WO2023245598A1

WO2023245598A1 - Transmitting reflected signals that indicate data multiplexed with reference signals

Info

Publication number: WO2023245598A1
Application number: PCT/CN2022/101032
Authority: WO
Inventors: Ahmed Elshafie; Huilin Xu; Yuchul Kim; Zhikun WU; Seyedkianoush HOSSEINI; Linhai He; Wanshi Chen; Peter Gaal; Krishna Kiran Mukkavilli; Tingfang Ji
Original assignee: Qualcomm Incorporated
Priority date: 2022-06-24
Filing date: 2022-06-24
Publication date: 2023-12-28

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a radio frequency identification (RFID) tag may receive, from a reader or a radio frequency (RF) source, a signal. The RFID tag may transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data. Numerous other aspects are described.

Description

TRANSMITTING REFLECTED SIGNALS THAT INDICATE DATA MULTIPLEXED WITH REFERENCE SIGNALS

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for transmitting reflected signals that indicate data multiplexed with reference signals.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, or the like) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless network may include one or more network nodes that support communication for wireless communication devices, such as a user equipment (UE) or multiple UEs. A UE may communicate with a network node via downlink communications and uplink communications. “Downlink” (or “DL” ) refers to a communication link from the network node to the UE, and “uplink” (or “UL” ) refers to a communication link from the UE to the network node. Some wireless networks may support device-to-device communication, such as via a local link (e.g., a sidelink (SL) , a wireless local area network (WLAN) link, and/or a wireless personal area network (WPAN) link, among other examples) .

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate on a municipal, national, regional, and/or global level. New Radio (NR) , which may be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink, using CP-OFDM and/or single-carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink, as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with the present disclosure.

Fig. 2 is a diagram illustrating an example of a network node in communication with a user equipment (UE) in a wireless network, in accordance with the present disclosure.

Fig. 3 is a diagram illustrating an example disaggregated base station architecture, in accordance with the present disclosure.

Figs. 4-5 are diagrams illustrating examples of backscatter communication, in accordance with the present disclosure.

Figs. 6-8 are diagrams illustrating examples associated with transmitting reflected signals that indicate data multiplexed with reference signals, in accordance with the present disclosure.

Figs. 9-10 are diagrams illustrating example processes associated with transmitting reflected signals that indicate data multiplexed with reference signals, in accordance with the present disclosure.

Figs. 11-12 are diagrams of example apparatuses for wireless communication, in accordance with the present disclosure.

SUMMARY

In some implementations, an apparatus for wireless communication at a radio frequency identification (RFID) tag includes a memory and one or more processors, coupled to the memory, configured to: receive, from a reader or a radio frequency (RF) source, a signal; and transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, an apparatus for wireless communication at a reader includes a memory and one or more processors, coupled to the memory, configured to: transmit, to an RFID tag, a signal; and receive, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, a method of wireless communication performed by an RFID tag includes receiving, from a reader or an RF source, a signal; and transmitting, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, a method of wireless communication performed by a reader includes transmitting, to an RFID tag, a signal; and receiving, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of an RFID tag, cause the RFID tag to: receive, from a reader or an RF source, a signal; and transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a reader, cause the reader to: transmit, to an RFID tag, a signal; and receive, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, an apparatus for wireless communication includes means for receiving, from a reader or an RF source, a signal; and means for transmitting, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

In some implementations, an apparatus for wireless communication includes means for transmitting, to an RFID tag, a signal; and means for receiving, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, network entity, network node, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed 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. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages, will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

While aspects are described in the present disclosure by illustration to some examples, those skilled in the art will understand that such aspects may be implemented in many different arrangements and scenarios. Techniques described herein may be implemented using different platform types, devices, systems, shapes, sizes, and/or packaging arrangements. For example, some aspects may be implemented via integrated chip embodiments or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, and/or artificial intelligence devices) . Aspects may be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components, and/or system-level components. Devices incorporating described aspects and features may include additional components and features for implementation and practice of claimed and described aspects. For example, transmission and reception of wireless signals may include one or more components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders, and/or summers) . It is intended that aspects described herein may be practiced in a wide variety of devices, components, systems, distributed arrangements, and/or end-user devices of varying size, shape, and constitution.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. One skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

While aspects may be described herein using terminology commonly associated with a 5G or New Radio (NR) radio access technology (RAT) , aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G) .

Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with the present disclosure. The wireless network 100 may be or may include elements of a 5G (e.g., NR) network and/or a 4G (e.g., Long Term Evolution (LTE) ) network, among other examples. The wireless network 100 may include one or more network nodes 110 (shown as a network node 110a, a network node 110b, a network node 110c, and a network node 110d) , a user equipment (UE) 120 or multiple UEs 120 (shown as a UE 120a, a UE 120b, a UE 120c, a UE 120d, and a UE 120e) , and/or other entities. A network node 110 is a network node that communicates with UEs 120. As shown, a network node 110 may include one or more network nodes. For example, a network node 110 may be an aggregated network node, meaning that the aggregated network node is configured to utilize a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node (e.g., within a single device or unit) . As another example, a network node 110 may be a disaggregated network node (sometimes referred to as a disaggregated base station) , meaning that the network node 110 is configured to utilize a protocol stack that is physically or logically distributed among two or more nodes (such as one or more central units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) .

In some examples, a network node 110 is or includes a network node that communicates with UEs 120 via a radio access link, such as an RU. In some examples, a network node 110 is or includes a network node that communicates with other network nodes 110 via a fronthaul link or a midhaul link, such as a DU. In some examples, a network node 110 is or includes a network node that communicates with other network nodes 110 via a midhaul link or a core network via a backhaul link, such as a CU. In some examples, a network node 110 (such as an aggregated network node 110 or a disaggregated network node 110) may include multiple network nodes, such as one or more RUs, one or more CUs, and/or one or more DUs. A network node 110 may include, for example, an NR base station, an LTE base station, a Node B, an eNB (e.g., in 4G) , a gNB (e.g., in 5G) , an access point, a transmission reception point (TRP) , a DU, an RU, a CU, a mobility element of a network, a core network node, a network element, a network equipment, a RAN node, or a combination thereof. In some examples, the network nodes 110 may be interconnected to one another or to one or more other network nodes 110 in the wireless network 100 through various types of fronthaul, midhaul, and/or backhaul interfaces, such as a direct physical connection, an air interface, or a virtual network, using any suitable transport network.

In some examples, a network node 110 may provide communication coverage for a particular geographic area. In the Third Generation Partnership Project (3GPP) , the term “cell” can refer to a coverage area of a network node 110 and/or a network node subsystem serving this coverage area, depending on the context in which the term is used. A network node 110 may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs 120 with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs 120 with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs 120 having association with the femto cell (e.g., UEs 120 in a closed subscriber group (CSG) ) . A network node 110 for a macro cell may be referred to as a macro network node. A network node 110 for a pico cell may be referred to as a pico network node. A network node 110 for a femto cell may be referred to as a femto network node or an in-home network node. In the example shown in Fig. 1, the network node 110a may be a macro network node for a macro cell 102a, the network node 110b may be a pico network node for a pico cell 102b, and the network node 110c may be a femto network node for a femto cell 102c. A network node may support one or multiple (e.g., three) cells. In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a network node 110 that is mobile (e.g., a mobile network node) .

In some aspects, the term “base station” or “network node” may refer to an aggregated base station, a disaggregated base station, an integrated access and backhaul (IAB) node, a relay node, or one or more components thereof. For example, in some aspects, “base station” or “network node” may refer to a CU, a DU, an RU, a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) , or a Non-Real Time (Non-RT) RIC, or a combination thereof. In some aspects, the term “base station” or “network node” may refer to one device configured to perform one or more functions, such as those described herein in connection with the network node 110. In some aspects, the term “base station” or “network node” may refer to a plurality of devices configured to perform the one or more functions. For example, in some distributed systems, each of a quantity of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to duplicate performance of at least a portion of the function, and the term “base station” or “network node” may refer to any one or more of those different devices. In some aspects, the term “base station” or “network node” may refer to one or more virtual base stations or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the term “base station” or “network node” may refer to one of the base station functions and not another. In this way, a single device may include more than one base station.

The wireless network 100 may include one or more relay stations. A relay station is a network node that can receive a transmission of data from an upstream node (e.g., a network node 110 or a UE 120) and send a transmission of the data to a downstream node (e.g., a UE 120 or a network node 110) . A relay station may be a UE 120 that can relay transmissions for other UEs 120. In the example shown in Fig. 1, the network node 110d (e.g., a relay network node) may communicate with the network node 110a (e.g., a macro network node) and the UE 120d in order to facilitate communication between the network node 110a and the UE 120d. A network node 110 that relays communications may be referred to as a relay station, a relay base station, a relay network node, a relay node, a relay, or the like.

The wireless network 100 may be a heterogeneous network that includes network nodes 110 of different types, such as macro network nodes, pico network nodes, femto network nodes, relay network nodes, or the like. These different types of network nodes 110 may have different transmit power levels, different coverage areas, and/or different impacts on interference in the wireless network 100. For example, macro network nodes may have a high transmit power level (e.g., 5 to 40 watts) whereas pico network nodes, femto network nodes, and relay network nodes may have lower transmit power levels (e.g., 0.1 to 2 watts) .

A network controller 130 may couple to or communicate with a set of network nodes 110 and may provide coordination and control for these network nodes 110. The network controller 130 may communicate with the network nodes 110 via a backhaul communication link or a midhaul communication link. The network nodes 110 may communicate with one another directly or indirectly via a wireless or wireline backhaul communication link. In some aspects, the network controller 130 may be a CU or a core network device, or may include a CU or a core network device.

The UEs 120 may be dispersed throughout the wireless network 100, and each UE 120 may be stationary or mobile. A UE 120 may include, for example, an access terminal, a terminal, a mobile station, and/or a subscriber unit. A UE 120 may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device, a biometric device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring or a smart bracelet) ) , an entertainment device (e.g., a music device, a video device, and/or a satellite radio) , a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, a UE function of a network node, and/or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs 120 may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. An MTC UE and/or an eMTC UE may include, for example, a robot, a drone, a remote device, a sensor, a meter, a monitor, and/or a location tag, that may communicate with a network node, another device (e.g., a remote device) , or some other entity. Some UEs 120 may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband IoT) devices. Some UEs 120 may be considered a Customer Premises Equipment. A UE 120 may be included inside a housing that houses components of the UE 120, such as processor components and/or memory components. In some examples, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, and/or electrically coupled.

In general, any number of wireless networks 100 may be deployed in a given geographic area. Each wireless network 100 may support a particular RAT and may operate on one or more frequencies. A RAT may be referred to as a radio technology, an air interface, or the like. A frequency may be referred to as a carrier, a frequency channel, or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some examples, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a network node 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or a vehicle-to-pedestrian (V2P) protocol) , and/or a mesh network. In such examples, a UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the network node 110.

Devices of the wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided by frequency or wavelength into various classes, bands, channels, or the like. For example, devices of the wireless network 100 may communicate using one or more operating bands. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz –7.125 GHz) and FR2 (24.25 GHz –52.6 GHz) . It should be understood that although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “Sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz –24.25 GHz) . Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6 GHz –71 GHz) , FR4 (52.6 GHz –114.25 GHz) , and FR5 (114.25 GHz –300 GHz) . Each of these higher frequency bands falls within the EHF band.

With the above examples in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and/or FR5, or may be within the EHF band. It is contemplated that the frequencies included in these operating bands (e.g., FR1, FR2, FR3, FR4, FR4-a, FR4-1, and/or FR5) may be modified, and techniques described herein are applicable to those modified frequency ranges.

In some aspects, an RFID tag (e.g., RFID tag 122) may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 may receive, from a reader or an RF source, a signal; and transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data. Additionally, or alternatively, the communication manager 140 may perform one or more other operations described herein.

In some aspects, a reader (e.g., reader 124) may include a communication manager 150. As described in more detail elsewhere herein, the communication manager 150 may transmit, to an RFID tag, a signal; and receive, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data. Additionally, or alternatively, the communication manager 150 may perform one or more other operations described herein.

As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

Fig. 2 is a diagram illustrating an example 200 of a network node 110 in communication with a UE 120 in a wireless network 100, in accordance with the present disclosure. The network node 110 may be equipped with a set of antennas 234a through 234t, such as T antennas (T ≥ 1) . The UE 120 may be equipped with a set of antennas 252a through 252r, such as R antennas (R ≥ 1) . The network node 110 of example 200 includes one or more radio frequency components, such as antennas 234 and a modem 254. In some examples, a network node 110 may include an interface, a communication component, or another component that facilitates communication with the UE 120 or another network node. Some network nodes 110 may not include radio frequency components that facilitate direct communication with the UE 120, such as one or more CUs, or one or more DUs.

At the network node 110, a transmit processor 220 may receive data, from a data source 212, intended for the UE 120 (or a set of UEs 120) . The transmit processor 220 may select one or more modulation and coding schemes (MCSs) for the UE 120 based at least in part on one or more channel quality indicators (CQIs) received from that UE 120. The network node 110 may process (e.g., encode and modulate) the data for the UE 120 based at least in part on the MCS (s) selected for the UE 120 and may provide data symbols for the UE 120. The transmit processor 220 may process system information (e.g., for semi-static resource partitioning information (SRPI) ) and control information (e.g., CQI requests, grants, and/or upper layer signaling) and provide overhead symbols and control symbols. The transmit processor 220 may generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) or a demodulation reference signal (DMRS) ) and synchronization signals (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems 232 (e.g., T modems) , shown as modems 232a through 232t. For example, each output symbol stream may be provided to a modulator component (shown as MOD) of a modem 232. Each modem 232 may use a respective modulator component to process a respective output symbol stream (e.g., for OFDM) to obtain an output sample stream. Each modem 232 may further use a respective modulator component to process (e.g., convert to analog, amplify, filter, and/or upconvert) the output sample stream to obtain a downlink signal. The modems 232a through 232t may transmit a set of downlink signals (e.g., T downlink signals) via a corresponding set of antennas 234 (e.g., T antennas) , shown as antennas 234a through 234t.

At the UE 120, a set of antennas 252 (shown as antennas 252a through 252r) may receive the downlink signals from the network node 110 and/or other network nodes 110 and may provide a set of received signals (e.g., R received signals) to a set of modems 254 (e.g., R modems) , shown as modems 254a through 254r. For example, each received signal may be provided to a demodulator component (shown as DEMOD) of a modem 254. Each modem 254 may use a respective demodulator component to condition (e.g., filter, amplify, downconvert, and/or digitize) a received signal to obtain input samples. Each modem 254 may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from the modems 254, may perform MIMO detection on the received symbols if applicable, and may provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE 120 to a data sink 260, and may provide decoded control information and system information to a controller/processor 280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and/or a CQI parameter, among other examples. In some examples, one or more components of the UE 120 may be included in a housing 284.

The network controller 130 may include a communication unit 294, a controller/processor 290, and a memory 292. The network controller 130 may include, for example, one or more devices in a core network. The network controller 130 may communicate with the network node 110 via the communication unit 294.

One or more antennas (e.g., antennas 234a through 234t and/or antennas 252a through 252r) may include, or may be included within, one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, and/or one or more antenna arrays, among other examples. An antenna panel, an antenna group, a set of antenna elements, and/or an antenna array may include one or more antenna elements (within a single housing or multiple housings) , a set of coplanar antenna elements, a set of non-coplanar antenna elements, and/or one or more antenna elements coupled to one or more transmission and/or reception components, such as one or more components of Fig. 2.

On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, and/or CQI) from the controller/processor 280. The transmit processor 264 may generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the modems 254 (e.g., for DFT-s-OFDM or CP-OFDM) , and transmitted to the network node 110. In some examples, the modem 254 of the UE 120 may include a modulator and a demodulator. In some examples, the UE 120 includes a transceiver. The transceiver may include any combination of the antenna (s) 252, the modem (s) 254, the MIMO detector 256, the receive processor 258, the transmit processor 264, and/or the TX MIMO processor 266. The transceiver may be used by a processor (e.g., the controller/processor 280) and the memory 282 to perform aspects of any of the methods described herein (e.g., with reference to Figs. 6-12) .

At the network node 110, the uplink signals from UE 120 and/or other UEs may be received by the antennas 234, processed by the modem 232 (e.g., a demodulator component, shown as DEMOD, of the modem 232) , detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to a data sink 239 and provide the decoded control information to the controller/processor 240. The network node 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. The network node 110 may include a scheduler 246 to schedule one or more UEs 120 for downlink and/or uplink communications. In some examples, the modem 232 of the network node 110 may include a modulator and a demodulator. In some examples, the network node 110 includes a transceiver. The transceiver may include any combination of the antenna (s) 234, the modem (s) 232, the MIMO detector 236, the receive processor 238, the transmit processor 220, and/or the TX MIMO processor 230. The transceiver may be used by a processor (e.g., the controller/processor 240) and the memory 242 to perform aspects of any of the methods described herein (e.g., with reference to Figs. 6-12) .

The controller/processor 240 of the network node 110, the controller/processor 280 of the UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with transmitting reflected signals that indicate data multiplexed with reference signals, as described in more detail elsewhere herein. In some aspects, the reader and the tag described herein include one or more components of the UE 120 shown in Fig. 2. For example, the controller/processor 240 of the network node 110, the controller/processor 280 of the UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 900 of Fig. 9, process 1000 of Fig. 10, and/or other processes as described herein. The memory 242 and the memory 282 may store data and program codes for the network node 110 and the UE 120, respectively. In some examples, the memory 242 and/or the memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and/or program code) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, and/or interpreting) by one or more processors of the network node 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the network node 110 to perform or direct operations of, for example, process 900 of Fig. 9, process 1000 of Fig. 10, and/or other processes as described herein. In some examples, executing instructions may include running the instructions, converting the instructions, compiling the instructions, and/or interpreting the instructions, among other examples.

In some aspects, an RFID tag (e.g., RFID tag 122) includes means for receiving, from a reader or an RF source, a signal; and/or means for transmitting, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data. In some aspects, the means for the tag to perform operations described herein may include, for example, one or more of communication manager 140, antenna 252, modem 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, controller/processor 280, or memory 282.

In some aspects, a reader (e.g., reader 124) includes means for transmitting, to an RFID tag, a signal; and/or means for receiving, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data. In some aspects, the means for the reader to perform operations described herein may include, for example, one or more of communication manager 140, antenna 252, modem 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, controller/processor 280, or memory 282.

While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of the controller/processor 280.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Deployment of communication systems, such as 5G NR systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, a base station, or a network equipment may be implemented in an aggregated or disaggregated architecture. For example, a base station (such as a Node B (NB) , an evolved NB (eNB) , an NR BS, a 5G NB, an access point (AP) , a TRP, or a cell, among other examples) , or one or more units (or one or more components) performing base station functionality, may be implemented as an aggregated base station (also known as a standalone base station or a monolithic base station) or a disaggregated base station. “Network entity” or “network node” may refer to a disaggregated base station, or to one or more units of a disaggregated base station (such as one or more CUs, one or more DUs, one or more RUs, or a combination thereof) .

An aggregated base station (e.g., an aggregated network node) may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node (e.g., within a single device or unit) . A disaggregated base station (e.g., a disaggregated network node) may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more CUs, one or more DUs, or one or more RUs) . In some examples, a CU may be implemented within a network node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other network nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU, and RU also can be implemented as virtual units, such as a virtual central unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) , among other examples.

Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an IAB network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance) ) , or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN) ) to facilitate scaling of communication systems by separating base station functionality into one or more units that can be individually deployed. A disaggregated base station may include functionality implemented across two or more units at various physical locations, as well as functionality implemented for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station can be configured for wired or wireless communication with at least one other unit of the disaggregated base station.

Fig. 3 is a diagram illustrating an example disaggregated base station architecture 300, in accordance with the present disclosure. The disaggregated base station architecture 300 may include a CU 310 that can communicate directly with a core network 320 via a backhaul link, or indirectly with the core network 320 through one or more disaggregated control units (such as a Near-RT RIC 325 via an E2 link, or a Non-RT RIC 315 associated with a Service Management and Orchestration (SMO) Framework 305, or both) . A CU 310 may communicate with one or more DUs 330 via respective midhaul links, such as through F1 interfaces. Each of the DUs 330 may communicate with one or more RUs 340 via respective fronthaul links. Each of the RUs 340 may communicate with one or more UEs 120 via respective radio frequency (RF) access links. In some implementations, a UE 120 may be simultaneously served by multiple RUs 340.

Each of the units, including the CUs 310, the DUs 330, the RUs 340, as well as the Near-RT RICs 325, the Non-RT RICs 315, and the SMO Framework 305, may include one or more interfaces or be coupled with one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to one or multiple communication interfaces of the respective unit, can be configured to communicate with one or more of the other units via the transmission medium. In some examples, each of the units can include a wired interface, configured to receive or transmit signals over a wired transmission medium to one or more of the other units, and a wireless interface, which may include a receiver, a transmitter or transceiver (such as an RF transceiver) , configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

In some aspects, the CU 310 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) functions, packet data convergence protocol (PDCP) functions, or service data adaptation protocol (SDAP) functions, among other examples. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 310. The CU 310 may be configured to handle user plane functionality (for example, Central Unit –User Plane (CU-UP) functionality) , control plane functionality (for example, Central Unit –Control Plane (CU-CP) functionality) , or a combination thereof. In some implementations, the CU 310 can be logically split into one or more CU-UP units and one or more CU-CP units. A CU-UP unit can communicate bidirectionally with a CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 310 can be implemented to communicate with a DU 330, as necessary, for network control and signaling.

Each DU 330 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 340. In some aspects, the DU 330 may host one or more of a radio link control (RLC) layer, a MAC layer, and one or more high physical (PHY) layers depending, at least in part, on a functional split, such as a functional split defined by the 3GPP. In some aspects, the one or more high PHY layers may be implemented by one or more modules for forward error correction (FEC) encoding and decoding, scrambling, and modulation and demodulation, among other examples. In some aspects, the DU 330 may further host one or more low PHY layers, such as implemented by one or more modules for a fast Fourier transform (FFT) , an inverse FFT (iFFT) , digital beamforming, or physical random access channel (PRACH) extraction and filtering, among other examples. Each layer (which also may be referred to as a module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 330, or with the control functions hosted by the CU 310.

Each RU 340 may implement lower-layer functionality. In some deployments, an RU 340, controlled by a DU 330, may correspond to a logical node that hosts RF processing functions or low-PHY layer functions, such as performing an FFT, performing an iFFT, digital beamforming, or PRACH extraction and filtering, among other examples, based on a functional split (for example, a functional split defined by the 3GPP) , such as a lower layer functional split. In such an architecture, each RU 340 can be operated to handle over the air (OTA) communication with one or more UEs 120. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU (s) 340 can be controlled by the corresponding DU 330. In some scenarios, this configuration can enable each DU 330 and the CU 310 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework 305 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 305 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 305 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) platform 390) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements can include, but are not limited to, CUs 310, DUs 330, RUs 340, non-RT RICs 315, and Near-RT RICs 325. In some implementations, the SMO Framework 305 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 311, via an O1 interface. Additionally, in some implementations, the SMO Framework 305 can communicate directly with each of one or more RUs 340 via a respective O1 interface. The SMO Framework 305 also may include a Non-RT RIC 315 configured to support functionality of the SMO Framework 305.

The Non-RT RIC 315 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 325. The Non-RT RIC 315 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 325. The Near-RT RIC 325 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 310, one or more DUs 330, or both, as well as an O-eNB, with the Near-RT RIC 325.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 325, the Non-RT RIC 315 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 325 and may be received at the SMO Framework 305 or the Non-RT RIC 315 from non-network data sources or from network functions. In some examples, the Non-RT RIC 315 or the Near-RT RIC 325 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 315 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 305 (such as reconfiguration via an O1 interface) or via creation of RAN management policies (such as A1 interface policies) .

As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with regard to Fig. 3.

Fig. 4 is a diagram illustrating an example 400 of backscatter communication, in accordance with the present disclosure.

As shown in Fig. 4, in an ultra-high frequency (UHF) RFID system, a reader (e.g., an RFID reader) may be coupled to an antenna, and the reader may communicate with an RFID tag, which may be a passive device. The RFID tag may include a dipole antenna and an integrated circuit (IC) . The reader may transmit an RF signal via a forward link. The RFID tag may receive the RF signal, and the received RF signal may be reflected from the RFID tag via a backscatter link. The RFID tag may use the received RF signal to transmit data without a battery or power source. The RFID tag may employ a passive reflection and modulation of the received RF signal. When the RFID tag has data to send, the RFID tag may harvest the received RF signal to obtain power to operate. The RFID tag may harvest (or absorb) power from the received RF signal using a rectifier, and the RFID tag may operate using the harvested power. The rectifier may include a diode and a capacitor, and the rectifier may achieve a certain energy conversion efficiency. The RFID tag may modulate the received RF signal to encode the data, and then the RFID tag may reflect (or backscatter) the modulated received RF signal back to the reader in a far-field manner, thereby achieving the backscatter communication. The modulation in the RFID tag may be based at least in part on an IC/antenna resistance match, which may provide a backscatter power, as opposed to an IC/antenna resistance mismatch, which would provide no/minimal backscatter power. A modulation efficiency may be based at least in part on a practical radiation power and an idealized radiation power. The backscatter communication may be associated with a low energy requirement and a low complexity of deployment.

The reader, or interrogator, may include a transmitter, a receiver, and a baseband processor. The antenna coupled to the reader may include a transmit antenna and a receive antenna. The reader may transmit, to the RFID tag, an unmodulated or modulated wave (e.g., a command) . The reader may transmit a continuous wave (CW) , which may power up the RFID tag. The reader may transmit modulated commands, which may include packets. The RFID tag may transmit, to the reader, a modulated wave (e.g., a response) . A modulated response may include a packet. A reader-tag interaction may be based at least in part on a command-response model.

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with regard to Fig. 4.

Fig. 5 is a diagram illustrating an example 500 of backscatter communication, in accordance with the present disclosure.

As shown in Fig. 5, an interrogator (reader) -talks-first (ITF) procedure may occur between a reader and an RFID tag. The reader may transmit a first continuous wave to the RFID tag, which may power up (or turn on) the RFID tag. The first continuous wave may be transmitted for a duration of 400 microseconds (μs) or more. The first continuous wave may cause a “turn on” voltage to be achieved at the RFID tag. The reader may transmit a first command to the RFID tag, which may include information and may provide power to the RFID tag (e.g., -20 dBm or more) . The reader may transmit a second continuous wave to the RFID tag, which may maintain a “turn on” state of the RFID tag. The reader may transmit a third continuous wave to the RFID tag, which may provide power and a carrier wave for RFID tag modulation. The RFID tag may modulate and backscatter the third continuous wave, thereby providing a response to the reader. The response may include data (or a payload) . The reader may transmit a fourth continuous wave to the RFID tag, which may maintain a “turn on” state of the RFID tag. The reader may transmit a second command to the RFID tag, which may include information and may provide power to the RFID tag. When the reader no longer provides continuous waves and/or commands to the reader, an IC voltage at the RFID tag may become zero. In some cases, the first, second, third, and fourth continuous waves may not be separate waves, but rather separate pulses within the same wave.

As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with regard to Fig. 5.

In some cases, a reader may be integrated with an RF source. In other words, the RF source and the reader may be the same device (e.g., a full-duplex device) . A monostatic backscatter may involve a single antenna of the reader. The antenna may transmit a transmitted signal to a RFID tag, and the antenna may receive a backscattered signal from the RFID tag. Alternatively, the monostatic backscatter may involve separate antennas of the reader. A Tx antenna of the reader may transmit the transmitted signal to the RFID tag, and an Rx antenna of the reader may receive the backscattered signal from the RFID tag, wherein some amount of leakage may occur between the Tx antenna and the Rx antenna. In some cases, the reader and the RF source may be different devices, which may provide a half-duplex communication. A bistatic backscatter may involve a single antenna that is not co-located with the reader. The antenna may transmit a transmitted signal to an RFID tag via a forward link, and the reader may receive a backscattered signal from the RFID tag via a backscatter link.

The RFID tag (or backscatter device) may modulate information on a reflected signal (or backscattered signal) using amplitude shift keying (ASK) , which may involve the RFID tag switching on a reflection when transmitting an information bit “1” and switching off the reflection when transmitting an information bit “0” . The reader (or device) may transmit a radio wave (denoted, e.g., as x (n) . Information bits of the RFID tag may be denoted by s (n) ∈ {0, 1} . Then, a received signal at the reader may be denoted by y (n) = (h _BU (n) +σ _fh _BD (n) h _DU (n) s (n) ) x (n) +noise. When s (n) =0, the reflection may be switched off at the RFID tag, so the reader only receives a direct link signal, e.g., y (n) =h _BU (n) x (n) +noise. When s (n) =1, the reflection may be switched on at the RFID tag, so the reader receives a superposition of both the direct link signal and a backscatter link signal, e.g., y (n) = (h _BU (n) + σ _fh _BD (n) h _DU (n) ) x (n) +noise, where σ _f denotes a reflection coefficient. In order to receive transmitted information bits by the RFID tag, the reader may decode x (n) based at least in part on a known h _BU (n) , by treating the backscatter link signal as interference, and then the reader may detect an existence of the term σ _fh _BD (b) h _DU (n) x (n) by subtracting h _BU (n) x (n) from y (n) .

In a first approach, K information bits may undergo a channel coding, a modulation, a waveform generation, and an information and DMRS multiplexing with a DMRS sequence, and a result may be transmitted. A DMRS-based coherent communication may suffer from performance loss at a low signal-to-noise ratio (SNR) , due to a DMRS overhead, a poor channel estimation quality at the low SNR, and/or an existing channel code not being optimized at a low rate. In a second approach, K information bits may undergo a conversion of an information bit stream to a decimal value l, a selection of an l-th sequence (sequence N) from a sequence pool, and a mapping to N resource elements (REs) in a granted resource, and a result may be transmitted. A sequence-based DMRS-less noncoherent transmission may be supported with more than one bit, which may involve orthogonal sequences for small payload sizes, or non-orthogonal sequences for medium/large payload sizes.

In some cases, communications between a reader and a RFID tag may be associated with decoding errors, time/frequency errors, pathloss, and other problems. Such problems may be associated with commands transmitted by the reader to the RFID tag, as well as responses transmitted by the RFID tag to the reader. As a result, read and write operations performed by the reader and the RFID tag may be affected.

In various aspects of techniques and apparatuses described herein, an RFID tag may receive, from a reader (e.g., an RFID reader) or an RF source, a signal. The tag may transmit, to the reader, a reflected signal (or backscattered signal) . The reflected signal may be based at least in part on the signal received from the reader or the RF source. The reflected signal may indicate data and a reference signal that is multiplexed with the data

In some aspects, in an RFID system, the RFID tag may add or append the reference signal to the data, which may improve a decoding ability at a receiver side, as well as correct timing/frequency errors. The reference signal added by the RFID tag may be a second reference signal. The RFID tag may multiplex the reference signal with the data. The RFID tag may add the reference signal to a backscattered payload/sequence from the RFID tag. In some aspects, the reader (or reader UE) , which may be integrated with an RF source to achieve a full-duplex capability, may use the reference signal added by the RFID tag to perform various functions. The functions may include adjusting a timing of the RFID tag (e.g., estimating a Doppler shift) , adjusting a time/frequency error of a reflected signal, determining pathloss and power control elements, and/or determining a charging rate of the RFID tag and adjusting a transmission power at the RF source accordingly. The RFID tag may add a known sequence to the data, which may allow for a channel estimation at the reader for a timing and/or frequency correction at the reader. The RFID tag may reflect or add the reference signal to allow other devices (e.g., the reader) to estimate an overall channel timing/frequency error.

In some aspects, in the RFID system, the reader (e.g., in addition to the RFID tag) may add or append a reference signal to data. The reference signal added by the reader may be a first reference signal, where the first reference signal may be transmitted earlier in time as compared to the second reference signal. The reader may multiplex the reference signal with the data. The RFID tag may use the reference signal added by the reader to determine time/frequency errors and/or pathloss, which may improve writing and reading processes of the RFID system. When transmitting commands/queries to the RFID tag, the reader may include the reference signal, which may be multiplexed with the data, to enable the RFID tag to perform a measurement using the reference signal. The reader may transmit the reference signal based at least in part on a data puncturing or a rate matching. The reader may add the reference signal to the commands/queries transmitted to the RFID tag for increased RFID tag signal reliability, such that the RFID tag may estimate a channel and timing error, which may improve backscattering (reading) and command (writing to the RFID tag) cases.

In some aspects, the reader may trigger a process for adding the reference signal based at least in part on pathloss and channel measurements (e.g., timing, frequency, and/or SNR) , priority, a quality of service (QoS) of a reading signal, and/or a required signal reliability. In some aspects, the RFID tag may trigger the process for adding the reference signal based at least in part on a signal measurement. The RFID tag may add an explicit bit for triggering the process for adding the reference signal. In some aspects, the reader or the RFID tag may trigger the process for adding the reference signal based at least in part on explicit signaling between the reader and the RFID tag.

Fig. 6 is a diagram illustrating an example 600 associated with transmitting reflected signals that indicate data multiplexed with reference signals, in accordance with the present disclosure. As shown in Fig. 6, communication may occur between an RFID tag (e.g., RFID tag 122) and a reader (e.g., reader 124) . In some aspects, the RFID tag and the reader may be included in a wireless network, such as wireless network 100.

In some aspects, the RFID tag may refer to an RFID tag, a UE that contains an RFID tag radio, or a UE that contains both an RFID tag radio and a main radio (e.g., NR and/or LTE) . The RFID tag radio may be used in some cases including at low power modes or at power saving modes. In some aspects, the reader may be co-located with an RF source as part of a same device (e.g., a full duplex device, such as a UE) , which may perform both transmitting RF signals and reading to and from the RF tag. In some aspects, the RF source and the reader may be associated with different entities, in which case the RF source and the reader may transmit various reports and signals between each other.

As shown by reference number 602, the RFID tag may receive, from the reader or the RF source, a signal. The signal may be a continuous wave signal. The signal may be a modulated command, which may include a packet. The modulated command may indicate a string of bits. The signal may indicate data and a first reference signal that is multiplexed with the data. When transmitting the modulated command to the RFID tag, the reader may add the first reference signal into the data transmitted to the RFID tag.

As shown by reference number 604, the RFID tag may transmit, to the reader, a reflected signal (or backscattered signal) . The reflected signal may be based at least in part on the signal received from the reader or the RF source. The reflected signal may be a reflection of the signal received from the reader.

In some aspects, the reflected signal may indicate data and a second reference signal that is multiplexed with the data. The RFID tag may add the second reference signal to the reflected signal, where the reflected signal may indicate the data on a first set of samples and the reference signal on a second set of samples. The reflected signal may indicate one or more elements from a sequence associated with the second reference signal. The RFID tag may add, to the reflected signal, the one or more elements from the sequence of the second reference signal. The RFID tag may indicate the second reference signal to the reader based at least in part on a reference signal pattern.

In some aspects, the reference signal pattern may be configured or indicated to the RFID tag and/or the reader. The reference signal pattern may be configured or indicated using an index of the reference signal pattern, or the reference signal pattern may be configured or indicated based at least in part on an actual reference signal pattern. In some aspects, the sequence associated with the second reference signal, which may be from the set of sequences, may be configured or indicated to the RFID tag and/or the reader. The sequence may be configured or indicated using an index of the sequence, or the sequence may be configured or indicated based at least in part on an actual sequence.

In some aspects, the second reference signal may be associated with a start indication, a length indication, and a periodicity, and the RFID tag may transmit each element of the sequence associated with the second reference signal using a corresponding resource element. In some aspects, the reader may store information associated with the RFID tag, where the information may be parameterized based at least in part on a RFID tag identifier associated with the RFID tag. In other words, the reader may save information for each RFID tag that communicates with the reader, and the information may be parameterized per RFID tag identifier for the reader.

As shown by reference number 606, the RFID tag may determine, using the first reference signal, a round trip time associated with the signal. The RFID tag may determine, using the first reference signal, an RSRP associated with the signal. The RFID tag may determine, using the first reference signal, a pathloss associated with the signal. The RFID tag may determine, using the first reference signal, a charging rate associated with the RFID tag, and the reflected signal may include an indication of the charging rate. The charging rate may be based at least in part on a power averaged per reference signal element, which may be multiplied by time or may be averaged to calculate the charging rate. The charging rate may be calculated using (P ₁+P ₂+…+P _M) /M for M reference signal elements embedded in a data signal, where P _M represents a power value. The charging rate may be calculated using E ₁+E ₂+…+E _M, where E _M = P _M *T_RS_duration and T_RS_duration is a reference signal element duration. The charging rate may be (E ₁+E ₂+...+E _M) /M. The RFID tag may perform, using the first reference signal, a Doppler shift and delay spread estimation. The RFID tag may perform, using the first reference signal, a time-frequency error estimation. The RFID tag may report, to the reader, the indication of the charging rate as part of, or at an end of, a backscattering process, or the RFID tag may store charging rate information in memory. The charging rate information may be stored as latest charging rate information, but may be replaced when a new charging rate report is triggered based at least in part on a new signal from the reader or the RF source.

As shown by reference number 608, the reader may determine, using the second reference signal, an adjustment of a timing of the RFID tag. The reader may determine the adjustment of the timing based at least in part on an estimation of a Doppler shift associated with the RFID tag. The reader may determine, using the second reference signal, an adjustment for a time-frequency error of the reflected signal. The reader may determine, using the second reference signal, pathloss and power control elements. The reader may determine, using the second reference signal, a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal. In some aspects, the RF source may also use the second reference signal to determine the adjustment of the timing of the RFID tag, determine the adjustment for the time-frequency error of the reflected signal, determine the pathloss and power control elements, and/or determine the charging rate and the adjustment to the transmit power associated with the signal.

In some aspects, the RFID tag may determine to incorporate the second reference signal in the reflected signal based at least in part on a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, and/or a QoS associated with the signal. The RFID tag may receive, from the reader or the RF source or a network node, an indication that indicates that the second reference signal is to be incorporated in the reflected signal. The reader may receive, from the RF source or the network node, an indication that indicates that the second reference signal is to be incorporated in the reflected signal. In some aspects, a mode/indication associated with using the second reference signal or not using the second reference signal may be based at least in part on the pathloss measurement at the reader, a required reliability of the signal, the priority of the signal, and/or the QoS of the signal. The indication may be signaled using layer 1 (L1) , layer 2 (L2) , or layer 3 (L3) signaling from the RF reader or the network node to the RF source (when a separate entity from the reader) and the RFID tag. The indication may be signaled using L1/L2/L3 signaling from the RF source to the RFID tag and the reader. The indication may be signaled using L1/L2/L3 signaling from the RF source or the network node to the RFID tag (when the RF source and the reader are associated with a same node) . In some cases, a default configuration may enable or disable adding the second reference signal to the reflected signal based at least in part on the pathloss measurement (or measurements taken by the RFID tag) , reliability (which may be associated with a priority/QoS) , and/or QoS/priority.

In some aspects, the RFID tag may harvest energy associated with the first reference signal. The RFID tag may store harvested energy from the first reference signal in a storage unit of the RFID tag. During a writing process to the RFID tag (e.g., transmitting commands to the RFID tag) , the reader may transmit the first reference signal, but the RFID tag may not use the first reference signal. In this case, the RFID tag may harvest the energy from the first reference signal, and then store the harvested energy when the RFID tag has the storage unit (e.g., a super capacity or a battery) .

In some aspects, the RFID tag may determine to incorporate the second reference signal in the reflected signal based at least in part on a measurement by the RFID tag. The reflected signal may include an indication of the second reference signal, and an indication of the reference signal pattern associated with the second reference signal. In some aspects, a process of adding the second reference signal to the reflected signal, and the indication to add the second reference signal to the reflected signal, may be triggered by the RFID tag based at least in part on the measurement taken by the RFID tag. The RFID tag may add one bit after receiving an initialization of a reading trigger from the reader to start reading from the RFID tag. The RFID tag may transmit the one bit, and the RFID tag may start to add the second reference signal based at least in part on a previous configuration. The previous configuration may be signaled by the reader or the RF source using L1/L2/L3 signaling. The RFID tag may be able to determine whether to incorporate the second reference signal in the reflected signal based at least in part on a configuration received from the reader, the RF source, or the network node. In some aspects, the RFID tag may select the reference signal pattern, and the RFID tag may indicate the reference signal pattern to the reader, where the reference signal pattern may be indicated as part of a control signal along with the indication that the second reference signal is being added to the reflected signal. The RFID tag may select the reference signal pattern to be a dense/sparse reference signal pattern, or to be associated with a certain configuration, based at least in part on RFID tag preference information and/or the measurement taken by the RFID tag.

In some aspects, the RFID tag and/or the reader may multiplex reference signal elements with data symbols based at least in part on a rate matching around the data symbols or a puncturing of the data symbols. The RFID tag and/or the reader may rate match around the data symbols or puncture the data symbols based at least in part on an indication/configuration received by the RFID tag and/or the reader. With rate matching, data bits/sequence may be generated based at least in part on a quantity of the data symbols. With puncturing, data bits may be generated based at least in part on a quantity of the data symbols and a quantity of reference signal symbols, and then the data bits may be punctured on reference signal symbols. In some aspects, the reader may be configured with configurations on rate matching or puncturing resources, such that the reader may rate match around reference signals, which may occur in a time domain around the RFID tag’s transmission.

As an example, ten time resource elements and two reference signals on resources 3 and 7 may be assumed. With rate matching, 8 (10-2=8) data symbols may be generated, which may be represented by a1, a2, a3, a4, a5, a6, a7, and a8, and 8 data elements may be transmitted on 8 resources. With puncturing, 10 data elements may be generated, which may be represented by a1, a2, a3, a4, a5, a6, a7, a8, a9, and a10. In this case, a3 and a7 (which correspond to the two reference signals on resources 3 and 7) may be removed, and as a result, a1, a2, a4, a5, a6, a8, a9, and a10 may be transmitted using 10 resources.

As indicated above, Fig. 6 is provided as an example. Other examples may differ from what is described with regard to Fig. 6.

Fig. 7 is a diagram illustrating an example 700 associated with transmitting reflected signals that indicate data multiplexed with reference signals, in accordance with the present disclosure.

As shown in Fig. 7, an RFID tag and/or a reader may transmit data that is multiplexed with a reference signal. A quantity of data symbols may be followed by a portion of a sequence associated with the reference signal based at least in part on a reference signal pattern. The data and the reference signal may be indicated via a signal that is transmitted from the reader to the RFID tag. Additionally, or alternatively, the data and the reference signal may be indicated via a reflected signal (or backscattered signal) that is transmitted from the RFID tag, where the reflected signal may be derived from the signal transmitted by the reader.

As indicated above, Fig. 7 is provided as an example. Other examples may differ from what is described with regard to Fig. 7.

Fig. 8 is a diagram illustrating an example 800 associated with transmitting reflected signals that indicate data multiplexed with reference signals, in accordance with the present disclosure.

As shown in Fig. 8, an RFID tag may transmit a response to a reader, where the response may be based at least in part on a reflected signal (or backscattered signal) . The RFID tag may include, in the response, an indication (e.g., a one-bit indication) , which may indicate that the response includes a reference signal. The RFID tag may include, in the response, an indication (e.g., a two-bit indication) , which may indicate a reference signal pattern that is used by the RFID tag to indicate the reference signal. The reference signal pattern may be one of a plurality of reference signal patterns which may be preconfigured or configured for the RFID tag. The RFID tag may include, in the response, data multiplexed with the reference signal.

As indicated above, Fig. 8 is provided as an example. Other examples may differ from what is described with regard to Fig. 8.

Fig. 9 is a diagram illustrating an example process 900 performed, for example, by an RFID tag, in accordance with the present disclosure. Example process 900 is an example where the RFID tag (e.g., RFID tag 122) performs operations associated with transmitting reflected signals that indicate data multiplexed with reference signals.

As shown in Fig. 9, in some aspects, process 900 may include receiving, from a reader or an RF source, a signal (block 910) . For example, the RFID tag (e.g., using communication manager 140 and/or reception component 1102, depicted in Fig. 11) may receive, from a reader or an RF source, a signal, as described above.

As further shown in Fig. 9, in some aspects, process 900 may include transmitting, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data (block 920) . For example, the RFID tag (e.g., using communication manager 140 and/or transmission component 1104, depicted in Fig. 11) may transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data, as described above.

Process 900 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, the reference signal is associated with one or more of an adjustment of a timing of the RFID tag, an adjustment for a time-frequency error of the reflected or backscattered signal, a determination of pathloss and power control elements, or a determination of a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal.

In a second aspect, alone or in combination with the first aspect, the reflected or backscattered signal indicates one or more elements from a sequence associated with the reference signal.

In a third aspect, alone or in combination with one or more of the first and second aspects, the sequence associated with the reference signal, from a set of sequences, is indicated to one or more of the RFID tag or the reader using an index of the sequence, or is indicated based at least in part on an actual sequence.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the reference signal is indicated to the reader based at least in part on a reference signal pattern, and the RFID tag and the reader are configured with the reference signal pattern.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, the reference signal pattern is indicated to one or more of the RFID tag or the reader using an index of the reference signal pattern, or is indicated to one or more of the RFID tag or the reader based at least in part on an actual reference signal pattern.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the reference signal is associated with a start indication, a length indication, and a periodicity, and each element of a sequence associated with the reference signal is transmitted using a corresponding resource element.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process 900 includes determining to incorporate the reference signal in the reflected or backscattered signal based at least in part on one or more of a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, process 900 includes receiving, from the reader or an RF source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, the reference signal is a second reference signal and the signal received from the reader indicates a first reference signal, and process 900 includes harvesting energy associated with the first reference signal, and storing harvested energy from the first reference signal in a storage unit of the RFID tag.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, process 900 includes determining to incorporate the reference signal in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the reference signal is a second reference signal and the signal received from the reader indicates a first reference signal, and process 900 includes determining, using the first reference signal, one or more of a round trip time associated with the signal, an RSRP associated with the signal, a pathloss associated with the signal, a charging rate associated with the RFID tag, a Doppler shift and delay spread estimation, or a time-frequency error estimation, and the reflected or backscattered signal includes an indication of the charging rate.

In a twelfth aspect, alone or in combination with one or more of the first through eleventh aspects, referencing signal elements are multiplexed with data symbols based at least in part on a rate matching around the data symbols or a puncturing of the data symbols.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the RF source and the reader are associated with a same device.

Although Fig. 9 shows example blocks of process 900, in some aspects, process 900 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 9. Additionally, or alternatively, two or more of the blocks of process 900 may be performed in parallel.

Fig. 10 is a diagram illustrating an example process 1000 performed, for example, by a reader, in accordance with the present disclosure. Example process 1000 is an example where the reader (e.g., reader 124) performs operations associated with transmitting reflected signals that indicate data multiplexed with reference signals.

As shown in Fig. 10, in some aspects, process 1000 may include transmitting, to an RFID tag, a signal (block 1010) . For example, the reader (e.g., using communication manager 140 and/or transmission component 1204, depicted in Fig. 12) may transmit, to an RFID tag, a signal, as described above.

As further shown in Fig. 10, in some aspects, process 1000 may include receiving, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data (block 1020) . For example, the reader (e.g., using communication manager 140 and/or reception component 1202, depicted in Fig. 12) may receive, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data, as described above.

Process 1000 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, process 1000 includes determining, using the reference signal, one or more of an adjustment of a timing of the RFID tag, an adjustment for a time-frequency error of the reflected or backscattered signal, pathloss and power control elements, or a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, process 1000 includes storing information associated with the RFID tag, wherein the information is parameterized based at least in part on a tag identifier associated with the RFID tag.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, the reference signal is associated with a start indication, a length indication, and a periodicity, and each element of a sequence associated with the reference signal is received using a corresponding resource element.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the reference signal is incorporated in the reflected or backscattered signal based at least in part on one or more of a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal.

In a ninth aspect, alone or in combination with one or more of the first through eighth aspects, process 1000 includes receiving, from an RF source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.

In a tenth aspect, alone or in combination with one or more of the first through ninth aspects, the reference signal is incorporated in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.

In an eleventh aspect, alone or in combination with one or more of the first through tenth aspects, the reference signal is a second reference signal and the signal transmitted to the RFID tag indicates a first reference signal, wherein the first reference signal is associated with one or more of a round trip time associated with the signal, an RSRP associated with the signal, a pathloss associated with the signal, a charging rate associated with the RFID tag, a Doppler shift and delay spread estimation, or a time-frequency error estimation, and the reflected or backscattered signal includes an indication of the charging rate.

In a thirteenth aspect, alone or in combination with one or more of the first through twelfth aspects, the reader is co-located with an RF source.

Although Fig. 10 shows example blocks of process 1000, in some aspects, process 1000 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 10. Additionally, or alternatively, two or more of the blocks of process 1000 may be performed in parallel.

Fig. 11 is a diagram of an example apparatus 1100 for wireless communication, in accordance with the present disclosure. The apparatus 1100 may be an RFID tag, or an RFID tag may include the apparatus 1100. In some aspects, the apparatus 1100 includes a reception component 1102 and a transmission component 1104, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 1100 may communicate with another apparatus 1106 (such as a UE, a base station, or another wireless communication device) using the reception component 1102 and the transmission component 1104. As further shown, the apparatus 1100 may include the communication manager 140. The communication manager 140 may include one or more of a determination component 1108, or a harvesting component 1110, among other examples.

In some aspects, the apparatus 1100 may be configured to perform one or more operations described herein in connection with Figs. 6-8. Additionally, or alternatively, the apparatus 1100 may be configured to perform one or more processes described herein, such as process 900 of Fig. 9. In some aspects, the apparatus 1100 and/or one or more components shown in Fig. 11 may include one or more components of the RFID tag described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 11 may be implemented within one or more components described in connection with Fig. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 1102 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1106. The reception component 1102 may provide received communications to one or more other components of the apparatus 1100. In some aspects, the reception component 1102 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 1100. In some aspects, the reception component 1102 may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the RFID tag described in connection with Fig. 2.

The transmission component 1104 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1106. In some aspects, one or more other components of the apparatus 1100 may generate communications and may provide the generated communications to the transmission component 1104 for transmission to the apparatus 1106. In some aspects, the transmission component 1104 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 1106. In some aspects, the transmission component 1104 may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the RFID tag described in connection with Fig. 2. In some aspects, the transmission component 1104 may be co-located with the reception component 1102 in a transceiver.

The reception component 1102 may receive, from a reader or an RF source, a signal. The transmission component 1104 may transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

The determination component 1108 may determine to incorporate the reference signal in the reflected or backscattered signal based at least in part on one or more of: a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal. The reception component 1102 may receive, from the reader or an RF source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal. The harvesting component 1110 may harvest energy associated with a first reference signal, where the signal received from the reader indicates the first reference signal, and store harvested energy from the first reference signal in a storage unit of the RFID tag. The determination component 1108 may determine to incorporate the reference signal in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.

The number and arrangement of components shown in Fig. 11 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 11. Furthermore, two or more components shown in Fig. 11 may be implemented within a single component, or a single component shown in Fig. 11 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 11 may perform one or more functions described as being performed by another set of components shown in Fig. 11.

Fig. 12 is a diagram of an example apparatus 1200 for wireless communication, in accordance with the present disclosure. The apparatus 1200 may be a reader, or a reader may include the apparatus 1200. In some aspects, the apparatus 1200 includes a reception component 1202 and a transmission component 1204, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 1200 may communicate with another apparatus 1206 (such as a UE, a base station, or another wireless communication device) using the reception component 1202 and the transmission component 1204. As further shown, the apparatus 1200 may include the communication manager 140. The communication manager 140 may include one or more of a determination component 1208, or a storage component 1210, among other examples.

In some aspects, the apparatus 1200 may be configured to perform one or more operations described herein in connection with Figs. 6-8. Additionally, or alternatively, the apparatus 1200 may be configured to perform one or more processes described herein, such as process 1000 of Fig. 10. In some aspects, the apparatus 1200 and/or one or more components shown in Fig. 12 may include one or more components of the reader described in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 12 may be implemented within one or more components described in connection with Fig. 2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 1202 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 1206. The reception component 1202 may provide received communications to one or more other components of the apparatus 1200. In some aspects, the reception component 1202 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 1200. In some aspects, the reception component 1202 may include one or more antennas, a modem, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the reader described in connection with Fig. 2.

The transmission component 1204 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 1206. In some aspects, one or more other components of the apparatus 1200 may generate communications and may provide the generated communications to the transmission component 1204 for transmission to the apparatus 1206. In some aspects, the transmission component 1204 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 1206. In some aspects, the transmission component 1204 may include one or more antennas, a modem, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the reader described in connection with Fig. 2. In some aspects, the transmission component 1204 may be co-located with the reception component 1202 in a transceiver.

The transmission component 1204 may transmit, to an RFID tag, a signal. The reception component 1202 may receive, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

The determination component 1208 may determine, using the reference signal, one or more of an adjustment of a timing of the RFID tag; an adjustment for a time-frequency error of the reflected or backscattered signal; pathloss and power control elements; or a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal. The storage component 1210 may store information associated with the RFID tag, wherein the information is parameterized based at least in part on a tag identifier associated with the RFID tag. The reception component 1202 may receive, from an RF source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.

The number and arrangement of components shown in Fig. 12 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 12. Furthermore, two or more components shown in Fig. 12 may be implemented within a single component, or a single component shown in Fig. 12 may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown in Fig. 12 may perform one or more functions described as being performed by another set of components shown in Fig. 12.

The following provides an overview of some Aspects of the present disclosure:

Aspect 1: A method of wireless communication performed by a radio frequency identification (RFID) tag, comprising: receiving, from a reader or a radio frequency (RF) source, a signal; and transmitting, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

Aspect 2: The method of Aspect 1, wherein the reference signal is associated with one or more of: an adjustment of a timing of the RFID tag; an adjustment for a time-frequency error of the reflected or backscattered signal; a determination of pathloss and power control elements; or a determination of a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal.

Aspect 3: The method of any of Aspects 1 through 2, wherein the reflected or backscattered signal indicates one or more elements from a sequence associated with the reference signal.

Aspect 4: The method of Aspect 3, wherein the sequence associated with the reference signal, from a set of sequences, is indicated to one or more of the RFID tag or the reader using an index of the sequence, or is indicated based at least in part on an actual sequence.

Aspect 5: The method of any of Aspects 1 through 4, wherein the reference signal is indicated to the reader based at least in part on a reference signal pattern, and wherein the RFID tag and the reader are configured with the reference signal pattern.

Aspect 6: The method of Aspect 5, wherein the reference signal pattern is indicated to one or more of the RFID tag or the reader using an index of the reference signal pattern, or is indicated based at least in part on an actual reference signal pattern.

Aspect 7: The method of any of Aspects 1 through 6, wherein the reference signal is associated with a start indication, a length indication, and a periodicity, and wherein each element of a sequence associated with the reference signal is transmitted using a corresponding resource element.

Aspect 8: The method of any of Aspects 1 through 7, further comprising: determining to incorporate the reference signal in the reflected or backscattered signal based at least in part on one or more of: a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal.

Aspect 9: The method of any of Aspects 1 through 8, further comprising receiving, from the reader or a radio frequency source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.

Aspect 10: The method of any of Aspects 1 through 9, wherein the reference signal is a second reference signal and the signal received from the reader indicates a first reference signal, and further comprising: harvesting energy associated with the first reference signal; and storing harvested energy from the first reference signal in a storage unit of the RFID tag.

Aspect 11: The method of any of Aspects 1 through 10, further comprising: determining to incorporate the reference signal in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.

Aspect 12: The method of any of Aspects 1 through 11, wherein the reference signal is a second reference signal and the signal received from the reader indicates a first reference signal, and further comprising: determining, using the first reference signal, one or more of: a round trip time associated with the signal, a reference signal received power associated with the signal, a pathloss associated with the signal, a charging rate associated with the RFID tag, a Doppler shift and delay spread estimation, or a time-frequency error estimation, and wherein the reflected or backscattered signal includes an indication of the charging rate.

Aspect 13: The method of any of Aspects 1 through 12, wherein reference signal elements are multiplexed with data symbols based at least in part on a rate matching around the data symbols or a puncturing of the data symbols.

Aspect 14: The method of any of Aspects 1 through 13, wherein the RF source and the reader are associated with a same device.

Aspect 15: A method of wireless communication performed by a reader, comprising: transmitting, to a radio frequency identification (RFID) tag, a signal; and receiving, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.

Aspect 16: The method of Aspect 15, further comprising: determining, using the reference signal, one or more of: an adjustment of a timing of the RFID tag; an adjustment for a time-frequency error of the reflected or backscattered signal; pathloss and power control elements; or a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal.

Aspect 17: The method of any of Aspects 15 through 16, wherein the reflected or backscattered signal indicates one or more elements from a sequence associated with the reference signal.

Aspect 18: The method of Aspect 17, wherein the sequence associated with the reference signal, from a set of sequences, is indicated to one or more of the RFID tag or the reader using an index of the sequence, or is indicated based at least in part on an actual sequence.

Aspect 19: The method of any of Aspects 15 through 18, wherein the reference signal is indicated to the reader based at least in part on a reference signal pattern, and wherein the RFID tag and the reader are configured with the reference signal pattern.

Aspect 20: The method of Aspect 19, wherein the reference signal pattern is indicated to one or more of the RFID tag or the reader using an index of the reference signal pattern, or is indicated based at least in part on an actual reference signal pattern.

Aspect 21: The method of any of Aspects 15 through 20, further comprising: storing information associated with the RFID tag, wherein the information is parameterized based at least in part on a tag identifier associated with the RFID tag.

Aspect 22: The method of any of Aspects 15 through 21, wherein the reference signal is associated with a start indication, a length indication, and a periodicity, and wherein each element of a sequence associated with the reference signal is received using a corresponding resource element.

Aspect 23: The method of any of Aspects 15 through 22, wherein the reference signal is incorporated in the reflected or backscattered signal based at least in part on one or more of: a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal.

Aspect 24: The method of any of Aspects 15 through 23, further comprising receiving, from a radio frequency source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.

Aspect 25: The method of any of Aspects 15 through 24, wherein the reference signal is incorporated in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.

Aspect 26: The method of any of Aspects 15 through 25, wherein the reference signal is a second reference signal and the signal transmitted to the RFID tag indicates a first reference signal, wherein the first reference signal is associated with one or more of:a round trip time associated with the signal, a reference signal received power associated with the signal, a pathloss associated with the signal, a charging rate associated with the RFID tag, a Doppler shift and delay spread estimation, or a time-frequency error estimation, and wherein the reflected or backscattered signal includes an indication of the charging rate.

Aspect 27: The method of any of Aspects 15 through 26, wherein reference signal elements are multiplexed with data symbols based at least in part on a rate matching around the data symbols or a puncturing of the data symbols.

Aspect 28: The method of any of Aspects 15 through 27, wherein the reader is co-located with a radio frequency source.

Aspect 29: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 1-14.

Aspect 30: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 1-14.

Aspect 31: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 1-14.

Aspect 32: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-14.

Aspect 33: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 1-14.

Aspect 34: An apparatus for wireless communication at a device, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of one or more of Aspects 15-28.

Aspect 35: A device for wireless communication, comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method of one or more of Aspects 15-28.

Aspect 36: An apparatus for wireless communication, comprising at least one means for performing the method of one or more of Aspects 15-28.

Aspect 37: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 15-28.

Aspect 38: A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform the method of one or more of Aspects 15-28.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware and/or a combination of hardware and software. “Software” shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, and/or functions, among other examples, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. As used herein, a “processor” is implemented in hardware and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods are described herein without reference to specific software code, since those skilled in the art will understand that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

As used herein, “satisfying a threshold” may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. Many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. The disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a + b, a + c, b + c, and a + b + c, as well as any combination with multiples of the same element (e.g., a + a, a + a + a, a + a + b, a +a + c, a + b + b, a + c + c, b + b, b + b + b, b + b + c, c + c, and c + c + c, or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more. ” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” or the like are intended to be open-ended terms that do not limit an element that they modify (e.g., an element “having” A may also have B) . Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or, ” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of” ) .

Claims

An apparatus for wireless communication at a radio frequency identification (RFID) tag, comprising:

a memory; and

one or more processors, coupled to the memory, configured to:

receive, from a reader or a radio frequency (RF) source, a signal; and

transmit, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.
The apparatus of claim 1, wherein the reference signal is associated with one or more of:

an adjustment of a timing of the RFID tag;

an adjustment for a time-frequency error of the reflected or backscattered signal;

a determination of pathloss and power control elements; or

a determination of a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal.
The apparatus of claim 1, wherein the reflected or backscattered signal indicates one or more elements from a sequence associated with the reference signal.
The apparatus of claim 3, wherein the sequence associated with the reference signal, from a set of sequences, is indicated to one or more of the RFID tag or the reader using an index of the sequence, or is indicated based at least in part on an actual sequence.
The apparatus of claim 1, wherein the reference signal is indicated to the reader based at least in part on a reference signal pattern, and wherein the RFID tag and the reader are configured with the reference signal pattern.
The apparatus of claim 5, wherein the reference signal pattern is indicated to one or more of the RFID tag or the reader using an index of the reference signal pattern, or is indicated based at least in part on an actual reference signal pattern.
The apparatus of claim 1, wherein the reference signal is associated with a start indication, a length indication, and a periodicity, and wherein each element of a sequence associated with the reference signal is transmitted using a corresponding resource element.
The apparatus of claim 1, wherein the one or more processors are further configured to:

determine to incorporate the reference signal in the reflected or backscattered signal based at least in part on one or more of: a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal.
The apparatus of claim 1, wherein the one or more processors are further configured to:

receive, from the reader or a radio frequency source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.
The apparatus of claim 1, wherein the reference signal is a second reference signal and the signal received from the reader indicates a first reference signal, and wherein the one or more processors are further configured to:

harvest energy associated with the first reference signal; and

store harvested energy from the first reference signal in a storage unit of the RFID tag.
The apparatus of claim 1, wherein the one or more processors are further configured to:

determine to incorporate the reference signal in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.
The apparatus of claim 1, wherein the reference signal is a second reference signal and the signal received from the reader indicates a first reference signal, and wherein the one or more processors are further configured to:

determine, using the first reference signal, one or more of: a round trip time associated with the signal, a reference signal received power associated with the signal, a pathloss associated with the signal, a charging rate associated with the RFID tag, a Doppler shift and delay spread estimation, or a time-frequency error estimation, and wherein the reflected or backscattered signal includes an indication of the charging rate.
The apparatus of claim 1, wherein reference signal elements are multiplexed with data symbols based at least in part on a rate matching around the data symbols or a puncturing of the data symbols.
The apparatus of claim 1, wherein the RF source and the reader are associated with a same device.
An apparatus for wireless communication at a reader, comprising:

a memory; and

one or more processors, coupled to the memory, configured to:

transmit, to a radio frequency identification (RFID) tag, a signal; and

receive, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.
The apparatus of claim 15, wherein the one or more processors are further configured to:

determine, using the reference signal, one or more of:

an adjustment of a timing of the RFID tag;

an adjustment for a time-frequency error of the reflected or backscattered signal;

pathloss and power control elements; or

a charging rate of the RFID tag and an adjustment of a transmit power associated with the signal.
The apparatus of claim 15, wherein the reflected or backscattered signal indicates one or more elements from a sequence associated with the reference signal.
The apparatus of claim 17, wherein the sequence associated with the reference signal, from a set of sequences, is indicated to one or more of the RFID tag or the reader using an index of the sequence, or is indicated based at least in part on an actual sequence.
The apparatus of claim 15, wherein the reference signal is indicated to the reader based at least in part on a reference signal pattern, and wherein the RFID tag and the reader are configured with the reference signal pattern.
The apparatus of claim 19, wherein the reference signal pattern is indicated to one or more of the RFID tag or the reader using an index of the reference signal pattern, or is indicated based at least in part on an actual reference signal pattern.
The apparatus of claim 15, wherein the one or more processors are further configured to:

store information associated with the RFID tag, wherein the information is parameterized based at least in part on a tag identifier associated with the RFID tag.
The apparatus of claim 15, wherein the reference signal is associated with a start indication, a length indication, and a periodicity, and wherein each element of a sequence associated with the reference signal is received using a corresponding resource element.
The apparatus of claim 15, wherein the reference signal is incorporated in the reflected or backscattered signal based at least in part on one or more of: a pathloss measurement at the reader, a reliability requirement of the signal, a priority associated with the signal, or a quality of service associated with the signal.
The apparatus of claim 15, wherein the one or more processors are further configured to:

receive, from a radio frequency source or a network node, an indication that indicates that the reference signal is to be incorporated in the reflected or backscattered signal.
The apparatus of claim 15, wherein the reference signal is incorporated in the reflected or backscattered signal based at least in part on a measurement by the RFID tag, wherein the reflected or backscattered signal includes an indication of the reference signal, and an indication of a reference signal pattern associated with the reference signal.
The apparatus of claim 15, wherein the reference signal is a second reference signal and the signal transmitted to the RFID tag indicates a first reference signal, wherein the first reference signal is associated with one or more of: a round trip time associated with the signal, a reference signal received power associated with the signal, a pathloss associated with the signal, a charging rate associated with the RFID tag, a Doppler shift and delay spread estimation, or a time-frequency error estimation, and wherein the reflected or backscattered signal includes an indication of the charging rate.
The apparatus of claim 15, wherein reference signal elements are multiplexed with data symbols based at least in part on a rate matching around the data symbols or a puncturing of the data symbols.
The apparatus of claim 15, wherein the reader is co-located with a radio frequency source..
A method of wireless communication performed by a radio frequency identification tag, comprising:

receiving, from a reader or a radio frequency (RF) source, a signal; and

transmitting, to the reader, a reflected or backscattered signal that is based at least in part on the signal received from the reader or the RF source, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.
A method of wireless communication performed by a reader, comprising:

transmitting, to a radio frequency identification (RFID) tag, a signal; and

receiving, from the RFID tag, a reflected or backscattered signal that is based at least in part on the signal transmitted to the RFID tag, wherein the reflected or backscattered signal indicates data and a reference signal that is multiplexed with the data.