bandwidth of the PRS 374), or a combination thereof. In some specific embodiments, the PRS information 307 may include or indicate sequence selection for the PRS 374, such as m-sequence or Zadoff-Chu sequence. In some specific embodiments, the PRS information 307 may be generated or stored based on the PRS configuration (e.g., 381).

[0111] The measurement gap information 308 indicates the period during which one or more TRPs are to monitor the PRS 374, backscatter signal 376, or a combination thereof. In some specific embodiments, the measurement gap information 308 may indicate the period during which one or more TRPs suppress the transmission of signals (such as the PRS 374). For example, the measurement gap information 308 may indicate the period during which the first TRP 340 suppresses scheduling of one or more transmissions. The measurement gap information 308 may be based on the measurement gap (GP) configuration 382. In some specific embodiments, the measurement gap information 308 may indicate one or more reflections to be monitored for the backscatter signal from the SAW tag device. For example, the backscatter signal of the SAW tag device may include one or more reflections, and the TRP 340 may monitor one or more specific reflections and identify the reception time of each specific reflection among the one or more specific reflections.

[0112] The tag device information 309 includes or corresponds to information about one or more tag devices, such as tag device 120. In some embodiments, the tag device information 309 corresponds to the information indicated by the tag device indicator 370. For example, the tag device information 309 may include the frequency shift capability of the tag device 120, the phase scrambling capability of the tag device 120, or a combination thereof. The frequency shift capability may include or correspond to the ability of the tag device 120 to manipulate or change the frequency of the reflected backscatter signal 376 generated at the tag device 120. Examples of the frequency shift capability include the bandwidth of the backscatter signal 376, the frequency shift waveform configurable by the tag device 120, the time delay associated with switching the frequency of the backscatter signal 376, the amount of time the tag device 120 can be configured to perform the frequency shift operation, the power level available at the tag device 120 for performing the frequency shift operation, or a combination thereof. The phase scrambling capability may include or correspond to the ability of the tag device 120 to manipulate or change the phase of the reflected backscatter signal 376 generated at the tag device. Examples of the phase scrambling capability include the supported phase values of the tag device 120, the scaling factor values selectable by the tag device 120, the amount of time the phase scattering operation can be performed, the amount of power the tag device 120 can use to perform the phase scattering operation, or a combination thereof.

[0113] The tag device information 309 may alternatively or additionally include or indicate information or characteristics regarding one or more tag devices, such as tag device 120. For example, for a tag device, the tag device information 309 may include tag type, bandwidth, PRS slot periodicity, sensitivity, tag delay (e.g., group delay), or a combination thereof. The tag type may correspond to whether the tag device (e.g., tag device 120) is a passive tag, a semi-passive tag, or an active tag. Additionally or alternatively, the tag type may indicate the technology or use of the tag device, such as a surface acoustic wave (SAW) tag device, an IoT tag device, a security tag device, a medical tag device, or a combination thereof. 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 delay may correspond to the amount of time that the tag device 120 processes the PRS 374 and generates a backscatter signal 376 in response to the reception at the tag device 120 or the PRS 374. For example, a tag delay such as a radio frequency (RF) group delay may include or be based on one or more components of the tag device, such as 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 transmit the backscatter signal. When the tag device 120 includes a SAW tag device, the tag delay may be understood as the time between receiving the PRS and transmitting the first reflection (e.g., the initial reflection). The time difference between two reflections, such as the first reflection and the second reflection, may be known. As a specific example, the time delay between the initial reflection and the next subsequent reflection may be known. In some specific implementations, the tag delay is the amount of time between the tag device 120 receiving a positioning reference signal and transmitting a backscatter signal based on the received positioning reference signal. In some specific implementations, one or more characteristics of the tag device 120, such as the tag delay, may be unknown or unavailable to the first TRP 340.

[0114] The measurement information 310 includes or corresponds to one or more propagation times associated with the backscatter signal 376. 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 backscatter signal 376, the amount of time elapsed from the transmission of the PRS 374 to the reception of the backscatter signal 376, or a combination thereof. In some embodiments, when the first 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 backscatter signal 376, the amount of time elapsed from the reception of the PRS 374 to the reception of the backscatter signal 376, or a combination thereof. The first TRP 340 may be configured to generate a measurement report based on the measurement information 310. In some embodiments, the measurement information 310 indicates the channel conditions monitored or experienced by the TRPs 340 to 346, the interference monitored or experienced by the TRPs 340 to 346, or a combination thereof. In some embodiments, the reception time of the backscatter signal may include or indicate the reception time of one or more reflections from the SAW tag device.

[0115] 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 positioning reference signal (e.g., 374), while the receiver 318 may receive a backscatter signal (e.g., 376). In some embodiments, 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 UE 115 or the base station 105 in the reference Figure 2 . In some embodiments, the transmitter 316 or the receiver 318 may be configured to operate in full-duplex mode.

[0116] In some specific implementations, the first 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). 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, and the corresponding beam 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, for example, 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 first TRP 340 may be configured as or include a reader device, such as an RFID reader device.

[0117] The second TRP 342, the third TRP 346, the fourth TRP 348, and the fifth TRP 349 may include or correspond to the first TRP 340. For example, the second TRP 342, the third TRP 346, the fourth TRP 348, or the fifth TRP 349 may include one or more components similar to the first TRP 340 and may be configured to perform one or more operations or combinations thereof as described with reference to the first TRP 340. In some specific implementations, the first TRP 340, the second TRP 342, the third TRP 346, the fourth TRP 348, or the fifth TRP 349 may include or correspond to the reader device 121. In some specific implementations, the first TRP 340, the second TRP 342, the third TRP 346, the fourth TRP 348, and the fifth TRP 349 may be synchronized, such as time synchronization. For example, multiple TRPs may be configured to enable TDOA or TOA backscatter positioning of the tag device 120 via the LMF 131. In other specific implementations, one or more of the first TRP 340, the second TRP 342, the third TRP 346, the fourth TRP 348, and the fifth TRP 349 may be asynchronous with another of the first TRP 340, the second TRP 342, the third TRP 346, the fourth TRP 348, and the fifth TRP 349.

[0118] 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 TRPs 340, 342, 346, 348, or 349. The core network 130 may include or correspond to the LMF 131.

[0119] Although shown and described as being included in the core network 130, in some embodiments, the LMF 131 may be different from the core network 130. For example, the LMF 131 may include one or more servers, such as multiple distributed servers. The LMF 131 may 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 131 is configured to control the positioning parameters of the TRPs 340, 342, 346, 348, or 349 or the tag device 120, and the LMF 131 may provide information to the TRPs 340, 342, 346, 348, or 349 or the tag device 120 such that actions or operations may be taken or performed at the TRPs 340, 342, 346, 348, or 349. The TRPs 340, 342, 346, 348, or 349 (e.g., the base station 105 or the reader device 121) may communicate information to the LMF 131 and may communicate with the LMF 131 via a protocol such as the NR positioning protocol A (NRPPa). In some embodiments, the TRPs 340, 342, 346, 348, or 349, the tag device 120, or a combination thereof is configured to communicate with the LMF 131 via the access and mobility management function (AMF).

[0120] In some embodiments, the LMF 131 is configured to support backscatter-based positioning. Thus, the LMF 131 may 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 may be configured to store tag device information 366. The tag device information 366 may include a tag delay 368 and a positioning 369. In some embodiments, the tag delay 368 of the tag device 120 is unknown or unavailable to the LMF 131. In such embodiments, the memory 364 may not store the tag delay 368 or may store a predetermined value (such as a null value) to indicate that the tag delay 368 is unknown or unavailable.

[0121] To support backscatter-based positioning, the LMF 131 can be configured to perform one or more operations. These functions can include the generation of the TRP configuration 372 and the transmission of the TRP configuration 372 to one or more TRPs (e.g., 340, 342, 346, 348, or 349). 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 specific implementations, the LMF 131 can be configured to receive one or more measurement reports (collectively referred to as "measurement reports 378" hereinafter) generated by one or more TRPs (e.g., 340, 342, 346, 348, 349). In some specific implementations, 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 delay 368. However, the LMF 131 can know the delay between two reflectors (e.g., two reflections) associated with the tag device 120.

[0122] The LMF 131 can be configured to determine the positioning of the tag device 120 based on multiple measurement reports (collectively referred to as "measurement reports 378") and without knowing the tag delay 368 corresponding to the tag device 120. Determining the positioning 369 of the tag device 120 can include calculating the positioning based on the TDoA technique. The positioning can be 2D positioning or 3D positioning. Additionally, the LMF 131 can be configured to use the positioning 369 for one or more operations, or send a positioning indicator indicating the positioning 369 of the tag device 120.

[0123] 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 UEs 115 and multiple 5G-capable base stations 105, such as UEs and base stations configured to operate according to 5G NR network protocols defined, for example, by 3GPP. In some other specific implementations, the wireless communication system 300 implements a 6G network. As described herein, the wireless communication system 300 implements or supports the identification, tracking, monitoring, and coexistence of the tag device 120 with devices and infrastructure in the frequency bands of current 3GPP technologies.

[0124] During the operation of the wireless communication system 300, the LMF 131 can send a request for the tag capabilities of the tag device 120 to the tag device 120. The tag device 120 can transmit a tag device indicator 370 in response to the request. In some specific implementations, the tag device indicator 370 can be received by the core network 130, the LMF 131, one or more TRPs 340 to 348, or a combination thereof.

[0125] The LMF 131 can receive a tag device indicator 370 that indicates the tag capabilities of the tag device 120. The tag capabilities can include or correspond to tag device information 309, 366.

[0126] The LMF 131 (or the TRP 340) can generate or transmit a tag configuration 390 associated with the transmission of a backscatter signal 376 (such as a backscatter signal based on a positioning reference signal (PRS) 374). The tag configuration 390 can include or indicate a frequency shift parameter based on the frequency shift capabilities of the tag device 120, a phase scrambling parameter based on the phase scrambling capabilities of the tag device 120, or both. In some embodiments, the frequency shift parameter includes or indicates a backscatter frequency offset value of the backscatter signal 376, an indication of a frequency shift waveform, a time frame during which the frequency shift operation is to be performed, or a combination thereof. The frequency shift parameter can be configured based on the frequency shift capabilities of the tag device 120. In some embodiments, the phase scrambling parameter includes or indicates a scaling factor, a phase sequence with a phase shift, a length of the phase sequence, or a combination thereof, each corresponding to the backscatter signal 376. The scaling factor (sometimes referred to as the "K scaling factor") can be a proportional value of the frequency of the PRS 374. For example, the frequency of the backscatter signal 376 can be equal to the frequency of the PRS 374 multiplied by the scaling factor. The phase scrambling parameter can be generated or configured based on the phase scrambling capabilities of the tag device 120. The LMF 131 can send the tag configuration 390 to the tag device 120, one or more TRPs, or a combination thereof.

[0127] In some embodiments, the tag configuration 390 can include or indicate a first tag configuration for a first tag device (such as the tag device 120). In some embodiments, the first tag device includes a SAW tag device. Additionally or alternatively, the first tag device can include a plurality of reflectors, interdigital transducers, a controller, or a combination thereof. The first tag configuration can include or indicate a reflector configuration. In some embodiments, the first tag configuration indicates that a first set of reflectors among the plurality of reflectors of the tag device will be activated, a second set of reflectors among the plurality of reflectors will be deactivated, or a combination thereof. Additionally or alternatively, the first tag configuration indicates one reflector among the plurality of reflectors of the first tag device to be configured as an initial reflector, a configuration of the plurality of reflectors, or frequency response parameters. The frequency response parameters can include or indicate an up-chirp or a down-chirp, a frequency offset, or a combination thereof. In some embodiments, the first tag configuration can additionally or alternatively include or indicate an amplitude, a phase shift, or a frequency associated with a first backscatter signal.

[0128] In some specific implementations, the first tag configuration further indicates the tag address of the first tag device. The tag address may include or indicate the active state of at least one reflector of the first tag device. The tag device 120 may receive the tag configuration 390 and determine whether the first tag configuration is for the tag device based on the tag address (e.g., tag ID or group ID) included in the tag configuration 390 or corresponding to the first tag configuration.

[0129] In some specific implementations, the tag configuration 390 indicates a second tag configuration for a second tag device among a plurality of tag devices. By way of illustration, the plurality of tag devices may include a first tag device and a second tag device. The second tag device may include one or more components, perform one or more operations, or a combination thereof, as described with reference to the tag device 120. The second tag configuration may indicate deactivating a set of reflectors of the second tag device. In some specific implementations, the second tag configuration indicates that the second tag deactivates all of its reflectors. Additionally or alternatively, the network entity may receive a second backscatter signal from the second tag device in response to the PRS. The second backscatter signal may be based on the second tag configuration.

[0130] The LMF 131 can generate a TRP configuration 372. In some specific implementations, the LMF 131 can generate the TRP configuration 372 based on a tag device indicator 370, the tag capabilities of the tag device 120, a tag configuration 390, tag device information 309, 366, or a combination thereof. The TRP configuration 372 can indicate designating one or more TRPs as Tx TRPs, designating one or more TRPs as Rx TRPs, or a combination thereof. Additionally or alternatively, the TRP configuration 372 can include a PRS configuration 381 and an MG configuration 382. The PRS configuration 381 can include or indicate information (such as PRS information 307) for one or more TRPs designated as Tx TRPs to transmit PRSs (such as positioning reference signals 374). In some specific implementations, the PRS configuration 381 includes or indicates a frequency shift parameter, a phase scrambling parameter, or a combination thereof. Additionally or alternatively, the PRS configuration 381 can include or indicate a backscatter frequency offset value of the backscatter signal 376, a waveform corresponding to the PRS 374, a bandwidth corresponding to the PRS 374, a sequence type corresponding to the PRS 374 (e.g., m-sequence, ZC-sequence), a sequence length corresponding to the PRS 374, or a combination thereof. The MG configuration 382 can include or indicate information, such as measurement gap information 308, for one or more TRPs designated as Rx TRPs to receive the positioning reference signal 374, the backscatter signal 376, or a combination thereof. In some specific implementations, the TRP configuration 372 indicates one or more reflections to be monitored by the TRP 340 to determine the RTT or positioning of the tag device 120. Additionally or alternatively, the TRP configuration 372 can indicate a pair of TRPs including the TRP 340 and another TRP to perform positioning signaling with the tag device 120.

[0131] The LMF 131 can send the TRP configuration 372 to one or more TRPs, such as TRPs 340 to 348. One or more TRPs can receive the TRP configuration 372 and determine that the first TRP 340 is designated as a Tx TRP and the second TRP 342 to the fourth TRP 348 are designated as Rx TRPs. Additionally or alternatively, one or more TRPs can receive the TRP configuration 372 and update information 306, such as PRS information 307 and measurement gap information 308, based on the TRP configuration 372.

[0132] The first TRP 340 can send the PRS 374 based on or according to the PRS information 307 (e.g., the PRS configuration 381). The PRS 374 can be received by the tag device 120 and one or more of the TRPs 342 to 348.

[0133] The tag device 120 may receive the PRS 374 and transmit a backscatter signal 376 based on the PRS 374. For example, the tag device 120 may reflect the PRS 374 to generate the backscatter signal 376. In some embodiments, the backscatter signal 376 may include one or more reflections. Additionally or alternatively, the tag device 120 may generate the backscatter signal 376 based on a tag configuration 390. For example, the tag device 120 may receive the tag configuration 390 before receiving the PRS 374. The tag device 120 may configure one or more components of the tag device 120 based on the tag configuration 390. After configuring the one or more components, the tag device 120 may receive the PRS 374 and transmit the backscatter signal 376. Additionally or alternatively, the tag device 120 may generate the backscatter signal 376 according to a frequency shift parameter, a phase scrambling parameter, or a combination thereof.

[0134] The backscatter signal 376 may be received by one or more of the TRPs 340 to 348. In some embodiments, one or more of the TRPs 340 to 348 may receive the backscatter signal 376 during a time period (e.g., the measurement gap information 308) indicated by the MG configuration 382. One or more of the TRPs 340 to 348 that receive the backscatter signal 376 may generate a measurement report 378. For example, the second TRP 342 may generate the measurement report 378 and transmit the measurement report 378. As another example, the first TRP 340 may receive the backscatter signal 376 and generate a measurement report (e.g., 378) based on the measurement information 310.

[0135] The LMF 131 receives one or more measurement reports (e.g., 378) and determines the location of the tag device 120 based on the data included in the measurement report 378. For example, the LMF 131 (or the TRP 340) may determine the location of the tag device 120 as described at least herein Figures 7 to 10 Further described. The measurement report 378 may indicate the channel conditions experienced by the TRPs 340 to 348, the interference experienced by the TRPs 340 to 348, the interference associated with the backscatter signal 376 (e.g., interference caused by the environment near the tag device 120), or a combination thereof. In some embodiments, the LMF 131 may generate the tag configuration 390 based on the measurement report 378.

[0136] In some cases, the positioning of the identification tag device 120 may be time-critical. In such cases, the tag device 120 may indicate to the LMF 131 the energy level of the tag device 120. In some specific implementations, the tag device indicator 370 may indicate the energy level of the tag device 120. If the energy level is less than or equal to a threshold, or not high enough to support multiple backscatter repetitions, and the positioning is time-critical, then the LMF 131 may initiate energy harvesting as needed. For example, the LMF 131 may use the PRS configuration 381 to indicate that the PRS 374 will be sent so that the tag device 120 can harvest energy. Alternatively, if the positioning is not time-critical or if the energy level is greater than the threshold, then the LMF 131 may indicate that a regular energy harvesting signal can be provided.

[0137] In some specific implementations, the tag device 120 provides the LMF 131 with the current energy level of the tag device 120. If the energy level is not sufficient for multiple (e.g., backscatter repetitions), then the TRPs 340 to 348 may choose between providing on-demand energy harvesting if the positioning is time-critical, or if the positioning is not time-critical, then the TRPs 340 to 348 may periodically provide energy harvesting operations.

[0138] In some specific implementations, using more than one Tx TRP may help the LMF 131 determine the direction and speed of the mobile tag device 120. For example, two or more of the TRPs 340 to 348 may be designated as Tx TRPs via the TRP configuration 372.

[0139] In some specific implementations, the LMF 131 may be configured to calculate or may configure other devices (such as one or more of the TRPs 340 to 348) to calculate the power level of the PRS 374 and the power level of the backscatter signal 376. Thereafter, the ratio of the power level of the backscatter signal 376 to the power level of the PRS 374 may be determined. If the ratio is less than or equal to a threshold, indicating that the backscatter signal 376 is attenuated, then the LMF 131 may configure the PRS 374 via the PRS configuration 381 to operate at certain frequencies of the available bandwidth. Conversely, if the ratio meets the threshold, then the LMF 131 may configure the TRPs 340 to 348 via the PRS configuration 381 to generate the PRS 374 and transmit the PRS across the entire available PRS bandwidth.

[0140] Additionally or alternatively, the LMF 131 may be configured to select a positioning method that the LMF 131 identifies as most likely to accurately and precisely identify the location of the tag device 120, such as one of TOA, TDOA, or AOA. As a non-limiting example illustrated, the LMF 131 may select the positioning method based on the tag device indicator 370, tag capabilities, TRP capabilities, network topology, environmental information (e.g., known structure or location of one or more devices), or a combination thereof. In some specific implementations, the LMF 131 may select TDOA based on the determination that the tag device 120 includes a SAW tag.

[0141] As referenced Figure 3 As described, the present disclosure provides techniques for supporting backscatter-based positioning. The described techniques facilitate determining the location of a tag device (such as the 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, the LMF 131 is capable of determining the location of the tag device 120 based on one or more measurement reports 378. In some specific implementations, one or more tag devices (such as SAW tag devices) may be configured such that a backscatter signal identifiable by the TRP can be provided. For example, a configuration indicates one reflector among a plurality of reflectors of a first tag device to be configured as an initial reflector, the configuration of the plurality of reflectors, frequency response parameters, or an amplitude, phase shift, or frequency associated with the backscatter signal. In some specific implementations, the described techniques enable determining the location of one or more tag devices, such as SAW tag devices. For example, when the tag delay of the tag device 120 is unknown or unavailable, the LMF 131 is capable of determining the location of the tag device 120 based on one or more measurement reports 378. By way of illustration, for example, when the tag delay 368 of the tag device is unknown or unavailable to the device calculating the location 369 of the tag device 120, the LMF 131 may perform measurements of TDoA-based backscatter-based positioning of multiple TRPs 340 to 349.

[0142] Figure 7 is a block diagram illustrating an example wireless communication system 700 that supports backscatter-based positioning according to one or more aspects. The wireless communication system 700 may include or correspond to the wireless communication system 100, 300, 400, or 500. Figure 7Depicts the asynchronous operation of TRPs 340 to 349, where backscatter-based positioning can be used to determine the positioning of the tag device 120 (e.g., SAW tag). Specifically, the first TRP 340 can send the PRS 731, and one or more of the TRPs 340 to 349 can receive the corresponding backscatter signal 741 reflected from the tag device 120 based on the PRS 731. The PRS 731 can include or correspond to the PRS 374 or 731, and the backscatter signal 741 can include or correspond to the backscatter signal 376 or 741. In some specific implementations, one or more of the TRPs 340 to 349 may or may not be configured to operate in full-duplex operation. As Figure 7 shown, the first TRP 340 is configured to operate in full-duplex operation, while the TRPs 342 to 349 are not configured to operate in full-duplex operation.

[0143] During operation, the first TRP 340 can send the PRS 731 to the tag device 120, and the tag device 120 can reflect the backscatter signal 741 to the TRPs 340 to 349. The TRPs 342 to 349 can also receive the PRS 731. The PRS 731 can include or correspond to the PRS 374, and the backscatter signal 741 can include or correspond to the backscatter signal 376.

[0144] In some specific implementations, a TRP pair (such as TRP 340 and 342) can be designated to contribute to backscatter-based positioning. For example, the TRP 340 can send the PRS 731 to the tag device 120, and the second TRP 342 can receive the reflected backscatter signal 741 sent by the tag device 120. After receiving the reflected backscatter signal 741, the second TRP 342 can send a PRS to the tag device 120, such as Figure 7 a second PRS not depicted in, and the tag device 120 can send another reflected backscatter signal (not shown) received by the first TRP 340. The first TRP 340 can send its Tx time and Rx time to the second TRP 342 or the LMF 131, or the second TRP 342 can send its Tx time and Rx time to the first TRP 340 or the LMF 131. Additionally or alternatively, the first TRP 340 can receive the Tx and Rx times of the second TRP 340, and can send its Tx time and Rx time and the Tx time and Rx time of the second TRP 340 to the LMF 131. In this way, the transmission and / or reception times can be used for TDOA positioning techniques to determine the positioning 369 of the tag device 120. At least with reference to Figure 7 further describes examples of TRP pairs.

[0145] AlthoughFigure 7 The first TRP 340 is depicted as transmitting the PRS 731, but another TRP (such as the second TRP 342 to the fifth TRP 349) may also transmit a corresponding positioning reference signal, which may similarly cause the tag device 120 to generate a corresponding reflected backscatter signal received by one or more of the first TRP 340 to the fifth TRP 349.

[0146] Figure 8 FIG. is a block diagram illustrating an example wireless communication system 800 that supports backscatter-based positioning according to one or more aspects. The wireless communication system 800 may include or correspond to the wireless communication system 100 or 300. Figure 8 The asynchronous operation of the TRPs 340 to 349 is depicted, where backscatter-based positioning is used to determine the positioning of the tag device 120 (e.g., a SAW tag). Specifically, the TRPs 340 to 349 may each transmit a corresponding PRS 831 to 835 and receive the corresponding backscatter signals 841 to 845 reflected from the tag device 120 based on the PRSs 832 to 835. The PRSs 831 to 835 may include or correspond to the PRS 374, and the backscatter signals 841 to 845 may include or correspond to the backscatter signal 376.

[0147] In some specific implementations, TRPs 340 to 349 sequentially transmit PRSs 831 to 835 in a time-division multiplexing (TDM) manner to avoid interference. For example, the PRS configuration 381 sent to one or more of TRPs 340 to 349 may include timing information for configuring one or more of TRPs 340 to 349 to transmit PRSs 831 to 835 in sequence. Thus, when TRPs 340 to 349 are not synchronized (e.g., lack a common clock), the sequential transmission of PRSs 831 to 835 and the reception of the resulting backscattered signals are achieved by one or more TRPs monitoring the PRSs of another TRP and transmitting accordingly. Additionally or alternatively, one or more of TRPs 340 to 349 simultaneously transmit PRSs 831 to 835 in a frequency-division multiplexing (FDM) manner (e.g., the transmissions of at least two different PRSs at least partially overlap in time) to avoid interference. For example, the PRS configuration 381 sent to one or more of TRPs 340 to 349 may include information for configuring each of TRPs 340 to 349 to transmit PRSs 831 to 835 at different frequencies from each other to avoid interference from simultaneous PRS transmissions. For illustration, the PRS configuration 381 received at TRP 342 may configure the first TRP 340 to generate and transmit PRS 831 at a first frequency, while the PRS configuration 381 received at TRP 342 may configure TRP 340 to generate and transmit PRS 832 at a second frequency different from the first frequency. In this way, at least one of TRPs 340 to 349 can be configured to transmit PRSs 831 to 835 at different non-overlapping frequencies to avoid interference, and such that each of the backscattered signals 841 to 845 will be transmitted at a unique non-overlapping frequency.

[0148] In some specific implementations, TRPs 340 to 349 are assigned to a first group including a subset of TRPs 340 to 349 and a second group including a subset of TRPs 340 to 349 different from the first group. As described above, the first group may be configured to operate according to TDM, and as described above, the second group may be configured to operate according to FDM. For example, the first group may include TRPs 340 to 348 configured to sequentially transmit PRSs 831 to 834. The second group may include TRPs 348 to 349 configured to simultaneously transmit PRSs at different frequencies such that the frequency of PRS 834 is different from the frequency of PRS 835.

[0149] Figure 9 is a block diagram illustrating an example wireless communication system 900 that supports backscatter-based positioning according to one or more aspects. The wireless communication system 900 may include or correspond to the wireless communication system 100, 300, or 400. Figure 9Describes the full-duplex operation of the first TRP 340, where backscatter-based positioning is used to determine the positioning of the tag device 120 (e.g., SAW tag). Specifically, the first TRP 340 may send the PRS 931 and receive the corresponding backscatter signal 941 reflected from the tag device 120 based on the PRS 931. The PRS 931 may include or correspond to the PRS 374 or 731, and the backscatter signal 941 may include or correspond to the backscatter signal 376 or 741.

[0150] The tag device 120 may receive the PRS 931 and send the backscatter signal 941. Between the tag device receiving the PRS 931 and sending the backscatter signal 941, the PRS 931 may be reflected to generate the backscatter signal 941, as indicated by the tag group delay 651. For example, the tag group delay 651 may include or correspond to the tag delay 368. In some specific implementations, the tag group delay 651 includes the amount of time or is associated with the amount of time between the tag device 120 receiving the positioning reference signal and sending the backscatter signal based on the received positioning reference signal. Additionally or alternatively, the tag group delay 651 may correspond to the amount of time elapsed based on the circuit 351, transmitter 356, or receiver 358 of the tag device 120 for the tag device 120 to backscatter or process the received PRS and reflect the PRS as a backscatter signal.

[0151] In some specific implementations, the first TRP 340 may determine the transmission time of the PRS 931 (e.g., the transmitted signal), the reception time of the backscatter signal 941, the amount of time elapsed from the transmission of the PRS 931 to the reception of the backscatter signal 941, or a combination thereof. The first TRP 340 may store the transmission time, reception time, amount of time, or a combination thereof as measurement information 310. Additionally or alternatively, the first TRP 340 may generate a measurement report (e.g., 378) including or indicating the transmission time, reception time, amount of time, or a combination thereof. In some specific implementations, the RTT may be based on a first duration (e.g., a first amount of time) corresponding to the PRS 931, a second duration corresponding to the tag group delay 651, and a third duration corresponding to the backscatter signal 941.

[0152] In some specific implementations, the tag device 120 does not know its tag group delay 651, or may not be configured to support the reporting of its tag delay of the tag group delay 651. In some specific implementations, the first TRP does not know the tag group delay 651 of the tag device 120, the tag group delay 651 of the tag device 120 is not available to the first TRP 340, or a combination thereof.

[0153] At least refer to Figure 7 and Figure 8, Backscatter-based positioning may involve at least one Tx TRP (e.g., TRP 340) that performs one or more functions of a reader (e.g., 121), multiple Rx TRPs (e.g., TRPs 340 to 348), and a tag device (e.g., 120), and the positioning of the tag device is determined by applying backscatter-based positioning. An estimate associated with the positioning of the tag device 120 is obtained by measuring the round-trip time (RTT), which is the sum of a first amount of time for the PRS 374 to propagate from the Tx TRP (such as TRP 340) to the tag device 120 (e.g., SAW tag), a second amount of time for the backscattered signal 376 to be reflected from the tag device 120 to one or more TRPs (e.g., TRPs 340 to 349), and a third amount of time indicating the tag delay. The tag delay corresponds to the amount of time elapsed based on the circuit 351, transmitter 356, or receiver 358 of the tag device 120 for the tag device 120 to backscatter or process the received PRS and reflect the PRS as a backscattered signal.

[0154] The first amount of time for the PRS to propagate from the Tx TRP (e.g., TRP 340) to the tag device 120 can be represented as τ TRP_x→Tag Device , where the value of x represents the first TRP 340 (x = 1), the second TRP 342 (x = 2), the third TRP 346 (x = 3), the fourth TRP 348 (x = 4), and the fifth TRP 349 (x = 5). The second amount of time for the backscattered signal to be reflected from the tag device 120 to the TRP (e.g., TRPs 340 to 349) can be represented as τ Tag Device→TRP_x . The third amount of time attributable to the tag delay can be represented as τ Tag Delay. . For example, based on the received PRS, the amount of time for the backscattered signal to be reflected and transmitted by the tag device 120 can be represented as τ Tag Device→TRP_2. . Thus, based on the above notation, the RTT for each of the TRPs 340 to 349 can be:

[0155]

[0156] τ TRP_2 = τ TRP_2→Tag Device + τ Tag Delay + τ tag Device→TRP_2 ,

[0157]

[0158] τ TRP_4 = τ tRP_4→Tag Device + τ Tag Delay + τ Tag Device→TRP_4 , and

[0159] τ TRP_5 = τTRP_5→Tag Device +τ Tag Delay +τ Tag Device→TRP_5 。

[0160] Based on the assumption the above equation can be rewritten as:

[0161] τ TRP_1 = 2(τ TRP_1→Tag Device ) + τ Tag Delay ,

[0162] τ TRP_2 = 2(τ TRP_2→Tag Device ) + τ Tag Delay ,

[0163] τ TRP_3 = 2(τ TRP_3→Tag Device ) + τ Tag Delay ,

[0164] τ TRP_4 = 2(τ TRP_4→Tag Device ) + τ Tag Delay ,and

[0165] τ TRP_5 = 2(τ TRP_5→Tag Device ) + τ Tag Delay 。

[0166] Using the RTT estimates from all TRPs, if the tag delay τ_tag (e.g., 368) is known, a multilateration method can be used to determine the location of the tag device 120. However, if the tag delay τ_tag (e.g., 368) is unknown or unavailable, another technique such as the time difference of arrival technique can be used. For illustration, the time difference between two TRPs (such as the first TRP 340 and the second TRP 342, where the first TRP 340 is the reference TRP) can be determined as:

[0167]

[0168] It should be noted that by subtracting the measurements and dividing by 2, a time differential value that can be used with the TDoA technique is obtained. It should also be noted that the tag delay τ_tag (e.g., 368) is canceled out after the subtraction operation. Therefore, in the case where the tag delay τ_tag (e.g., 368) is unknown or unavailable, the time error based on the tag delay τ_tag (e.g., 368) is mitigated.

[0169] Similarly, additional time differences can be determined such that:

[0170]

[0171] And

[0172]

[0173] Specifically, it is the RTT value used to obtain the location 369 of the tag device 120 in the Time Difference of Arrival (TDOA) technology. For illustration, to implement TDOA positioning, the device can be configured to perform the following TDOA positioning calculations:

[0174]

[0175] where TRP ref is the reference TRP, and TRP i is another TRP.

[0176] In some specific implementations, one or more devices such as the LMF 131 can be configured to determine the AoA by using data included in a measurement report such as the measurement report 378. For illustration, the TRPs 340 to 349 can include a directional antenna array and can be configured to determine the angle from which one or more backscattered signals (such as the backscattered signal 376) are received. The TRPs 340 to 349 can include the reception angles of one or more backscattered signals in the measurement report 378 sent to the LMF 131. Then, the LMF 131 can determine the AoA based on the reception angle data included in one or more measurement reports.

[0177] Figure 10 is a block diagram illustrating an example wireless communication system 1000 that supports backscatter-based positioning according to one or more aspects. The wireless communication system 1000 can include or correspond to the wireless communication system 100 or 300. Figure 10 Depicts the asynchronous operation of the TRPs 340 and 342, where backscatter-based positioning can be used to determine the location of the tag device 120 (e.g., SAW tag). In some specific implementations, the first TRP 340 or the second TRP 342 may not be configured for full-duplex operation.

[0178] During operation, the first TRP 340 can send the PRS 1031 to the tag device 120. For example, the PRS 1031 can include or correspond to the PRS 374. The first TRP 340 can determine the Tx time of the transmission of the PRS 1031. Based on the PRS 1031, the tag device 120 can send the backscattered signal 1041. For example, the backscattered signal 1041 can include or correspond to the backscattered signal 376. A tag group delay (such as the tag delay 368 or the tag group delay 651) can occur between the tag device 120 receiving the PRS 1031 and sending the backscattered signal 1041.

[0179] The second TRP 342 can receive the backscatter signal 1041 and determine the Rx time of receiving the backscatter signal 1041. In response to the reception of the backscatter signal 1041, the second TRP 342 can generate and transmit the PRS 1032. For example, the PRS 1032 can include or correspond to the PRS 374. The second TRP 342 can determine the Tx time of transmitting the PRS 1032. In some specific embodiments, the second TRP 342 can include or indicate its Rx time and Tx time, or the difference between its Tx time and Rx time, in a measurement report (e.g., 378) sent to the first TRP 340, the LMF 131, or a combination thereof. In some specific embodiments, the difference between the Tx time and Rx time of the second TRP 342 can be the TRP delay of the second TRP 342.

[0180] Based on the PRS 1031, the tag device 120 can transmit the backscatter signal 1042. For example, the backscatter signal 1042 can include or correspond to the backscatter signal 376. A tag group delay may occur between the tag device 120 receiving the PRS 1032 and transmitting the backscatter signal 1042.

[0181] The first TRP 340 can receive the backscatter signal 1042 and determine the Rx time of receiving the backscatter signal 1042. In some specific embodiments, the first TRP 340 can include its Rx time and Tx time, or the difference between its Tx time and Rx time, in a measurement report (e.g., 378) sent to the second TRP 342, the LMF 131, or a combination thereof. In a specific embodiment where the first TRP receives a measurement report from the second TRP 342 that includes or indicates the Tx time and Rx time of the second TRP 342 (or the difference between its Tx time and Rx time), the first TRP 340 can include or indicate the measurement report (or its information) of the second TRP 342 in the measurement report of the first TRP 340.

[0182] The second TRP 342 can receive the reflected backscatter signal 1041 transmitted by the tag device 120. After receiving the reflected backscatter signal 1041, the second TRP 342 can send the PRS 1032 to the tag device 120, and the tag device 120 can transmit the backscatter signal 1042 received by the first TRP 340. In this way, the transmission and / or reception times can be used for TDOA positioning technology to determine the positioning 369 of the tag device 120.

[0183] The first TRP 340 may send its Tx time and Rx time to the second TRP 342 or the LMF 131, or the second TRP 342 may send its Tx time and Rx time to the first TRP 340 or the LMF 131. Additionally or alternatively, the first TRP 340 may receive the Tx and Rx times of the second TRP 340 and may send its Tx time and Rx time and the Tx time and Rx time of the second TRP 340 to the LMF 131. In this way, the transmit and / or receive times may be used in TDOA positioning techniques to determine the location 369 of the tag device 120.

[0184] In some specific implementations, the LMF 131 may select or identify multiple pairs of TRPs, such as a first pair including the first TRP 340 and the second TRP 342, a second pair including the first TRP 340 and the third TRP 346, a third pair including the first TRP 340 and the fourth TRP 348, and a fourth pair including the first TRP 340 and the fifth TRP 349. Referring to the first pair, the round-trip time from the first TRP 340 sending a TRP to the first TRP 340 receiving the backscattered signal can be expressed as:

[0185]

[0186] Based on the assumption the above equation can be rewritten as:

[0187]

[0188] It should be noted that and therefore, the above equation can be rewritten as:

[0189]

[0190] If τ 1,2 is defined as then

[0191]

[0192] Similarly, each of the second, third, and fourth pairs can be expressed as:

[0193]

[0194] and

[0195]

[0196] If it is the first pair τ 1,2As a reference TRP, the time difference between the first pair and the second pair can be determined as:

[0197]

[0198] Similarly, additional time differences can be determined such that:

[0199] And

[0200]

[0201] The time differences can be used with the TDOA positioning technique to determine the location 369 of the tag device 120.

[0202] Although the above TDOA technique is a general technique that can be used with any tag device, the implementation of the technique in the context of SAW tags (such as Figure 4 depicted in) is a trivial extension of the foregoing technique. For illustration, a typical scenario may include a Tx TRP, two Rx TRPs, and a SAW tag. The SAW tag may be similar to Figure 4 the SAW tag depicted, but may include two reflectors instead of Figure 4 the three reflectors shown.

[0203] The Tx TRP may transmit a PRS, and the first Rx TRP may detect the first reflection (e.g., the first backscattered signal) transmitted by the first reflector of the SAW tag. Thus, the RTT associated with the propagation of the PRS from the Tx TRP to the first reflector and the reflection of the first backscattered signal from the first reflector to the first Rx TRP can be expressed as: T RTT,tot,RXTRP1,Path1 = T SAW,1 + T OTA,1 . In the above, T SAW,1 represents the unknown time delay corresponding to the time elapsed from the first time of transmitting the PRS to the second time when the first reflector generates the first backscattered signal. T OTA,1 . represents the known amount of time elapsed for the backscattered signal to reach the first RxTRP (e.g., the air time associated with the first backscattered signal). Subsequently, the second RxTRP detects the second backscattered signal transmitted by the second reflector. The RTT associated with this second backscattered signal can be expressed as T RT,tot,RxTRP2,Path2 = T SAW,1 +(T SAW,2 - T SAW,1 )+ T OTA,2 , where T SAW,2 - T SAW,1Corresponding to a known time delay between the transmission of a first backscatter signal associated with a first reflector and the transmission of a second backscatter signal associated with a second reflector. T OTA,2 Indicates the amount of time it takes for the second backscatter signal to reach the second Rx TRP. Thus, the total RTT can be determined as follows: T RTT,tot,RXTRP1,Path1 -T RTT,tot,RxTRP2,Path2 =T OTA,1 -T OTA,2 +(T SAW,2 -T 2AW,1 ). Thus, in addition to other types of tag devices, the above TDOA technique can also be applied to SAW tag devices.

[0204] Figure 11 Is a flowchart illustrating an example process 1100 that supports backscatter-based positioning according to one or more aspects. The operations of process 1100 can be performed by a tag device, such as tag device 120 or the tag device described in reference Figure 12 For example, the example operations (also referred to as "boxes") of process 1100 can enable the tag device to support backscatter-based positioning.

[0205] In box 1102, the tag device receives a tag configuration indicator that indicates a tag configuration for the tag device. The tag configuration indicator can include or correspond to tag configuration 390 or tag device information 309. The tag configuration can indicate a reflector configuration. The tag configuration can also indicate the tag address of the tag device. In some specific implementations, the tag configuration indicates that a first set of reflectors among the multiple reflectors of the tag device will be activated, a second set of reflectors among the multiple reflectors will be deactivated, or a combination thereof. In some specific implementations, the tag configuration indicates the reflector among the multiple reflectors of the tag device to be configured as an initial reflector, the configuration of the multiple reflectors, frequency response parameters, the amplitude associated with the backscatter signal, the phase shift associated with the backscatter signal, or the frequency associated with the backscatter signal.

[0206] In box 1104, the tag device transmits a backscatter signal in response to the PRS based on the tag configuration.

[0207] In some specific implementations, the tag device includes a SAW tag device. The tag device can include multiple reflectors, interdigital transducers, a controller, or a combination thereof.

[0208] In some specific implementations, the tag device configures one or more components of the tag device based on the tag configuration. For example, configuring one or more components includes activating a first reflector, deactivating a second reflector, or a combination thereof.

[0209] In some specific implementations, the tag device sends tag device indicators indicating programming latency, tag type, category type, bandwidth, positioning reference signal slot periodicity, sensitivity, tag latency, energy harvesting capability, or a combination thereof. Additionally or alternatively, the tag device identifies a tag address indicated by the tag configuration, where the tag address includes a tag ID or a group ID, and determines that the identified tag address corresponds to the tag device. In some specific implementations, the tag device receives a PRS from the TRP. For example, the TRP may include or correspond to the TRP 340. Additionally or alternatively, the tag device generates a backscatter signal based on the PRS.

[0210] Figure 12 FIG. is a block diagram of an example tag device 1200 that supports backscatter-based positioning according to one or more aspects. The tag device 1200 may include or correspond to the tag device 120. For example, the tag device 1200 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.

[0211] The tag device 1200 may be configured to perform operations including reference Figure 12 to the blocks of the processes described. In some specific implementations, the tag device 1200 includes the structures, hardware, and components shown and described with reference to the tag device 120. For example, the tag device 1200 includes a controller 1280 that operates to execute logic or computer instructions stored in a memory 1282 and controls the components that provide the features and functionality of the tag device 1200. The controller 1280 and the memory 1282 may include or correspond to the circuit 351. The tag device 1200 is configured to send and receive signals via a wireless radio component 1201 and an antenna 1252 under the control of the controller 1280. In some specific implementations, the wireless radio component 1201 and the antenna 1252 may include or correspond to a transmitter 356, a receiver 358, or a combination thereof. The wireless radio component 1201 includes various components and hardware. As an illustrative non-limiting example, as described with reference to Figure 2 the tag device 1200 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.

[0212] The tag device 1200 also includes an energy harvesting circuit 1290. The energy harvesting circuit 1290 may include or correspond to circuit 351. The energy harvesting circuit 1290 may include hardware (e.g., circuitry), software, or a combination thereof configured to harvest energy from an energy source of the tag device 1200. 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 1290 may be coupled to circuitry such as controller 1280, memory 1282, wireless radio component 1201, a power source of the tag device 1200, or a combination thereof. In some embodiments, the harvested energy may be used to charge a power source such as a battery or a capacitor. The power source may be coupled to controller 1280, memory 1282, wireless radio component 1201, or a combination thereof. Additionally or alternatively, the harvested energy may be configured to power one or more components of the tag device 1200.

[0213] As shown, the memory 1282 may include tag capability information 1202, tag configuration information 1203, and communication logic 1204. The tag capability information 1202 may include or correspond to tag device information 309, tag device indicator 370, tag configuration 390, or a combination thereof. The tag configuration information 1203 may correspond to tag configuration 390. The communication logic 1204 may be configured to enable communication between the tag device 1200 and one or more other devices. The tag device 1200 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, 342, 346, 348, or 349 or network entities as illustrated in FIG. 16).

[0214] Note that the tag device 1200 may include fewer or more components than described with respect to Figure 12 For example, in some embodiments, the tag device 1200 may include a power storage device. As another example, the tag device 1200 may not include the controller 1280.

[0215] Figure 13 is a flowchart illustrating an example process 1300 that supports backscatter-based positioning in accordance with one or more aspects. The operations of process 1300 may be performed by a network entity such as base station 105, UE 115, reader device 121, core network 130, LMF 131, TRP 340, 342, 346, 348, or 349 or as referenced Figure 15The described network entity. For example, the exemplary operations of process 1300 may enable the network entity to support backscatter-based positioning. In some specific implementations, as an illustrative non-limiting example, the network entity may include or correspond to a network, a base station, a reader device 121, a core network 130, an LMF 131, a TRP, or a combination thereof.

[0216] At block 1302, the network entity transmits a tag configuration indicator indicating a first tag configuration for a first tag device. For example, the first tag configuration may include or correspond to tag configuration 390. The first tag device may include or correspond to tag device 120. In some specific implementations, the first tag device includes a SAW tag device. Additionally or alternatively, the first tag device may include a plurality of reflectors, interdigital transducers, a controller, or a combination thereof. The first tag configuration may include or indicate a reflector configuration.

[0217] In some specific implementations, the first tag configuration indicates that a first set of reflectors among the plurality of reflectors of the tag device will be activated, a second set of reflectors among the plurality of reflectors will be deactivated, or a combination thereof. Additionally or alternatively, the first tag configuration indicates one reflector among the plurality of reflectors of the first tag device to be configured as an initial reflector, the configuration of the plurality of reflectors, or frequency response parameters. The frequency response parameters may include or indicate a chirp up or a chirp down, a frequency offset, or a combination thereof. In some specific implementations, the first tag configuration may additionally or alternatively include or indicate an amplitude, a phase shift, or a frequency associated with the first backscatter signal.

[0218] In some specific implementations, the first tag configuration further indicates the tag address of the first tag device. The tag address may include or indicate the active state of at least one reflector of the first tag device.

[0219] At block 1304, the network entity receives a first backscatter signal from the first tag device in response to a PRS. The first backscatter signal may include or correspond to backscatter signal 376. The first backscatter signal may be based on the first tag configuration. In some specific implementations, the network entity may also determine the RTT associated with the first tag device, the positioning of the first tag device, the tag delay of the first tag device, or a combination thereof based on the first backscatter signal.

[0220] In some specific implementations, the network entity receives a tag indicator from the first tag device, where the tag indicator indicates a programming delay, a tag type, a category type, a bandwidth, a positioning reference signal slot periodicity, a sensitivity, a tag delay, an energy harvesting capability, or a combination thereof. Additionally or alternatively, the network entity generates the first tag configuration for the first tag device among the plurality of tag devices based on the tag indicator.

[0221] In some specific implementations, the tag configuration indicator indicates a second tag configuration for a second tag device among a plurality of tag devices. By way of illustration, the plurality of tag devices may include a first tag device and a second tag device. The second tag device may include one or more components, perform one or more operations, or a combination thereof, as described with reference to tag device 120. The second tag configuration may indicate that the second tag device deactivates a set of reflectors of the second tag device. In some specific implementations, the second tag configuration indicates that the second tag deactivates all of its reflectors. Additionally or alternatively, the network entity may receive a second backscatter signal from the second tag device in response to the PRS. The second backscatter signal may be based on the second tag configuration.

[0222] Figure 14 is a flowchart illustrating an example process 1400 that supports backscatter-based positioning according to one or more aspects. The operations of process 1400 may be performed by a network entity, such as base station 105, UE 115, reader device 121, core network 130, LMF 131, TRPs 340, 342, 346, 348, or 349, or a network entity as described with reference to Figure 15 For example, the example operations of process 1400 may enable the network entity to support backscatter-based positioning. In some specific implementations, the network entity is a TRP or a reader device. Additionally or alternatively, the network entity (e.g., a TRP) may be configured to operate in a full-duplex mode.

[0223] At block 1402, the network entity receives a plurality of measurement reports associated with a SAW tag device. The SAW tag device may include or correspond to tag device 120. For each of the plurality of TRPs, the plurality of measurement reports may include the measurement report for that TRP. The measurement report may include or correspond to measurement report 378. The plurality of TRPs may include or correspond to TRPs 340 through 348. In some specific implementations, the plurality of measurement reports include a first measurement report received from a first TRP that is associated with a first RTT and is based on a first reflector of the SAW tag device; and a second measurement report received from a second TRP that is associated with a second RTT and is based on a second reflector of the SAW tag device. Additionally or alternatively, the positioning of the SAW tag device may be determined when the tag delay is unknown to the network entity.

[0224] In some specific implementations, the SAW tag device may have a tag delay associated with the first reflector and the tag delay is unknown to the network entity. The tag delay may include the radio frequency group delay or the acoustic delay of one or more components of the SAW tag device. The one or more components are configured to: receive a positioning reference signal, generate a backscattered signal based on the positioning reference signal, and transmit the backscattered signal. Additionally or alternatively, the delay between the first reflector and the second reflector of the SAW tag device is known to the network entity.

[0225] At block 1404, the network entity determines the positioning of the SAW tag device based on multiple measurement reports.

[0226] In some specific implementations, the network entity sends a TRP configuration. The TRP configuration may include or correspond to a TRP configuration 372, a PRS configuration 381, an MG configuration 382, PRS information 307, and measurement gap information 308. In some specific implementations, the TRP configuration includes or indicates that the first TRP is configured to receive the first reflection of the backscattered signal from the SAW tag device based on the first reflector of the SAW tag device. Additionally or alternatively, the TRP configuration may include or indicate that the second TRP is configured to receive the second reflection of the backscattered signal from the SAW tag device based on the second reflector of the SAW tag device.

[0227] In some specific implementations, for each TRP among multiple TRPs, the value of the measurement report of the TRP indicates the RTT. For each TRP among multiple TRPs, the TRP may be configured for full-duplex operation.

[0228] In some specific implementations, each TRP among the multiple TRPs includes a pair of TRPs, and the pair of TRPs has the same TRP as the first TRP of the pair of TRPs and the same TRP as the second TRP of the pair of TRPs. The network entity may select the first TRP among the multiple TRPs as a reference TRP. The multiple TRPs may include a reference TRP and a set of TRPs. For example, the reference TRP may be TRP340, and the set of TRPs may include TRPs 342 to 348. Additionally or alternatively, the network entity may determine a set of time differences based on the multiple TRPs. For each TRP among the multiple TRPs, the network entity determines a measurement value based on the measurement report of the TRP. To determine the set of time differences, the network entity may, for each TRP in the set of TRPs, subtract the measurement value of the reference TRP from the measurement value of the TRP to determine a difference, and divide the difference by two to determine a quotient, and the quotient includes the time difference in the set of time differences. The network entity may calculate the positioning of the SAW tag device based on the set of time differences. For example, the positioning may be calculated using the time difference of arrival technique.

[0229] Figure 15 is a block diagram of an example network entity 1500 that supports backscatter-based positioning according to one or more aspects. The network entity 1500 may include or correspond to the core network 130, the LMF 131, the reader device 121, the TRPs 340, 342, 346, 348, or 349, the UE 115, or the base station 105. The network entity 1500 may be configured to perform operations including the blocks of process 1300 or 1400. In some specific implementations, the network entity 1500 includes the reference Figure 1 or Figure 2 the structures, hardware, and components shown and described for the base station 105 or the UE 115 of Figure 2 . As an example illustrated, the network entity 1500 may include a controller 240 that operates to execute logic or computer instructions stored in a memory 242 and controls the components that provide the features and functionality of the network entity 1500. The network entity 1500 transmits and receives signals under the control of the controller 240 via wireless radio components 1501a to 1501t and antennas 234a to 234t. The wireless radio components 1501a to 1501t include various components and hardware as illustrated for the base station 105 in

[0230] , including modulators and demodulators 232a to 232t, a transmit processor 220, a TX MIMO processor 230, a MIMO detector 236, and a receive processor 238.

[0231] Note that the reference Figure 12 , Figure 14 , or Figure 15One or more of the blocks (or operations) described may be combined with one or more of the blocks (or operations) described with reference to another figure. For example, Figure 14 one or more of the blocks (or operations) of Figure 15 may be combined with one or more of the blocks (or operations) of Figure 12 . As another example, one or more of the blocks associated with Figure 14 may be combined with one or more of the blocks associated with Figure 12 , Figure 14 or Figure 15 . As another example, one or more of the blocks associated with Figures 1 to 5 may be combined with one or more of the blocks (or operations) associated with Figures 1 to 5 . Additionally or alternatively, one or more of the operations described above with reference to Figure 13 or FIG. 16 may be combined with one or more of the operations described with reference to

[0232] .

[0232] 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 transmitting a tag configuration indicator indicating a first tag configuration for a first tag device. The first tag configuration indicates a reflector configuration. The technique may also include receiving a first backscatter signal from the tag device in response to a PRS. The backscatter signal is based on the first tag configuration. 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.

[0233] In a second aspect, in combination with the first aspect, the tag device includes a SAW tag device.

[0234] In a third aspect, in combination with the first aspect or the second aspect, the tag device includes a plurality of reflectors, interdigital transducers, a controller, or a combination thereof.

[0235] In a fourth aspect, in combination with one or more of the first aspect to the third aspect, the tag configuration indicates that a first set of reflectors among the plurality of reflectors of the tag device will be activated, a second set of reflectors among the plurality of reflectors will be deactivated, or a combination thereof.

[0236] In a fifth aspect, in combination with one or more of the first aspect to the fourth aspect, the tag configuration indicates one reflector among the plurality of reflectors of the tag device to be configured as an initial reflector, the configuration of the plurality of reflectors, or frequency response parameters.

[0237] In a sixth aspect, in combination with the fifth aspect, the frequency response includes a linear frequency chirp up or down, a frequency offset, or a combination thereof.

[0238] In a seventh aspect, in combination with one or more of the first aspect to the sixth aspect, the tag configuration indicates the amplitude, phase shift, or frequency associated with the first backscatter signal.

[0239] In an eighth aspect, in combination with one or more of the first aspect to the seventh aspect, the tag configuration further indicates the tag address of the first tag device.

[0240] In a ninth aspect, in combination with the eighth aspect, the tag address indicates the active state of at least one reflector of the first tag device.

[0241] In a tenth aspect, in combination with one or more of the first aspect to the ninth aspect, the technique further includes receiving a tag indicator from the tag device, where the tag indicator indicates a programming delay, a tag type, a category type, a bandwidth, a positioning reference signal slot periodicity, a sensitivity, a tag delay, an energy harvesting capability, or a combination thereof.

[0242] In an eleventh aspect, in combination with one or more of the first aspect to the tenth aspect, the technique further includes generating tag configuration information for a first tag device among a plurality of tag devices.

[0243] In a twelfth aspect, in combination with one or more of the first aspect to the eleventh aspect, the tag configuration indicator indicates a second tag configuration for a second tag device among a plurality of tag devices.

[0244] In a thirteenth aspect, in combination with the twelfth aspect, the second tag configuration indicates that the second tag device deactivates a set of reflectors of the second tag device.

[0245] In a fourteenth aspect, in combination with the twelfth or thirteenth aspect, the technique further includes receiving, in response to the PRS, a second backscatter signal from the second tag device, the second backscatter signal being based on the second tag configuration.

[0246] In a fifteenth aspect, in combination with one or more of the first through fourteenth aspects, the technique further includes determining, based on the first backscatter signal, the RTT associated with the first tag device, the location of the first tag device, the tag latency of the first tag device, or a combination thereof.

[0247] 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 sixteenth aspect, techniques for supporting backscatter-based positioning may include receiving a tag configuration indicator indicating a tag configuration for a tag device. The tag configuration indicates a reflector configuration. The technique may further include transmitting a backscatter signal in response to the PRS based on the tag configuration. In some examples, the technique in the sixteenth aspect may be implemented in a method or process. In some other examples, the technique of the sixteenth 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 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) 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.

[0248] In a seventeenth aspect, in combination with the sixteenth aspect, the tag device includes a SAW tag device.

[0249] In an eighteenth aspect, in combination with the sixteenth or seventeenth aspect, the tag device includes a plurality of reflectors, interdigital transducers, a controller, or a combination thereof.

[0250] In a nineteenth aspect, in combination with one or more of the sixteenth through eighteenth aspects, the technique further includes configuring one or more components of the tag device based on the tag configuration.

[0251] In a twentieth aspect, in combination with the nineteenth aspect, for configuring one or more components, the technique further includes activating a first reflector, deactivating a second reflector, or a combination thereof.

[0252] In a twenty - first aspect, in combination with one or more of the sixteenth aspect to the twentieth aspect, the tag configuration indicates that a first set of reflectors among the multiple reflectors of the tag device will be activated, a second set of reflectors among the multiple reflectors will be deactivated, or a combination thereof.

[0253] In a twenty - second aspect, in combination with one or more of the sixteenth aspect to the twenty - first aspect, the tag configuration indicates one reflector among the multiple reflectors of the tag device to be configured as an initial reflector, the configuration of the multiple reflectors, or frequency response parameters.

[0254] In a twenty - third aspect, in combination with the twenty - second aspect, the frequency response includes a linear frequency chirp upwards or downwards, a frequency offset, or a combination thereof.

[0255] In a twenty - fourth aspect, in combination with one or more of the sixteenth aspect to the twenty - third aspect, the tag configuration indicates the amplitude, phase shift, or frequency associated with a first backscatter signal.

[0256] In a twenty - fifth aspect, in combination with one or more of the sixteenth aspect to the twenty - fourth aspect, the tag configuration further indicates the tag address of the first tag device.

[0257] In a twenty - sixth aspect, in combination with the twenty - fifth aspect, the tag address indicates the active state of at least one reflector of the first tag device.

[0258] In a twenty - seventh aspect, in combination with the twenty - fifth aspect or the twenty - sixth aspect, the technique further includes identifying the tag address indicated by the tag configuration, where the tag address includes a tag ID or a group ID.

[0259] In a twenty - eighth aspect, in combination with the twenty - seventh aspect, the technique further includes: determining that the identified tag address corresponds to a tag device.

[0260] In a twenty - ninth aspect, in combination with one or more of the sixteenth aspect to the twenty - eighth aspect, the technique further includes receiving a PRS from a TRP.

[0261] In a thirtieth aspect, in combination with the twenty - ninth aspect, the technique further includes generating a backscatter signal based on the PRS.

[0262] In a thirty - first aspect, in combination with one or more of the sixteenth aspect to the thirtieth aspect, the technique further includes transmitting a tag device indicator that indicates a programming delay, a tag type, a category type, a bandwidth, a positioning reference signal slot periodicity, a sensitivity, a tag delay, an energy harvesting capability, or a combination thereof.

[0263] 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 thirty - second aspect, techniques for supporting backscatter - based positioning may include receiving a plurality of measurement reports associated with a SAW tag device. For each of a plurality of TRPs, the plurality of measurement reports includes a measurement report for the TRP. The technique may further include determining the positioning of the SAW tag device based on the plurality of measurement reports. In some examples, the technique in the thirty - second aspect may be implemented in a method or process. In some other examples, the technique in the thirty - second 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, 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) 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.

[0264] In a thirty - third aspect, in combination with the thirty - second aspect, the SAW tag device has a tag delay associated with a first reflector and the tag delay is unknown to the network entity.

[0265] In a thirty - fourth aspect, in combination with the thirty - third aspect, the delay between a first reflector and a second reflector of the SAW tag device is known to the network entity.

[0266] In a thirty - fifth aspect, in combination with the thirty - fourth aspect, the tag delay includes a radio frequency group delay of one or more components of the SAW tag device.

[0267] In a thirty-sixth aspect, in combination with the thirty-fifth aspect, one or more components are configured to: receive a positioning reference signal, generate a backscatter signal based on the positioning reference signal, and transmit the backscatter signal.

[0268] In a thirty-seventh aspect, in combination with the thirty-sixth aspect, the positioning of the SAW tag device is determined when the tag delay is unknown to the network entity.

[0269] In a thirty-eighth aspect, in combination with one or more of the thirty-second to thirty-seventh aspects, a plurality of measurement reports include a first measurement report received from a first TRP associated with a first RTT and based on a first reflector of the SAW tag device; and a second measurement report received from a second TRP associated with a second RTT and based on a second reflector of the SAW tag device.

[0270] In a thirty-ninth aspect, in combination with one or more of the thirty-second to thirty-eighth aspects, the technique further includes transmitting a TRP configuration.

[0271] In a fortieth aspect, in combination with the thirty-ninth aspect, the TRP configuration indicates that the first TRP is configured to receive a first reflection of a backscatter signal from the SAW tag device based on a first reflector of the SAW tag device.

[0272] In a forty-first aspect, in combination with the fortieth aspect, the TRP configuration indicates that the second TRP is configured to receive a second reflection of a backscatter signal from the SAW tag device based on a second reflector of the SAW tag device.

[0273] In a forty-second aspect, in combination with one or more of the thirty-second to thirty-seventh aspects, for each TRP among a plurality of TRPs, the value of the measurement report of the TRP indicates the RTT.

[0274] In a forty-third aspect, in combination with one or more of the thirty-second to forty-second aspects, for each TRP among a plurality of TRPs, the TRP is configured for full-duplex operation to perform positioning signaling.

[0275] In a forty-fourth aspect, in combination with one or more of the thirty-second to thirty-seventh aspects, each TRP among a plurality of TRPs includes a pair of TRPs, and the pair of TRPs has a TRP as the first TRP of the pair of TRPs and the same TRP as the second TRP of the pair of TRPs.

[0276] In a forty-fifth aspect, in combination with the forty-fourth aspect, the technique further includes selecting a first TRP among a plurality of TRPs as a reference TRP.

[0277] In a forty-sixth aspect, in combination with the forty-fifth aspect, the technique further includes determining a set of time differences based on a plurality of TRPs.

[0278] In a forty-seventh aspect, in combination with the forty-sixth aspect, the plurality of TRPs includes a reference TRP and a set of TRPs.

[0279] In a forty-eighth aspect, in combination with the forty-seventh aspect, the technique further includes, for each TRP among the plurality of TRPs, determining a measurement value based on a measurement report of the TRP.

[0280] In a forty-ninth aspect, in combination with the forty-eighth aspect, to determine a set of time differences, the technique further includes, for each TRP among the set of TRPs, subtracting the measurement value of the reference TRP from the measurement value of the TRP to determine a difference.

[0281] In a fiftieth aspect, in combination with the forty-ninth aspect, to determine a set of time differences, the technique further includes, for each TRP among the set of TRPs, dividing the difference by two to determine a quotient, where the quotient includes the time differences in the set of time differences.

[0282] In a fifty-first aspect, in combination with the forty-seventh aspect, the technique further includes calculating the positioning of the SAW tag device based on a set of time differences.

[0283] In a fifty-second aspect, in combination with the fifty-first aspect, the positioning is calculated using the time difference of arrival technique.

[0284] 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, the 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.

[0285] As described herein with respect to Figures 1 to 15 the components, functional blocks, and modules include processors, electronic devices, hardware devices, electronic components, logic circuits, memories, software codes, firmware codes, etc., or any combination thereof. Software should be broadly interpreted to mean instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, execution threads, 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.

[0286] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithmic steps described in connection with the disclosure herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. Those skilled in the art will also readily recognize that the order or combination of the components, methods, or interactions described herein are merely examples, and the components, methods, or interactions of the various aspects of the present disclosure can be combined or performed in ways other than those illustrated and described herein.

[0287] The various illustrative logics, logic blocks, modules, circuits, and algorithmic processes described in connection with the specific implementations disclosed herein can be implemented as electronic hardware, computer software, or combinations 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 design constraints imposed on the overall system.

[0288] 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 realized using a general purpose 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 designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. In some particular implementations, the processor may 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 conjunction with a DSP core, or any other such configuration. In some particular implementations, specific processes and methods may be performed by circuitry specific to a given function.

[0289] In one or more aspects, the described functionality can be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and structural equivalents thereof, or any combination thereof. The specific 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.

[0290] If implemented in software, the functions may be stored on or transmitted through 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, which communication media includes any medium that can be implemented to transfer a computer program from one place to another. The storage media can 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 set of code and instructions or any combination of sets of code and instructions on a machine-readable medium and a computer-readable medium, which may be incorporated into a computer program product.

[0291] Various modifications to the specific implementations described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to some other specific implementations without departing from the spirit or scope of this disclosure. Therefore, the claims are not intended to be limited to the specific implementations shown herein, but rather to cover the broadest scope consistent with this disclosure, the principles disclosed herein, and novel features.

[0292] Additionally, those of ordinary skill in the art will readily recognize that the terms "upper" and "lower" are sometimes used for ease of describing 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.

[0293] 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 a sub-combination.

[0294] Similarly, although operations are depicted in the figures in a particular order, this should not be construed as requiring that the 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 that are not depicted can be incorporated in 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 specific 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 specific 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.

[0295] 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 alone 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 largely but not necessarily wholly what is specified (and includes what 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 disclosed specific embodiments, the term "substantially" can be replaced by "[percentage] within" what is specified, where the percentage includes 0.1%, 1%, 5%, or 10%.

[0296] 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 for wireless communication performed by a transmit / receive point (TRP), the method comprising: Transmitting a tag configuration indicator indicating a first tag configuration for a first tag device, the first tag configuration indicating a reflector configuration; And Receiving, in response to a positioning reference signal (PRS), a first backscatter signal from the first tag device, the first backscatter signal being based on the first tag configuration.

2. The method according to claim 1, wherein: The first tag device comprises a surface acoustic wave (SAW) tag device; The first tag device comprises a plurality of reflectors, interdigital transducers, a controller, or a combination thereof; and The first tag configuration indicates that a first set of reflectors among the plurality of reflectors of the tag device will be activated, a second set of reflectors among the plurality of reflectors will be deactivated, or a combination thereof.

3. The method according to claim 1, wherein the first tag configuration indicates one reflector among the plurality of reflectors of the first tag device to be configured as an initial reflector, the configuration of the plurality of reflectors, or frequency response parameters.

4. The method according to claim 3, wherein the frequency response parameters comprise up-chirp or down-chirp, frequency offset, or a combination thereof.

5. The method according to claim 1, wherein the first tag configuration indicates an amplitude, a phase shift, or a frequency associated with the first backscatter signal.

6. The method according to claim 1, wherein the first tag configuration further indicates a tag address of the first tag device.

7. The method according to claim 6, wherein the tag address indicates an active state of at least one reflector of the first tag device.

8. The method according to claim 1, the method further comprising: Receiving a tag indicator from the first tag device, wherein the tag indicator indicates a programming delay, a tag type, a category type, a bandwidth, a positioning reference signal time slot periodicity, a sensitivity, a tag delay, an energy harvesting capability, or a combination thereof; Generating, based on the tag indicator, the first tag configuration for the first tag device among a plurality of tag devices; And Determining, based on the first backscatter signal, a round-trip time (RTT) associated with the first tag device, a positioning of the first tag device, a tag delay of the first tag device, or a combination thereof.

9. The method according to claim 1, wherein: The tag configuration indicator indicates a second tag configuration for a second tag device among a plurality of tag devices, the plurality of tag devices comprising the first tag device and the second tag device, and The second tag configuration indicates that the second tag device deactivates a set of reflectors of the second tag device.

10. The method according to claim 9, the method further comprising: Receiving, in response to the PRS, a second backscatter signal from the second tag device, the second backscatter signal being based on the second tag configuration.

11. A transmit / receive point (TRP), the 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 indicator indicating a tag configuration for a tag device, the tag configuration indicating a reflector configuration; and receive a backscatter signal from the tag device in response to a PRS, the backscatter signal being based on the tag configuration.

12. The TRP according to claim 11, wherein the tag device includes a surface acoustic wave (SAW) tag device; the tag device includes a plurality of reflectors, interdigital transducers, a controller, or a combination thereof; and the tag configuration indicates that a first set of reflectors among the plurality of reflectors of the tag device will be activated, a second set of reflectors among the plurality of reflectors will be deactivated, or a combination thereof.

13. The TRP according to claim 11, wherein the tag configuration indicates a tag address of the tag device, one reflector among the plurality of reflectors of the tag device to be configured as an initial reflector, a configuration of the plurality of reflectors, or frequency response parameters.

14. The TRP according to claim 13, wherein the frequency response parameters include a chirp up or a chirp down, a frequency offset, or a combination thereof.

15. The TRP according to claim 11, wherein the tag configuration indicates an amplitude, a phase shift, or a frequency associated with the backscatter signal.

16. A method for a tag device to perform wireless communication, the method comprising: receiving a tag configuration indicator indicating a tag configuration for the tag device, the tag configuration indicating a reflector configuration; and sending a backscatter signal in response to a positioning reference signal (PRS) based on the tag configuration.

17. The method according to claim 16, wherein: the tag device includes a surface acoustic wave (SAW) tag device; the tag device includes a plurality of reflectors, interdigital transducers, a controller, or a combination thereof; the tag configuration further indicates a tag address of the tag device; and the tag configuration indicates that a first set of reflectors among the plurality of reflectors of the tag device will be activated, a second set of reflectors among the plurality of reflectors will be deactivated, or a combination thereof.

18. The method according to claim 16, the method further comprising: configuring one or more components of the tag device based on the tag configuration, and wherein configuring the one or more components includes activating a first reflector, deactivating a second reflector, or a combination thereof.

19. The method according to claim 16, wherein: the tag configuration indicates a reflector among the plurality of reflectors of the tag device to be configured as an initial reflector, a configuration of the plurality of reflectors, frequency response parameters, an amplitude associated with the backscatter signal, a phase shift associated with the backscatter signal, or a frequency associated with the backscatter signal.

20. The method according to claim 16, the method further comprising: Transmit a tag device indicator indicating programming delay, tag type, category type, bandwidth, positioning reference signal slot periodicity, sensitivity, tag delay, energy harvesting capability, or a combination thereof; Identify a tag address indicated by the tag configuration indication, wherein the tag address includes a tag ID or a group ID; And Determine that the identified tag address corresponds to the tag device; Receive the PRS from a transmit / receive point (TRP); And Generate the backscatter signal based on the PRS.

21. A method for wireless communication performed by a network entity, the method comprising: Receiving a plurality of measurement reports associated with a surface acoustic wave (SAW) tag device, for each of a plurality of transmit / receive points (TRPs), the plurality of measurement reports including the measurement report of the TRP; And Determine the positioning of the SAW tag device based on the plurality of measurement reports.

22. The method according to claim 21, wherein: The SAW tag device has a tag delay associated with a first reflector and the tag delay is unknown to the network entity; and Wherein the delay between the first reflector and the second reflector of the SAW tag device is known to the network entity.

23. The method according to claim 22, wherein: The tag delay includes the radio frequency group delay of one or more components of the SAW tag device; The one or more components are configured to: receive a positioning reference signal, generate a backscatter signal based on the positioning reference signal, and transmit the backscatter signal; and The positioning of the SAW tag device is determined when the tag delay is unknown to the network entity.

24. The method according to claim 21, wherein the plurality of measurement reports include: A first measurement report received from a first TRP is associated with a first RTT and is based on a first reflector of the SAW tag device; And A second measurement report received from a second TRP is associated with a second RTT and is based on a second reflector of the SAW tag device.

25. The method according to claim 21, the method further comprising: Transmit a TRP configuration, and Wherein the TRP configuration indicates that: The first TRP is configured to receive a first reflection of the backscatter signal from the SAW tag device based on a first reflector of the SAW tag device, and the second TRP is configured to receive a second reflection of the backscatter signal from the SAW tag device based on a second reflector of the SAW tag device.

26. The method according to claim 21, wherein: For each of the plurality of TRPs, the value of the measurement report of the TRP indicates the round-trip time (RTT); and For each of the plurality of TRPs, the TRP is configured for full-duplex operation.

27. The method according to claim 21, wherein: Each of the plurality of TRPs includes a pair of TRPs, and the pair of TRPs has the same TRP as the first TRP of the pair of TRPs and the same TRP as the second TRP of the pair of TRPs.

28. The method according to claim 27, the method further comprising: selecting a first TRP of the plurality of TRPs as a reference TRP; and determining a set of time differences based on the plurality of TRPs, and wherein the plurality of TRPs includes the reference TRP and a set of TRPs.

29. The method according to claim 28, the method further comprising: for each of the plurality of TRPs, determining a measurement value based on the measurement report of the TRP; and for each of the set of TRPs, determining the set of time differences: subtracting the measurement value of the reference TRP from the measurement value of the TRP to determine a difference; and dividing the difference by two to determine a quotient, and the quotient includes the time difference in the set of time differences.

30. The method according to claim 28, the method further comprising: calculating the positioning of the SAW tag device based on the set of time differences, and wherein the positioning is calculated using the time difference of arrival technique.

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