Radio frequency identification tag for reconfigurable smart surfaces

Abstract

A reconfigurable smart surface (RIS) includes one or more radio frequency identification (RFID) tags. The one or more RFID tags may perform a function of a controller of the RIS. The one or more RFID tags receive a reference signal from a wireless communication device. The RIS may process the received reference signal, and the one or more RFID tags backscatter a response signal to the wireless communication device. The wireless communication device may also perform processing of the backscatter response. The processing includes measuring a channel from the wireless communication to the RFID tag. The processing also includes estimating a channel from the wireless communication to an element of the RIS. Based on the estimated channel, a beam matrix corresponding to the optimized weights of the RIS elements is determined and sent to the RIS.

Description

Technical Field

[0001] The present disclosure relates to wireless communication systems and methods, and more particularly to devices, systems and methods for implementing RFID tags within RIS devices and using the RFID tags to perform channel measurement and estimation to increase the training efficiency of the RIS devices. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to communicate with various devices using, for example, reflective surfaces, such as reconfigurable smart surfaces (RIS). A wireless communication system may include several base stations (BS), each of which simultaneously supports communication for multiple communication devices, which may be otherwise referred to as user equipment (UE). A wireless communication system may additionally include several RIS.

[0003] RIS can extend the range of wireless communication devices by reflecting signals in all directions to other wireless communication devices around obstacles that would otherwise limit the range of the device. For example, the RIS surface includes a plurality of RIS elements that can be configured by corresponding RIS element weights. A weight set of RIS elements can be determined and adopted to optimize communication, which generally involves training for RIS elements. Existing training methods for RIS devices include sequentially modifying RIS element weights when a wireless communication device transmits a reference signal to another wireless communication device, until an ideal RIS element weight is identified. RIS devices typically include controllers and antennas that require a dedicated power supply.

[0004] In some cases, the use of RIS devices is not employed due to the constraints imposed by the power requirements of the devices. Furthermore, the training of RIS devices is inefficient, requiring processing power and time on the part of the RIS controller and any participating wireless communication devices. Therefore, there is a need for improved methods of training RIS devices and reducing the power consumption of RIS devices. Summary of the invention

[0005] The following summarizes some aspects of the present disclosure to provide a basic understanding of the technology discussed. This summary is not an exhaustive overview of all the expected features of the present disclosure, and is neither intended to identify the key or important elements of all aspects of the present disclosure, nor to delineate the scope of any or all aspects of the present disclosure. The sole purpose of this summary is to present some concepts of one or more aspects of the present disclosure in a summarized form as a prelude to more specific embodiments presented later.

[0006] According to one aspect of the present disclosure, a method of wireless communication includes: receiving a first signal from a second wireless communication device by a first wireless communication device, the first wireless communication device also including: a reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) including an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and transmitting a second signal to the second wireless communication device using backscatter communication based on the first signal by the RFID tag of the first wireless communication device.

[0007] According to another aspect of the present disclosure, a method of wireless communication includes: sending a first signal by a first wireless communication device to a second wireless communication device, the second wireless communication device including: a reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) including an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and receiving a second signal based on the first signal from the second wireless communication device using backscatter communication by the first wireless communication device.

[0008] According to another aspect of the present disclosure, a wireless communication device includes: a reconfigurable smart surface (RIS), which includes an array of one or more RIS elements; a RIS controller; a radio frequency identification (RFID) tag, and the first signal is received by the RFID tag; and a processor, wherein the wireless communication device is configured to: receive the first signal by the RFID tag; and transmit a second signal by the RFID tag based on the first signal using backscatter communication.

[0009] According to another aspect of the present disclosure, a wireless communication device includes: a transceiver; and a processor coupled to the transceiver, wherein the wireless communication device is configured to: send a first signal to a reconfigurable smart surface (RIS), the RIS including: an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and receive a second signal based on the first signal from the RIS.

[0010] After reading the following description of specific exemplary aspects in conjunction with the accompanying drawings, other aspects, features, and embodiments will become apparent to those of ordinary skill in the art. Although each feature may be discussed below with respect to certain aspects and drawings, all aspects may include one or more of the advantageous features discussed herein. In other words, although one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used according to the various aspects discussed herein. In a similar manner, although the exemplary aspects may be discussed below as aspects of devices, systems, or methods, it should be understood that such exemplary aspects may be implemented in various devices, systems, and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A wireless communication network according to some aspects of the present disclosure is illustrated.

[0012] Figure 2 Channel estimation and communication scenarios involving a BS, a UE, and a RIS according to some aspects of the present disclosure are illustrated.

[0013] Figure 3 is a block diagram of an exemplary UE according to some aspects of the present disclosure.

[0014] Figure 4 is a block diagram of an exemplary BS according to some aspects of the present disclosure.

[0015] Figure 5 is a block diagram of an exemplary RIS according to some aspects of the present disclosure.

[0016] Fig. 6A A diagrammatic view of a RIS with an RFID tag controller is illustrated in accordance with some aspects of the present disclosure.

[0017] Figure 6B A diagrammatic view of a RIS with an RFID tag is illustrated in accordance with some aspects of the present disclosure.

[0018] Figure 7 A simplified diagram illustrating an energy charging scheme according to some aspects of the present disclosure.

[0019] Figure 8 is a diagrammatic view of channel estimation for individual RIS elements in accordance with aspects of the present disclosure.

[0020] Fig. 9 is a signaling diagram of communications between a BS, a RIS, and a UE according to some aspects of the present disclosure.

[0021] Fig.10 is a signaling diagram of communications between a BS, a RIS, and a UE according to some aspects of the present disclosure.

[0022] Fig.11 is a flow chart of a method of wireless communication according to some aspects of the present disclosure.

[0023] Fig.12 is a flow chart of a method of wireless communication according to some aspects of the present disclosure.

[0024] Fig.13 is a diagram illustrating an example decomposed BS architecture according to some aspects of the present disclosure.

[0025] Fig.14 A diagram illustrating a system including devices supporting RU sharing technology in wireless communications according to some aspects of the present disclosure is illustrated. DETAILED DESCRIPTION

[0026] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. In order to provide a comprehensive understanding of the various concepts, the specific embodiments include specific details. However, it is apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, in order to avoid obscuring such concepts, well-known structures and components are shown in block diagram form.

[0027] The present disclosure as a whole relates to wireless communication systems, which are also referred to as wireless communication networks. In various embodiments, each technology and device can be used for wireless communication networks, such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single carrier FDMA (SC-FDMA) networks, LTE networks, global mobile communication systems (GSM) networks, fifth generation (5G) or new radio (NR) networks, and other communication networks. As described herein, the terms "network" and "system" can be used interchangeably.

[0028] OFDMA network can implement radio technology such as Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM, etc. UTRA, E-UTRA and GSM are part of Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a version of UMTS using E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided by an organization named "3rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). These radio technologies and standards are known or under development. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between telecommunication association groups with the goal of defining globally applicable third generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP plan to improve UMTS mobile phone standards. 3GPP may define specifications for next generation mobile networks, mobile systems, and mobile devices. The present disclosure relates to the evolution from LTE, 4G, 5G, NR and beyond wireless technologies, where access to the wireless spectrum is shared between networks using a range of new and different radio access technologies or radio air interfaces.

[0029] Specifically, 5G networks consider various deployments, various spectrums, and various services and devices that can be implemented using a unified air interface based on OFDM. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to scale to (1) ultra-high density (e.g., about 1M nodes / km) 2 (1) provide coverage for the massive Internet of Things (IoT) with ultra-low complexity (e.g., on the order of tens of bits / second), ultra-low energy (e.g., on the order of 10+ years battery life), and deep coverage with the ability to reach challenging locations; (2) provide coverage including mission-critical control with strong security to protect sensitive personal, financial, or classified information, ultra-high reliability (e.g., on the order of 99.9999% reliability), ultra-low latency (e.g., on the order of 1 millisecond), and for users with extensive mobility or lack of mobility; and (3) provide coverage with enhanced mobile broadband (including extremely high capacity (e.g., on the order of 10Tbps / km 2 ), extremely high data rates (e.g., multi-Gbps rates, 100+Mbps user experience rates), and deep awareness coverage with advanced discovery and optimization.

[0030] The 5G NR communication system can be implemented as an optimized OFDM-based waveform with a scalable parameter set and a transmission time interval (TTI). Additional features may also include a common, flexible framework to efficiently multiplex services and features using a dynamic low-latency time division duplex (TDD) / frequency division duplex (FDD) design; and advanced wireless technologies such as massive multiple-input multiple-output (MIMO), robust millimeter wave (mmWave) transmission, advanced channel decoding, and device-centric mobility. The scalability of the parameter set in 5G NR and the scaling of the subcarrier spacing can efficiently solve various services across different spectrums and different deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD / TDD implementations, the subcarrier spacing may appear at 15kHz on bandwidths (BW) such as 5MHz, 10MHz, and 20MHz. For other various outdoor and small cell coverage deployments of TDD greater than 3GHz, the subcarrier spacing may appear at 30kHz on 80MHz / 100MHz BW. For various other indoor broadband implementations, using TDD on the unlicensed portion of the 5 GHz band, subcarrier spacing may occur at 60 kHz over 160 MHz BW. Finally, for various deployments transmitting with the mmWave component at 28 GHz TDD, subcarrier spacing may occur at 120 kHz over 500 MHz BW.

[0031] 5G NR's scalable parameter sets facilitate scalable TTIs for different latency and quality of service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long and short TTIs allows transmission to start on symbol boundaries. 5G NR also envisions a self-contained integrated subframe design with UL / downlink scheduling information, data, and acknowledgment in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL / downlink (which can be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet current business needs).

[0032] The various other aspects and features of the present disclosure are further described below. It should be apparent that the teachings herein can be embodied in various forms, and any specific structure, function, or both disclosed herein are merely representative and not restrictive. Based on the teachings herein, it should be understood by those of ordinary skill in the art that the aspects disclosed herein can be implemented independently of any other aspects, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement a device or practice a method. In addition, such a device can be implemented or such a method can be practiced using other structures, functionality, or structures and functionality other than or different from one or more of the aspects set forth herein. For example, the method can be implemented as a part of a system, device, device, and / or as an instruction stored on a computer-readable medium for execution on a processor or computer. In addition, one aspect can include at least one element of a claim.

[0033] 5G NR provides increased reliability and ubiquity of wireless data transmission. In order to better facilitate the increased coverage of wireless data transmission, a reconfigurable smart surface (RIS) is used. In a communication scenario where a wireless communication device (such as a UE) is separated from another wireless communication device (such as a BS) by an obstacle, wireless communication between the devices may be degraded, prohibited or impossible. The RIS can be positioned relative to the obstacle and the communicating wireless communication device so that a signal from one device to another can be reflected from the RIS surface and around the obstacle. In this way, the wireless coverage of any wireless communication device is improved.

[0034] The RIS surface may include multiple RIS elements. Each RIS element may be configured with RIS element weights. Different RIS element weights may change the reflected wireless signal. For example, the RIS element may direct the signal in different directions, adjust the frequency or time delay of the signal, invert the signal, or otherwise modify the signal through beam steering. Different RIS weights may increase the strength and reliability of communication between wireless communication devices. In this regard, an ideal set of weights for the RIS elements should be determined and adopted to optimize communication. Some methods of training RIS elements include sequentially modifying the RIS element weights when one wireless communication device transmits a reference signal to another wireless communication device. The wireless communication device may determine which RIS element weight set (beam matrix) corresponds to the highest signal quality. The beam matrix may be sent to the RIS, and the RIS may implement the weights of the RIS elements according to the matrix.

[0035] According to aspects of the present disclosure, a RIS may include one or more radio frequency identification (RFID) tags. The RFID tags of the RIS may be used to receive or transmit signals. For example, one or more RFID tags may be included in a RIS controller as a transceiver for the RIS controller. In some aspects, the RIS controller may be one or more RFID tags. In some aspects, the previously described beam matrix may be received by the RIS through one or more RFID tags of the RIS. In some aspects, the RFID tags may additionally perform various processing techniques. In this regard, the RFID tags may operate as a controller of the RIS, including performing the functions of the RIS controller, such as receiving and implementing RIS element weights of the beam matrix.

[0036] In some aspects, multiple RFID tags may be positioned on a RIS surface and may communicate with a RIS controller (which may further have its own integrated controller). For example, the RFID tags may be positioned on the RIS surface in a pattern along with the RIS elements. In such aspects, the channel between each RFID tag and one of the previously mentioned wireless communication devices may be measured, which may be used to interpolate channel information between the RIS elements and the communication devices (such as a BS and / or UE).

[0037] For example, an RFID tag of a RIS may receive a reference signal from one of the wireless communication devices. The RFID tag may compare the received signal with the expected reference signal and determine one or more values ​​to characterize the communication channel relative to each RFID tag. The measured channel data may then be used to estimate the channel between the RIS element and the wireless communication device (e.g., by interpolation or extrapolation). The RFID tag may similarly estimate the channel between the RIS element and the other wireless communication device. In some aspects, other components (such as a RIS controller or any one of the wireless communication devices) may measure and / or estimate the channel. The controller of the RIS, the RFID tag of the RIS, or any wireless communication device may then determine a beam matrix including optimal weights for the RIS elements based on the estimated channels of the RIS elements relative to the two wireless communication devices.

[0038] Aspects of the present disclosure advantageously reduce the computational and / or processing power of the wireless communication device that trains the RIS or the RIS itself. Furthermore, the use of RFID tags for RIS devices reduces the power requirements of the RIS devices, resulting in potentially passive or nearly passive RIS devices. This in turn increases the opportunity to employ RIS devices to increase wireless coverage in many locations and reduces specific implementation costs and complexity. Furthermore, aspects of the present disclosure enable measurement of channels between RF sources (e.g., BS or UE) and the RIS surface, which in turn enables estimation of (or indication of) separate channels between the BS and the RIS and between the RIS and the UE, which was not previously an option.

[0039] Figure 1 A wireless communication network 100 according to some aspects of the present disclosure is illustrated. The network 100 may be a 5G network. The network 100 includes several base stations (BSs) 105 (respectively labeled 105a, 105b, 105c, 105d, 105e, and 105f) and other network entities. The BS 105 may be a station that communicates with the UE 115, and may also be referred to as an evolved Node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the particular geographic coverage area of ​​the BS 105 and / or the BS subsystem serving the coverage area, depending on the context in which the term is used.

[0040] BS105 may provide communication coverage for macro cells or small cells (such as pico cells or femto cells) and / or other types of cells. Macro cells generally cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with a network provider. Small cells (such as pico cells) will generally cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions with a network provider. Small cells (such as femto cells) will generally also cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs associated with the femto cells (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS, or a home BS. In Figure 1In the example shown, BS105d and 105e may be conventional macro BSs, while BS105a-105c may be macro BSs with one of three-dimensional (3D), full-dimensional (FD) or massive MIMO capabilities. BS105a-105c may utilize its higher-dimensional MIMO capabilities to employ 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. BS105f may be a small cell BS, which may be a home node or a portable access point. BS105 may support one or more (e.g., two, three, four, etc.) cells.

[0041] Network 100 may support synchronous operation or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

[0042] UE 115 is dispersed throughout the wireless network 100, and each UE 115 can be stationary or mobile. UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, etc. UE 115 may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, etc. In one aspect, UE 115 may be a device including a universal integrated circuit card (UICC). On the other hand, UE may be a device that does not include a UICC. In some aspects, UE 115 that does not include a UICC may also be referred to as an IoT device or an Internet of Everything (IoE) device. UE 115a-115d is an example of a mobile smart phone type device that accesses the network 100. UE 115 may also be a machine that is specifically configured for connected communications (including machine type communications (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc.). UE 115e-115h are examples of various machines configured for communication to access network 100. UE 115i to 115k are examples of vehicles equipped with wireless communication devices configured for communication to access network 100. UE 115 may be able to communicate with any type of BS (whether macro BS, small cell, etc.). Figure 1 , a lightning symbol (e.g., a communication link) indicates wireless transmission between UE 115 and a serving BS 105 (which is a BS designated to provide service to UE 115 on a downlink (DL) and / or uplink (UL), desired transmission between BSs 105, backhaul transmission between BSs, or sidelink transmission between UE 115.

[0043] In operation, BSs 105a-105c use 3D beamforming and cooperative spatial techniques such as coordinated multipoint (CoMP) or multiple connections to serve UEs 115a and 115b. Macro BS 105d may perform backhaul communications with BSs 105a-105c and small cell BS 105f. Macro BS 105d may also transmit multicast services that UEs 115c and 115d subscribe to and receive. Such multicast services may include mobile TV or streaming video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

[0044] The BSs 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be examples of gNBs or access node controllers (ANCs)) may interface with the core network via a backhaul link (e.g., NG-C, NG-U, etc.) and may perform radio configuration and scheduling for communications with the UE 115. In various examples, the BSs 105 may communicate with each other directly or indirectly (e.g., via a core network) via a backhaul link (e.g., X1, X2, etc.), which may be a wired communication link or a wireless communication link.

[0045] The network 100 may also support mission-critical communications using ultra-reliable and redundant links for mission-critical devices such as UE 115e, which may be a drone. The redundant communication links with UE 115e may include links from macro BSs 105d and 105e, and links from small cell BS 105f. Other machine-type devices such as UE 115f (e.g., a thermometer), UE 115g (e.g., a smart meter), and UE 115h (e.g., a wearable device) may communicate directly with BSs such as small cell BS 105f and macro BS 105e through the network 100, or communicate through the network in a multi-step configuration by communicating with another user device such as UE 115f that communicates temperature measurement information to a smart meter (UE 115g), which then reports to the network through the small cell BS 105f, which relays its information to the network. The network 100 may also provide additional network efficiency through dynamic low latency TDD / FDD communications, such as V2V, V2X, C-V2X communications (e.g., sidelink communications) between UE 115i, 115j, or 115k and other UEs 115, and / or vehicle-to-infrastructure (V2I) communications between UE 115i, 115j, or 115k and BS 105.

[0046] In some implementations, the network 100 utilizes an OFDM-based waveform for communication. An OFDM-based system may divide the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, frequency bins, etc. Each subcarrier may be modulated with data. In some instances, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system BW. The system BW may also be divided into subbands. In other instances, the subcarrier spacing and / or the duration of the TTI may be scalable.

[0047] In some aspects, BS105 may assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RBs)) for downlink (DL) and uplink (UL) transmissions in network 100. DL refers to the transmission direction from BS105 to UE 115, and UL refers to the transmission direction from UE 115 to BS105. The communication may be in the form of a radio frame. A radio frame may be divided into a plurality of subframes or time slots, for example, about 10. Each time slot may also be divided into micro-time slots. In FDD mode, simultaneous UL transmission and DL transmission may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In TDD mode, UL transmission and DL transmission occur in different time periods using the same frequency band. For example, a subframe subset (e.g., a DL subframe) in a radio frame may be used for DL ​​transmission, and another subframe subset (e.g., an UL subframe) in a radio frame may be used for UL transmission.

[0048] DL subframes and UL subframes may also be divided into several zones. For example, each DL subframe or UL subframe may have a predefined zone for the transmission of reference signals, control information, and data. A reference signal is a predetermined signal that facilitates communication between BS105 and UE 115. For example, a reference signal may have a specific pilot pattern or structure, wherein a pilot tone may span an operational BW or frequency band, and each pilot tone is located at a predefined time and a predefined frequency. For example, BS105 may send a cell-specific reference signal (CRS) and / or a channel state information-reference signal (CSI-RS) to enable UE 115 to estimate a DL channel. Similarly, UE 115 may send a sounding reference signal (SRS) to enable BS105 to estimate an UL channel. As further discussed below with respect to the remaining figures, a sidelink UE 115 may send a sidelink reference signal between each other, such as, for example, a sidelink reference signal modeled after a CSI-RS, although other types are also possible.

[0049] The control information may include resource assignments and protocol controls. The data may include protocol data and / or operational data. In some aspects, the BS 105 and the UE 115 may communicate using self-contained subframes. The self-contained subframe may include a portion for DL ​​communication and a portion for UL communication. The self-contained subframe may be DL-centric or UL-centric. A DL-centric subframe may include a DL communication duration that is longer than the UL communication duration. A UL-centric subframe may include a UL communication duration that is longer than the UL communication duration.

[0050] In some aspects, the network 100 may be an NR network deployed on a licensed spectrum. The BS 105 may send synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS)) in the network 100 to facilitate synchronization. The BS 105 may broadcast system information associated with the network 100 (e.g., including a master information block (MIB), remaining system information (RMSI), and other system information (OSI)) to facilitate initial network access. In some cases, the BS 105 may broadcast the PSS, SSS, and / or MIB in the form of a synchronization signal block (SSB) over a physical broadcast channel (PBCH), and may broadcast the RMSI and / or OSI over a physical downlink shared channel (PDSCH).

[0051] In some aspects, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from the BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identification value. The UE 115 may then receive the SSS. The SSS may enable radio frame synchronization and may provide a cell identification value that may be combined with the physical layer identification value to identify a cell. The PSS and SSS may be located in the center portion of a carrier or at any suitable frequency within a carrier.

[0052] After receiving the PSS and SSS, the UE 115 may receive the MIB. The MIB may include system information for initial network access and scheduling information for RMSI and / or OSI. After decoding the MIB, the UE 115 may receive the RMSI and / or OSI. The RMSI and / or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource sets (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS.

[0053] After obtaining the MIB, RMSI and / or OSI, the UE 115 may perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE 115 may send a random access preamble, and the BS 105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, UL grant, temporary cell radio network temporary identifier (C-RNTI), and / or a backoff indicator. Upon receiving the random access response, the UE 115 may send a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response may be referred to as message 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4 (MSG4), respectively. In some examples, the random access process may be a two-step random access procedure, where the UE 115 may send a random access preamble and a connection request in a single transmission, and the BS 105 may respond by sending a random access response and a connection response in a single transmission.

[0054] After establishing the connection, UE 115 may initiate an initial network attachment process with network 100. When UE 115 does not perform active data communication with BS 105 after network attachment, UE 115 may return to an idle state (e.g., RRC idle mode). Alternatively, UE 115 and BS 105 may enter an operational state or an active state, in which operational data may be exchanged (e.g., RRC connected mode). For example, BS 105 may schedule UE 115 for UL communication and / or DL ​​communication. BS 105 may send UL scheduling grant and / or DL ​​scheduling grant to UE 115 via PDCCH. Scheduling grant may be sent in the form of DL control information (DCI). BS 105 may send DL communication signals (e.g., carrying data) to UE 115 via PDSCH according to the DL scheduling grant. UE 115 may send UL communication signals to BS 105 via PUSCH and / or PUCCH according to the UL scheduling grant.

[0055] In some aspects, BS105 may communicate with UE 115 using HARQ technology to improve communication reliability, for example, to provide URLLC services. BS105 may schedule UE 115 to perform PDSCH communication by sending DL grant in PDCCH. BS105 may send DL data packets to UE 115 according to the scheduling in PDSCH. DL data packets may be sent in the form of transport blocks (TBs). If UE 115 successfully receives the DL data packet, UE 115 may send HARQ ACK to BS105. On the contrary, if UE115 fails to successfully receive the DL transmission, UE 115 may send HARQ NACK to BS105. Upon receiving HARQ NACK from UE 115, BS105 may retransmit the DL data packet to UE 115. The retransmission may include a decoded version of the DL data that is the same as the initial transmission. Alternatively, the retransmission may include a decoded version of the DL data that is different from the initial transmission. The UE 115 may apply soft combining to combine the coded data received from the initial transmission and the retransmission for decoding. The BS 105 and the UE 115 may also apply HARQ to UL communications using a substantially similar mechanism as DL HARQ.

[0056] In some aspects, the network 100 may operate on a system BW or a component carrier (CC) BW. The network 100 may divide the system BW into multiple BWPs (e.g., parts). The BS 105 may dynamically assign the UE 115 to operate on a specific BWP (e.g., a specific part of the system BW). The assigned BWP may be referred to as an active BWP. The UE 115 may monitor the active BWP to find signaling information from the BS 105. The BS 105 may schedule the UE 115 to perform UL or DL ​​communications in the active BWP. In some aspects, the BS 105 may assign a pair of BWPs within the CC to the UE 115 for UL and DL communications. For example, the BWP pair may include a BWP for UL communication and a BWP for DL ​​communication.

[0057] In some aspects, BS 105 may send a PRACH configuration to UE 115. The PRACH configuration may indicate a set of ROs in the PRACH configuration. BS 105 and / or UE 115 may divide the ROs into different groups, including a first group of ROs configured for PRACH repetition and a second group configured for a single PRACH transmission. In addition to the BS-UE communications as briefly noted above, various UEs 115 may additionally or alternatively participate in sidelink communications with each other. And, according to an embodiment of the present disclosure, the UEs so participating in sidelink communications may be configured to multiplex the sidelink reference signals of multiple UEs onto the same resources by configuring and sharing one or more sidelink reference signal parameters between the participating UEs, as will be further described below with respect to the accompanying drawings.

[0058] Figure 2 A channel estimation and communication scenario 200 involving a BS, a UE, and a RIS according to some aspects of the present disclosure is illustrated. In some aspects, the BS 105 can communicate with the UE 115 by wirelessly transmitting information via various channels or types of radio frequency (RF) waves reflected by the RIS 202. In this regard, the RIS 202 can include multiple RIS elements that can be reconfigured to correspond to different weights to steer reflected signals from one device to another. It should be noted that although in Figure 2 BS 105 and UE 115 are shown in FIG. 2 , but any suitable type of wireless communication device may wirelessly send and / or receive signals via RIS 202. For example, a UE may send a signal to another UE via a sidelink connection by reflecting the signal using RIS 202. Similarly, a BS or network element may send a signal to another BS or network element via RIS 202 in a similar manner.

[0059] In some aspects, a RIS (such as Figure 2 RIS202 shown in FIG202 may also be referred to as a reflective array or a (near) passive MIMO array. RIS202 may include a reflective surface configured to reflect signals to and from a transmit / receive device. In some aspects, RIS202 may include a reflector array configured to direct signal energy. UE / BS115 / 105 may use RIS202 by performing transmit and / or receive beamforming in a direction associated with RIS202. RIS202 may be configured with parameters that affect its reflection properties. In addition to controlling the reflection direction, RIS202 may potentially shift the frequency of the reflected signal. RIS202 may be used to reflect signals sent by BS105 and to be received by UE 115. RIS202 may include one or more RFID tags. One or more RFID tags of RIS202 may be used to send and / or receive signals.

[0060] In some aspects, beam training may be implemented with respect to RIS 202 to optimize communication between BS 105 and UE 115 or any other wireless communication device. A reference signal may be sent by BS 105 to UE 115. The reference signal may be reflected by RIS 202. When sending a reference signal, RIS 202 may configure the RIS elements according to a specific set of weights corresponding to, for example, a specific beam index or beam matrix. UE 115 may receive the reflected reference signal and analyze the received reference signal to determine the quality of the signal. In some aspects, BS 105 may also send additional reference signals to UE 115. When each reference signal is sent from BS 105, RIS 202 may adjust the weights of the various RIS elements, thereby changing the direction of the reflection or otherwise changing various aspects of the signal itself (e.g., signal modulation). UE 115 may similarly analyze each received reference signal. In some aspects, UE 115 may send various signals to BS 105 during the beam training process. In this way, UE 115 and / or BS 105 can determine which reference signal corresponds to the best signal quality, and identify the beam index or beam matrix (e.g., weights of RIS elements) of the reference signal that results in the highest signal quality. BS 105 and / or UE 115 can then send a signal to RIS 202 identifying the beam index or beam matrix corresponding to the highest quality signal. RIS 202 can receive a signal indicating the selected beam index or beam matrix for communication between BS 105 and UE 115 through one or more RFID tags. In some aspects, the beam index or beam matrix is ​​received by all RFID tags of RIS 202. In some aspects, the beam index or beam matrix is ​​received by a collection of RFID tags for better beamforming and reliability. In some aspects, RIS 202 can send a confirmation of the received signal through backscatter communication, as described in more detail below. The beam matrix sent from BS 105 to RIS 202 may also be referred to as a beam index. The beam matrix may include at least one parameter or setting for each RIS element of RIS 202, such as a weight value. RIS 202 may configure each RIS element according to the beam matrix upon receiving the beam matrix.

[0061] In some aspects, the beam matrix may be determined for each channel between each RIS element and the BS 105 and / or UE 115, respectively, by various channel estimation techniques. Specifically, during a beam training process in which a plurality of reference signals are transmitted from, for example, BS 105 to UE 115 via RIS 202, the properties of the channel from BS 105 to one or more elements of RIS 202 may be unknown. Similarly, the properties of the channel from one or more elements of RIS 202 to UE 115 may be unknown. In contrast, when the beam index of RIS 202 is changed, the transmission of reference signals from BS 105, reflected from RIS 202, and received at UE 115 is analyzed as a whole. Thus, an optimal beam matrix may be selected for communication between BS 105 and UE 115 without separately determining the optimal communication between BS 105 and RIS 202 or separately determining the optimal communication between UE 115 and RIS 202. This may correspond to a configuration in which a controller of RIS 202 includes an RFID tag. However, the introduction of multiple RFID tags on RIS 202 (e.g., in an array of RIS elements) allows for estimation of individual channels between BS 105 and elements of RIS 202 and / or between RIS 202 and UE 115 based on measured properties of the channels between BS 105 and the RFID tags and relative to UE 115. Optimal beam matrices or weighting values ​​for the elements of RIS 202 may then be determined based on the individual channel estimates, thereby increasing the accuracy and efficiency of beam training for RIS 202.

[0062] For illustration purposes, Figure 2 A simple example is illustrated. As shown in transmission 210, BS 105 sends a reference signal to RIS 202. RIS 202 measures the channel corresponding to the reference signal received for each RFID tag of RIS 202. Fig. 9 As explained in more detail, RIS 202 then estimates the channel to each RIS element of RIS 202. This may be accomplished by interpolation or extrapolation based on the measured channels to the RFID tags. Thus, RIS 202 may determine a matrix G that includes channel estimates for each RIS element of RIS 202 and BS 105. As will be explained below, various wireless communication devices or components or processors of various wireless communication devices may measure and / or estimate the channel to determine matrix G. For example, a controller of RIS 202, an RFID tag of RIS 202, BS 105, and / or UE 115 may perform any of these functions. In Figure 2 In the example shown, a processor of a controller of RIS 202 may determine a matrix G based on the channel measurements and estimates. RIS 202 may then transmit the channel estimates within matrix G to BS 105 , as shown by transmission 212 .

[0063] In some aspects, an estimate of the channel between the UE 115 and the RIS 202 may additionally be made. For example, the UE 115 may send a reference signal to the RIS 202, as shown by sending 214. The RIS 202 may measure the channel corresponding to the reference signal received at each RFID tag of the RIS 202. The RIS 202 may then estimate the channel between each RIS element of the RIS 202 and the UE 115 in a manner similar to that described above. In this manner, the RIS 202 may determine a matrix H that includes channel estimates between each RIS element of the RIS 202 and the UE 115. A controller of the RIS 202, an RFID tag of the RIS 202, a UE 115, or a BS 105 may perform any of these functions. In Figure 2 In the example shown, a processor of a controller of RIS 202 may determine matrix H based on channel measurements and estimates. RIS 202 may then transmit channel estimates within matrix H to UE 115, as shown by transmission 216. In some aspects, additionally or alternatively, channel estimates within matrix H may be transmitted to BS 105. For example, RIS 202 may transmit both matrices G and H to BS 105 via transmission 212 and / or to UE 115 via transmission 216.

[0064] In one aspect where BS105 receives matrices G and H, BS105 may determine a matrix Φ including weight values ​​for RIS202 elements based on matrices G and H. In some aspects, Φ may be a diagonal matrix. Communication between BS105 and UE 115 may be modeled as Equation 1: x*P*G*Φ*H*R, where x represents a transmitted signal (such as a reference signal), P represents a pre-decoder of BS105, and R represents a filter of UE 115. In some aspects, BS105 may optimize Equation 1 to determine the matrix Φ. Thus, the matrix Φ may be the same optimal beam matrix determined by the beam training method described above. In this regard, the matrix Φ may include weight values ​​for each of the RIS elements of RIS202. In some aspects, BS105 may additionally determine values ​​for the matrix P and / or the matrix R. In some aspects, the matrix P may correspond to a beam selection of BS105, and the matrix R may correspond to a beam selection of UE 115. As previously described, any wireless communication device may perform any of the functions described. In this regard, the matrix P may correspond to any beam steering parameters of a transmitting wireless communication device, and the matrix R may correspond to any beam steering parameters of a receiving wireless communication device.

[0065] In some aspects, after determining any or all of the matrices Φ, P, or R, the BS 105 may send the matrix Φ to the RIS 202. In response to receiving the matrix Φ, the RIS 202 may configure the RIS elements according to the weighted values ​​of the matrix Φ. The BS 105 may then send a signal to the UE 115, wherein the RIS 202 implements the weights of the matrix Φ. For example, the BS 105 may send a signal (such as various data or command signals) via transmission 218. The signal may be reflected by the RIS 202 according to the weighted values ​​of the matrix Φ, and the signal may be received by the UE 115 according to the transmission 220 shown. In a similar manner, the UE 115 may send one or more signals to the BS 105. Additional aspects of beam training, channel estimation, and signal transmission between wireless communication devices utilizing a RIS including one or more RFID tags will be described in more detail with reference to the following figures.

[0066] Figure 3 300 is a block diagram of an exemplary UE 300 according to some aspects of the present disclosure. The UE 300 may be as described in reference Figure 1 UE 115 discussed and shown in multiple figures. As shown, UE 300 may include a processor 302, a memory 304, a side link reference signal (SL-RS) module 308, a transceiver 310 including a modem subsystem 312 and a radio frequency (RF) unit 314, and one or more antennas 316. These elements may be coupled to each other. The term "coupled" may refer to being directly or indirectly coupled or connected to one or more intervening elements. For example, these elements may communicate directly or indirectly with each other, such as via one or more buses.

[0067] The processor 302 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 302 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

[0068] The memory 304 may include cache memory (e.g., cache memory of the processor 302), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory devices, hard drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In one aspect, the memory 304 includes a non-transitory computer-readable medium. The memory 304 may store or have recorded thereon instructions 306. The instructions 306 may include instructions that, when executed by the processor 302, cause the processor 302 to perform the various aspects of the present disclosure (e.g., Figure 2 and FIG. 6A to FIG. 12 Instructions 306 may also be referred to as codes, which may be broadly interpreted to include any type of computer-readable statements.

[0069] The RIS channel estimation module 308 may be implemented via hardware, software, or a combination thereof. For example, the RIS channel estimation module 308 may be implemented as a processor, circuit, and / or instructions 306 stored in the memory 304 and executed by the processor 302. In some aspects, the RIS channel estimation module 308 may be integrated within the modem subsystem 312. For example, the RIS channel estimation module 308 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuits) within the modem subsystem 312. The RIS channel estimation module 308 may communicate with one or more components of the UE 300 to implement aspects of the present disclosure, such as, Figure 2 and FIG. 6A to FIG. 12 all aspects.

[0070] The RIS channel estimation module 308 may be configured to perform various functions related to channel estimation or other data transfer between the UE 300 and the RIS (e.g., RIS 500 described below). Such functions may include sending a password required to activate an RFID tag of the RIS (e.g., RIS 500 and / or RIS 202), sending a reference signal to the RIS, receiving channel estimation data from the RIS or from another wireless communication device such as a BS (e.g., BS 400 and / or BS 105). In some aspects, the RIS channel estimation module 308 may additionally receive a reference signal from an RFID tag of the RIS through backscatter communication, and perform channel measurements associated with the RFID tag by comparing the received reference signal with an expected reference signal or a reference signal sent by the UE 300. The RIS channel estimation module 308 may additionally perform channel estimation of RIS elements of the RIS based on the channel measurement data. In some aspects, the RIS channel estimation module 308 may determine a beam matrix containing ideal weights for each RIS element of the RIS. The RIS channel estimation module 308 may send the beam matrix to the RIS.

[0071] UE 300 may be any one or more of a transmitting UE, a receiving UE, or a master UE. As a master UE, UE 300 may be responsible for making determinations related to reference signal parameters (e.g., sidelink reference signal parameters) discussed herein, and controlling the configuration of any RIS that may be involved (or communicating with a controller of the RIS to achieve the desired parameters, including having the RIS participate in a beam training process with other UEs). UE 300 may operate as different UE types under different groups (e.g., concurrently or at different times). In the case where UE 300 does not operate as a master UE, if channel parameters are received from RIS 202, UE 300 may still determine the channel parameters between UE 300 and RIS 202, and send the resulting information to RIS 202 for configuration.

[0072] As shown, the transceiver 310 may include a modem subsystem 312 and an RF unit 314. The transceiver 310 may be configured to communicate bidirectionally with other devices, such as the BS 105. The modem subsystem 312 may be configured to modulate and / or encode data from the memory 304 and / or the SL-RS module 308 according to a modulation and coding scheme (MCS) (e.g., a low-density parity check (LDPC) decoding scheme, a turbo decoding scheme, a convolutional decoding scheme, a digital beamforming scheme, etc.). The RF unit 314 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) the modulated / encoded data (e.g., channel sensing reports, PUCCH UCI, PUSCH data, etc.) transmitted from another source, such as the UE 115, the BS 105, or the anchor. The RF unit 314 may be further configured to perform analog beamforming in conjunction with digital beamforming. Although shown as being integrated together in the transceiver 310, the modem subsystem 312 and the RF unit 314 may be separate devices that are coupled together at the UE 300 to enable the UE 300 to communicate with other devices.

[0073] The RF unit 314 may provide modulated and / or processed data, such as data packets (or more generally, data messages that may include one or more data packets and other information), to the antenna 316 for transmission to one or more other devices. The antenna 316 may also receive data messages sent from other devices. The antenna 316 may provide the received data messages for processing and / or demodulation at the transceiver 310. The transceiver 310 may provide demodulated and decoded data (e.g., RRC tables for channel access configuration, scheduling grant, channel access configuration activation, timing advance configuration, RRC configuration, PUSCH configuration, SRS resource configuration, PUCCH configuration, BWP configuration, PDSCH data, PDCCH DCI, side link configuration, etc.) to the SL-RS module 308 for processing. The antenna 316 may include multiple antennas with similar designs or different designs in order to maintain multiple transmission links.

[0074] In one aspect, the UE 300 may include multiple transceivers 310 that implement different RATs (e.g., NR and LTE). In one aspect, the UE 300 may include a single transceiver 310 that implements multiple RATs (e.g., NR and LTE). In one aspect, the transceiver 310 may include various components, where different combinations of components may implement different RATs.

[0075] Furthermore, in some aspects, the processor 302 is coupled to the memory 304 and the transceiver 310. The processor 302 is configured to, under the control of the RIS channel estimation module 308: determine resources and / or parameters of reference signals, analyze and / or measure signal quality of reference signals associated with different training beams, select the best beam, generate, send and / or receive beam training reports, implement reference signal parameters, and / or otherwise facilitate the transmission of data between the UE 400 and the RIS 302 (as an intermediate point to a final destination such as the BS 105).

[0076] Figure 4 is a block diagram of an exemplary BS 400 according to some aspects of the present disclosure. BS 400 may be such as Figure 1 BS 105 discussed, and / or a transmit receive point (TRP). For example, BS 400 may be configured as one of a plurality of TRPs in a network configured to communicate with at least one UE (such as one of UE 115). As shown, BS 400 may include a processor 402, a memory 404, a side link reference signal (SL-RS) module 408, a transceiver 410 including a modem subsystem 312 and an RF unit 414, and one or more antennas 414. These elements may be coupled to each other. The term "coupled" may refer to direct or indirect coupling or connection to one or more intermediate elements. For example, these elements may communicate directly or indirectly with each other, for example, via one or more buses.

[0077] The processor 402 may have various features as a particular type of processor. For example, these features may include a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 402 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0078] Memory 404 may include cache memory (e.g., cache memory of processor 402), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid-state memory devices, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, memory 404 may include non-transitory computer-readable media. Memory 404 may store instructions 406. Instructions 406 may include instructions that, when executed by processor 402, cause processor 402 to perform the operations described herein (e.g., Figure 2 and FIG. 6A to FIG. 12Instructions 406 may also be referred to as program code. The program code may cause the wireless communication device to perform these operations, for example by causing one or more processors (such as processor 402) to control or command the wireless communication device to do so. The terms "instructions" and "code" should be interpreted broadly to include any type of computer-readable statements. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, procedures, etc. "Instructions" and "code" may include a single computer-readable statement or multiple computer-readable statements.

[0079] RIS channel estimation module 408 may be implemented via hardware, software, or a combination thereof. For example, RIS channel estimation module 408 may be implemented as a processor, circuit, and / or instructions 406 stored in memory 404 and executed by processor 402. In some examples, RIS channel estimation module 408 may be integrated within modem subsystem 412. For example, RIS channel estimation module 408 may be implemented by a combination of software components (e.g., executed by a DSP or general purpose processor) and hardware components (e.g., logic gates and circuits) within modem subsystem 412. RIS channel estimation module 408 may communicate with one or more components of BS 400 to implement aspects of the present disclosure, such as, Figure 2 and FIG. 6A to FIG. 12 all aspects.

[0080] RIS channel estimation module 408 may be configured to perform various functions related to channel estimation or other data transfer between BS 400 and RIS (e.g., RIS 202). Such functions may include sending a password required to activate an RFID tag of the RIS, sending a reference signal to the RIS, receiving channel estimation data from the RIS or from another wireless communication device such as a UE (e.g., UE 300 and / or UE 115). In some aspects, RIS channel estimation module 408 may additionally receive a reference signal from an RFID tag of the RIS and perform channel measurements associated with the RFID tag by comparing the received reference signal with an expected reference signal or a reference signal sent by BS 400. RIS channel estimation module 408 may additionally perform channel estimation of RIS elements of the RIS based on the channel measurement data received from the RIS. In some aspects, RIS channel estimation module 408 may determine a beam matrix containing ideal weights for each RIS element of the RIS. RIS channel estimation module 408 may send the beam matrix to the RIS, such as to a RIS controller (where the RFID tags are integrated with the controller), multiple RFID tags at the RIS, or some combination of the location of the RIS controller relative to the locations of the RFID tags.

[0081] As shown, the transceiver 410 may include a modem subsystem 412 and an RF unit 414. The transceiver 410 may be configured to communicate bidirectionally with other devices, such as the UE 115 and / or the BS 400 and / or another core network element. The modem subsystem 412 may be configured to modulate and / or encode data according to an MCS (e.g., an LDPC decoding scheme, a turbo decoding scheme, a convolutional decoding scheme, a digital beamforming scheme, etc.). The RF unit 414 may be configured to process (e.g., perform analog-to-digital conversion or digital-to-analog conversion, etc.) modulated / encoded data (e.g., RRC tables for channel access configuration, scheduling grants, channel access configuration activation, RRC configuration, PDSCH data, PDCCH DCI, RACH preamble assignments, random access messages, sidelink resource pool configurations, sidelink reference signal parameter configurations, etc.) from the modem subsystem 412 (on outbound transmissions) or from another source, such as the UE 115. RF unit 414 may be further configured to perform analog beamforming in conjunction with digital beamforming.Although shown as integrated together in transceiver 410, modem subsystem 412 and / or RF unit 414 may be separate devices coupled together at BS 400 to enable BS 400 to communicate with other devices.

[0082] The RF unit 414 may provide modulated and / or processed data, such as data packets (or more generally, data messages that may include one or more data packets and other information), to the antenna 414 for transmission to one or more other devices. The antenna 414 may also receive data messages sent from other devices and provide the received data messages for processing and / or demodulation at the transceiver 410. The transceiver 410 may provide the demodulated and decoded data (e.g., PRACH messages, channel sensing reports, PUCCH UCI, PUSCH data, etc.) to the RIS channel estimation module 408 for processing. The antenna 414 may include multiple antennas of similar design or different design to maintain multiple transmission links.

[0083] In one aspect, the BS 400 may include multiple transceivers 410 that implement different RATs (e.g., NR and LTE). In one aspect, the BS 400 may include a single transceiver 410 that implements multiple RATs (e.g., NR and LTE). In one aspect, the transceiver 410 may include various components, where different combinations of components may implement different RATs.

[0084] Moreover, in some aspects, the processor 402 is coupled to the memory 404 and the transceiver 410. The processor 402 is configured to communicate a plurality of channel access configurations with the second wireless communication device via the transceiver 410. The processor 402 is further configured to communicate a scheduling grant for communicating a communication signal in the unlicensed band with the second wireless communication device via the transceiver 410, wherein the scheduling grant includes an indication of a first channel access configuration of the plurality of channel access configurations.

[0085] Figure 5 5 is a block diagram of an exemplary reconfigurable smart surface (RIS) 500 according to some aspects of the present disclosure. As shown, RIS 500 may include a processor 502, a memory 504 including instructions 506, a power rectifier 508, a modulation module 510, a channel estimation unit 512, and one or more radio frequency identification (RFID) tags 514. These elements may be coupled to each other. The term "coupled" may refer to being directly or indirectly coupled or connected to one or more intervening elements. For example, these elements may communicate directly or indirectly with each other, such as via one or more buses.

[0086] The processor 502 may have various features as a particular type of processor. For example, these features may include a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 502 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0087] The memory 504 may include cache memory (e.g., cache memory of the processor 502), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, solid-state memory devices, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, the memory 504 may include a non-transitory computer-readable medium. The memory 504 may store instructions 506. The instructions 506 may include instructions that, when executed by the processor 502, cause the processor 502 to perform the operations described herein (e.g., Figure 2 and FIG. 6A to FIG. 12Instructions 506 may also be referred to as program code. The program code may cause the wireless communication device to perform these operations, for example by causing one or more processors (such as processor 502) to control or command the wireless communication device to do so. The terms "instructions" and "code" should be interpreted broadly to include any type of computer-readable statements. For example, the terms "instructions" and "code" may refer to one or more programs, routines, subroutines, functions, procedures, etc. "Instructions" and "code" may include a single computer-readable statement or multiple computer-readable statements.

[0088] The power rectifier 508 of the RIS 500 can perform various functions. For example, the power rectifier 508 can modulate the power from, for example, a power source (e.g., FIG. 6A to FIG. 6B RIS 500 may include a power rectifier 508. In this regard, the power rectifier 508 may include various electrical components, such as diodes, capacitors, or any other components. In some aspects, the power rectifier may modulate the power received from a received RF signal from another wireless communication device. In some aspects, the power rectifier 508 may convert the input power from a DC format to an AC format or vice versa.

[0089] Modulation module 510 may perform various functions related to backscattering of signals from RFID tags of RIS 500. In some aspects, one or more RFID tags of RIS 500 may include modulation module 510. Modulation module 510 may modulate signals received from separate wireless communication devices (e.g., UE 300 and / or BS 400). For example, RFID tags of RIS 500 may receive unmodulated or modulated signals. In some aspects, a baseband processor or a leakage carrier canceller may be implemented within modulation module 510 to modulate signals received before backscattering. Such modulation may include inverting a signal, adjusting the frequency, amplitude, or delay of a received signal, or any other parameter. In some aspects, modulation module 510 may implement a state corresponding to a matched load for backscattering and a state corresponding to an open circuit when backscattering is not performed. In some aspects, modulation module 510 may operate at various efficiency levels. For example, an actual or idealized radiated power may correspond to a 1 / 3 ratio or a 5dB loss.

[0090] The channel estimation unit 512 can estimate the channels of the RIS elements of the RIS 500 based on the measured channels. For example, the channels of communication between an individual wireless communication device (e.g., UE 300 and / or BS 400) and the RIS elements of the RIS 500 can be estimated. Estimation of the channels between the RIS elements and another wireless communication device can include first establishing communication between one or more RFID tags and the wireless communication device. The channels between the wireless communication device and the one or more RFID tags of the RIS 500 can then be measured. The channel estimation unit 512 can then estimate the channels of the individual RIS elements based on the channel measurements of the RFID tags. As described in reference to Figure 8 As explained in more detail, this may be achieved based on the relative positions of the RFID tag and the RIS element or based on any other parameter.

[0091] The radio frequency identification (RFID) tag 514 of the RIS 500 may be configured to wirelessly receive and / or transmit or backscatter signals. In some aspects, the RFID tag 514 may include various components of the RIS 500, including, for example, the power rectifier 508, the modulation module 510, or the channel estimation unit 512. In some aspects, the RFID tag 514 may receive a forward link from a separate wireless communication device, and may transmit a backscatter link in response to the reception of the forward link. The RFID tag 514 may be passive, semi-passive, or active. In this regard, the RFID tag 514 may be powered by an onboard energy source of the RIS 500, including, for example, an energy harvesting device, a battery, or any other device. In some aspects, the RFID tag 514 may include a dipole antenna for transmission and reception of signals and an integrated circuit (IC) for various processing of the received or transmitted signals. The RFID tag may provide several advantages over other components for wireless transmission, including lower cost and increased efficiency, thereby allowing implementation in passive or near-passive devices.

[0092] Fig. 6A A diagrammatic view of a RIS 202a with an RFID tag controller 514 is illustrated in accordance with some aspects of the present disclosure. As shown, the RIS 202a may include an RFID tag 514, a RIS surface 605a including a two-dimensional array of RIS elements 610, and an energy source 630.

[0093] In some aspects, such as Fig. 6AAs shown in , RIS202a can use RFID tag 514 as a controller (e.g., controller 502). In this regard, RFID tag 514 can perform various functions of the controller of RIS. For example, RFID tag 514 may include a processor, a memory, an antenna 516, and any other suitable components. In some aspects, the processor of RFID tag 514 may include one or more microchips. Alternatively, RIS202a may include a controller (e.g., controller 502) and RFID tag 514, wherein the RFID tag is contained in the controller or communicates with the controller. The various aspects discussed below are applicable to any scenario. In some aspects, RFID tag 514 may alternatively include multiple antennas in addition to antenna 516. Multiple antennas 516 can facilitate various beamforming techniques for directing beams received by RIS202a or transmitted from the RIS.

[0094] RFID tag 514 can transmit and / or receive various signals, for example, via antenna 414. Figure 2 For example, BS 105 may send a beam matrix to RIS 202a. The beam matrix may be received by antenna 516 and stored in a memory of RFID tag 514. In some aspects, a processor of RFID tag 514 may configure weights 610 of RIS surface 605a based on the beam matrix.

[0095] like Fig. 6A 625, the RFID tag 514 can communicate with the RIS surface 605a. In some aspects, the link 625 can include multiple conductors for conveying signals between the RIS 605a and the RFID tag 514. For example, the link 625 can include two or more conductors dedicated to each RSI element 610.

[0096] RIS surface 605a may include any suitable number of RIS elements 610 arranged in any suitable manner. For example, Fig. 6A The RIS elements 610 shown in the figure can be arranged in a two-dimensional array. In some aspects, the RIS elements 610 can be arranged in a grid pattern, as shown, or can be arranged in any other manner. In some aspects, the RIS elements 610 can alternatively form a 1D array.

[0097] Fig. 6AEnergy source 630 is also depicted. In some aspects, energy source 630 can provide energy to RFID tag 514 and / or RIS surface 605a. Energy source 630 can include a battery for storing energy and an energy harvesting element. The energy harvesting element can obtain energy in various ways. For example, the energy harvesting element can include a solar panel configured to harvest energy from sunlight. The energy harvesting element can include a device configured to harvest energy in any other way, such as by converting thermal energy to electrical energy or converting mechanical energy to electrical energy (e.g., from wind or water movement). In some aspects, the energy harvesting device can obtain energy from radio frequency transmissions, electromagnetic waves, light, laser sources, or by any other method.

[0098] In some aspects, the energy harvesting element of the RFID tag 514 can be in electrical communication with a battery. The battery can store energy harvested by the energy harvesting element. The battery can release the stored energy to the RFID tag 514 and / or the power element of the RIS surface 605a.

[0099] Energy source 630 may communicate with RFID tag 514 via link 635 to transfer power from energy source 630 to RFID tag 514. Power may be transferred from RFID tag 514 to RIS surface 605a via link 625. In some aspects, energy source 630 may additionally or alternatively be directly connected to RFID surface 605a.

[0100] like Fig. 6A As shown, in some implementations, the energy source 630 can be an optional component of the RIS 202a. For example, the RIS 202a can be a completely passive RIS. A completely passive RIS can operate without a power source. In some aspects, a completely passive RIS can operate by energy harvested from a received signal from a separate wireless communication device (such as the BS 105 or UE 115 described previously). In some aspects, the RIS 202a can be an active or semi-passive RIS 202a in which the energy source 630 can be included.

[0101] According to some aspects, RIS 202a can advantageously require less power than conventional wireless communication devices. Thus, a greater number of energy sources can be used to power RIS 202a, including smaller energy sources or less expensive energy sources for more compact implementations. This reduced energy requirement can be a result of using RFID tag 514 as a transceiver for RIS 202a. For example, RFID tag 514 can operate on only 10-30 μW of energy.

[0102] Fig. 6AAspects related to a RIS controller including or replaced by an RFID tag 514 are described. Alternatively or in addition, the RIS surface 605 may include a plurality of RFID tags dispersed among the RIS elements. This is relative to Figure 6B To illustrate and discuss. Figure 6B A diagrammatic view of a RIS 202b with an RFID tag 514 is illustrated in accordance with some aspects of the present disclosure. The RIS 202b shown may include a device similar to that of reference 1. Fig. 6A RIS 202b may additionally include RIS controller 502, RIS surface 605b including a plurality of RFID tags 514 and RIS elements 610, and energy source 630.

[0103] As shown, the RIS surface 605b may include one or more RFID tags 514. The RFID tags 514 may be distributed on the RIS surface 605b in any arrangement. In the example shown, the RIS elements 610 may be arranged in a grid pattern forming a plurality of columns 650 and rows 660. As shown, the RFID tags 514 may be aligned with each column 650 of the RIS elements 610 and positioned at the top and bottom of each column 650. In other specific implementations, the RFID tags 514 may be positioned on the right and left sides of each row 660 of the RIS elements 610. In other specific implementations, the RFID tags 514 may be arranged in any other manner. For example, the RFID tags 514 may be positioned anywhere between the RIS elements 610. Any number of RFID tags 514 may be positioned on the RIS surface 605b.

[0104] Figure 6B The RFID tag 514 shown may include a reference Fig. 6A and Figure 5 514 of the RFID tag. For example, the RFID tag 514 of the RIS 202b may include a processor, a memory, an antenna, and any other suitable components. In some aspects, and as described below with reference to Figure 8 Explaining in more detail, channel estimation of the RIS element 610 may be performed based on the position of the RFID tag 514 relative to the RIS element 610 .

[0105] The RIS controller 502 may communicate with the RFID tags 514 via the links 625 shown. For example, the RFID tag 514a shown above the column 650a may communicate with the RIS controller 502 via the link 625a. Similarly, the RFID tag 514b shown above the column 650b may communicate with the RIS controller 502 via the link 625b. Although not explicitly labeled, separate links may also provide communication between each of the respective RFID tags 514 and the RIS controller 502. In some aspects, the link 625 may convey command signals from the RIS controller 502 to the RFID tags 514. Additionally, signals received and / or processed by the RFID tags 514 may be sent to the RIS controller 502 via the link 625. For example, the RIS controller 502 may access the memory of the RFID tag 514 via the link 625. In this regard, the RIS controller 502 may access control signals, reference signals, measurement information, estimation information, or any other information from the memory of the RFID tag 514 via the link 625.

[0106] Any or all RFID tags 514 of the RIS surface 605b may be used as transceivers of the controller 502. For example, in some aspects, the controller 502 may not include an antenna and therefore may not independently send or receive wireless signals. The RFID tags 514 of the RIS surface 605b may collect control information from the BS 105 and / or the UE 115. The control information may include a beam index and / or a beam matrix to be used at the RIS surface 605b. The control information may also include DCI related to the timing or reflection of the signal by the RIS surface 605b. In some aspects, the DCI may include a sequence-based DCI used between the BS 105 and the RIS 202b. In some aspects, the RFID tags 514 may individually or jointly backscatter data from the RIS 202b to the BS 105 and / or the UE 115. The data backscattered from the RIS 202b may include an ACK for the DCI.

[0107] In some aspects, the RFID tag 514 may perform channel measurements of the received reference signal. These channel measurements may correspond to channels between one or more RFID tags 514 and the BS 105 and / or between one or more RFID tags 514 and the UE 115.

[0108] In some aspects, the RIS 202 can include an RFID tag positioned on the RIS surface 605b and one or more RFID tags included with the controller 502. In this aspect, the controller 502 can send or receive signals via the RFID tag of the controller 502 and / or any of the other RFID tags 514 positioned on the RIS surface.

[0109] As previously referenced Figure 2 As described, the positioning of the RFID tag on the RIS surface 605b can enable the estimation of the channel between the RIS element and other wireless communication devices. The ideal RIS element weights can then be determined based on the channel estimation.

[0110] In one example, aspects of determining ideal RIS element weights may include determining the desired RIS element weights by obtaining the desired RIS element weights from RIS 202a ( Fig. 6A ) to sequentially transmit reference signals from BS 105 to UE 115. By evaluating the quality of the received reference signal for each transmitted reference signal, RIS 202a can implement RIS element weights corresponding to the highest quality received signal.

[0111] Utilizing multiple RFID tags distributed on RIS surface 605b, ideal RIS element weights can be determined without sequential transmission of reference signals and modifying RIS element weights to find ideal RIS element weights. Instead, the channel between each RFID tag of RIS surface 605b and BS105 can be measured. Based on these channel measurements, for example, by interpolation or extrapolation, the channel between the RIS element and BS105 can be estimated. The same process can be completed with respect to RIS202b and UE 115. Therefore, a matrix of estimated channels between RIS elements of RIS202b and BS 105 can be determined, and an additional matrix of estimated channels between RIS elements and UE 115 can also be determined. Then a matrix of ideal weights of RIS elements of RIS202b can be determined so that the channels of these matrices are optimized. In this regard, the RIS elements of RIS202b can be trained after BS 105 transmits a single reference signal to RIS202b and UE 115 transmits a single reference signal to RIS202b. In this way, the energy and processing power used to train the RIS is significantly reduced (relative to each communicating device), the time of such training is also significantly reduced, and the accuracy of the training is increased.

[0112] It should be noted that any subset of the RFID tags 514 of the RIS202b can be enabled or disabled according to various functions. For example, the RIS controller 502 can send a command signal to the RFID tags 514, which indicates that the RFID tags 514 enter an enable or disable mode. The RIS202b can receive instructions from the UE 115 and / or BS105 on which RFID tags 514 should be enabled for a specific function. In some aspects, the subset of the enabled RFID tags 514 can be based on performance metrics. For example, the best RFID tag 514 can be selected to be enabled for communication with a control network unit (e.g., BS105) and / or UE 115. This can be based on one or more signal quality metrics such as determined according to channel information. In some aspects, the RIS controller 502 can be an entity for determining which RFID tags 514 will be enabled or disabled based on performance metrics. In other aspects, information can be transmitted to the BS105 (or UE 115) for determining which RFID tags 514 to enable or disable, and the information is transmitted to the RIS202b for implementation.

[0113] Figure 7 A simplified diagram 700 illustrating an energy charging scheme according to some aspects of the present disclosure is shown. The diagram 700 represents charging performed by the energy harvesting RIS 202. In this regard, the simplified diagram 700 may illustrate aspects of a method implemented by the energy source 630. For example, the diagram 700 may represent aspects of a method implemented by the energy source 630, which is configured to harvest energy from an RF signal sent from another wireless communication device (such as a BS 105 or a UE 115). The vertical axis represents energy in certain units, and the horizontal axis represents time in certain units. The hashed portion of the graph represents the accumulated energy over time as harvested by the energy harvesting RIS 202. The horizontal axis is divided into symbol periods, which is the granularity of communication with the energy harvesting RIS 202.

[0114] As illustrated in diagram 700, a target energy level may be defined. The target energy level may be determined based on data requirements indicated by a network element such as BS 105 or UE 115. For example, RIS 202 may specify a cycle or number of cycles representing the amount of time that RIS 202 is consuming power to perform any function described herein. In this regard, power requirements may be determined. In some aspects, BS 105 or UE 115 may determine that for each cycle "on" duration, RIS 202 will send a certain number of signals, receive a certain number of signals, and / or perform one or more other processing operations. BS 105 or UE 115 may also have information about how much energy RIS 105 uses when performing those operations. Using this information, BS 105 or UE 115 may determine the target energy level that the UE will ideally charge to between "on" durations, so that during the "on" duration, RIS 202 stores enough energy to perform the desired operation. The time required for RIS 202 to charge to the target energy level may be defined in units of symbol periods as shown in the figure.

[0115] Figure 8 is a diagrammatic view of channel estimation for individual RIS elements according to various aspects of the present disclosure. As shown in the figure, Figure 8 A view of the RIS surface 605b, BS 105, and the measured and estimated channels between the components of BS 105 and RIS surface 605b. In other words, Figure 8 The example in is based on multiple RFID tags on the RIS surface 605b, following Figure 6B .

[0116] In some aspects, BS 105 may send a reference signal to a RIS (eg, RIS 202b). Figure 6B As explained, the controller of the RIS may receive reference signals via RFID tags 514 on RIS surface 605b. In this regard, each of the RFID tags 514 may receive the same reference signal from BS105 and may measure the channel of each RFID tag. In some aspects, any RFID tag 514 may receive separate or distinct reference signals from BS105 at the same time or at different times. As an illustrative example, RFID tag 514a may receive a reference signal from BS105 and measure channel 835a. Channel 835a may characterize parameters of communications from BS105 to RFID tag 514a, and vice versa. Similarly, RFID tag 514e may receive a reference signal from BS105 and measure channel 835b. In this manner, Figure 8 Each of the RFID tags 514 shown can receive the reference signal and measure the corresponding channel, although each channel is Figure 8 Not shown in the example.

[0117] Figure 8 605b. The channels 845a, 845b, 845c, and 845d shown in FIG. 605b may correspond to channels for communication between BS 105 and RIS elements 610a, 610b, 610c, and 610d of RIS surface 605b, respectively. Similar channels exist for each RIS element of RIS surface 605b, although each channel may not be illustrated. Specifically, channel 845a may represent a communication path from BS 105 to RIS element 610a, channel 845b may represent a communication path from BS 105 to RIS element 610b, and so on. While in previous approaches, RIS element 610 is not able to measure corresponding channels 845 and thus determine the ideal weight of each RIS element 610 of RIS surface 605b, according to aspects of the present disclosure, the channel from BS 105 to each individual RIS element 610 may be obtained via extrapolation or interpolation based on the channel estimates obtained for channels 835a and 835b (and so between each RFID tag 514 and the source). The channel estimate from BS 105 to each individual RIS element 610 may be referenced Figure 2 The matrix G described by .

[0118] Because channel 845 may not be directly measured by RIS element 610, channel 845 may instead be estimated based on measured channel 835. For example, a processor of any wireless communication device described herein may implement various channel estimation techniques to estimate channel 845. For example, any suitable interpolation or extrapolation technique as well as minimum mean square error (MMSE) techniques or any other channel estimation technique may be implemented to estimate channel 845. In this way, communication parameters from BS 105 to each RIS element 610 may be estimated.

[0119] In some aspects, any suitable processing component of any suitable wireless communication device may perform the measurement or estimation of the channel. For example, the controller of RIS 202 may estimate the channel based on any of the channel estimation techniques described above. In some aspects, the RFID tag of RIS 202 may perform the channel estimation. The processor of BS 105 may perform the channel estimation (e.g., after receiving or performing the channel measurement of the RFID tag of RIS 202). The processor of UE 115 may perform the channel estimation (e.g., after receiving or performing the channel measurement of the RFID tag of RIS 202). Figures 9 and 10 Describes which components and / or wireless communication devices may perform additional details of various aspects of channel measurement and estimation.

[0120] In the example shown, channels 835a, 845b, 845c, and 845d corresponding to RIS elements 610a, 610b, 610c, and 610d, respectively, may be estimated based on measured channels 845a and 835b corresponding to RFID tags 514a and 514e, respectively. In some aspects, channels of RIS elements of adjacent columns may be similarly estimated. For example, channels corresponding to RIS elements 610e, 610f, 610g, and 610h may be estimated based on measured channels of RFID tags 514b and 414f. In some aspects, channels of any RIS element 610 of RIS surface 605b may be estimated based on measurements of any RFID tag. For example, estimates of channels 610e-f may be determined based on channel measurements of RFID tags 514a and 514e and any other RFID tags 514. It is contemplated that RFID tags and RIS elements may be positioned on RIS surface 605b according to any suitable pattern. In this regard, a channel estimate for any of the RIS elements 610 may be determined based on the location of the RIS element 610 relative to any of the RFID tags 514 .

[0121] In some aspects, and as will be referred to Fig. 9 and Fig.10 As explained in more detail, different wireless communication devices may perform various steps to measure and estimate the channel of the RIS element 610.

[0122] Now go to Fig. 9 , according to aspects of the present disclosure, a signaling diagram 900 is illustrated for communication between BS 105, RIS 202, and UE 115. Signaling diagram 900 may be implemented by any suitable wireless communication device. In some aspects, BS 105 may utilize one or more components, such as Figure 4 The processor 402, memory 404, RIS channel estimation module 408, transceiver 410, modem 412 and one or more antennas 414 are shown. As illustrated, the signaling diagram 900 includes several enumerated actions, but Fig. 9 The various aspects of the invention may include additional actions before, after, and between the actions listed. In some aspects, one or more of the actions listed may be omitted, combined together, or performed in a different order.

[0123] Group 902 includes actions 904 - 916 . Group 902 may correspond to a channel estimation process performed to measure and estimate a channel between BS 105 and a RIS element of RIS 202 .

[0124] At action 904, BS 105 may send an RFID password to RIS 202. In some aspects, the RFID tags of RIS 202 may be activated by the password. For example, a specific password may be preconfigured for a separate RFID tag. The RFID tag may begin monitoring the transmitted signal, perform various processing functions, and / or transmit a signal only in response to receiving and decoding the specific password. In an implementation in which RIS 202 includes multiple RFID tags, each RFID tag may correspond to the same preconfigured password. In this regard, each RFID tag of RIS 202 may simultaneously perform any function described herein in response to receiving the same password.

[0125] In some aspects, action 904 may include sending additional command signals to the RIS. The command signal sent to the RIS 202 at action 904 may include a command packet, a modulated command packet, a forward link, or any other command signal. In some aspects, the command signal transmitted to the RIS 202 may include a command for powering up one or more RFID tags, maintaining an on state, or performing any other function described herein. In some aspects, the signal transmission from the BS 105 to the RIS 202 may include backscatter communication from the RIS 202 to the BS 105. In some aspects, the transmission from the BS to the RIS 202 may not include backscatter communication. For example, action 904 may not include backscatter communication from the RIS 202 to the BS 105.

[0126] At act 906, the RFID tag of RIS 202 may be activated. For example, the RFID tag may be activated in response to receiving the same pre-configured password from BS 105 at act 904.

[0127] At action 908, BS 105 may send a reference signal to RIS 202. In some aspects, RIS 202 may include a single RFID tag, such as an RFID tag of a RIS controller, and / or may include multiple RFID tags distributed along a surface of the RIS. The reference signal sent from BS 105 may be received by any RFID tag of RIS 202.

[0128] At act 910, the RFID tag receiving the reference signal may store the received data. For example, the RFID tags of RIS 202 may each include a memory. At act 910, the RFID tag may store the received reference signal in a corresponding memory.

[0129] First, the RFID stores data, and then the controller accesses it. The controller measures, estimates, and writes to the RFID memory, which the RFID transmits to the BS.

[0130] At act 912, the reference signal received at RIS 202 can be analyzed to measure the channel of the RIS elements. In some aspects, this can include comparing the reference signal received by the RFID tag of RIS 202 with the expected reference signal. In this regard, the channel measurement can record or account for the change between the received reference signal and the expected reference signal. In this way, the channel between each RFID tag of RIS 202 can be quantified.

[0131] As explained below, action 912 of signaling diagram 900 may be performed by the RFID tag itself (including all RFID tags or a subset of RFID tags), or by a controller of RIS 202. In this regard, action 912 may include accessing a reference signal stored in a memory of the RFID tag. For example, the controller of RIS 202 may access the memory of each RFID tag that receives the reference signal and read the data in the memory. The controller may then process the received reference signal to measure the channel corresponding to the particular RFID tag.

[0132] At act 914, the controller of RIS 202 and / or one or more RFID tags of RIS 202 may estimate the channel. In this regard, the controller and / or RFID tags may use reference Figure 8 The controller of RIS 202 may estimate the channels associated with each of the RIS elements of RIS 202 using any of the processes described above. For example, because the RIS elements themselves are not capable of measuring the channels from BS 105 to the RIS elements, the channels may be estimated based on the measured channels of the RFID tags. In the above example where the controller of RIS 202 receives reference signals from the RFID tags and processes the signals to measure the channels, the controller of RIS 202 may additionally estimate the channels of the RIS elements based on the measured channels of the RFID tags and based on the positions of the RFID tags distributed on the surface of the RIS relative to the RIS elements.

[0133] At act 916, a component that measures the RFID channel and / or estimates the RIS element channel (e.g., a controller of RIS 202, an RFID of the controller, a subset of the plurality of RFID tags, etc.) may write the channel estimation data to a memory of the RFID tag. In some aspects, only the channel estimation data corresponding to a particular RFID tag may be written to the memory of that tag. In some aspects, the channel estimation data for a plurality of RFID tags may be written to the memory of one RFID tag. In some aspects, the channel estimation data may be written to the memory of the RFID tag to be used to send the channel estimation data to the BS (e.g., at act 918).

[0134] At action 918, the channel estimation data may be transferred to the BS 105. In some aspects, the data transfer may be accomplished through backscatter communication of the RFID tag. In this regard, the BS 105 may send a command signal that may request the RFID tag to send the channel estimation data. In some aspects, the command signal may also provide energy to be harvested by the energy harvesting device of the RIS 202, thereby supplying the necessary energy to the sending RFID tag. All RFID tags may send the channel estimation data, or a subset of the RFID tags may send the channel estimation data. In some aspects, more than one RFID tag may jointly send the channel estimation data. In some aspects, the RFID tags may send the channel estimation data individually. Some RFID tags may be configured to send the same channel estimation data to ensure that the channel estimation data is correctly sent from the RIS 202 to the BS 105.

[0135] In some aspects, channel estimation data may be sent from RIS 202 to UE 115. This may occur in response to a command signal from UE 115 or BS 105. For example, BS 105 or UE 115 may determine a beam matrix based on the received channel estimation data. Fig. 9 The channel estimation data is depicted as being sent to the BS 105, but the RIS 202 may send the channel estimation data to the wireless communication device at act 918, which will determine the beam matrix for the RIS 202. For example, the signaling diagram 900 may illustrate a single-station RFID communication method, where the BS 105 sends a command signal to the RIS 202 to initiate backscatter communication for channel estimation and also receives the channel estimate at act 918. However, in some aspects, a dual-station RFID communication method may be implemented, where the BS 105 may send a command signal for backscatter communication and the UE 115 may receive the channel estimate at act 918. In some aspects, the UE 115 may send the command and receive the channel estimate, or the UE 115 may send the command and the BS 105 may receive the channel estimate.

[0136] Aspects of actions 908 - 916 of signaling diagram 900 may be performed by various components of RIS 202 , as described below.

[0137] In aspects where RIS 202 includes two or more RFID tags distributed on the surface of the RIS, at action 908, each RFID tag of RIS 202 may receive a reference signal from BS 105. Each RFID tag may store the reference signal received from BS 105 in a memory of each RFID tag (e.g., at action 910). In one aspect, a subset of the RFID tags of RIS 202 may be selected to receive and process the reference signal stored in the memory of each RFID tag. For example, the subset may include a single RFID tag. The subset of RFID tags may be a subset of RFID tags on a controller of RIS 202. Each RFID tag may transmit its corresponding stored reference signal to the subset of RFID tags. The subset of RFID tags may be selected based on various characteristics of the subset of RFID tags. For example, the RFID tags of the subset may be RFID tags with increased processing power or memory storage. In the described aspects, the subset of RFID tags may perform channel measurements for each RFID tag that receives a reference signal (e.g., at action 912). The subset of RFID tags may then perform channel estimation for each RIS element of RIS 202 based on the channel measurements (e.g., at act 914). In the described aspects, the subset of RFID tags may send the channel estimates to BS 105 (e.g., at act 918). In some aspects, the subset of RFID tags may write the channel estimates to a memory of each of the RFID tags of RIS 202, and all RFID tags may send the channel estimates to BS 105 at act 918.

[0138] In another aspect where RIS 202 includes two or more RFID tags distributed on the surface of the RIS, at act 908, each RFID tag of RIS 202 may receive a reference signal from BS 105. Each RFID tag may store the reference signal received from BS 105 in a memory of each RFID tag (e.g., at act 910). Each RFID tag may deliver its corresponding stored reference signal to a controller of RIS 202. In some aspects, the controller of RIS 202 may access the reference signal of each RFID tag. In the described aspect, the controller may perform channel measurements for each RFID tag that receives a reference signal (e.g., at act 912). The controller may then perform channel estimation for each RIS element of RIS 202 based on the channel measurements (e.g., at act 914). In the described aspect, the controller may send the channel estimation to BS 105, for example, via the controller's RFID tag (e.g., at act 918). In some aspects, the controller of RIS 202 may write the channel estimation to the memory of each of the RFID tags of RIS 202, and all RFID tags may send the channel estimation to BS 105 at act 918.

[0139] In another aspect where RIS202 includes two or more RFID tags distributed on the surface of the RIS, at action 908, each RFID tag of RIS202 may receive a reference signal from BS105. Each RFID tag may then perform channel measurements. In some aspects, each of the RFID tags may then store the channel measurements in a corresponding memory. Each RFID tag may deliver its corresponding stored channel measurements to a controller of RIS202 and / or a subset of RFID tags. In some aspects, a controller of RIS202 or a subset of RFID tags may access the channel measurements of each RFID tag. In the described aspects, a controller or a subset of RFID tags may perform channel estimation for each RIS element of RIS202 based on the channel measurements. In the described aspects, a controller or a subset of RFID tags may, for example, send a channel estimation to BS105 via the controller's RFID tags. In some aspects, a controller of RIS202 or a subset of RFID tags may write the channel estimation to the memory of each of the RFID tags of RIS202, and all RFID tags may send the channel estimation to BS105 at action 918.

[0140] In another aspect where RIS 202 includes two or more RFID tags distributed on a surface of the RIS, at act 908, each RFID tag of RIS 202 may receive a reference signal from BS 105. Each RFID tag may then perform channel measurements (e.g., at act 912) and perform channel estimation (e.g., at act 914). In this manner, acts 910 and 916 may not be completed. In the described aspect, the RFID tag may send the channel estimation to BS 105 (e.g., at act 918).

[0141] At action 920, channel estimation may be performed relative to UE 115. For example, referring again to the previous Figure 2 , group 902 describes various methods of estimating the channel between BS 105 and individual RIS elements of RIS 202. These channel estimates may be included in matrix G. At action 920, the channel between UE 115 and individual elements of RIS 202 may be estimated. These channel estimates may be included in matrix H. In some aspects, action 920 may be a set of actions similar to group 902. In this regard, action 920 may include any of actions 904-916, but with respect to UE 115. For example, UE 115 may send an RFID password to RIS 202, and may activate an RFID tag. UE 115 may then send a reference signal to RIS 202. The RFID tag of RIS 202 may store the reference signal, and any component of RIS 202 may measure the channel of the RFID tag and estimate the channel of the RIS element by transmitting any information and any processing method previously described with reference to actions 908-916.

[0142] In some aspects, the signaling diagram 900 may include action 922. At action 922, the channel estimation data obtained at action 920 may be sent to the BS 105. In some aspects, the sending may be facilitated by the RIS 202. At action 922, the channel estimation of the BS 105 and the channel estimation of the UE 115 may be moved to the same wireless communication device before action 924. In this regard, as shown, the channel estimation of the UE 115 may be sent to the BS 105. In other aspects, the channel estimation of the BS 105 may be sent to the UE 115. In such aspects, the UE 115 may perform action 924. As will be described in more detail below, in some aspects, the RIS 202 may perform action 924.

[0143] At action 924, BS 105 may determine a beam matrix for RIS 202. Figure 2As described, determining the beam matrix at act 924 may include determining optimal RIS element weights for the matrix Φ based on the matrix G corresponding to the BS 105 and the matrix H corresponding to the UE 115. In some aspects, the UE 115 may perform act 924.

[0144] At act 926, BS 105 may send the beam matrix to RIS 202. In some aspects, UE 115 may send the beam matrix to RIS 202. RIS 202 may receive the beam matrix via an RFID tag of RIS 202. For example, each of the RFID tags distributed on the surface of the RIS may jointly receive the beam matrix.

[0145] In some aspects, the beam matrix may be sent to a subset of the RFID tags of the RIS 202. In this regard, the beamforming and reliability of the transmission may be improved. In some aspects, the beam matrix may be divided for transmission. For example, a first portion of the beam matrix may be sent to a first subset of RFID tags, and a second portion of the beam matrix may be sent to a second subset of RFID tags. The controller of the RIS 202 or one or more RFID tags of the RIS 202 may then access the first portion and the second portion of the beam matrix and combine them to form a complete beam matrix. It should be noted that the beam matrix may be divided into any suitable number of portions, and the RFID tags may be divided into a corresponding number of subsets configured to receive each of the portions of the beam matrix.

[0146] At act 928, RIS 202 may implement RIS element weights. For example, each RIS element may be modified according to the weights within the beam matrix received at act 926.

[0147] In some aspects, a controller or a subset of RFID tags of RIS 202 may perform an action 924 of determining a beam matrix. In such aspects, signaling diagram 900 may include group 902 as previously described, an action or group 920 as previously described, followed by actions 924 and 928, both of which are performed by RIS 202. For example, BS 105 may send a reference signal to RIS 202, and RIS 202 (through a controller or one or more RFID tags) may perform channel measurements and estimates. The channel estimate of BS 105 (e.g., matrix G) may then be stored at RIS 202. Then, UE 115 may send a reference signal to RIS 202, and RIS 202 may perform channel measurements and estimates for UE 115 (e.g., matrix H). The channel estimate may also be stored at RIS 202. Then, RIS 202 may determine a beam matrix at action 924, and implement RIS element weights based on the beam matrix at action 928. In some aspects, RIS 202 may additionally transmit a notification to BS 105 and / or UE 115 indicating that the beam matrix is ​​determined and implemented, such that elements of RIS 202 are optimized for communication between BS 105 and UE 115 .

[0148] Fig.10 1000 is a signaling diagram of communication between a BS, a RIS, and a UE according to some aspects of the present disclosure. The signaling diagram 1000 may be implemented by any suitable wireless communication device. In some aspects, the BS 105 may utilize one or more components such as Figure 4 The processor 402, memory 404, RIS channel estimation module 408, transceiver 410, modem 412 and one or more antennas 414 are shown. As illustrated, the signaling diagram 1000 includes several enumerated actions, but Fig.10 The various aspects of the invention may include additional actions before, after, and between the actions listed. In some aspects, one or more of the actions listed may be omitted, combined together, or performed in a different order.

[0149] Group 1002 includes actions 1004 - 1014 . Group 1002 may correspond to a channel estimation process performed to measure and estimate a channel between BS 105 and RIS elements of RIS 202 .

[0150] Action 1004 may be substantially similar to reference Fig. 9 At action 1004, BS 105 may send an RFID password to RIS 202. As previously described, if RIS 202 includes multiple RFID tags, each RFID tag may correspond to the same preconfigured password. However, aspects of signaling diagram 1000 may be performed by RIS 202 that includes only a single RFID tag.

[0151] At act 1006, the RFID tag of RIS 202 may be activated. For example, the RFID tag may be activated in response to receiving a pre-configured password from BS 105 at act 1004.

[0152] At action 1008, BS 105 may send a reference signal to RIS 202. In some aspects, RIS 202 may include a single RFID tag, such as an RFID tag of a RIS controller. The reference signal sent from BS 105 may be received by any RFID tag of RIS 202.

[0153] At act 1010, the RFID of RIS 202 may backscatter a signal to BS 105. In some aspects, the backscattered signal may include the same reference signal received by the RFID tag of RIS 202 at act 1008. However, in some aspects, the reference signal received by the RFID tag has been modified during wireless transmission of the reference signal in any of the manners previously described.

[0154] At act 1012, a reference signal received from RIS 202 at BS 105 may be analyzed to measure the channel of the RIS element. In some aspects, this may include comparing the received reference signal to the transmitted reference signal. In this regard, the channel measurement may record or account for changes between the received reference signal and the transmitted reference signal. In this manner, the channel between each RFID tag of RIS 202 and BS 105 may be quantified.

[0155] In some aspects, as previously referenced Fig. 9 As depicted, the RIS 202 (including the controller of the RIS 202 and / or the RFID tag) can perform a channel measurement act 1012. In this regard, the RIS 202 can perform a channel measurement prior to act 1014 and send the channel measurement to the BS 105.

[0156] At action 1014, BS 105 may estimate the channel. In this regard, BS 105 may use reference Figure 8 Any of the processes described may be used to estimate the channels associated with each of the RIS elements of RIS 202.

[0157] At action 1016, channel estimation with respect to UE 115 may be completed. For example, group 1002 describes estimating a channel between BS 105 and a RIS element of RIS 202, and action 1016 may include any of the same actions of group 1002 to estimate a channel between UE 115 and a separate element of RIS 202. In this regard, action 1016 may be a set of actions similar to group 1002. For example, UE 115 may send an RFID password to RIS 202, and an RFID tag may be activated. UE 115 may then send a reference signal to RIS 202, and the RFID tag of RIS 202 may send a reference signal back to UE 115. UE 115 may then measure the channel of the RFID tag and estimate the channel of the RIS element.

[0158] At act 1018, the channel estimation data obtained at act 1016 may be sent to BS 105. In some aspects, the sending may be facilitated by RIS 202. At act 1016, the channel estimation of BS 105 and the channel estimation of UE 115 may be moved to the same wireless communication device prior to act 1020. In this regard, as shown, the channel estimation of UE 115 may be sent to BS 105. In other aspects, the channel estimation of BS 105 may be sent to UE 115. In such aspects, UE 115 may perform act 1020. As will be described with reference to act 924, similarly, RIS 202 may perform act 1020.

[0159] At action 1020, BS 105 may determine a beam matrix for RIS 202. Figure 2 As described, determining the beam matrix at act 924 may include determining optimal RIS element weights for the matrix Φ based on the matrix G corresponding to the BS 105 and the matrix H corresponding to the UE 115. In some aspects, the UE 115 may perform act 1020.

[0160] At action 1022, BS 105 may send the beam matrix to RIS 202. In some aspects, UE 115 may send the beam matrix to RIS 202. RIS 202 may receive the beam matrix via an RFID tag of RIS 202. For example, each of the RFID tags distributed on the surface of the RIS may jointly receive the beam matrix or a portion of the beam matrix, as described in reference to FIG. Fig. 9 as described in action 926.

[0161] At act 1024, RIS 202 may implement RIS element weights. For example, each RIS element may be modified according to the weights within the beam matrix received at act 1022.

[0162] Fig.111 is a flow chart of a wireless communication method 1100 according to some aspects of the present disclosure. Aspects of the method 1100 may be performed by a computing device (e.g., a processor, processing circuitry, and / or other suitable components) of a wireless communication device or other suitable means for performing such aspects. For example, a wireless communication device (such as RIS 500) may utilize one or more components (such as processor 502, memory 504, power rectifier 508, modulation module 510, channel estimation module 512, and / or RFID tag 514) to perform aspects of the method 1100. The method 1100 may be performed in a manner similar to that described above with respect to the present disclosure. Figures 5 to 10 The method 1100 includes several aspects enumerated, but the method 1100 may include additional aspects before, after, and / or between the aspects enumerated. In some aspects, one or more of these enumerated aspects may be omitted or performed in a different order.

[0163] At block 1110, a first wireless communication device receives a first signal from a second wireless communication device. The first wireless communication device may include: a reconfigurable smart surface (RIS) including an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag. In some aspects, the first signal may include a password, a reference signal, a DCI, or any other signal required to activate the RFID tag. In some aspects, the first signal may be a reference signal.

[0164] At block 1120, the first wireless communication device may store the first signal in a memory of an RFID tag of the first wireless communication device. In some aspects, each RFID tag of a RIS (e.g., RIS 202, RIS 500, or any other RIS) may receive the first signal, and each RFID tag may store the first signal in a corresponding memory of each RFID.

[0165] At block 1130, the first wireless communication device may access the first signal from a memory of the RFID tag. In some aspects, a controller of the RIS may access the first signal. In some aspects, at block 1130, an RFID tag of the controller may access the first signal. In some aspects, the controller of the RIS may be an RFID tag.

[0166] At block 1140, the first wireless communication device may measure a channel of the RFID tag based on the first signal. In some aspects, the channel of each RFID tag of the first wireless communication device may be measured. A controller of the first wireless communication device may measure the channel of the RFID tag. The RFID tag of the controller may measure the channel of the RFID tag. The channel of the RFID tag may be measured in any suitable manner. For example, the controller of the first wireless communication device may compare the first signal received at block 1110 with an expected reference signal. Based on the comparison, the controller of the first wireless communication device may determine one or more values ​​for characterizing the communication channel corresponding to each RFID tag. These values ​​may be included in the channel estimation information.

[0167] At block 1150, the first wireless communication device may estimate the channels of the RIS elements. In this regard, the first wireless communication device may estimate the channels of each RIS element of the RIS surface of the first wireless communication device. Figure 8 As described, the channel estimation can be based on various channel estimation techniques, such as interpolation, extrapolation, or MMSE of the measured channel of the RFID tag. The channel estimation of each RIS element can be an approximation of the channel measurement of the RIS element. In this regard, the channel estimation similarly characterizes how to modulate the signal from the second wireless communication device to the RIS element of the first wireless communication device.

[0168] At block 1160, the first wireless communication device transmits a second signal to the second wireless communication device using backscatter communication based on the first signal by the RFID tag of the first wireless communication device. In some aspects, the second signal may include a reference signal received by the RFID tag at block 1110, channel measurement data corresponding to the RFID tag, channel estimation data of a RIS element of RIS 202, or any other signal. In some aspects, RIS 202 (by the controller or the RFID tag) may perform channel measurement and estimation before sending the second signal.

[0169] Fig.121 is a flow chart of a wireless communication method 1200 according to some aspects of the present disclosure. Various aspects of the method 1200 may be performed by a computing device (e.g., a processor, processing circuitry, and / or other suitable components) of a wireless communication device or other suitable means for performing such aspects. For example, a wireless communication device (such as UE 115) may utilize one or more components (such as processor 302, memory 304, RIS channel estimation module 308, transceiver 310, modem 312, and one or more antennas 316) to perform various aspects of the method 1200. In some aspects, a wireless communication device (such as BS 105) may utilize one or more components (such as processor 402, memory 404, RIS channel estimation module 408, transceiver 410, modem 412, and one or more antennas 414) to perform various aspects of the method 1000. The method 1200 may be implemented in a manner similar to that described with respect to Figures 5 to 10 The method 1200 includes several aspects enumerated, but the method 1200 may include additional aspects before, after, and / or between the aspects enumerated. In some aspects, one or more of these enumerated aspects may be omitted or performed in a different order.

[0170] At block 1210, a first wireless communication device may send a first signal to a second wireless communication device. In some aspects, the first wireless communication device may be a base station or user equipment. In some aspects, the second wireless communication device may be a RIS (e.g., RIS202 and / or 500). The second wireless communication device may include: a reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) including an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag. In some aspects, the first signal may be a reference signal. The second wireless communication device may receive the first signal by the RFID tag. In some aspects, the second wireless communication device may include a plurality of RFID tags. In such a case, the second wireless communication device may receive the first signal by the plurality of RFID tags.

[0171] At block 1220, the first wireless communication device may receive a second signal from the second wireless communication device. In some aspects, the second signal may be a reference signal. In some aspects, the second signal may include information received by the second wireless communication device at block 1210. In this regard, the second signal may correspond to the same reference signal as the first signal, but may have been modulated or otherwise modified by a communication channel between the first wireless communication device and the second wireless communication device. In some aspects, the second signal may include channel measurement data or channel estimation data, such as a reference signal. Figures 9 and 10 As described.

[0172] At block 1230, the first wireless communication device may measure a channel of an RFID tag of the second wireless communication device based on the second signal. In some aspects, the first wireless communication device may measure a channel of each RFID tag of the second wireless communication device. The first wireless communication device may measure a channel of an RFID tag. The channel of an RFID tag may be measured by comparing the first signal sent at block 1210 with the second signal received at step 1220. Based on the comparison, the first wireless communication device may determine one or more values ​​characterizing a communication channel of each RFID tag corresponding to the second wireless communication device.

[0173] At block 1240, the first wireless communication device may estimate the channel of the RIS element of the second wireless communication device. In this regard, the first wireless communication device may estimate the channel of each RIS element of the RIS surface of the second wireless communication device based on the channel measurement data of block 1230. Figure 8 As described, the channel estimation can be based on various channel estimation techniques, such as interpolation, extrapolation, or MMSE of the measured channel of the RFID tag. The channel estimation of each RIS element can be an approximation of the channel measurement of the RIS element. In this regard, the channel estimation similarly characterizes how to modulate the signal from the first wireless communication device to the RIS element of the second wireless communication device.

[0174] Fig.13 A diagram illustrating an example decomposed base station 1300 architecture is shown. The decomposed base station 1300 architecture may include one or more central units (CUs) 1310 that may communicate directly with a core network 1320 via a backhaul link, or indirectly with the core network 1320 through one or more decomposed base station units, such as a near real-time (near-RT) RAN intelligent controller (RIC) 1325 via an E2 link, or a non-real-time (non-RT) RIC 1315 associated with a service management and orchestration (SMO) framework 1305, or both. The CU 1310 may communicate with one or more distributed units (DUs) 1330 via respective midhaul links, such as an F1 interface. The DU 1330 may communicate with one or more radio units (RUs) 1340 via respective fronthaul links. The RU 1340 may communicate with respective UEs 120 via one or more radio frequency (RF) access links. In some implementations, a UE 120 may be served simultaneously by multiple RUs 1340. Aspects of the disclosure described as occurring at or controlled by the BS may occur at any one or more of these different units.

[0175] Each of the units (i.e., CU 1310, DU 1330, RU 1340, and near-RT RIC 1325, non-RT RIC 1315, and SMO framework 1305) may include or be coupled to one or more interfaces configured to receive or send signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units or an associated processor or controller that provides instructions to the communication interface of these units may be configured to communicate with one or more of the other units via a transmission medium. For example, these units may include a wired interface configured to receive or send signals to one or more of the other units via a wired transmission medium. Additionally, these units may include a wireless interface that may include a receiver, a transmitter, or a transceiver (such as a radio frequency (RF) transceiver) that is configured to receive or send signals, or both, to one or more of the other units on a wireless transmission medium.

[0176] In some aspects, CU 1310 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function may be implemented using an interface configured to communicate signals with other control functions hosted by CU 1310. CU1310 may be configured to handle user plane functionality (i.e., central unit-user plane (CU-UP)), control plane functionality (i.e., central unit-control plane (CU-CP)), or a combination thereof. In some specific implementations, CU 1310 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, CU 1310 may be implemented to communicate with DU 1330 for network control and signaling.

[0177] DU 1330 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 1340. In some aspects, DU 1330 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) at least in part according to a functional split such as defined by the Third Generation Partnership Project (3GPP). In some aspects, DU 1330 may further host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by DU 1330 or with control functions hosted by CU 1310.

[0178] The lower layer functionality may be implemented by one or more RUs 1340. In some deployments, the RU 1340 controlled by the DU 1330 may correspond to a logical node that hosts RF processing functions or low PHY layer functions (such as performing Fast Fourier Transform (FFT), Inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc.), or both, based at least in part on functional splitting (such as lower layer functional splitting). In such an architecture, the RU 1340 may be implemented to handle over-the-air (OTA) communications with one or more UEs 120. In some implementations, real-time and non-real-time aspects of communicating with the control plane and user plane of the RU 1340 may be controlled by the corresponding DU 1330. In some scenarios, this configuration may enable the DU 1330 and CU 1310 to be implemented in a cloud-based RAN architecture (such as a vRAN architecture).

[0179] The SMO framework 1305 may be configured to support RAN deployment and configuration of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 1305 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 1305 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 1390) to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements may include, but are not limited to, CU 1310, DU 1330, RU 1340, and near-RT RIC 1325. In some specific implementations, the SMO framework 1305 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 1311) via the O1 interface. Additionally, in some implementations, the SMO framework 1305 can communicate directly with one or more RUs 1340 via the O1 interface. The SMO framework 1305 can also include a non-RT RIC 1315 configured to support the functionality of the SMO framework 1305.

[0180] The non-RT RIC 1315 may be configured to include logic functions that implement non-real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 1325. The non-RT RIC 1315 may be coupled to or communicate with the near-RT RIC 1325 (such as via an A1 interface). The near-RT RIC 1325 may be configured to include logic functions that implement near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 1310, one or more DUs 1330, or both, and O-eNBs with the near-RT RIC 1325.

[0181] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 1325, the non-RT RIC 1315 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 1325 and may be received from a non-network data source or from a network function at the SMO framework 1305 or the non-RT RIC 1315. In some examples, the non-RT RIC 1315 or the near-RT RIC 1325 may be configured to adjust RAN behavior or performance. For example, the non-RT RIC 1315 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 1305 (such as via reconfiguration of O1) or via the creation of RAN management policies (such as A1 policies).

[0182] Fig.14 A diagram of a system 1400 including a device 1405 supporting RU sharing technology in wireless communications according to various aspects of the present disclosure is shown. The device 1405 can communicate with one or more RUs 1455. The device 1405 may include components for two-way voice and data communications, including components for sending and receiving communications, such as a communication manager 1420, a network communication manager 1410, a memory 1430, a code 1435, a processor 1440, and a RU communication manager 1445. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1450). One or more of the components of the system 1400 may perform as described herein with reference to Figures 5 to 10 The functions described are, for example, described as functions performed by a base station or a network element.

[0183] The network communications manager 1410 may manage communications with the core network 1460 (eg, via one or more wired backhaul links). For example, the network communications manager 1410 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0184] Memory 1430 may include RAM and ROM. Memory 1430 may store computer-readable, computer-executable code 1435 including instructions that, when executed by processor 1440, cause device 1405 to perform various functions described herein. Code 1435 may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some cases, code 1435 may not be directly executable by processor 1440, but may (for example, when compiled and executed) cause a computer to perform the functions described herein. In some cases, in addition to this, memory 1430 may also include BIOS, which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0185] Processor 1440 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1440 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 1440. Processor 1440 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1430) to enable device 1405 to perform various functions (e.g., functions or tasks supporting RU sharing technology in wireless communications). For example, device 1405 or a component of device 1405 may include processor 1440 and memory 1430 coupled to processor 1440, and processor 1440 and memory 1430 are configured to perform the various functions described herein.

[0186] RU communication manager 1445 may manage communications with RU 1455 and may include a controller or scheduler for controlling communications with UE 115 in coordination with RU 1455. For example, RU communication manager 1445 may coordinate scheduling of transmissions to UE 115. In some examples, RU communication manager 1445 may provide an F1 interface within a wireless communication network technology to provide communications with RU 1455.

[0187] According to examples as disclosed herein, the communication manager 1420 may support wireless communications at a network node. For example, the communication manager 1420 may be configured to or otherwise support components for sending a request for a radio resource configuration to a first RU during a first time period. The communication manager 1420 may be configured to or otherwise support components for sending an interference query associated with the radio resource configuration to a second RU during a first time period. The communication manager 1420 may be configured to or otherwise support components for receiving a response to the interference query from the second RU. The communication manager 1420 may be configured to or otherwise support components for sending a payload to the first RU for transmission during the first time period based on the response to the interference query.

[0188] By including or configuring a communication manager 1420 according to the examples described herein, the device 1405 may support technology for RU sharing, wherein DUs of different MNOs may access wireless resources of other MNOs, which may increase the efficiency of resource utilization while providing competition and innovation among different MNOs, which may increase the reliability of wireless communications, reduce latency, and enhance user experience.

[0189] In some examples, the communication manager 1420 may be configured to use or otherwise cooperate with other components to perform various operations (e.g., receive, monitor, send). Although the communication manager 1420 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1420 may be supported or performed by the processor 1440, the memory 1430, the code 1435, or any combination thereof. For example, the code 1435 may include instructions that can be executed by the processor 1440 to cause the device 1405 to perform various aspects of the RU sharing technology in wireless communications as described herein, or the processor 1440 and the memory 1430 may be otherwise configured to perform or support such operations.

[0190] Other aspects of the present disclosure include the following:

[0191] Aspect 1 includes a method of wireless communication, comprising: receiving a first signal from a second wireless communication device by a first wireless communication device, the first wireless communication device also including: a reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) including an array of one or more RIS elements; a RIS controller; and transmitting a second signal to the second wireless communication device using backscatter communication based on the first signal by the RFID tag of the first wireless communication device.

[0192] Aspect 2 includes the method of aspect 1, wherein the RIS controller includes the RFID tag.

[0193] Aspect 3 includes the method of any of aspects 1 to 2, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller.

[0194] Aspect 4 includes the method according to any one of aspects 1 to 3, wherein the first signal includes a reference signal.

[0195] Aspect 5 includes the method according to any one of aspects 1 to 4, wherein the second signal includes channel estimation information.

[0196] Aspect 6 includes the method of any one of aspects 1 to 5, further comprising determining the channel estimation information by the plurality of RFID tags, wherein the second signal is transmitted by the plurality of RFID tags.

[0197] Aspect 7 includes a method according to any one of Aspects 1 to 6, wherein the first wireless communication device also includes a channel estimation unit, and the method further includes: storing, by the plurality of RFID tags, at least a portion of the first signal from the second wireless communication device in a corresponding memory; and determining, by the channel estimation unit, the channel estimation information based on the first signal stored in the corresponding memory.

[0198] Aspect 8 includes the method of any one of aspects 1 to 7, further comprising estimating one or more weights for each of the one or more RIS elements.

[0199] Aspect 9 includes the method of any one of aspects 1 to 8, wherein the second signal includes channel measurement data from each of the plurality of RFID tags for channel estimation by the second wireless communication device.

[0200] Aspect 10 includes the method of any one of aspects 1 to 9, further comprising: receiving, by one or more of the plurality of RFID tags, a third signal including RIS configuration information from the second wireless communication device based on the channel measurement data.

[0201] Aspect 11: A method according to any one of Aspects 1 to 10, wherein the RIS configuration information includes a beam index.

[0202] Aspect 12 includes a method according to any one of aspects 1 to 11, wherein the RIS configuration information includes a matrix, the matrix including one or more weights for each of the one or more RIS elements determined based on interpolation or extrapolation according to the measurement data from each of the plurality of RFID tags.

[0203] Aspect 13 includes the method according to any one of aspects 1 to 12, wherein receiving the third signal includes: receiving a first portion of the matrix by a first subset of the plurality of RFID tags; and receiving a second portion of the matrix by a second subset of the plurality of RFID tags.

[0204] Aspect 14 includes the method of any one of aspects 1 to 13, wherein the receiving the first signal further comprises receiving the first signal by each of the plurality of RFID tags.

[0205] Aspect 15 includes the method of any one of aspects 1 to 14, wherein the receiving the first signal further comprises receiving the first signal by a subset of the plurality of RFID tags.

[0206] Aspect 16 includes the method according to any one of aspects 1 to 15, wherein the receiving the first signal further comprises: receiving a first portion of the first signal by a first subset of the plurality of RFID tags, and receiving a second portion of the first signal by a second subset of the plurality of RFID tags.

[0207] Aspect 17 includes the method of any one of aspects 1 to 16, further comprising defining a common password for each of the plurality of RFID tags.

[0208] Aspect 18 includes the method of any one of aspects 1 to 17, wherein the second wireless communication device is one of a base station (BS), a user equipment (UE), or a programmable logic controller (PLC).

[0209] Aspect 19 includes a method of wireless communication, comprising: sending a first signal by a first wireless communication device to a second wireless communication device, the second wireless communication device comprising: a reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) comprising an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and receiving a second signal based on the first signal from the second wireless communication device using backscatter communication by the first wireless communication device.

[0210] Aspect 20 includes the method of aspect 19, wherein the RIS controller includes the RFID tag.

[0211] Aspect 21 includes the method of any of aspects 19 to 20, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller.

[0212] Aspect 22 includes the method of any one of aspects 19 to 21, wherein the sending the first signal further comprises sending the first signal to each of the plurality of RFID tags.

[0213] Aspect 23 includes the method of any one of aspects 19 to 22, wherein the transmitting the first signal further comprises transmitting the first signal to a subset of the plurality of RFID tags.

[0214] Aspect 24 includes the method according to any one of aspects 19 to 23, wherein sending the first signal further comprises: sending a first portion of the first signal to a first subset of the plurality of RFID tags, and sending a second portion of the first signal to a second subset of the plurality of RFID tags.

[0215] Aspect 25 includes the method of any one of aspects 19 to 24, further comprising defining a common password for each of the plurality of RFID tags.

[0216] Aspect 26 includes a method according to any one of aspects 19 to 25, wherein the first signal comprises a reference signal.

[0217] Aspect 27 includes the method of any of aspects 19 to 26, wherein the second signal includes channel measurement data from each of the plurality of RFID tags for channel estimation by the first wireless communication device.

[0218] Aspect 28 includes a method according to any one of aspects 19 to 27, wherein the second signal includes channel estimation information.

[0219] Aspect 29 includes the method of any one of aspects 19 to 28, further comprising determining, by the first wireless communication device, channel estimation information.

[0220] Aspect 30 includes the method of any of aspects 19 to 29, further comprising estimating one or more weights for each of the one or more RIS elements.

[0221] Aspect 31 includes a method according to any one of aspects 19 to 30, the method further comprising: sending, by the first wireless communication device, a third signal including RIS configuration information to the second wireless communication device based on the one or more estimated weights.

[0222] Aspect 32: A method according to any one of Aspects 19 to 31, wherein the RIS configuration information includes a beam matrix.

[0223] Aspect 33 includes a method according to any one of aspects 19 to 32, wherein the RIS configuration information includes a matrix, the matrix including the one or more estimated weights for each of the one or more RIS elements determined based on interpolation or extrapolation according to measurement data of the RFID tag.

[0224] Aspect 34 includes a method according to any one of aspects 19 to 33, wherein the RFID tag includes a plurality of RFID tags and wherein sending the third signal includes: sending a first portion of the matrix to a first subset of the plurality of RFID tags; and sending a second portion of the matrix to a second subset of the plurality of RFID tags.

[0225] Aspect 35 includes a method according to any one of aspects 19 to 34, wherein the first wireless communication device is one of a base station (BS), a user equipment (UE), or a programmable logic controller (PLC). Aspect 36 includes a wireless communication device, the wireless communication device comprising: a reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) comprising an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and a processor, wherein the wireless communication device is configured to: receive the first signal by the RFID tag; and transmit a second signal by the RFID tag based on the first signal using backscatter communication.

[0226] Aspect 37 includes the wireless communication device of aspect 36, wherein the RIS controller comprises the RFID tag.

[0227] Aspect 38 includes the wireless communication device of any of aspects 36 to 37, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller.

[0228] Aspect 39 includes the wireless communication device of any one of aspects 36 to 38, the wireless communication device being further configured to receive the first signal by each of the plurality of RFID tags.

[0229] Aspect 40 includes the wireless communication device of any of aspects 36 to 39, the wireless communication device being further configured to receive the first signal by a subset of the plurality of RFID tags.

[0230] Aspect 41 includes a wireless communication device according to any one of aspects 36 to 40, the wireless communication device being further configured to: receive a first portion of the first signal by a first subset of the plurality of RFID tags, and receive a second portion of the first signal by a second subset of the plurality of RFID tags.

[0231] Aspect 42 includes the wireless communication device of any one of aspects 36 to 41, the wireless communication device being further configured to define a common password for each of the plurality of RFID tags.

[0232] Aspect 43 includes a wireless communications apparatus according to any one of aspects 36 to 42, wherein the first signal comprises a reference signal.

[0233] Aspect 44 includes a wireless communication apparatus as set forth in any one of aspects 36 to 43, wherein the second signal includes channel measurement data from each of the plurality of RFID tags for channel estimation.

[0234] Aspect 45 includes a wireless communications apparatus according to any one of aspects 36 to 44, wherein the second signal includes channel estimation information.

[0235] Aspect 46 includes the wireless communication device of any one of aspects 36 to 45, the wireless communication device being further configured to determine the channel estimation information by the plurality of RFID tags and to transmit the second signal by the plurality of RFID tags.

[0236] Aspect 47 includes a wireless communication device according to any one of Aspects 36 to 46, the wireless communication device also including a channel estimation unit, wherein the wireless communication device is further configured to: store at least a portion of the first signal from the second wireless communication device in a corresponding memory by the multiple RFID tags; and determine the channel estimation information based on the first signal stored in the corresponding memory by the channel estimation unit.

[0237] Aspect 48 includes the wireless communication device of any of aspects 36 to 47, the wireless communication device being further configured to estimate one or more weights for each of the one or more RIS elements.

[0238] Aspect 49 includes the wireless communication device of any one of aspects 36 to 48, the wireless communication device being further configured to: receive, by one or more of the plurality of RFID tags, a third signal including RIS configuration information based on the channel measurement data.

[0239] Aspect 50 includes a wireless communications apparatus as described in any one of aspects 36 to 49, wherein the RIS configuration information includes a beam index.

[0240] Aspect 51 includes a wireless communication device according to any one of aspects 36 to 50, wherein the RIS configuration information includes a matrix, the matrix including one or more weights for each of the one or more RIS elements determined based on interpolation or extrapolation according to the measurement data from each of the plurality of RFID tags.

[0241] Aspect 52 includes a wireless communication device according to any one of aspects 36 to 51, the wireless communication device being further configured to: receive a first portion of the matrix by a first subset of the plurality of RFID tags; and receive a second portion of the matrix by a second subset of the plurality of RFID tags.

[0242] Aspect 53 includes a wireless communication device according to any one of aspects 36 to 52, the wireless communication device being further configured to receive the first signal from one of a base station (BS), a user equipment (UE), or a programmable logic controller (PLC).

[0243] Aspect 54 includes a wireless communication device, comprising: a transceiver; and a processor, the processor coupled to the transceiver, wherein the wireless communication device is configured to: send a first signal to a reconfigurable smart surface (RIS), the RIS comprising: an array of one or more RIS elements; a RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and receive a second signal based on the first signal from the RIS.

[0244] Aspect 55 includes the wireless communication device of aspect 54, wherein the RIS controller comprises the RFID tag.

[0245] Aspect 56 includes the wireless communication device of any of aspects 54 to 55, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller.

[0246] Aspect 57 includes the wireless communication device of any one of aspects 54 to 56, the wireless communication device being further configured to transmit the first signal to each of the plurality of RFID tags.

[0247] Aspect 58 includes the wireless communication device of any of aspects 54 to 57, the wireless communication device being further configured to transmit the first signal to a subset of the plurality of RFID tags.

[0248] Aspect 59 includes a wireless communication device according to any one of aspects 54 to 58, the wireless communication device being further configured to send a first portion of the first signal to a first subset of the plurality of RFID tags and to send a second portion of the first signal to a second subset of the plurality of RFID tags.

[0249] Aspect 60 includes the wireless communication device of any of aspects 54 to 59, the wireless communication device being further configured to define a common password for each of the plurality of RFID tags.

[0250] Aspect 61 includes a wireless communications apparatus according to any one of aspects 54 to 60, wherein the first signal comprises a reference signal.

[0251] Aspect 62 includes a wireless communication device according to any one of aspects 54 to 61, wherein the second signal includes channel measurement data from each of the plurality of RFID tags for channel estimation by the wireless communication device.

[0252] Aspect 63 includes a wireless communications apparatus according to any one of aspects 54 to 62, wherein the second signal includes channel estimation information.

[0253] Aspect 64 includes a wireless communication device according to any one of aspects 54 to 63, the wireless communication device being further configured to determine channel estimation information.

[0254] Aspect 65 includes a wireless communication device according to any of aspects 54 to 64, the wireless communication device being further configured to estimate one or more weights for each of the one or more RIS elements.

[0255] Aspect 66 includes the wireless communication device of any of aspects 54 to 65, the wireless communication device being further configured to send a third signal including RIS configuration information to the RIS based on the one or more estimated weights.

[0256] Aspect 67 includes a wireless communications apparatus according to any one of aspects 54 to 66, wherein the RIS configuration information includes a beam index.

[0257] Aspect 68 includes a wireless communication device according to any one of aspects 54 to 67, wherein the RIS configuration information includes a matrix, the matrix including the one or more estimated weights for each of the one or more RIS elements determined based on interpolation or extrapolation according to measurement data of the RFID tag.

[0258] Aspect 69 includes a wireless communication device according to any one of aspects 54 to 68, wherein the RFID tag includes a plurality of RFID tags, and wherein the wireless communication device is further configured to: send a first portion of the matrix to a first subset of the plurality of RFID tags; and send a second portion of the matrix to a second subset of the plurality of RFID tags.

[0259] Aspect 70 includes a wireless communication device according to any one of aspects 54 to 69, wherein the wireless communication device is one of a base station (BS), a user equipment (UE), or a programmable logic controller (PLC).

[0260] Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0261] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration).

[0262] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on a computer-readable medium, or sent via a computer-readable medium. Other examples and specific implementations are within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software, hardware, firmware, hard wiring, or any combination thereof executed by a processor. The features that implement the functions may also be physically located at different locations, including being distributed so that the parts of the functions are implemented at different physical locations. In addition, as used herein (including in the claims), as used in an item enumeration (e.g., followed by an item enumeration such as "at least one of" or "one or more of"), "or" indicates an inclusive enumeration, such that, for example, an enumeration of [at least one of A, B, or C] means: A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0263] As those skilled in the art will understand by now and depending on the specific application at hand, many modifications, substitutions and changes may be made to the materials, devices, configurations and methods of use of the apparatus of the present disclosure without departing from the spirit and scope of the present disclosure. In view of this, the scope of the present disclosure should not be limited to the specific embodiments illustrated and described herein (as they are only some examples of the present disclosure), but should be fully equivalent to the appended claims and their functional equivalents.

Claims

1. A method for wireless communication, the method comprising: A first signal is received by a first wireless communication device from a second wireless communication device, the first wireless communication device further comprising: A reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) comprising an array of one or more RIS elements; RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and A second signal is transmitted by the RFID tag of the first wireless communication device to the second wireless communication device using backscatter communication based on the first signal.

2. The method of claim 1, wherein the RIS controller comprises the RFID tag.

3. The method of claim 1, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller. 4 . The method of claim 3 , wherein the receiving the first signal further comprises receiving the first signal by the plurality of RFID tags.

5. The method according to claim 3, wherein the receiving the first signal further comprises: A first portion of the first signal is received by a first subset of the plurality of RFID tags, and a second portion of the first signal is received by a second subset of the plurality of RFID tags.

6. The method of claim 3, wherein the second signal comprises channel measurement data from each of the plurality of RFID tags for use in channel estimation by the second wireless communication device. The method of claim 3 , wherein the second signal comprises channel estimation information.

8. The method according to claim 7, wherein the first wireless communication device further comprises a channel estimation unit, the method further comprising: storing, by the plurality of RFID tags, at least a portion of the first signal from the second wireless communication device in corresponding memories; as well as The channel estimation information is determined by the channel estimation unit based on the first signal stored in the corresponding memory.

9. The method according to claim 8, further comprising: A third signal including RIS configuration information is received by one or more of the plurality of RFID tags from the second wireless communication device based on the channel measurement data, wherein the RIS configuration information includes a matrix including one or more weights for each of the one or more RIS elements determined based on interpolation or extrapolation according to the measurement data from each of the plurality of RFID tags.

10. A method of wireless communication, the method comprising: A first signal is sent by a first wireless communication device to a second wireless communication device, wherein the second wireless communication device includes: A reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) comprising an array of one or more RIS elements; RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and A second signal based on the first signal is received by the first wireless communication device from the second wireless communication device using backscatter communication.

11. The method of claim 10, wherein the RIS controller comprises the RFID tag.

12. The method of claim 10, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller.

13. The method of claim 12, wherein the sending the first signal further comprises: A first portion of the first signal is transmitted to a first subset of the plurality of RFID tags, and a second portion of the first signal is transmitted to a second subset of the plurality of RFID tags.

14. The method of claim 12, further comprising defining a common password for each of the plurality of RFID tags.

15. The method of claim 10, further comprising determining, by the first wireless communication device, channel estimation information.

16. The method according to claim 15, further comprising: A third signal including RIS configuration information is sent by the first wireless communication device to the second wireless communication device based on the one or more estimated weights.

17. The method of claim 16, wherein the RFID tag comprises a plurality of RFID tags and wherein the sending the third signal comprises: sending a first portion of the RIS configuration information to a first subset of the plurality of RFID tags; as well as A second portion of the RIS configuration information is sent to a second subset of the plurality of RFID tags.

18. A wireless communication device, comprising: A reconfigurable smart surface (RIS), the reconfigurable smart surface (RIS) comprising an array of one or more RIS elements; RIS controller; a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and processor, wherein the wireless communication device is configured to: receiving a first signal by the RFID tag; and A second signal is transmitted by the RFID tag using backscatter communication based on the first signal.

19. The wireless communication device of claim 18, wherein the RFID tag comprises a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags being in communication with the RIS controller.

20. The wireless communication device of claim 19, further configured to receive the first signal by the plurality of RFID tags.

21. The wireless communication device of claim 19, further configured to define a common password for each of the plurality of RFID tags.

22. The wireless communication apparatus of claim 19, wherein the second signal comprises channel measurement data from each of the plurality of RFID tags for channel estimation.

23. The wireless communication device of claim 19, wherein the second signal comprises channel estimation information, and wherein the wireless communication device is further configured to determine the channel estimation information by the plurality of RFID tags and to transmit the second signal by the plurality of RFID tags.

24. The wireless communication device of claim 23, wherein the wireless communication device is further configured to: A third signal including RIS configuration information is received by one or more of the plurality of RFID tags based on the channel measurement data.

25. A wireless communication device, comprising: Transceiver; and a processor coupled to the transceiver, wherein the wireless communication device is configured to: A first signal is sent to a reconfigurable smart surface (RIS), the RIS comprising: an array of one or more RIS elements; RIS controller; and a radio frequency identification (RFID) tag, the first signal being received by the RFID tag; and A second signal based on the first signal is received from the RIS.

26. The wireless communication device of claim 25, wherein the RFID tags include a plurality of RFID tags in the array of one or more RIS elements, the plurality of RFID tags communicating with the RIS controller, and wherein the wireless communication device is further configured to send the first signal to the plurality of RFID tags.

27. The wireless communication device of claim 26, wherein the first signal comprises a reference signal.

28. The wireless communication device of claim 27, wherein the second signal comprises channel estimation information.

29. The wireless communication device of claim 25, further configured to determine channel estimation information comprising one or more weights for each of the one or more RIS elements.

30. The wireless communication device of claim 29, further configured to: A third signal including RIS configuration information is sent to the RIS based on the one or more estimated weights.

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