Reflection codebook for ris with sparse super-element array

Abstract

Reflective codebooks for RISs with sparse super-element arrays are described. One apparatus is configured to receive a reflected channel reference signal from a RIS based on a sparse super-element array of the RIS and reflection of a source channel reference signal from a network node. The apparatus is configured to obtain a reflected channel reflection coefficient based on a sparse super-element array codebook and reflection channel measurements, and provide an indication of the reflection coefficient for the RIS and / or the network node. Another apparatus is configured to provide a UE with a source channel reference signal via a reflected channel reflection based on a sparse super-element array of a RIS. The apparatus is configured to receive an indication of a reflected channel reflection coefficient from the UE based on a sparse super-element array codebook and reflection channel measurements, and configure the RIS with the reflected channel reflection coefficient.

Description

Technical Field

[0001] This disclosure relates generally to communication systems, and more specifically to wireless communication utilizing reconfigurable smart surfaces (RIS). Background Technology

[0002] Wireless communication systems are widely deployed to provide a variety of telecommunications services, such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems.

[0003] These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the city, national, regional, and even global levels. An example telecommunications standard is 5G New Radio (NR). 5G NR is part of the Continuous Evolution of Mobile Broadband (CEM) program issued by the 3rd Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT),) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC). Some aspects of 5G NR can be based on the 4G Long Term Evolution (LTE) standard. Further improvements to 5G NR technology are needed. Furthermore, these improvements can also be applied to other multiple access technologies and telecommunications standards that adopt these technologies. Summary of the Invention

[0004] The following is a simplified summary of one or more aspects to provide a basic understanding of these aspects. This summary is not a comprehensive overview of all conceived aspects. It neither identifies key or essential elements of all aspects nor describes the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed descriptions that follow.

[0005] In one aspect of this disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus may include user equipment (UE), and the method may be performed at or by the UE. The apparatus is configured to receive a reference signal from a reconfigurable smart surface (RIS) via a reflection channel, wherein the reflection channel is based on a sparse metaelement array of the RIS and the reference signal is reflected from a network node via a source channel. The apparatus is also configured to obtain a reflection coefficient of the reflection channel based on a codebook of the sparse metaelement array and measurements of the reflection channel. The apparatus is further configured to provide an indication of the reflection coefficient of the reflection channel to at least one of the RIS or a network node.

[0006] In this respect, the method includes receiving a reference signal from a RIS via a reflection channel, wherein the reflection channel is based on a sparse metaelement array of the RIS and the reference signal is reflected from a network node via a source channel. The method also includes obtaining a reflection coefficient of the reflection channel based on measurements of the sparse metaelement array codebook and the reflection channel. The method further includes providing an indication of the reflection coefficient of the reflection channel to at least one of the RIS or the network node.

[0007] In another aspect of this disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus is configured to provide a reference signal on a source channel to a user equipment (UE) via reflection on a reflection channel of a RIS-based sparse metaelement array. The apparatus is also configured to receive from the UE an indication of the reflection coefficients of the reflection channel, wherein the reflection coefficients of the reflection channel are based on a sparse metaelement array codebook and measurements of the reflection channel. The apparatus is further configured to configure the RIS using the reflection coefficients of the reflection channel.

[0008] In this respect, the method includes providing a reference signal on the source channel to a user equipment (UE) via reflection on a reflection channel of a RIS-based sparse meta-element array. The method also includes receiving from the UE an indication of the reflection coefficients of the reflection channel, wherein the reflection coefficients of the reflection channel are based on a sparse meta-element array codebook and measurements of the reflection channel. The method further includes configuring the RIS using the reflection coefficients of the reflection channel.

[0009] To achieve the foregoing and related objectives, one or more aspects may include the features fully described below and specifically pointed out in the claims. The following description and drawings set forth some exemplary features of one or more aspects in detail. However, these features indicate only a few of the various ways in which the principles of the various aspects may be employed. Attached Figure Description

[0010] Figure 1 This is a diagram illustrating an example of a wireless communication system and an access network.

[0011] Figure 2AThis is an illustration of an example of the first frame according to various aspects of this disclosure.

[0012] Figure 2B This is a diagram illustrating examples of downlink (DL) channels within a subframe according to various aspects of this disclosure.

[0013] Figure 2C This is an illustration of an example of a second frame according to various aspects of this disclosure.

[0014] Figure 2D This is a diagram illustrating examples of uplink (UL) channels within a subframe according to various aspects of this disclosure.

[0015] Figure 3 This is a diagram illustrating examples of base stations and user equipment (UEs) in an access network.

[0016] Figure 4 This is a diagram illustrating an example of a reconfigurable Smart Surface (RIS) configuration.

[0017] Figure 5 This is a diagram illustrating example RIS configurations used for sparse and uniform arrays.

[0018] Figure 6 This is a call flow diagram for wireless communication based on various aspects of this disclosure.

[0019] Figure 7 This is a diagram illustrating examples of nested sparse superelement array configurations according to various aspects of this disclosure.

[0020] Figure 8 This is a diagram illustrating examples of coprime sparse superelement array configurations according to various aspects of this disclosure.

[0021] Figure 9 This is a diagram illustrating examples of sparse superelement array codebooks according to various aspects of this disclosure.

[0022] Figure 10 This is a diagram illustrating examples of RIS configurations for sparse superelement array codebooks and auxiliary reflection coefficients according to various aspects of this disclosure.

[0023] Figure 11 This is a flowchart of a wireless communication method according to various aspects of this disclosure.

[0024] Figure 12 This is a flowchart of a wireless communication method according to various aspects of this disclosure.

[0025] Figure 13 This is a flowchart of a wireless communication method according to various aspects of this disclosure.

[0026] Figure 14 This is a flowchart of a wireless communication method according to various aspects of this disclosure.

[0027] Figure 15 These are illustrations illustrating specific hardware implementations used for example devices and / or network entities.

[0028] Figure 16 This is a diagram illustrating an example of a hardware implementation used for an example network entity. Detailed Implementation

[0029] Wireless communication networks can be designed to support communication between network nodes (e.g., base stations, gNBs, etc.) and UEs. For example, network nodes and UEs in a wireless communication network can communicate in various spatial configurations to account for UE mobility and obstacles or obstructions in the environment. An example device or system that can be used in a communication environment with obstacles or obstructions is a RIS that may include a surface with a large number of densely placed reconfigurable meta-elements that can reflect or refract electromagnetic waves in a target direction. The RIS can be configured to reflect, transmit (e.g., refract), or be configured to transmit and reflect simultaneously. The RIS can provide low-cost and low-power communication options based on, for example, a combination of positive intrinsic-negative / varactor diodes and a lack of radiated power (e.g., the RIS control can use power, but the meta-elements may not transmit power).

[0030] However, RIS configurations can be based on uniform meta-element arrays, such as uniform linear arrays (ULAs) or uniform planar arrays (UPAs). In the high-frequency spectrum (e.g., frequency ranges specified as FR2, THz, etc.), given a half-wavelength spacing and RIS surface size, small wavelengths can result in a large number of ULA / UPA meta-elements. This, in turn, leads to higher hardware costs (e.g., the more meta-elements placed on the surface, the higher the hardware cost) and higher power consumption (e.g., the power consumed by the control circuitry of the meta-elements). Additionally, if the inter-element spacing is greater than half the wavelength of the reflected signaling, aliasing beams and associated ambiguity in sensing results may occur. Furthermore, when utilizing smaller RIS surface sizes, the beamwidth increases accordingly, and therefore the spatial resolution decreases.

[0031] The overall scope involves wireless communication systems utilizing RIS (Reflection Reference Array). Some aspects are more specifically related to reflection codebooks for RISs with sparse meta-element arrays. For example, a UE can be configured with a sparse meta-element array codebook for the RIS. The UE can receive a reflection reference signal, which can be initiated by a network node and reflected by the RIS; and measure the reflection channel on which the reflection reference signal is received from the RIS. Based on the configured sparse meta-element array codebook for the RIS and the measurements, the UE can obtain reflection coefficients, which can be provided / reported to the RIS / network node to optimize the sparse meta-element array of the RIS.

[0032] Specific aspects of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages. In some examples, by utilizing sparse metaelement arrays, the described techniques can be used to provide spatial resolution for RIS at lower cost and power than ULA / UPA implementations. In some examples, by providing a more accurate codebook-based reflection coefficient reporting scheme for RIS with sparse metaelement arrays, the described techniques can be used to optimize the RIS's sparse metaelement array for channel gain and throughput by matching the RIS's reflection coefficients with the utilized radio channel. In some examples, by utilizing the codebook of nested and coprime sparse metaelement arrays on the subsurfaces of the RIS, the described techniques can be used to improve implementation flexibility while still optimizing the RIS configuration.

[0033] The detailed descriptions following, illustrated with reference to the accompanying drawings, describe various configurations and do not represent the only configurations in which the concepts described herein can be practiced. To provide a thorough understanding of the various concepts, the detailed descriptions include specific details. However, these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0034] Various apparatuses and methods are presented with reference to several aspects of a telecommunications system. These apparatuses and methods are described in detail below and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively, “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the system as a whole.

[0035] As an example, an element, any part of an element, or any combination of elements may be implemented as a "processing system" including one or more processors. When multiple processors are implemented, the multiple processors may perform functions individually or in combination. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. One or more processors in the processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, or any combination thereof.

[0036] Therefore, in one or more example aspects, specific implementations, and / or use cases, the described functionality may be implemented in hardware, software, or any combination thereof. If implemented in software, the functionality may be stored or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media. Storage media may be any available medium accessible to a computer. By way of example, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disc storage devices, magnetic disk storage devices, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures accessible to a computer.

[0037] While aspects, implementations, and / or use cases are described herein by way of example, additional or different aspects, implementations, and / or use cases may arise in many different arrangements and scenarios. The aspects, implementations, and / or use cases described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and package arrangements. For example, aspects, implementations, and / or use cases may arise via integrated chip implementations and other devices based on non-modular components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specific to a use case or application, the described examples may exhibit broad applicability. Aspects, implementations, and / or use cases can range from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more of the technologies described herein. In some practical settings, devices incorporating the described aspects and features may also include additional components and features for implementing and practicing the claimed and described aspects. For example, the transmission and reception of wireless signals necessarily involve multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The techniques described herein can be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or decomposed components, end-user equipment, etc., of various sizes, shapes, and configurations.

[0038] The deployment of communication systems such as 5G NR systems can be arranged in a variety of ways using various components or parts. In a 5G NR system or network, network nodes, network entities, network mobility elements, radio access network (RAN) nodes, core network nodes, network elements or network equipment (such as base stations (BS)), or one or more units (or components) performing base station functionality can be implemented in aggregated or decomposed architectures. For example, BSs (such as Node B (NB), evolved NB (eNB), NR BS, 5G NB, access point (AP), transmit / receive point (TRP), or cell, etc.) can be implemented as aggregated base stations (also known as standalone BS or monolithic BS) or decomposed base stations.

[0039] Aggregated base stations can be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. Decentralized base stations can be configured to utilize a protocol stack that is physically or logically distributed across two or more units, such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs). In some respects, the CU may be implemented within a RAN node, and one or more DUs may co-located with the CU, or alternatively, may be geographically or virtually distributed across one or more other RAN nodes. DUs may be implemented to communicate with one or more RUs. Each of the CU, DU, and RU may be implemented as a virtual unit, namely a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU).

[0040] Base station operation or network design can take into account the aggregation characteristics of base station functionality. For example, decomposed base stations can be utilized in Integrated Access Backhaul (IAB) networks, Open Radio Access Networks (O-RAN (such as network configurations initiated by the O-RAN Alliance)), or Virtualized Radio Access Networks (vRAN, also known as Cloud Radio Access Networks (C-RAN)). Decomposition can include distributing functionality across two or more units in various physical locations, as well as virtually distributing the functionality of at least one unit, which enables flexibility in network design. The various units of a decomposed base station or decomposed RAN architecture can be configured to communicate wirelessly with at least one other unit.

[0041] Figure 1 Figure 100 illustrates an example of a wireless communication system and access network. The illustrated wireless communication system includes a decomposed base station architecture. The decomposed base station architecture may include one or more CUs 110, which may communicate directly with the core network 120 via a backhaul link, or indirectly with the core network 120 via one or more decomposed base station units, such as a near real-time (near-RT) RAN Intelligent Controller (RIC) 125 via an E2 link, or a non-real-time (non-RT) RIC 115 associated with a Service Management and Orchestration (SMO) framework 105, or both. CUs 110 may communicate with one or more DUs 130 via a corresponding midhaul link (such as an F1 interface). DUs 130 may communicate with one or more RUs 140 via a corresponding fronthaul link. RUs 140 may communicate with a corresponding UE 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served simultaneously by multiple RUs 140.

[0042] Each of the units (i.e., CU 110, DU 130, RU 140, and near-RT RIC 125, non-RT RIC 115, and SMO frame 105) may include or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via wired or wireless transmission media. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of these units, may be configured to communicate with one or more other units via transmission media. For example, these units may include wired interfaces configured to receive signals or transmit signals to one or more other units via wired transmission media. Additionally, these units may include wireless interfaces that may include receivers, transmitters, or transceivers (such as RF transceivers) configured to receive signals via wireless transmission media and / or transmit signals to one or more other units.

[0043] In some aspects, the CU 110 can host one or more higher-level control functions. Such control functions may include Radio Resource Control (RRC), Packet Data Convergence Protocol (PDCP), Serving Data Adaptation Protocol (SDAP), etc. Each control function can be implemented using an interface configured to signal to other control functions hosted by the CU 110. The CU 110 can 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 implementations, the CU 110 can be logically divided into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP units can communicate bidirectionally with the CU-CP units via an interface such as an E1 interface. The CU 110 can be implemented to communicate with the DU 130 for network control and signaling, as needed.

[0044] DU 130 may correspond to a logic unit that includes one or more base station functions for controlling the operation of one or more RU 140s. In some aspects, DU 130 may at least partially host one or more of the Radio Link Control (RLC) layer, Media 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.) according to functional splits (such as those defined by 3GPP). In some aspects, DU 130 may further host one or more low PHY layers. Each layer (or module) may be implemented using an interface configured to communicate signals with other layers (and modules) hosted by DU 130 or with control functions hosted by CU 110.

[0045] Lower-layer functionality can be implemented by one or more RU 140s. In some deployments, an RU140 controlled by a DU 130 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, or both, based at least in part on functional decomposition (such as lower-layer functional decomposition). In such architectures, the RU 140 may be implemented to handle over-the-air (OTA) communications with one or more UEs 104. In some specific implementations, the real-time and non-real-time aspects of control plane and user plane communications with the RU 140 may be controlled by the corresponding DU 130. In some scenarios, this configuration allows the DU 130 and CU 110 to be implemented in cloud-based RAN architectures such as vRAN architectures.

[0046] SMO framework 105 can be configured to support RAN deployment and provisioning of both non-virtualized and virtualized network elements. For non-virtualized network elements, SMO framework 105 can be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which can be managed via operation and maintenance interfaces such as the O1 interface. For virtualized network elements, SMO framework 105 can be configured to interact with a cloud computing platform such as Open Cloud (O-Cloud) 190 to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface such as the O2 interface. Such virtualized network elements may include, but are not limited to, CU 110, DU 130, RU 140, and near-RT RIC 125. In some implementations, SMO framework 105 can communicate with hardware aspects of the 4G RAN, such as Open eNB (O-eNB) 111, via the O1 interface. Additionally, in some implementations, SMO framework 105 can communicate directly with one or more RU 140s via the O1 interface. SMO framework 105 may also include a non-RT RIC 115 configured to support the functionality of SMO framework 105.

[0047] The non-RT RIC 115 can be configured to include logical functions enabling non-real-time control and optimization of RAN elements and resources, including artificial intelligence (AI) / machine learning (ML) workflows for model training and updates, or policy-based guidance for applications / features in the near-RT RIC 125. The non-RT RIC 115 can be coupled to or communicate with the near-RT RIC 125, such as via an A1 interface. The near-RT RIC 125 can be configured to include logical functions enabling near real-time control and optimization of RAN elements and resources via data collection and actions through an interface such as an E2 interface, connecting one or more CU 110s, one or more DU 130s, or both, and O-eNBs to the near-RT RIC 125.

[0048] In some implementations, to generate AI / ML models to be deployed in the near-RT RIC 125, the non-RT RIC 115 may receive parameters or external enrichment information from an external server. This information can be utilized by the near-RT RIC 125 and may be received from non-network data sources or network functions at the SMO framework 105 or the non-RT RIC 115. In some examples, the non-RT RIC 115 or the near-RT RIC 125 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 115 may monitor long-term trends and patterns in performance and employ AI / ML models to perform corrective actions via the SMO framework 105 (such as reconfiguration via O1) or by creating RAN management policies (such as A1 policies).

[0049] At least one of CU 110, DU 130, and RU 140 may be referred to as base station 102. Therefore, base station 102 may include one or more of CU 110, DU 130, and RU 140 (each component is indicated by a dashed line to indicate that each component may or may not be included in base station 102). Base station 102 provides UE 104 with an access point to core network 120. Base station 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Small cells include femtocells, picocells, and microcells. A network that includes both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include an evolved home node B (eNB) (HeNB), which can provide service to a restricted group referred to as a closed subscriber group (CSG). The communication link between RU 140 and UE 104 may include uplink (UL) transmission (also known as reverse link) from UE 104 to RU 140 and / or downlink (DL) transmission (also known as forward link) transmission from RU 140 to UE 104. The communication link may utilize multiple-input multiple-output (MIMO) antenna techniques, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link may use one or more carriers. For each direction, the total number of carriers used for transmission can be up to [number missing]. Yx MHz ( x For each carrier allocated in carrier aggregation (of component carriers), base station 102 / UE 104 can use up to [number] carriers. Y A spectrum with a bandwidth of MHz (e.g., 5MHz, 10MHz, 15MHz, 20MHz, 100MHz, 400MHz, etc.). Carriers may be adjacent to each other or may not be adjacent to each other. Carrier allocation may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL compared to UL). Component carriers may include primary component carriers and one or more secondary component carriers. The primary component carrier may be referred to as the primary cell (PCell) and the secondary component carrier may be referred to as the secondary cell (SCell).

[0050] Some UEs 104 can communicate with each other using device-to-device (D2D) communication link 158. D2D communication link 158 can use DL / UL wireless wide area network (WWAN) spectrum. D2D communication link 158 can use one or more sidelink channels, such as Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Discovery Channel (PSDCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Control Channel (PSCCH). D2D communication can be achieved through various wireless D2D communication systems, such as Bluetooth. ™ (Bluetooth is a trademark of the Bluetooth Special Interest Group (SIG), and is based on the IEEE 802.11 standard for Wi-Fi.)™ (Wi-Fi is a trademark of the Wi-Fi Alliance, LTE or NR)

[0051] The wireless communication system may also include a Wi-Fi AP 150, which communicates with the UE 104 (also referred to as a Wi-Fi station (STA)) via a communication link 154, for example, in an unlicensed spectrum such as 5 GHz. When communicating in unlicensed spectrum, the UE 104 / AP 150 may perform a free channel assessment (CCA) to determine whether a channel is available before communication.

[0052] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc., based on frequency / wavelength. In 5G NR, two initial operating bands have been designated as frequency ranges FR1 (410MHz to 7.125GHz) and FR2 (24.25GHz to 52.6GHz). Although a portion of FR1 is greater than 6GHz, FR1 is generally (interchangeably) referred to as the "sub-6GHz" band in various documents and articles. Similar naming issues sometimes occur with FR2, which is generally (interchangeably) referred to as the "millimeter wave" band in documents and articles, although this is distinct from the Extremely High Frequency (EHF) band (30GHz to 300GHz) designated as "millimeter wave" by the International Telecommunication Union (ITU).

[0053] The frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR studies have designated the operating bands for these mid-band frequencies as the frequency range designation FR3 (7.125 GHz to 24.25 GHz). Bands falling within FR3 can inherit FR1 and / or FR2 characteristics, thus effectively extending the features of FR1 and / or FR2 to mid-band frequencies. Additionally, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been designated as the frequency range designations FR2-2 (52.6 GHz to 71 GHz), FR4 (71 GHz to 114.25 GHz), and FR5 (114.25 GHz to 300 GHz). Each of these higher bands falls within the EHF band.

[0054] In view of the above, unless otherwise specified, the term "below 6 GHz" as used herein can broadly refer to frequencies less than 6 GHz, within FR1, or including intermediate frequency band frequencies. Furthermore, unless otherwise specified, the term "millimeter wave" as used herein can broadly refer to frequencies that can include intermediate frequency band frequencies, within FR2, FR4, FR2-2 and / or FR5, or within the EHF band.

[0055] Base station 102 and UE 104 may each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming. Base station 102 may transmit beamformed signals 182 to UE 104 in one or more transmit directions. UE 104 may receive beamformed signals from base station 102 in one or more receive directions. UE 104 may also transmit beamformed signals 184 to base station 102 in one or more transmit directions. Base station 102 may receive beamformed signals from UE 104 in one or more receive directions. Base station 102 / UE 104 may perform beamforming training to determine the optimal receive and transmit directions for each of base station 102 / UE 104. The transmit and receive directions of base station 102 may be the same or different. The transmit and receive directions of UE 104 may be the same or different.

[0056] Base station 102 may include and / or be referred to as gNB, Node B, eNB, access point, transceiver base station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), TRP, network node, network entity, network equipment, or some other suitable terminology. Base station 102 may be implemented as an integrated access and backhaul (IAB) node, relay node, sidelink node, aggregated (monolithic) base station with baseband units (BBU) (including CU and DU) and RU, or may be implemented as a decomposed base station including one or more of CU, DU, and / or RU. A collection of base stations that may include decomposed base stations and / or aggregated base stations may be referred to as Next Generation (NG) RAN (NG-RAN).

[0057] The core network 120 may include Access and Mobility Management Function (AMF) 161, Session Management Function (SMF) 162, User Plane Function (UPF) 163, Unified Data Management (UDM) 164, one or more location servers 168, and other functional entities. AMF 161 is the control node that handles signaling between UE 104 and the core network 120. AMF 161 supports registration management, connection management, mobility management, and other functions. SMF 162 supports session management and other functions. UPF 163 supports packet routing, packet forwarding, and other functions. UDM 164 supports authentication and key agreement (AKA) credential generation, user identity processing, access authorization, and subscription management. One or more location servers 168 are exemplified as including a Gateway Mobile Location Center (GMLC) 165 and a Location Management Function (LMF) 166. However, generally, one or more location servers 168 may include one or more location / positioning servers, which may include one or more of GMLC 165, LMF 166, Position Determination Entity (PDE), Serving Mobile Location Center (SMLC), Mobile Location Center (MPC), etc. GMLC 165 and LMF 166 support UE location services. GMLC 165 provides an interface for clients / applications (e.g., emergency services) to access UE location information. LMF 166 receives measurement and auxiliary information from NG-RAN and UE 104 via AMF 161 to calculate the location of UE 104. NG-RAN may use one or more positioning methods to determine the location of UE 104. Positioning UE 104 may involve signal measurement, location estimation, and optional rate calculation based on these measurements. Signal measurement may be performed by UE 104 and / or base station 102 serving UE 104. The measured signals may be based on one or more of the following: Satellite Positioning System (SPS) 170 (e.g., one or more of Global Navigation Satellite System (GNSS), Global Positioning System (GPS), Non-Terrestrial Network (NTN) or other satellite positioning / location systems), LTE signals, Wireless Local Area Network (WLAN) signals, Bluetooth signals, Terrestrial Beacon System (TBS), sensor-based information (e.g., barometric pressure sensor, motion sensor), NR Enhanced Cell ID (NR E-CID) method, NR signals (e.g., multiple round-trip time (multiple RTT), DL departure angle (DL-AoD), DL time difference of arrival (DL-TDOA), UL time difference of arrival (UL-TDOA), and UL angle of arrival (UL-AoA) positioning) and / or other systems / signals / sensors.

[0058] Examples of UE 104 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, GPS devices, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electricity meters, air pumps, large or small kitchen appliances, healthcare devices, implants, sensors / actuators, displays, or any other similarly functional device. Some UEs in UE 104 may be referred to as IoT devices (e.g., parking meters, air pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, mobile phone, user agent, mobile client, client, or some other suitable terminology. In some scenarios, the term UE may also be applied to one or more companion devices, such as in a device constellation arrangement. One or more of these devices may access the network together and / or individually.

[0059] Refer again Figure 1In some aspects, UE 104 may have a RIS component 198 (“Component 198”) configured to receive a reference signal from a RIS via a reflection channel, wherein the reflection channel is based on a sparse metaelement array of the RIS and the reference signal is reflected from a network node via a source channel. Component 198 may also be configured to obtain the reflection coefficients of the reflection channel based on measurements of the sparse metaelement array codebook and the reflection channel. Component 198 may also be configured to provide an indication of the reflection coefficients of the reflection channel to at least one of the RIS or the network node. Component 198 may be configured to receive a configuration indicating the sparse metaelement array codebook from the network node. Component 198 may be configured to receive a resource and report configuration indicating at least one of resources associated with the reference signal or reports associated with the reflection coefficients from the network node. In some aspects, base station 102 may have a RIS component 199 (“Component 199”) configured to provide a reference signal on the source channel to the user equipment UE via reflection on a reflection channel based on a RIS-based sparse metaelement array. Component 199 can also be configured to receive from the UE an indication of the reflection coefficients of the reflection channel, wherein the reflection coefficients of the reflection channel are based on a sparse meta-element array codebook and measurements of the reflection channel. Component 199 can also be configured to configure the RIS using the reflection coefficients of the reflection channel. Component 199 can be configured to receive from the RIS a parameter indication of a set of RIS sparse array parameters, wherein the parameter indication of the RIS sparse array parameter set includes at least one of horizontal configuration parameters or vertical configuration parameters. Component 199 can be configured to configure the UE using a configuration indicating the sparse meta-element array codebook based on the parameter indication of the RIS sparse array parameter set. Component 199 can be configured to configure the UE using a resource and reporting configuration indicating at least one of resources associated with a reference signal or reports associated with the reflection coefficients. Therefore, aspects provide a reflection codebook for a RIS with a sparse meta-element array, wherein the UE can be configured with a sparse meta-element array codebook for the RIS such that the UE can obtain reflection coefficients of the sparse meta-element array that can be provided / reported to the RIS / network node to optimize the RIS. Therefore, spatial resolution for RIS can be provided at a lower cost and power than ULA / UPA implementations by utilizing sparse meta-element arrays; sparse meta-element arrays of RIS can be optimized for channel gain and throughput by providing a more accurate codebook-based reflection coefficient reporting scheme for RIS with sparse meta-element arrays via matching the RIS reflection coefficients with the utilized radio channels; and implementation flexibility can be improved by utilizing codebooks for nested and coprime sparse meta-element arrays on the sub-surfaces of RIS, while still optimizing RIS configuration.

[0060] Figure 2A Figure 200 illustrates an example of the first subframe within a 5G NR frame structure. Figure 2BFigure 230 illustrates an example of a DL channel within a 5G NR subframe. Figure 2C Figure 250 is an example of a second subframe within a 5G NR frame structure. Figure 2D Figure 280 illustrates an example of a UL channel within a 5G NR subframe. The 5G NR frame structure can be Frequency Division Duplex (FDD) (where subframes within a specific set of subcarriers (carrier system bandwidth) are dedicated to either DL or UL) or Time Division Duplex (TDD) (where subframes within a specific set of subcarriers (carrier system bandwidth) are dedicated to both DL and UL). Figure 2A , Figure 2C In the provided example, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible and can be used between DL / UL, and subframe 3 is configured with slot format 1 (all of which are UL). Although subframes 3 and 4 are shown as having slot formats 1 and 28 respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are both DL and UL, respectively. Other slot formats 2-61 include a mixture of DL, UL, and flexible symbols. The UE is configured using the slot format via the received Slot Format Indicator (SFI) (dynamically configured via DL Control Information (DCI) or semi-statically / statically configured via Radio Resource Control (RRC) signaling). Note that the following description also applies to the 5G NR frame structure as TDD.

[0061] Figures 2A to 2D The frame structure is illustrated, and aspects of this disclosure are applicable to other wireless communication technologies that may have different frame structures and / or different channels. A frame (10 ms) can be divided into 10 equal-sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include micro-time slots, which may include 7, 4, or 2 symbols. Each time slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each time slot may include 14 symbols, and for extended CP, each time slot may include 12 symbols. Symbols on the DL may be CP Orthogonal Frequency Division Multiplexing (OFDM) (CP-OFDM) symbols. Symbols on the UL may be CP-OFDM symbols (for high-throughput scenarios) or Discrete Fourier Transform (DFT) Extended OFDM (DFT-s-OFDM) symbols (for power-constrained scenarios; limited to single-stream transmission). The number of time slots within a subframe is based on the CP and a parameter set. The parameter set defines the subcarrier spacing (SCS) (see Table 1). The symbol length / duration can be scaled by 1 / SCS.

[0062] Table 1: Parameter Set, SCS, and CP For a normal CP (14 symbols / slot), different parameter sets µ 0 through 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For an extended CP, parameter set 2 allows 4 slots per subframe. Therefore, for a normal CP and parameter set µ, there are 14 symbols / slot and 2... µ One time slot / subframe. Subcarrier spacing can be equal to ,in The parameter sets are 0 to 4. Therefore, the subcarrier spacing is 15 kHz for parameter set µ=0 and 240 kHz for parameter set µ=4. The symbol length / duration is negatively correlated with the subcarrier spacing. Figures 2A to 2D Examples of a normal frequency division multiplexing (CP) with 14 symbols per time slot and a parameter set of µ=2 with 4 time slots per subframe are provided. The time slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within the frame set, there may be one or more distinct bandwidth portions (BWPs) of frequency division multiplexing (see [link to relevant documentation]). Figure 2B Each BWP can have a specific set of parameters and CP (normal or extended).

[0063] A resource grid can be used to represent the frame structure. Each time slot consists of a resource block (RB) extending for 12 consecutive subcarriers (also known as a physical RB (PRB)). The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0064] like Figure 2A As illustrated, some of the REs carry reference (pilot) signals (RS) for the UE. RS may include demodulation RS (DM-RS) (indicated as R for a particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. RS may also include beam measurement RS (BRS), beam refinement RS (BRRS), and phase tracking RS (PT-RS).

[0065] Figure 2BExamples of various DL channels within a subframe of a frame are illustrated. The Physical Downlink Control Channel (PDCCH) carries the DCI within one or more Control Channel Elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE comprising six RE Groups (REGs), each REG comprising 12 consecutive REs in the OFDM symbol of the RB. A PDCCH within a BWP can be referred to as a Control Resource Set (CORESET). The UE is configured to monitor PDCCH candidates in the PDCCH search space (e.g., the common search space, the UE-specific search space) during PDCCH monitoring timing on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at higher and / or lower frequencies on the channel bandwidth. The Primary Synchronization Signal (PSS) may be located within symbol 2 of a specific subframe of the frame. The PSS is used by the UE 104 to determine subframe / symbol timing and physical layer identification. The Secondary Synchronization Signal (SSS) may be located within symbol 4 of a specific subframe of the frame. The SSS is used by the UE to determine the Physical Layer Cell Identifier Group Number and radio frame timing. Based on the Physical Layer Identifier and the Physical Layer Cell Identifier Group Number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The Physical Broadcast Channel (PBCH), carrying the Master Information Block (MIB), can be logically grouped with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block (also known as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the System Frame Number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted via the PBCH (such as System Information Block (SIB)), and paging messages.

[0066] like Figure 2C As illustrated, some REs in the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and DM-RS for the Physical Uplink Shared Channel (PUSCH). The PUSCH DM-RS can be transmitted in the first or first two symbols of the PUSCH. Depending on whether a short or long PUCCH is transmitted and depending on the specific PUCCH format used, the PUCCH DM-RS can be transmitted in different configurations. The UE can transmit a Sounding Reference Signal (SRS). The SRS can be transmitted in the last symbol of a subframe. The SRS can have a comb structure, and the UE can transmit the SRS on one of the comb teeth. The SRS can be used by the base station for channel quality estimation to enable frequency-dependent scheduling of the UL.

[0067] Figure 2DExamples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), pre-decoding matrix indicators (PMI), rank indicators (RI), and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACKs and / or negative ACKs (NACKs)). The PUCCH carries data and may additionally be used to carry buffer status reports (BSR), power clearance reports (PHR), and / or UCIs.

[0068] Figure 3 This is a block diagram illustrating communication between base station 310 and UE 350 in the access network. In the DL, Internet Protocol (IP) packets can be provided to controller / processor 375. Controller / processor 375 implements Layer 3 and Layer 2 functionality. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Service Data Adaptation Protocol (SDAP) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-Radio Access Technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the delivery of upper-layer packet data units (PDUs), error correction via ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel priority ordering.

[0069] Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functionality associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection on the transport channel, forward error correction (FEC) decoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-order phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The decoded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to OFDM subcarriers, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domains, and then combined using inverse fast Fourier transform (IFFT) to produce a physical channel carrying a stream of time-domain OFDM symbols. The OFDM stream undergoes spatial pre-decoding to generate multiple spatial streams. Channel estimation from channel estimator 374 can be used to determine the decoding and modulation scheme, as well as for spatial processing. The channel estimation can be derived from a reference signal transmitted by UE 350 and / or channel condition feedback. Each spatial stream can then be provided to a different antenna 320 via a separate transmitter 318Tx. Each transmitter 318Tx can utilize the corresponding spatial stream to modulate a radio frequency (RF) carrier for transmission.

[0070] At UE 350, each receiver 354Rx receives signals via its corresponding antenna 352. Each receiver 354Rx recovers the information modulated onto the RF carrier and provides that information to the receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for UE 350. If multiple spatial streams are destined for UE 350, the RX processor 356 can combine them into a single OFDM symbol stream. The RX processor 356 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal consists of a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, along with the reference signal, are recovered and demodulated by determining the most probable signal constellation point transmitted by base station 310. These soft decisions can be based on a channel estimate calculated by channel estimator 358. The soft decision is then decoded and deinterleaved to recover the data and control signals originally transmitted by base station 310 on the physical channel. The data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functionality.

[0071] The controller / processor 359 may be associated with at least one memory 360 storing program code and data. The at least one memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels to recover IP packets. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0072] Similar to the functionality described in conjunction with DL transmission performed by base station 310, controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connectivity, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with upper-layer PDU delivery, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority handling, and logical channel priority ordering.

[0073] The TX processor 368 can use the reference signal transmitted from the base station 310 or the channel estimate derived from feedback by the channel estimator 358 to select an appropriate decoding and modulation scheme and facilitate spatial processing. The spatial stream generated by the TX processor 368 can be provided to different antennas 352 via individual transmitters 354Tx. Each transmitter 354Tx can use the corresponding spatial stream to modulate an RF carrier for transmission.

[0074] UL transmission is processed at base station 310 in a manner similar to that described in conjunction with the receiver function at UE 350. Each receiver 318Rx receives signals via its corresponding antenna 320. Each receiver 318Rx recovers the information modulated onto the RF carrier and provides that information to RX processor 370.

[0075] The controller / processor 375 may be associated with at least one memory 376 storing program code and data. The at least one memory 376 may be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets between transport and logical channels. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0076] At least one of the TX processor 368, RX processor 356, and controller / processor 359 can be configured to perform coupling. Figure 1 The components of 198 are all aspects.

[0077] At least one of the TX processor 316, RX processor 370, and controller / processor 375 can be configured to perform coupling. Figure 1 The components of 199 are all aspects.

[0078] Network nodes and UEs in a wireless communication network can communicate in various spatial configurations to take into account UE mobility and obstacles or obstructions in the environment. An example device or system that can be used in a communication environment with obstacles or obstructions is a RIS that may include a surface with a large number of densely placed reconfigurable meta-elements that can reflect or refract electromagnetic waves in a target direction. The RIS can be configured to reflect, transmit (e.g., refract), or be configured to transmit and reflect simultaneously.

[0079] Figure 4 Figure 400 illustrates an example RIS configuration. Figure 400 shows a reflective RIS 408 and a transmissive RIS 410 in the context of a UE 402, a base station 404, and an obstruction 406 (e.g., a barrier) between them. As noted, the reflective RIS 408 can be configured to reflect signals from the base station 404 in the direction of the UE 402, while the transmissive RIS 410 can be configured to refract signals from the base station 404 toward the UE 402, both doing so to provide signaling around the obstruction 406.

[0080] Figure 400 also illustrates a set of RIS elements 412 (e.g., a super-element) employing a general model configuration and a far-field model configuration (e.g., a reflective RIS 408). The RIS element set 412 may have a spacing d and may be aligned from -90 degrees to +90 degrees with 0 degrees as the center (e.g., the line of sight). In the configured general model, base station 404 may transmit a signal d on the source channel. i,n The signal is reflected towards the UE 402 by the RIS element assembly 412 as a reflected signal d on the reflection channel. r,n For the angle of incidence and reflection angle The reflection gain of RIS can be shown as: , in It is a super component n The reflection coefficient. In the far-field model, for the incident angle... and reflection angle The reflection gain of RIS can be shown as: .

[0081] Although the best case is , But in reality It is possible to derive from an enumerated set based on supercomponents.

[0082] Figure 400 also illustrates examples of uniform arrays 414 and sparse arrays 416 for RIS. For uniform arrays, the inter-element spacing is equal, while for non-uniform arrays, the inter-element spacing is unequal (e.g., as shown by inactive / empty array meta-elements for sparse array 416). Uniform arrays (e.g., uniform array 414) may experience cost and performance issues in various configurations / implementations. For example, in the context of spatial domain operations (e.g., MIMO, beamforming, DoA estimation, etc.), in high-frequency spectra (e.g., FR2, THz, etc.), given a half-wavelength spacing and RIS surface size, small wavelengths may result in a large number of ULA / UPA meta-elements. This, in turn, leads to higher hardware costs (e.g., the more meta-elements placed on the surface, the higher the hardware cost) and higher power consumption (e.g., the power consumed by the control circuitry of the meta-elements). Additionally, if the inter-element spacing is greater than half the wavelength of the reflected signaling, aliasing beams and associated sensing result ambiguity may occur. Furthermore, when utilizing a smaller RIS surface size, the beamwidth increases accordingly, and therefore the spatial resolution decreases.

[0083] To mitigate these issues, sparse arrays (such as sparse array 416) can be used to balance performance and cost. A sparse array can generally be a non-uniform array with fewer or far fewer elements than a uniform array, and can allow for the same array aperture size and minimum element spacing as a uniform array. Such a configuration can offer various benefits, including but not limited to low cost and low power consumption, and the same spatial resolution as a uniform array.

[0084] Figure 5 This is a diagram 500 illustrating example RIS configurations for sparse and uniform arrays. Diagram 500 shows example arrays: a sparse array 502, a uniform array 504 (e.g., ULA), and a uniform array 506 (e.g., ULA), each array relative to a half-wavelength (e.g., [missing information]). The x-axis of the unit is used for illustration. Sparse array 502 is defined as sparse(4) = {0, 1, 4, 6}, uniform array 504 is defined as ULA(4) = {0, 1, 2, 3}, and uniform array 506 is defined as ULA(7) = {0,1, 2, 3, 4, 5, 6}. Despite the differences in their configurations, it can be observed that the beamwidth of sparse(4) for sparse array 502 is equal to that of ULA(7) for uniform array 506 and smaller than that of ULA(4) for uniform array 504, while the spatial resolution of sparse(4) for sparse array 502 is the same as that of ULA(7) for uniform array 506 and higher than that of ULA(4) for uniform array 504.

[0085] An example of a sparse array is a differential co-array (DCA). This is for arrays with a set of array element locations. For a sparse array, DCA can be represented as the difference between the positions of two antennas. For a given sparse array, the complete set of DCA is... Spatial lag is one of them. The components have the following degrees of freedom: The cardinality, for example Regarding symmetry, , The weights for spatial lag are the number of antenna pairs that generate spatial lag. For a given sparse array, the effective DCA can be represented as the set of effective DCA. ,in The components in it are continuous. A unified degree of freedom is... The cardinality, for example And the number of irrelevant sources that can be identified within it. As an example, where , , , ,and Therefore, seven irrelevant sources can be identified.

[0086] Optimal sparse arrays can be characterized as minimal redundancy arrays (MRA) and / or minimal aperture arrays (MHA) (also known as non-redundant arrays or Golomb arrays / scales). For MRA, the antenna may be just sufficient to provide a range from 0 to... L All spatial hysteresis, e.g., holeless DCA. Zero-redundancy MRA generates each spatial hysteresis once. For robust MRA (RMRA), each spatial hysteresis can be generated at least twice. For MHA, each spatial hysteresis is generated at most once. Perfect MHA generates hysteresis from 0 to... L Each space is delayed once, but may not generate 0 and LAll spatial lags between them, for example, are not poreless. Compare MRA and MHA, when At that time, zero-redundancy MRA can be the same as perfect MHA, while when At that time, neither zero-redundancy MRA nor perfect MHA is possible. Furthermore, to determine antenna location, there may be no closed-form expression, and an exhaustive search will be performed.

[0087] Referring again to Figure 500, nested array 508 and coprime array 510 are shown. Nested arrays and coprime arrays may include two or more subarrays configured for sub-surfaces of RIS.

[0088] Generally speaking, for nested arrays, the total number of antennas For even numbers , And for odd numbers , , Nested arrays (such as nested array 508) may include two ULAs: The first ULA can be represented as: The second ULA can be represented as: While nested arrays can provide a closed-form expression and are easy to generate, they typically have high redundancy in cases of low spatial hysteresis. An example shown as nested array 508 can be represented by the following terms: N=10, N1=N2=5, and sparse (10): {0, 1, 2, 3, 4, 5, 11, 17, 23, 29}, where .

[0089] Generally speaking, for coprime arrays, the total number of antennas is... ,in and They are coprime integers, and among them Coprime arrays (such as coprime array 510) may include two ULAs: The first ULA can be represented as: The second ULA can be represented as: While coprime arrays can provide closed-form representations and are easily generated, they can also provide pore-free DCAs. An example of a coprime array 510 can be represented by the following terms: , Sparse (6): {0, 2, 3, 4, 6, 9}, where , and among them .

[0090] As noted herein, RIS can provide low-cost and low-power communication options based on, for example, a combination of positive intrinsic-negative / varactor diodes and a lack of radiated power (e.g., RIS control can use power, but the supercomponents may not transmit power). However, RIS configurations can be based on uniform arrays of supercomponents, such as uniform linear arrays ULA or UPA. In high-frequency spectra (e.g., frequency ranges specified as FR2, THz, etc.), given half-wavelength spacing and RIS surface size, small wavelengths can result in a large number of ULA / UPA supercomponents. This, in turn, leads to higher hardware costs (e.g., the more supercomponents placed on the surface, the higher the hardware cost) and higher power consumption (e.g., the control circuitry of the supercomponents consumes power). Additionally, if the inter-component spacing is greater than half the wavelength of the reflected signaling, aliasing beams and associated ambiguity in sensing results may occur. Furthermore, when utilizing smaller RIS surface sizes, the beamwidth increases accordingly, and therefore the spatial resolution decreases.

[0091] This paper relates to aspects of a reflection codebook for a RIS with a sparse metaelement array. One advantage of a sparse metaelement array at the RIS is that it achieves the same beamwidth (e.g., spatial resolution) as a uniform array, but with far fewer or fewer metaelements (e.g., as...). Figure 4 (As shown in (414, 416)), therefore, sparse metaelement arrays are well-suited for RIS-based communications while saving cost and power. According to various aspects of this paper, to achieve RIS reflection coefficient matching with the radio channel, network nodes (e.g., base stations, gNBs, etc.) can transmit a reference signal reflected by the RIS for UE reception. The UE can then measure such cascaded channels and determine / report the proposed RIS reflection coefficients for all metaelements used in the sparse metaelement array. However, as noted above, existing codebooks are based on uniform metaelement arrays; therefore, various aspects of this paper provide a codebook-based reflection coefficient reporting scheme for RIS with sparse metaelement arrays. That is, various aspects provide techniques for applying or generalizing sparse array codebook designs for RIS. In other words, it can be assumed that the RIS is formed by sparse elements.

[0092] It should also be noted that, for all aspects of this paper, while the reflective RIS may be described and / or illustrated as an example, the use of the transmissive RIS and / or the simultaneous use of the reflective RIS and the transmissive RIS is fully envisioned.

[0093] Figure 6This is a call flowchart 600 for various aspects of wireless communication. Call flowchart 600 illustrates various aspects of a wireless device (UE 602, for example, communicating with a network node (base station 604, such as a gNB or other type of base station, as shown) using a RIS with a sparse meta-element array, and wherein RIS 603 can be used for at least some of such communications. The aspects described herein with respect to base station 604 and to network nodes can generally be performed by one or more components of a base station in aggregate form and / or by a base station in decomposed form. Additionally or alternatively, as a supplement and / or alternative to the operation of base station 604, the aspects can be performed autonomously by UE 602.

[0094] In various aspects, the RIS 603 may include a sparse metaelement array configured to reflect and / or refract received signals, and the sparse metaelement array may be configured as nested sparse arrays and / or coprime sparse arrays that vertically or horizontally split the surface of the RIS 603 (e.g., split into two sub-surfaces). In various aspects, the vertical or horizontal splitting of the sparse metaelement array may be configured to form a horizontal / vertical uniform metaelement array using sparse metaelements. The horizontal / vertical uniform metaelement array may be associated with a corresponding sub-codebook including a codebook of the overall sparse metaelement array for the RIS 603. That is, the sparse metaelement array codebook may be based on the horizontal and vertical splitting configurations of the sparse metaelement array of the RIS 603, wherein the horizontal and vertical splitting configurations may each be associated with at least two sub-surface portions of the RIS 603 having a corresponding uniform metaelement array. In various aspects, the sub-codebook may be based on a DFT or a sine function.

[0095] RIS 603 can be configured to report its utilized and / or available sparse meta-element array parameters to base station 604. Base station 604 can be configured to configure UE 602 and / or RIS 603 using parameters of measured radio resources, reflection coefficient reporting resources, and / or the sparse meta-element array codebook. Such reporting and configuration are described in further detail below in the context of the remaining figures.

[0096] In the illustrated aspects, base station 604 may be configured to transmit / provide on a source channel and RIS 603 may be configured to receive reference signal 606 on the source channel. RIS 603 may be configured to reflect (at 650) reference signal 606 on the source channel to generate and provide reference signal 606' on a reflection channel. UE 602 may be configured to receive reference signal 606' on a reflection channel based on the reflection (at 650) of reference signal 606 from base station 604 on the source channel by RIS 603. In other words, UE 602 may be configured to receive reference signal (e.g., reference signal 606') from RIS 603 via a reflection channel, wherein the reflection channel is based on the sparse meta-element array of RIS 603 and the reference signal (reference signal 606) reflected (e.g., at 650) from the source channel by a network node (e.g., base station 604). In each aspect, reference signal 606 and / or reference signal 606' may be or may include CSI-RS. In each respect, at each radio resource configured by base station 604, base station 604 can be configured to transmit CSI-RS, while RIS 603 can utilize auxiliary reflection coefficients based on a sparse array and UE 602 can be configured to receive reflected signals to measure the reflection link of RIS 603.

[0097] UE 602 can be configured to obtain the reflection coefficients of the reflection channel (at 608) based on the sparse meta-element array codebook and measurements of the reflection channel. In various aspects, UE 602 can be configured to perform measurements of the reflection channel. In some aspects, in order to obtain the reflection coefficients (at 608), UE 602 can be configured to estimate the channel matrix of the reflection channel based on the measurements of the reflection channel, and UE 602 can then be configured to obtain / determine the reflection coefficients according to the configured sparse meta-element array codebook.

[0098] UE 602 may be configured to transmit / provide an indication 610 of the reflection coefficients obtained (at 608), and at least one of RIS 603 and / or base station 604 may be configured to receive the indication 610 of the reflection coefficients obtained (at 608). In various aspects, as part of providing the indication 610 of the reflection coefficients, UE 602 may be configured to transmit / provide an integration indication of the integration coefficient set for the first sub-surface portion and the second sub-surface portion. The integration indication of the integration coefficient set may be associated with the phase coherence of the beamforming gain of the beam between the first and second sub-surface portions. In various aspects, as part of providing the indication 610 of the reflection coefficients, UE 602 may be configured to transmit / provide a channel matrix indication of the estimated channel matrix of the reflection channel. In various aspects, UE 602 may be configured to transmit / provide the indication 610 of the reflection coefficients of the reflection channel as a CSI using at least one of configured channel state information resources and / or configured auxiliary reflection coefficient sets. In various respects, the indication 610 of the reflection coefficients of the reflection channel may include an index set associated with a first selected set of codewords (e.g., from its subcodebooks) of the sparse superelement array codebook and zero or more first associated quantization magnitudes and phases for the set of integration coefficients.

[0099] Base station 604 can be configured to provide reflection coefficient configuration 612 to RIS 603 based on indication 610 of reflection coefficient sent / provided by UE 602. Therefore, RIS 603 can be configured to recover the reflection coefficient (at 614) based on sparse superarray codebook, indication 610 of reflection coefficient, and / or codebook parameters configured by base station 604.

[0100] Figure 7 Figure 700 illustrates examples of nested sparse metaelement array configurations from various perspectives. Figure 700 shows a configuration for nested ( N =6) Example RIS horizontal split configuration 750 and vertical split configuration 760 for sparse meta-element arrays.

[0101] As noted, aspects of this document provide reflection codebooks (e.g., sparse superelement array codebooks) for RISs with nested or coprime sparse superelement arrays. A UE can be configured to measure the RIS reflection channel and then determine / select RIS reflection coefficients based on such a codebook / subcodebook. The UE can be configured to report the RIS reflection coefficients determined / selected based on the codebook to network nodes (e.g., base stations, gNBs, etc.), and / or can be configured to transmit the determined / selected RIS reflection coefficients directly to the RIS. According to aspects of this document, this new codebook can be based on the integration of two subcodebooks, each usable for a corresponding sub-surface of a RIS comprising a horizontal / vertical uniform superelement array.

[0102] For a horizontally split configuration 750 with nested sparse arrays, the first sub-surface 702 may include columns. (For example, for each row in column {0, 1, 2}, there is a horizontally uniform array of superelements), and the second sub-surface 704 may include columns. (For example, for each row in column {3, 7, 11}, there is a horizontally uniform array of superelements). At the first sub-surface 702, each row 706 can be a uniform array, and at the second sub-surface 704, each row 708 can be a uniform array.

[0103] For a vertically split configuration 760 with nested sparse arrays, the first sub-surface 710 may include rows. (For example, for each column in row {0, 1, 2}, there is a vertically uniform array of superelements), the second sub-surface 712 may include rows (For example, for each column in rows {3, 7, 11}, there is a vertical uniform array of superelements). At the first sub-surface 710, each column 714 can be a uniform array, and at the second sub-surface 712, each column 716 can be a uniform array.

[0104] When the UE reports the corresponding codeword in the two subcodebooks for the two sub-surfaces (e.g., UE 602 sends / provides a pair of codewords for the two sub-surfaces), Figure 6 When the reflection coefficient is indicated in the 610, the UE can also be configured to report a set of integral coefficients for two sub-surfaces (e.g., the first sub-surface 702 and the second sub-surface 704 in the horizontal split configuration 750; the first sub-surface 710 and the second sub-surface 712 in the vertical split configuration 760).

[0105] Figure 8 Figure 800 illustrates examples of coprime sparse superelement array configurations in various aspects. Figure 800 shows a configuration for arrays with coprime ( P =2; Q =3) Example RIS horizontal split configuration 750 and vertical split configuration 760 for sparse meta-element arrays.

[0106] As noted, aspects of this document provide reflection codebooks (e.g., sparse superelement array codebooks) for RISs with nested or coprime sparse superelement arrays. A UE can be configured to measure the RIS reflection channel and then determine / select RIS reflection coefficients based on such a codebook / subcodebook. The UE can be configured to report the RIS reflection coefficients determined / selected based on the codebook to network nodes (e.g., base stations, gNBs, etc.), and / or can be configured to transmit the determined / selected RIS reflection coefficients directly to the RIS. According to aspects of this document, this new codebook can be based on the integration of two subcodebooks, each usable for a corresponding sub-surface of a RIS comprising a horizontal / vertical uniform superelement array.

[0107] For a horizontally partitioned configuration 850 with a coprime sparse array, the first sub-surface 802 may include columns. (For example, for each row in column {0, 2, 4}, there is a horizontally uniform array of superelements), and the second sub-surface 704 may include columns. (For example, for each row in column {3, 6, 9}, there is a horizontally uniform array of superelements.) At the first sub-surface 802, each row 806 can be a uniform array, and at the second sub-surface 804, each row 808 can be a uniform array.

[0108] For a vertically split configuration 860 with a coprime sparse array, the first sub-surface 810 may include rows. (For example, for each column in row {0, 2, 4}, there is a vertically uniform array of superelements), and the second sub-surface 812 may include rows. (For example, for each column in row {3, 6, 9}, there is a vertical uniform array of superelements). At the first sub-surface 810, each column 814 can be a uniform array, and at the second sub-surface 812, each column 816 can be a uniform array.

[0109] Figure 9 Figure 900 illustrates examples of sparse superelement array codebooks in various aspects. Figure 900 shows configurations 950, 960, and 970.

[0110] As noted herein, the UE may provide the RIS and / or network nodes with an indication of the reflection coefficients of the reflection channel obtained by the UE, and the acquisition of the reflection coefficients of the reflection channel may be based on a reflection codebook (e.g., a sparse meta-element array codebook) and measurements of the reflection channel. The indication may be one or more codewords from the codebook, an index of a codeword, etc. In various aspects, an integral indication of the set of integral coefficients for the first and second sub-surface portions of the sparse array for the RIS may be included together with the indication of the reflection coefficients. The integral indication of the set of integral coefficients may be associated with the phase coherence of the beamforming gain between the first and second sub-surface portions, and in various aspects, the selection of codewords may be based on the integral coefficients. Since the aspects provide nested arrays or coprime arrays, the sparse array of the RIS may be divided into two uniform sub-arrays for the horizontal / vertical dimensions, as described herein, and the codebook may include two sub-codebooks for the two uniform sub-arrays (or sub-surfaces) and a set of integral coefficients.

[0111] Configuration 950 shows the rows / columns of the nested sparse superelement array of the RIS associated with codebook 908 and integral coefficient set 910. Configuration 960 shows the rows / columns of the coprime sparse superelement array of the RIS associated with codebook 912 and integral coefficient set 914. Configuration 970 shows the RIS configured using a far-field model (e.g., Figure 6 RIS 603 in the middle; Figure 7 The RIS740 in the middle; Figure 8 The RIS element set 906 (e.g., a super-element) of RIS 840 in the RIS 840. The RIS element set 906 may have a spacing d and may be aligned from -90 degrees to +90 degrees with 0 degrees as the center (e.g., the line of sight). The base station 904 may transmit a reference signal on the source channel, which is reflected towards the UE 902 by the RIS element set 906 as a reflected reference signal on the reflection channel. For the horizontal or vertical dimension in the codebook based on the sine function, the incident angle of the transmitted reference signal may be respectively And similarly, the reflection angle can be .

[0112] The codebook of a horizontally dimensional RIS sparse superelement can be a subcodebook of each uniform subarray in the horizontal dimension. Subcodebook (represented as...) ) can be used for subarrays The subarray has a size and space between components , Or 2. For nested arrays, , , , And for coprime arrays, , , , For subcodebooks: Each of them It is a candidate codeword, and This represents the total number of codewords in the subcodebook. Regarding codebooks based on sine functions, for each subcodebook... Each code word This can correspond to the RIS incident angle ( ) and reflection angle ( ),in It is an angle index. Each codeword can be constructed as: , in Represents the sub-surface portion in the vertical dimension Spacing between components Or 2, where , , It can be configured by network nodes. Or 2, where It should be pointed out that, , It can be a configuration parameter for the vertical dimension of a sparse array.

[0113] because Therefore, it can follow or , Additionally, or , ; In all aspects, Derivable from (For example, Larger It can improve codeword accuracy and precision, but may also lead to higher signaling overhead. It should be noted that... and It can be a configuration parameter for the horizontal dimension of a sparse array.

[0114] Alternatively, each subcodebook may use a DFT-based codebook. Each codeword can be constructed as: , in Or 2, , It can be configured by network nodes. Or 2. It should be noted that It can be a configuration parameter for the horizontal dimension of a sparse array.

[0115] Compared to DFT-based codebooks, the sine-based codebooks used in various aspects of this paper fit the RIS reflection coefficients better (e.g., DFT codebooks fit a one-hop channel (from network node to UE), while sine-based codebooks fit a two-hop channel (from network node to RIS to UE)).

[0116] In various aspects, combinations of one or more subarray codewords can be utilized. For example, the UE can be configured to select one or more subarray codewords and perform a weighted combination for each subarray. For example, in the first subarray, the first codeword... And in the second subarray, the second codeword ,in , , and It can be a configuration parameter for the vertical dimension of the sparse array and can be configured by network nodes, and where and Combining coefficients.

[0117] Regarding the integral coefficients of the codewords of the two subarrays, the integral coefficients This can be used to make the reflected beamforming gains of two subarrays coherent (e.g., with the same phase shift). The entire codeword can be generated by combining subcodewords. For example, for the entire sparse array in the horizontal dimension, the codeword... It can be based on a mapping from element location in a subarray to element location throughout the sparse array. and Cascading / randomized ordering.

[0118] As an example in a nested array, for the first subarray: For the second subarray: Therefore, the codebook It can be obtained through the following formula: In all aspects, the reporting parameters for the horizontal dimension may include at least one of the following: , , , and / or .

[0119] Regarding the various sine-based codebooks associated with the vertical dimension, for each sub-codebook Each code word This can correspond to the RIS incident angle ( ) and reflection angle ( ),in It is an angle index. Each codeword can be constructed as: , in Represents the sub-surface portion in the vertical dimension Spacing between components Or 2, where , , These can be configuration parameters for the vertical dimension of the sparse array and can be configured by network nodes. Or 2, and among them .

[0120] because Therefore, it can follow or , Additionally, or , ; In all aspects, Derivable from (For example, Larger It can improve codeword accuracy and precision, but may also lead to higher signaling overhead. It should be noted that... and It can be a configuration parameter for the c-dimensional sparse array.

[0121] Alternatively, each subcodebook may use a DFT-based codebook. Each codeword can be constructed as: , in Or 2, , It can be configured by network nodes. Or 2. It should be noted that It can be a configuration parameter for the v dimension of a sparse array.

[0122] In such vertical dimension scenarios, the vertical line The entire codeword can be obtained through pairs of codewords. and Integrating is used to generate the codeword. For the first subarray codeword: For the second subarray codeword: ,in , , and These can be configuration parameters for the vertical dimension of the sparse array and can be configured by network nodes. For the entire sparse array along the vertical dimension, the codewords... It can be based on a mapping from element location in a subarray to element location throughout the sparse array. and The cascading / out-of-order arrangement. Finally, the entire codeword of the sparse array RIS can be represented as... .

[0123] As an example in a nested array, for the first subarray: For the second subarray: Therefore, the codebook It is possible Obtain. In all aspects, the reporting parameters for the horizontal dimension may include at least one of the following: , , , and / or .

[0124] Figure 10 Figure 1000 illustrates examples of RIS configurations for sparse superelement array codebooks and auxiliary reflection coefficients. Figure 1000 also shows a call flowchart 1050 and configuration 1060.

[0125] Figure 10 Call flowchart 1050 illustrates various aspects of a wireless device (UE 1002, for example, communicating with a network node (base station 1004, such as a gNB or other type of base station, as shown) for a RIS with a sparse meta-element array, and wherein RIS 1003 can be used for at least some of such communications. The aspects described herein with respect to base station 1004 and to the network node can generally be performed by one or more components of a base station in aggregate form and / or by a base station in decomposed form. Additionally or alternatively, as a supplement and / or alternative to the operation of base station 1004, the aspects can be performed autonomously by UE 1002. Call flowchart 1050 can be... Figure 6 One aspect of the call flow diagram 600 (e.g., which may be executed before it).

[0126] In various aspects, the RIS 1003 may include a sparse metaelement array configured to reflect and / or refract received signals, and the sparse metaelement array may be configured as nested sparse arrays and / or coprime sparse arrays that vertically or horizontally split the surface of the RIS 1003 (e.g., split into two sub-surfaces). In various aspects, the vertical or horizontal splitting of the sparse metaelement array may be configured to form a horizontal / vertical uniform metaelement array using sparse metaelements. The horizontal / vertical uniform metaelement array may be associated with a corresponding sub-codebook including an overall sparse metaelement array codebook for the RIS 1003. That is, the sparse metaelement array codebook may be based on the horizontal and vertical splitting configurations of the sparse metaelement array of the RIS 1003, wherein the horizontal and vertical splitting configurations may each be associated with at least two sub-surface portions of the RIS 1003 having a corresponding uniform metaelement array. In various aspects, the sub-codebook may be based on a DFT or a sine function.

[0127] In the illustrated aspects, base station 1004 may be configured to receive sparse superelement codebook parameters 1006 from RIS 1003, as described herein. In various aspects, the sparse superelement array codebook may be based on a horizontally split configuration and a vertically split configuration of the sparse superelement array of RIS 1003, and the horizontally split configuration and the vertically split configuration may each be associated with at least two sub-surface portions having a corresponding uniform superelement array. Therefore, base station 1004 may be configured to receive parameter indications from RIS 1003 for a set of RIS sparse array parameters (e.g., sparse superelement codebook parameters 1006). Parameter indications for the set of RIS sparse array parameters may include at least one of horizontal configuration parameters and / or vertical configuration parameters, and may be used to configure UE 1002 to receive a reference signal and obtain associated reflection coefficients (e.g., as for...). Figure 6 As described in UE 602 (606', at 608).

[0128] For the horizontal dimension, the sparse superelement codebook parameter 1006 may include the sparse array type (e.g., nested array) and the array element number. Wait, for example, based on... Figure 5 The nested array 508 provides details for calculating the hyperelement location from these items. For the vertical dimension, the sparse hyperelement codebook parameter 1006 may include the sparse array type (e.g., coprime array), array parameters, etc. , etc., can be based on, for example, for Figure 5 The coprime array 510 provides details for calculating the superelement location from these items.

[0129] Base station 1004 can be configured to configure RIS 1003 with sparse supercomponent codebook configuration 1008. For example, base station 1004 can be configured to send / provide sparse supercomponent codebook configuration 1008 to RIS 1003 for configuration in operating mode based on sparse supercomponent codebook parameters 1006. Base station 1004 can also be configured to configure UE 1002 with sparse supercomponent codebook configuration 1010. For example, base station 1004 can be configured to send / provide sparse supercomponent codebook configuration 1010 to UE 1002 for configuration in operating mode based on sparse supercomponent codebook parameters 1006 for receiving and measuring reference signals (e.g., by...). Figure 6 (Referencing signal 606' measured by UE 602). For example, base station 1004 can use sparse superelement codebook configuration 1008 / sparse superelement codebook configuration 1010 to configure RIS 1003 and / or UE 1002 with codebook parameters, such as: for a sine function-based codebook, the codebook parameters are... and (or for DFT-based codebooks) For codebooks based on sine functions, and (or for DFT-based codebooks) ), in the horizontal dimension , For codebooks based on sine functions, and (or for DFT-based codebooks) For codebooks based on sine functions, and (or for DFT-based codebooks) ), in the vertical dimension , .

[0130] Base station 1004 can be configured to configure RIS 1003 with resource configuration 1012, which indicates that base station 1004 will be used to transmit / provide reference signals (e.g., Figure 6 The measurement radio resources (606, 606') in the reference signal. That is, the RIS 1003 can be configured with radio resources (e.g., CSI-RS resources) to be used for the reference signal and auxiliary reflection coefficients 1016 (if these are determined by the base station 1004; otherwise, the RIS 1003 can be configured to determine the auxiliary reflection coefficients 1016 and report them to the base station 1004, for example, together with the sparse superelement codebook parameters 1006).

[0131] Base station 1004 can also be configured to configure UE 1002 with resource / report configuration 1014, which indicates that base station 1004 will be used to transmit / provide reference signals (e.g., Figure 6 Resources 606, 606' in the reference signal are provided, and auxiliary reflection coefficients 1016 are indicated for channel estimation performed by UE 1002, as well as indications of reflection coefficients transmitted / provided by UE 1002 based on a reference signal (e.g., by...). Figure 6 The UE 602 provides a reporting instruction for the reflection coefficient (610).

[0132] In various respects, the auxiliary reflection coefficient 1016 can be the beamforming weight of the reflected beam set 1018, for example, it can be a sinusoidal reflected beam set, where the reflection coefficients at each subarray of the sparse array for the horizontal / vertical line are a series vector of sinusoidal functions, and the reflected beams 1018 of the two subarrays have the same incident / reflection direction. As an example of a nested array in the horizontal dimension, based on a sinusoidal series vector: and , The auxiliary reflection coefficient 1016 can be determined as: .

[0133] The auxiliary reflection coefficients used in the auxiliary reflection coefficients 1016 at the multiple radio resources being measured can be different, and the total number of auxiliary reflection coefficients 1016 can be less than or much less than the total number of existing beam scanning techniques in the compressed sensing (CS) based method.

[0134] UE 1002 can be configured to estimate the channel matrix of the reflected channel in order to determine / obtain / compute the optimal reflection coefficients, as described herein. For example, each time, base station 1004 can be configured to transmit a reference signal (e.g., CSI-RS) on the source channel, while RIS 1003 can be configured to reflect the reference signal using one or more of the auxiliary reflection coefficients 1016, such that UE 1002 receives and measures the reference signal. UE 1002 can be configured to estimate the channel matrix of the reflected channel / link based on the measurement results and / or channel estimation.

[0135] Using the least squares (LS) method, UE 1002 cannot obtain the individual channel matrix from base station 1004 to RIS 1003 (represented in Figure 1000 as follows). ) or the channel matrix from RIS 1003 to UE 1002 (although it may be through the target object, represented as Conversely, UE 1002 can be configured to obtain a cascaded matrix. ,in This is the index of the base station 1004 Tx antenna. For the CS method, UE 1002 can be configured to obtain this information separately. and For both methods, the received signal in the RIS 1003 link is ,in It is the RIS 1003 reflection coefficient at all supercomponents, and This is the pre-decoding matrix for base station 1004. After estimating the channel matrix, UE 1002 can be configured to calculate the optimal reflection coefficient in the RIS 1003 reflection coefficient based on the estimated concatenated channel matrix. ,For example .consider The entire cascaded matrix ,therefore It can be The highest effective dominant singular vector.

[0136] UE 1002 can be configured to obtain / determine the reflection coefficient for the optimal RIS 1003 based on the sparse meta-element array codebook. The reported RIS 1003 reflection coefficient is used to reduce signaling overhead. In the first configuration, if... Then UE 1002 can be configured to select four codewords (represented as...) , , , (Selected from subcodebooks respectively) , , , ), and can be configured to determine and (For example, based on its relationship with) Integral codeword with the highest correlation coefficient (As described above). UE 1002 can be configured to report (e.g., transmit / provide) one or more indices (e.g., as a set thereof) of selected codewords to base station 1004. , , , ) and / or and Zero or more of the quantized amplitude and phase (in some respects, the quantized amplitude and phase may be equal to 1). That is, in all respects, the indication of the reflection coefficients of the reflection channel includes a set of indices associated with a first selected set of codewords of the sparse superelement array codebook and zero or more first associated quantized amplitudes and phases for the set of integration coefficients.

[0137] In the second configuration, UE 1002 can be configured to first select multiple ( (typing) (Selected from codebook) For example, the selected codewords associated with the selected codeword set. The maximum number is greater than one and the codewords can be represented as UE 1002 can be configured to obtain / determine / calculate integral coefficients. For example, to maximize and The correlation coefficient between corresponding entries (e.g., all horizontal lines in the first sub-surface with a vertical surface split configuration). This can be performed for all subarrays in both the horizontal and vertical dimensions. UE1002 can be configured to report one or more of the following: , , , The value (e.g., if base station 1004 is not configured with such a value) or zero or more of such values; the selected codeword , , , The index (e.g., as its set); and , , , The quantization amplitude and phase of the reflection channel include zero or more values. Specifically, in all aspects, the indication of the reflection coefficient of the reflection channel includes an index set associated with a second selected set of codewords of the sparse superelement array codebook, zero or more values ​​associated with the second selected set of codewords of the sparse superelement array codebook, and zero or more second associated quantization amplitudes and phases of the integral coefficient set, wherein the maximum number of selected codewords associated with the second selected set of codewords is greater than one. In all aspects, because the reflection coefficient of the RIS 1003 element can have a constant modulus, after the base station 1004 receives a report from the UE 1002, the base station 1004 can be configured to use... As the RIS 1003 reflection coefficient vector in subsequent data signal transmission.

[0138] UE 1002 can be configured to report the pre-decoded matrix to base station 1004. Furthermore, base station 1004 can forward the reflection coefficient of RIS 1003 to RIS 1003, thereby configuring RIS 1003 to recover the reflection coefficient. For example, in UE 1002 as indicated above, Subsequently, UE 1002 can be configured to further determine When given At that time, the equivalent channel matrix can be transformed for the RIS 1003 reflection link (e.g., reflection channel) into Then, UE 1002 can be configured to be based on Determine and report broadband or subband using existing NR codebooks UE 1002 can be configured to report together or separately. and (For example, PMI). Finally, base station 1004 can be configured to... Information is sent / provided to RIS 1003. Use (For example, if the RIS 1003 is configured to adjust the amplitude and phase of each superelement) or (For example, if RIS 1003 is configured to adjust the phase of each superelement but not the amplitude) as a reflection coefficient vector and based on the previously configured sparse superelement array codebook parameters, RIS 1003 can be configured to recover the reflection coefficients at its sparse superelement array and maximize the reflection beamforming gain of UE 1002.

[0139] Figure 11 This is a flowchart 1100 of a wireless communication method. The method can be performed by a UE (e.g., UE 104, 602, 902, 1002; device 1504). In some aspects, the method may include combining... Figure 6 The communication process described in the document covers various aspects and / or Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 9 , Figure 10 The described aspects. This method is applicable to reflection codebooks for RIS with sparse meta-element arrays, where the UE can be configured with a sparse meta-element array codebook for the RIS, allowing the UE to obtain reflection coefficients that can be provided / reported to the RIS / network node to optimize the sparse meta-element array of the RIS. Therefore, spatial resolution for the RIS can be provided at lower cost and power than ULA / UPA implementations by utilizing sparse meta-element arrays; the sparse meta-element array of the RIS can be optimized for channel gain and throughput by providing a more accurate codebook-based reflection coefficient reporting scheme for the RIS via matching the RIS reflection coefficients with the utilized radio channel; and implementation flexibility can be improved by utilizing codebooks for nested and coprime sparse meta-element arrays on the sub-surfaces of the RIS, while still optimizing the RIS configuration.

[0140] At 1102, the UE receives a reference signal from the RIS via a reflection channel, where the reflection channel is based on a sparse meta-element array of the RIS and the reference signal is reflected from the network node via a source channel. As an example, this reception can be achieved by... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of UE 602 receiving such a reference signal from a network node (e.g., base station 604) via reflection from a RIS (e.g., RIS 603).

[0141] In all aspects, the RIS 603 (for example, Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the text may include an array of sparse metaelements configured to reflect and / or refract the received signal (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 950, 960), and sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 (950, 960) can be configured as a nested sparse array (e.g., for Figure 7 RIS 740 in the middle) and / or coprime sparse arrays (e.g., for RIS 740) and / or coprime sparse arrays (e.g., for Figure 8 These sparse arrays are suitable for RIS 840 (e.g., RIS 603), Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The surface of 1003 in the middle was vertically split (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 850 in the middle) (for example, is split into two sub-surfaces (for example, Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 (e.g., 802 / 804, 810 / 812). In all aspects, sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 Vertical division of 950, 960 (e.g., Figure 7 760 in the middle; Figure 8(860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 The 850 in the middle can be configured to form a horizontal (e.g., using sparse super-elements) Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 950, 960) uniform meta-element arrays (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 950, 960). Level (e.g., Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 950, 960) uniform meta-element arrays (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 The 950 and 960 in the series can be used with components including those for RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The overall sparse superelement array codebook (e.g., 1003) of the 1003) Figure 9 The corresponding subcodebooks of 908 and 912 (e.g., from...) Figure 9 The subarray 1 / 2 in the array is associated with this. That is, the sparse superelement array codebook (e.g., Figure 9 The 908 and 912 in the RIS can be based on the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The horizontal split configuration of 950, 960) (e.g., Figure 7 750 in the middle; Figure 8(850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle), where horizontal split configuration (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 The 860 in the RIS can each be used with the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The 1003 in the middle) has a corresponding uniform super-element array (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 At least two sub-surface portions (e.g., 950, 960) of the surface. Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 Related to 802 / 804 and 810 / 812 in [the codebook]. In various aspects, subcodebooks (e.g., from [the codebook]) are associated with [the codebook]... Figure 9 The subarray 1 / 2 in the RIS 603 can be based on DFT or on a sine function. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the diagram can be configured to report to base station 604 the parameters of its utilized and / or available sparse meta-element array (e.g., ...). Figure 10 (1006 in the original text). Base station 604 can be configured to report resources using measured radio resources, reflection coefficients, and / or sparse meta-element array codebooks (e.g., ...). Figure 9 The parameters of 908 and 912 in the text (e.g., Figure 10 Configure UE 602 and / or RIS 603 (e.g., 1006) to configure UE 602 and / or RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the figure). Such reports and configurations are described in further detail herein in the context of the accompanying drawings. Base station 604 can be configured to transmit / provide on the source channel and RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 RIS 603 (e.g., RIS 603) can be configured to receive reference signal 606 on the source channel. Figure 7740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle can be configured to reflect (at 650) the reference signal 606 on the source channel to generate and provide the reference signal 606' on the reflection channel.

[0142] UE 602 can be configured to be based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The UE 602 receives the reference signal 606' on the reflected channel (at 650) from the source channel of the base station 604 via the reflected channel (1003 in the original text). In other words, the UE 602 can be configured to receive the reference signal 606' from the RIS 603 (e.g., 1003 in the original text) via the reflected channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) receives a reference signal (e.g., reference signal 606'), wherein the reflection channel is based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The reference signal (reference signal 606) and the reference signal (reference signal 650, 960) are reflected from the source channel from the network node (e.g., base station 604) (e.g., at 650). In all aspects, reference signal 606 and / or reference signal 606' can be or may include CSI-RS. In all aspects, at each radio resource configured by base station 604, base station 604 can be configured to transmit CSI-RS, while RIS 603 (e.g., ...) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) can utilize the auxiliary reflection coefficient based on sparse array (e.g., Figure 10 (1016 in the original text) and UE 602 can be configured to receive reflected signals to measure RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The reflection link (1003 in the middle).

[0143] At position 1104, the UE obtains the reflection coefficient of the reflection channel based on the sparse meta-element array codebook and measurements of the reflection channel. As an example, this can be obtained from... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 exist Figures 7 to 10 An example of UE 602 obtaining such reflection coefficients of the reflection channel associated with RIS (e.g., RIS 603) is illustrated in the context of RIS.

[0144] UE 602 can be configured to be based on a sparse meta-element array codebook (e.g., Figure 9 The reflection coefficient of the reflected channel is obtained (at position 608) from the measurements of the reflected channel (908, 912) and the reflected channel. In various aspects, UE 602 can be configured to perform measurements of the reflected channel. In some aspects, in order to obtain the reflection coefficient (at position 608), UE 602 can be configured to estimate the channel matrix of the reflected channel based on the measurements of the reflected channel, and UE 602 can then be configured to, according to a configured sparse superelement array codebook (e.g., ... Figure 9 The reflection coefficient is obtained / determined by using 908 and 912 (in the original text).

[0145] At point 1106, the UE provides an indication of the reflection coefficient of the reflection channel to at least one of the RIS or network nodes. As an example, this provision / transmission may be made by... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of UE 602 providing such indications of the reflection coefficients of network nodes (e.g., base station 604) and / or RIS (e.g., RIS 603).

[0146] UE 602 may be configured to transmit / provide an indication 610 of the reflection coefficients obtained (at 608), and at least one of RIS 603 and / or base station 604 may be configured to receive the indication 610 of the reflection coefficients obtained (at 608). In various aspects, as part of providing the indication 610 of the reflection coefficients, UE 602 may be configured to transmit / provide an indication for the first subsurface portion and the second subsurface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The set of integral coefficients for 802 / 804 and 810 / 812 in the model (e.g., Figure 9 The integral indicators (910, 914) in the model. For the set of integral coefficients (e.g., ... Figure 9 The integral indications of 910 and 914 in the text can be used with the first sub-surface portion and the second sub-surface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The beams between 802 / 804 and 810 / 812 (e.g., Figure 10 The beamforming gain (1018) is associated with the phase coherence. In various aspects, as part of providing an indication of the reflection coefficients 610, UE 602 may be configured to transmit / provide a channel matrix indication of the estimated channel matrix of the reflection channel. In various aspects, UE 602 may be configured to use configured channel state information resources and / or configured auxiliary reflection coefficient sets (e.g., Figure 10 At least one of 1016 in the codebook is used to transmit / provide an indication 610 of the reflection coefficients of the reflection channel as a CSI. In various aspects, the indication 610 of the reflection coefficients of the reflection channel may include a codebook of sparse meta-element arrays (e.g., Figure 9 The first selected set of codewords (e.g., from its subcodebooks, e.g., from 908, 912) Figure 9 The set of indices associated with the subarray 1 / 2 in the array and the set of integration coefficients (e.g., Figure 9 The zero or more first associated quantization amplitudes and phases of (910, 914) in the model.

[0147] Base station 604 can be configured to provide reflection coefficient configuration 612 to RIS 603 (e.g., based on an indication 610 of reflection coefficient sent / provided by UE 602) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the middle). Therefore, RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the codebook can be configured to be based on a sparse superelement array codebook (e.g., Figure 9 908, 912 in the reference 610, the reflection coefficient indication and / or the codebook parameters configured by the base station 604 (e.g., Figure 10 The reflection coefficient is recovered at 1008 (at 614).

[0148] Figure 12 This is a flowchart 1200 of a wireless communication method. The method can be performed by a UE (e.g., UE 104, 602, 902, 1002; device 1504). In some aspects, the method may include combining... Figure 6 The communication process described in the document covers various aspects and / or Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 9 , Figure 10 The described aspects. This method is applicable to reflection codebooks for RIS with sparse meta-element arrays, where the UE can be configured with a sparse meta-element array codebook for the RIS, allowing the UE to obtain reflection coefficients that can be provided / reported to the RIS / network node to optimize the sparse meta-element array of the RIS. Therefore, spatial resolution for the RIS can be provided at lower cost and power than ULA / UPA implementations by utilizing sparse meta-element arrays; the sparse meta-element array of the RIS can be optimized for channel gain and throughput by providing a more accurate codebook-based reflection coefficient reporting scheme for the RIS via matching the RIS reflection coefficients with the utilized radio channel; and implementation flexibility can be improved by utilizing codebooks for nested and coprime sparse meta-element arrays on the sub-surfaces of the RIS, while still optimizing the RIS configuration.

[0149] At 1202, the UE receives a configuration indicating the sparse hyperelement array codebook from the network node. As an example, this reception can be achieved by... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 , Figure 10 exist Figures 7 to 9 The context illustrates an example of UE 602 / UE 1002 receiving such a configuration associated with RIS (e.g., RIS 603 / RIS 1003) from a network node (e.g., base station 604 / base station 1004).

[0150] Base station 1004 can be configured to configure RIS 1003 with sparse supercomponent codebook configuration 1008. For example, base station 1004 can be configured to send / provide sparse supercomponent codebook configuration 1008 to RIS 1003 for configuration in operating mode based on sparse supercomponent codebook parameters 1006. Base station 1004 can also be configured to configure UE 1002 with sparse supercomponent codebook configuration 1010. For example, base station 1004 can be configured to send / provide sparse supercomponent codebook configuration 1010 to UE 1002 for configuration in operating mode based on sparse supercomponent codebook parameters 1006 for receiving and measuring reference signals (e.g., by...). Figure 6 Reference signal 606' measured by UE 602 in the example. For example, base station 1004 can use sparse superelement codebook configuration 1008 / sparse superelement codebook configuration 1010 to configure RIS 1003 and / or UE 1002 with codebook parameters, such as: horizontal dimension , , , , , In the vertical dimension , , , , , .

[0151] At 1204, the UE receives from the network node a resource and report configuration indicating at least one of a resource associated with a reference signal or a report associated with a reflection coefficient. As an example, this reception may be performed by... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 , Figure 10 exist Figures 7 to 9 The context illustrates an example of UE 602 / UE 1002 receiving such resource and report configurations associated with the reflection coefficients of RIS (e.g., RIS 603 / RIS 1003) from a network node (e.g., base station 604 / base station 1004).

[0152] Base station 1004 can also be configured to configure UE 1002 with resource / report configuration 1014, which indicates that base station 1004 will be used to transmit / provide reference signals (e.g., Figure 6 Resources 606, 606' in the reference signal are provided, and auxiliary reflection coefficients 1016 are indicated for channel estimation performed by UE 1002, as well as indications of reflection coefficients transmitted / provided by UE 1002 based on a reference signal (e.g., by...). Figure 6 The UE 602 provides a reporting instruction for the reflection coefficient (610).

[0153] At position 1206, the UE receives a reference signal from the RIS via a reflection channel, where the reflection channel is based on a sparse meta-element array of the RIS and the reference signal is reflected from the network node via a source channel. As an example, this reception can be achieved by... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of UE 602 receiving such a reference signal from a network node (e.g., base station 604) via reflection from a RIS (e.g., RIS 603).

[0154] In all aspects, the RIS 603 (for example, Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 101003 in the text may include an array of sparse metaelements configured to reflect and / or refract the received signal (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 950, 960), and sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 (950, 960) can be configured as a nested sparse array (e.g., for Figure 7 RIS 740 in the middle) and / or coprime sparse arrays (e.g., for RIS 740) and / or coprime sparse arrays (e.g., for Figure 8 These sparse arrays are suitable for RIS 840 (e.g., RIS 603), Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The surface of 1003 in the middle was vertically split (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 850 in the middle) (for example, is split into two sub-surfaces (for example, Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 (e.g., 802 / 804, 810 / 812). In all aspects, sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 Vertical division of 950, 960 (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 The 850 in the middle can be configured to form a horizontal (e.g., using sparse super-elements) Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 The 950, 960) uniform super-element array. Horizontal (e.g., Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 The 950, 960) uniform metaelement arrays can be used with RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The overall sparse superelement array codebook (e.g., 1003) of the 1003) Figure 9 The corresponding subcodebooks of 908 and 912 (e.g., from...) Figure 9 The subarray 1 / 2 in the array is associated with this. That is, the sparse superelement array codebook (e.g., Figure 9 The 908 and 912 in the RIS can be based on the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The horizontal split configuration of 950, 960) (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle), where horizontal split configuration (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 The 860 in the RIS can each be used with the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The 1003 in the middle) has a corresponding uniform super-element array (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 At least two sub-surface portions (e.g., 950, 960) of the surface. Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 Related to 802 / 804 and 810 / 812 in [the codebook]. In various aspects, subcodebooks (e.g., from [the codebook]) are associated with [the codebook]... Figure 9 The subarray 1 / 2 in the RIS 603 can be based on DFT or on a sine function. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the diagram can be configured to report to base station 604 the parameters of its utilized and / or available sparse meta-element array (e.g., ...). Figure 10 (1006 in the original text). Base station 604 can be configured to report resources using measured radio resources, reflection coefficients, and / or sparse meta-element array codebooks (e.g., ...). Figure 9 The parameters of 908 and 912 in the text (e.g., Figure 10 Configure UE 602 and / or RIS 603 (e.g., 1006) to configure UE 602 and / or RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the figure). Such reports and configurations are described in further detail herein in the context of the accompanying drawings. Base station 604 can be configured to transmit / provide on the source channel and RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 RIS 603 (e.g., RIS 603) can be configured to receive reference signal 606 on the source channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle can be configured to reflect (at 650) the reference signal 606 on the source channel to generate and provide the reference signal 606' on the reflection channel.

[0155] UE 602 can be configured to be based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The UE 602 receives the reference signal 606' on the reflected channel (at 650) from the source channel of the base station 604 via the reflected channel (1003 in the original text). In other words, the UE 602 can be configured to receive the reference signal 606' from the RIS 603 (e.g., 1003 in the original text) via the reflected channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) receives a reference signal (e.g., reference signal 606'), wherein the reflection channel is based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The reference signal (reference signal 606) and the reference signal (reference signal 650, 960) are reflected from the source channel from the network node (e.g., base station 604) (e.g., at 650). In all aspects, reference signal 606 and / or reference signal 606' can be or may include CSI-RS. In all aspects, at each radio resource configured by base station 604, base station 604 can be configured to transmit CSI-RS, while RIS 603 (e.g., ...) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) can utilize the auxiliary reflection coefficient based on sparse array (e.g., Figure 10 (1016 in the original text) and UE 602 can be configured to receive reflected signals to measure RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The reflection link (1003 in the middle).

[0156] At position 1208, the UE obtains the reflection coefficient of the reflection channel based on the sparse meta-element array codebook and measurements of the reflection channel. As an example, this can be obtained from... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 exist Figures 7 to 10 An example of UE 602 obtaining such reflection coefficients of the reflection channel associated with RIS (e.g., RIS 603) is illustrated in the context of RIS.

[0157] UE 602 can be configured to be based on a sparse meta-element array codebook (e.g., Figure 9 The reflection coefficient of the reflected channel is obtained (at position 608) from the measurements of the reflected channel (908, 912) and the reflected channel. In various aspects, UE 602 can be configured to perform measurements of the reflected channel. In some aspects, in order to obtain the reflection coefficient (at position 608), UE 602 can be configured to estimate the channel matrix of the reflected channel based on the measurements of the reflected channel, and UE 602 can then be configured to, according to a configured sparse superelement array codebook (e.g., ... Figure 9 The reflection coefficient is obtained / determined by using 908 and 912 (in the original text).

[0158] At 1210, the UE provides an indication of the reflection coefficient of the reflection channel to at least one of the RIS or network nodes. As an example, this provision / transmission may be made by... Figure 15 One or more of the components 198, transceiver 1522 and / or antenna 1580 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of UE 602 providing such indications of the reflection coefficients of network nodes (e.g., base station 604) and / or RIS (e.g., RIS 603).

[0159] UE 602 may be configured to transmit / provide an indication 610 of the reflection coefficients obtained (at 608), and at least one of RIS 603 and / or base station 604 may be configured to receive the indication 610 of the reflection coefficients obtained (at 608). In various aspects, as part of providing the indication 610 of the reflection coefficients, UE 602 may be configured to transmit / provide an indication for the first subsurface portion and the second subsurface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The set of integral coefficients for 802 / 804 and 810 / 812 in the model (e.g., Figure 9 The integral indicators (910, 914) in the model. For the set of integral coefficients (e.g., ... Figure 9 The integral indications of 910 and 914 in the text can be used with the first sub-surface portion and the second sub-surface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The beams between 802 / 804 and 810 / 812 (e.g., Figure 10 The beamforming gain (1018) is associated with the phase coherence. In various aspects, as part of providing an indication of the reflection coefficients 610, UE 602 may be configured to transmit / provide a channel matrix indication of the estimated channel matrix of the reflection channel. In various aspects, UE 602 may be configured to use configured channel state information resources and / or configured auxiliary reflection coefficient sets (e.g., Figure 10 At least one of 1016 in the codebook is used to transmit / provide an indication 610 of the reflection coefficients of the reflection channel as a CSI. In various aspects, the indication 610 of the reflection coefficients of the reflection channel may include a codebook of sparse meta-element arrays (e.g., Figure 9 The first selected set of codewords (e.g., from its subcodebooks, e.g., from 908, 912) Figure 9 The set of indices associated with the subarray 1 / 2 in the array and the set of integration coefficients (e.g., Figure 9 The zero or more first associated quantization amplitudes and phases of (910, 914) in the model.

[0160] Base station 604 can be configured to provide reflection coefficient configuration 612 to RIS 603 (e.g., based on an indication 610 of reflection coefficient sent / provided by UE 602) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the middle). Therefore, RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the codebook can be configured to be based on a sparse superelement array codebook (e.g., Figure 9 908, 912 in the reference 610, the reflection coefficient indication and / or the codebook parameters configured by the base station 604 (e.g., Figure 10 The reflection coefficient is recovered at 1008 (at 614).

[0161] Figure 13 This is a flowchart 1300 of a wireless communication method. The method can be performed by network nodes such as base stations, gNBs, etc. (e.g., base stations 102, 604, 904, 1004; network entities 1502, 1602). In some aspects, the method may include combining... Figure 6 The communication process described in the document covers various aspects and / or Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 9 , Figure 10 The described aspects. This method is applicable to reflection codebooks for RIS with sparse meta-element arrays, where the UE can be configured with a sparse meta-element array codebook for the RIS, allowing the UE to obtain reflection coefficients that can be provided / reported to the RIS / network node to optimize the sparse meta-element array of the RIS. Therefore, spatial resolution for the RIS can be provided at lower cost and power than ULA / UPA implementations by utilizing sparse meta-element arrays; the sparse meta-element array of the RIS can be optimized for channel gain and throughput by providing a more accurate codebook-based reflection coefficient reporting scheme for the RIS via matching the RIS reflection coefficients with the utilized radio channel; and implementation flexibility can be improved by utilizing codebooks for nested and coprime sparse meta-element arrays on the sub-surfaces of the RIS, while still optimizing the RIS configuration.

[0162] At 1302, the network node provides the UE with a reference signal on the source channel via reflection on the reflection channel of a RIS-based sparse meta-element array. As an example, this provision / transmission can be performed by... Figure 15One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of a network node (e.g., base station 604) providing / transmitting such a reference signal to a UE (e.g., UE 602) via a reflection from a RIS (e.g., RIS 603).

[0163] In all aspects, the RIS 603 (for example, Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the text may include an array of sparse metaelements configured to reflect and / or refract the received signal (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 950, 960), and sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 (950, 960) can be configured as a nested sparse array (e.g., for Figure 7 RIS 740 in the middle) and / or coprime sparse arrays (e.g., for RIS 740) and / or coprime sparse arrays (e.g., for Figure 8 These sparse arrays are suitable for RIS 840 (e.g., RIS 603), Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The surface of 1003 in the middle was vertically split (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 850 in the middle) (for example, is split into two sub-surfaces (for example, Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 (e.g., 802 / 804, 810 / 812). In all aspects, sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 Vertical division of 950, 960 (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 The 850 in the middle can be configured to form a horizontal (e.g., using sparse super-elements) Figure 7706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 The 950, 960) uniform super-element array. Horizontal (e.g., Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 The 950, 960) uniform metaelement arrays can be used with RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The overall sparse superelement array codebook (e.g., 1003) of the 1003) Figure 9 The corresponding subcodebooks of 908 and 912 (e.g., from...) Figure 9 The subarray 1 / 2 in the array is associated with this. That is, the sparse superelement array codebook (e.g., Figure 9 The 908 and 912 in the RIS can be based on the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The horizontal split configuration of 950, 960) (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle), where horizontal split configuration (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 The 860 in the RIS can each be used with the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The 1003 in the middle) has a corresponding uniform super-element array (e.g., Figure 7The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 At least two sub-surface portions (e.g., 950, 960) of the surface. Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 Related to 802 / 804 and 810 / 812 in [the codebook]. In various aspects, subcodebooks (e.g., from [the codebook]) are associated with [the codebook]... Figure 9 The subarray 1 / 2 in the RIS 603 can be based on DFT or on a sine function. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the diagram can be configured to report to base station 604 the parameters of its utilized and / or available sparse meta-element array (e.g., ...). Figure 10 (1006 in the original text). Base station 604 can be configured to report resources using measured radio resources, reflection coefficients, and / or sparse meta-element array codebooks (e.g., ...). Figure 9 The parameters of 908 and 912 in the text (e.g., Figure 10 Configure UE 602 and / or RIS 603 (e.g., 1006) to configure UE 602 and / or RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the figure). Such reports and configurations are described in further detail herein in the context of the accompanying drawings. Base station 604 can be configured to transmit / provide on the source channel and RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 RIS 603 (e.g., RIS 603) can be configured to receive reference signal 606 on the source channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle can be configured to reflect (at 650) the reference signal 606 on the source channel to generate and provide the reference signal 606' on the reflection channel.

[0164] UE 602 can be configured to be based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10The UE 602 receives the reference signal 606' on the reflected channel (at 650) from the source channel of the base station 604 via the reflected channel (1003 in the original text). In other words, the UE 602 can be configured to receive the reference signal 606' from the RIS 603 (e.g., 1003 in the original text) via the reflected channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) receives a reference signal (e.g., reference signal 606'), wherein the reflection channel is based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The reference signal (reference signal 606) and the reference signal (reference signal 650, 960) are reflected from the source channel from the network node (e.g., base station 604) (e.g., at 650). In all aspects, reference signal 606 and / or reference signal 606' can be or may include CSI-RS. In all aspects, at each radio resource configured by base station 604, base station 604 can be configured to transmit CSI-RS, while RIS 603 (e.g., ...) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) can utilize the auxiliary reflection coefficient based on sparse array (e.g., Figure 10 (1016 in the original text) and UE 602 can be configured to receive reflected signals to measure RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The reflection link (1003 in the middle).

[0165] At 1304, the network node receives from the UE an indication of the reflection coefficient of the reflection channel, where the reflection coefficient is based on the sparse metaelement array codebook and measurements of the reflection channel. As an example, this reception can be achieved by... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of a network node (e.g., base station 604) receiving such an indication from a UE (e.g., UE 602) of the reflection coefficients of a reflection channel associated with a RIS (e.g., RIS 603).

[0166] UE 602 may be configured to transmit / provide an indication 610 of the reflection coefficients obtained (at 608), and at least one of RIS 603 and / or base station 604 may be configured to receive the indication 610 of the reflection coefficients obtained (at 608). In various aspects, as part of providing the indication 610 of the reflection coefficients, UE 602 may be configured to transmit / provide an indication for the first subsurface portion and the second subsurface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The set of integral coefficients for 802 / 804 and 810 / 812 in the model (e.g., Figure 9 The integral indicators (910, 914) in the model. For the set of integral coefficients (e.g., ... Figure 9 The integral indications of 910 and 914 in the text can be used with the first sub-surface portion and the second sub-surface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The beams between 802 / 804 and 810 / 812 (e.g., Figure 10 The beamforming gain (1018) is associated with the phase coherence. In various aspects, as part of providing an indication of the reflection coefficients 610, UE 602 may be configured to transmit / provide a channel matrix indication of the estimated channel matrix of the reflection channel. In various aspects, UE 602 may be configured to use configured channel state information resources and / or configured auxiliary reflection coefficient sets (e.g., Figure 10 At least one of 1016 in the codebook is used to transmit / provide an indication 610 of the reflection coefficients of the reflection channel as a CSI. In various aspects, the indication 610 of the reflection coefficients of the reflection channel may include a codebook of sparse meta-element arrays (e.g., Figure 9 The first selected set of codewords (e.g., from its subcodebooks, e.g., from 908, 912) Figure 9 The set of indices associated with the subarray 1 / 2 in the array and the set of integration coefficients (e.g., Figure 9 The UE602 can be configured to use zero or more first associated quantized amplitudes and phases (910, 914) based on a sparse metaelement array codebook (e.g., ...). Figure 9 The reflection coefficient of the reflected channel is obtained (at position 608) from the measurements of the reflected channel (908, 912) and the reflected channel. In various aspects, UE 602 can be configured to perform measurements of the reflected channel. In some aspects, in order to obtain the reflection coefficient (at position 608), UE 602 can be configured to estimate the channel matrix of the reflected channel based on the measurements of the reflected channel, and UE 602 can then be configured to, according to a configured sparse superelement array codebook (e.g., ... Figure 9 The reflection coefficient is obtained / determined by using 908 and 912 (in the original text).

[0167] At position 1306, the network node configures the RIS using the reflection coefficients of the reflection channel. As an example, this provide / transmit can be... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of a network node (e.g., base station 604) providing / transmitting such a reference signal to a UE (e.g., UE 602) via a reflection from a RIS (e.g., RIS 603).

[0168] Base station 604 can be configured to provide reflection coefficient configuration 612 to RIS 603 (e.g., based on an indication 610 of reflection coefficient sent / provided by UE 602) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the middle). Therefore, RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the codebook can thus be configured based on a sparse superelement array codebook (e.g., Figure 9 908, 912 in the reference 610, the reflection coefficient indication and / or the codebook parameters configured by the base station 604 (e.g., Figure 10 The reflection coefficient is recovered at 1008 (at 614).

[0169] Figure 14 This is a flowchart 1400 of a wireless communication method. The method can be performed by network nodes such as base stations, gNBs, etc. (e.g., base stations 102, 604, 904, 1004; network entities 1502, 1602). In some aspects, the method may include combining... Figure 6 The communication process described in the document covers various aspects and / or Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 9 , Figure 10The described aspects. This method is applicable to reflection codebooks for RIS with sparse meta-element arrays, where the UE can be configured with a sparse meta-element array codebook for the RIS, allowing the UE to obtain reflection coefficients that can be provided / reported to the RIS / network node to optimize the sparse meta-element array of the RIS. Therefore, spatial resolution for the RIS can be provided at lower cost and power than ULA / UPA implementations by utilizing sparse meta-element arrays; the sparse meta-element array of the RIS can be optimized for channel gain and throughput by providing a more accurate codebook-based reflection coefficient reporting scheme for the RIS via matching the RIS reflection coefficients with the utilized radio channel; and implementation flexibility can be improved by utilizing codebooks for nested and coprime sparse meta-element arrays on the sub-surfaces of the RIS, while still optimizing the RIS configuration.

[0170] At 1402, the network node receives a parameter indication of the RIS sparse array parameter set from the RIS, wherein the parameter indication of the RIS sparse array parameter set includes at least one of horizontal configuration parameters or vertical configuration parameters. As an example, this reception may be performed by... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 , Figure 10 exist Figures 7 to 9 The context illustrates an example of a network node (e.g., base station 604) receiving such parameter indications from a RIS (e.g., RIS 603 / RIS 1003).

[0171] Base station 1004 can be configured to receive sparse superelement codebook parameters 1006 from RIS 1003, as described herein. In various respects, the sparse superelement array codebook can be configured based on the horizontal partitioning of the sparse superelement array of RIS 1003 (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle), and horizontally split configuration (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 The 860 in the middle can each be connected with a corresponding uniform array of super-elements (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 At least two sub-surface portions (e.g., 950, 960) of the surface. Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 This is associated with 802 / 804, 810 / 812 in the RIS. Therefore, base station 1004 can be configured to receive parameter indications for the RIS sparse array parameter set (e.g., sparse superelement codebook parameters 1006) from RIS 1003. The parameter indications for the RIS sparse array parameter set (e.g., sparse superelement codebook parameters 1006) may include at least one of horizontal configuration parameters and / or vertical configuration parameters, and can be used to configure UE 1002 to receive reference signals and obtain associated reflection coefficients (e.g., as for...). Figure 6 As described in UE 602 (606', at 608).

[0172] For the horizontal dimension, the sparse superelement codebook parameter 1006 may include the sparse array type (e.g., nested array) and the array element number. Wait, for example, based on... Figure 5 The nested array 508 provides details for calculating the hyperelement location from these items. For the vertical dimension, the sparse hyperelement codebook parameter 1006 may include the sparse array type (e.g., coprime array), array parameters, etc. , etc., can be based on, for example, for Figure 5 The coprime array 510 provides details for calculating the superelement location from these items.

[0173] At 1404, the network node configures the UE based on the parameter indication of the RIS sparse array parameter set, using a configuration that indicates the sparse superelement array codebook. As an example, this configuration can be provided by... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 , Figure 10 exist Figures 7 to 9 In the context of this example, a network node (e.g., base station 604 / base station 1004) configures a UE (e.g., UE 602 / UE 1002) with such a configuration that indicates the sparse superelement array codebook associated with the RIS (e.g., RIS 603 / RIS 1003).

[0174] Base station 1004 can be configured to configure RIS 1003 with sparse supercomponent codebook configuration 1008. For example, base station 1004 can be configured to send / provide sparse supercomponent codebook configuration 1008 to RIS 1003 for configuration in operating mode based on sparse supercomponent codebook parameters 1006. Base station 1004 can also be configured to configure UE 1002 with sparse supercomponent codebook configuration 1010. For example, base station 1004 can be configured to send / provide sparse supercomponent codebook configuration 1010 to UE 1002 for configuration in operating mode based on sparse supercomponent codebook parameters 1006 for receiving and measuring reference signals (e.g., by...). Figure 6 Reference signal 606' measured by UE 602 in the example. For example, base station 1004 can use sparse superelement codebook configuration 1008 / sparse superelement codebook configuration 1010 to configure RIS 1003 and / or UE 1002 with codebook parameters, such as: horizontal dimension , , , , , In the vertical dimension , , , , , .

[0175] At 1406, the network node configures the UE using a resource and reporting configuration that indicates at least one of the resources associated with the reference signal or the reports associated with the reflection coefficient. As an example, this configuration can be provided by... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 , Figure 10 exist Figures 7 to 9 The context illustrates an example of a network node (e.g., base station 604) configuring a UE (e.g., UE 602) with such resources and reporting configurations.

[0176] Base station 1004 can be configured to configure RIS 1003 with resource configuration 1012, which indicates that base station 1004 will be used to transmit / provide reference signals (e.g., Figure 6The measurement radio resources (606, 606') in the reference signal. That is, RIS 1003 can be configured with radio resources (e.g., CSI-RS resources) to be used for the reference signal and auxiliary reflection coefficients 1016 (if these are determined by base station 1004; otherwise, RIS 1003 can be configured to determine the auxiliary reflection coefficients 1016 and report them to base station 1004, for example, together with sparse superelement codebook parameters 1006). Base station 1004 can also be configured to configure UE 1002 with resource / report configuration 1014, which indicates that base station 1004 will use to transmit / provide the reference signal (e.g., ...). Figure 6 Resources 606, 606' in the reference signal are provided, and auxiliary reflection coefficients 1016 are indicated for channel estimation performed by UE 1002, as well as indications of reflection coefficients transmitted / provided by UE 1002 based on a reference signal (e.g., by...). Figure 6 The UE 602 provides a reporting instruction for the reflection coefficient (610).

[0177] At 1408, the network node provides the UE with a reference signal on the source channel via reflection on the reflection channel of a RIS-based sparse meta-element array. As an example, this provision / transmission can be performed by... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of a network node (e.g., base station 604) providing / transmitting such a reference signal to a UE (e.g., UE 602) via a reflection from a RIS (e.g., RIS 603).

[0178] In all aspects, the RIS 603 (for example, Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the text may include an array of sparse metaelements configured to reflect and / or refract the received signal (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 950, 960), and sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 (950, 960) can be configured as a nested sparse array (e.g., for Figure 7 RIS 740 in the middle) and / or coprime sparse arrays (e.g., for RIS 740) and / or coprime sparse arrays (e.g., for Figure 8 These sparse arrays are suitable for RIS 840 (e.g., RIS 603), Figure 7740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The surface of 1003 in the middle was vertically split (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 850 in the middle) (for example, is split into two sub-surfaces (for example, Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 (e.g., 802 / 804, 810 / 812). In all aspects, sparse meta-element arrays (e.g., Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 Vertical division of 950, 960 (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle) or horizontal split (e.g., Figure 7 750 in the middle; Figure 8 The 850 in the middle can be configured to form a horizontal (e.g., using sparse super-elements) Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 950, 960) uniform meta-element arrays (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 950, 960). Level (e.g., Figure 7 706 and 708 in the middle; Figure 8 806 and 808 in the middle; Figure 9 (950, 960) or vertical (e.g., Figure 7 714 and 716 in the middle; Figure 8 814 and 816 in the middle; Figure 9 950, 960) uniform meta-element arrays (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 The 950 and 960 in the series can be used with components including those for RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9906 in the middle; Figure 10 The overall sparse superelement array codebook (e.g., 1003) of the 1003) Figure 9 The corresponding subcodebooks of 908 and 912 (e.g., from...) Figure 9 The subarray 1 / 2 in the array is associated with this. That is, the sparse superelement array codebook (e.g., Figure 9 The 908 and 912 in the RIS can be based on the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6 The horizontal split configuration of 950, 960) (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 (860 in the middle), where horizontal split configuration (e.g., Figure 7 750 in the middle; Figure 8 (850 in the middle) and vertical split configuration (e.g., Figure 7 760 in the middle; Figure 8 The 860 in the RIS can each be used with the RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The 1003 in the middle) has a corresponding uniform super-element array (e.g., Figure 7 The numbers 706, 708, 714, and 716 in the original text are included. Figure 8 The numbers 806, 808, 814, and 816 in the text are included. Figure 9 At least two sub-surface portions (e.g., 950, 960) of the surface. Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 Related to 802 / 804 and 810 / 812 in [the codebook]. In various aspects, subcodebooks (e.g., from [the codebook]) are associated with [the codebook]... Figure 9 The subarray 1 / 2 in the RIS 603 can be based on DFT or on a sine function. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the diagram can be configured to report to base station 604 the parameters of its utilized and / or available sparse meta-element array (e.g., ...). Figure 10(1006 in the original text). Base station 604 can be configured to report resources using measured radio resources, reflection coefficients, and / or sparse meta-element array codebooks (e.g., ...). Figure 9 The parameters of 908 and 912 in the text (e.g., Figure 10 Configure UE 602 and / or RIS 603 (e.g., 1006) to configure UE 602 and / or RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the figure). Such reports and configurations are described in further detail herein in the context of the accompanying drawings. Base station 604 can be configured to transmit / provide on the source channel and RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 RIS 603 (e.g., RIS 603) can be configured to receive reference signal 606 on the source channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle can be configured to reflect (at 650) the reference signal 606 on the source channel to generate and provide the reference signal 606' on the reflection channel.

[0179] UE 602 can be configured to be based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The UE 602 receives the reference signal 606' on the reflected channel (at 650) from the source channel of the base station 604 via the reflected channel (1003 in the original text). In other words, the UE 602 can be configured to receive the reference signal 606' from the RIS 603 (e.g., 1003 in the original text) via the reflected channel. Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) receives a reference signal (e.g., reference signal 606'), wherein the reflection channel is based on RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 sparse super-element arrays (e.g., 1003) in the middle Figure 7 750 and 760 in the middle; Figure 8 850 and 860 in the middle; Figure 6The reference signal (reference signal 606) and the reference signal (reference signal 650, 960) are reflected from the source channel from the network node (e.g., base station 604) (e.g., at 650). In all aspects, reference signal 606 and / or reference signal 606' can be or may include CSI-RS. In all aspects, at each radio resource configured by base station 604, base station 604 can be configured to transmit CSI-RS, while RIS 603 (e.g., ...) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the middle) can utilize the auxiliary reflection coefficient based on sparse array (e.g., Figure 10 (1016 in the original text) and UE 602 can be configured to receive reflected signals to measure RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 The reflection link (1003 in the middle).

[0180] At 1410, the network node receives from the UE an indication of the reflection coefficient of the reflection channel, where the reflection coefficient is based on the sparse meta-element array codebook and measurements of the reflection channel. As an example, this reception can be achieved by... Figure 16 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of a network node (e.g., base station 604) receiving such an indication from a UE (e.g., UE 602) of the reflection coefficients of a reflection channel associated with a RIS (e.g., RIS 603).

[0181] UE 602 may be configured to transmit / provide an indication 610 of the reflection coefficients obtained (at 608), and at least one of RIS 603 and / or base station 604 may be configured to receive the indication 610 of the reflection coefficients obtained (at 608). In various aspects, as part of providing the indication 610 of the reflection coefficients, UE 602 may be configured to transmit / provide an indication for the first subsurface portion and the second subsurface portion (e.g., Figure 7 702 / 704 and 710 / 712 in the series; Figure 8 The set of integral coefficients for 802 / 804 and 810 / 812 in the model (e.g., Figure 9 The integral indicators (910, 914) in the model. For the set of integral coefficients (e.g., ... Figure 9 The integral indications of 910 and 914 in the text can be used with the first sub-surface portion and the second sub-surface portion (e.g., Figure 7702 / 704 and 710 / 712 in the series; Figure 8 The beams between 802 / 804 and 810 / 812 (e.g., Figure 10 The beamforming gain (1018) is associated with the phase coherence. In various aspects, as part of providing an indication of the reflection coefficients 610, UE 602 may be configured to transmit / provide a channel matrix indication of the estimated channel matrix of the reflection channel. In various aspects, UE 602 may be configured to use configured channel state information resources and / or configured auxiliary reflection coefficient sets (e.g., Figure 10 At least one of 1016 in the codebook is used to transmit / provide an indication 610 of the reflection coefficients of the reflection channel as a CSI. In various aspects, the indication 610 of the reflection coefficients of the reflection channel may include a codebook of sparse meta-element arrays (e.g., Figure 9 The first selected set of codewords (e.g., from its subcodebooks, e.g., from 908, 912) Figure 9 The set of indices associated with the subarray 1 / 2 in the array and the set of integration coefficients (e.g., Figure 9 The UE602 can be configured to use zero or more first associated quantized amplitudes and phases (910, 914) based on a sparse metaelement array codebook (e.g., ...). Figure 9 The reflection coefficient of the reflected channel is obtained (at position 608) from the measurements of the reflected channel (908, 912) and the reflected channel. In various aspects, UE 602 can be configured to perform measurements of the reflected channel. In some aspects, in order to obtain the reflection coefficient (at position 608), UE 602 can be configured to estimate the channel matrix of the reflected channel based on the measurements of the reflected channel, and UE 602 can then be configured to, according to a configured sparse superelement array codebook (e.g., ... Figure 9 The reflection coefficient is obtained / determined by using 908 and 912 (in the original text).

[0182] At position 1412, the network node configures the RIS using the reflection coefficients of the reflection channel. As an example, this provide / transmit can be... Figure 15 One or more of the components 199, transceiver 1646 and / or antenna 1680 are performed. Figure 6 exist Figures 7 to 10 The context illustrates an example of a network node (e.g., base station 604) providing / transmitting such a reference signal to a UE (e.g., UE 602) via a reflection from a RIS (e.g., RIS 603).

[0183] Base station 604 can be configured to provide reflection coefficient configuration 612 to RIS 603 (e.g., based on an indication 610 of reflection coefficient sent / provided by UE 602) Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 (1003 in the middle). Therefore, RIS 603 (e.g., Figure 7 740 in the middle; Figure 8 840 in the middle; Figure 9 906 in the middle; Figure 10 1003 in the codebook can thus be configured based on a sparse superelement array codebook (e.g., Figure 9 908, 912 in the reference 610, the reflection coefficient indication and / or the codebook parameters configured by the base station 604 (e.g., Figure 10 The reflection coefficient is recovered at 1008 (at 614).

[0184] Figure 15Figure 1500 illustrates an example of a hardware implementation of device 1504. Device 1504 may be a UE, a component of a UE, or implement UE functionality. In some aspects, device 1504 may include at least one cellular baseband processor 1524 (also referred to as a modem) coupled to one or more transceivers 1522 (e.g., cellular RF transceivers). Cellular baseband processor 1524 may include at least one on-chip memory 1524'. In some aspects, device 1504 may also include one or more Subscriber Identity Module (SIM) cards 1520 and at least one application processor 1506 coupled to a Secure Digital Card (SD) card 1508 and a screen 1510. Application processor 1506 may include on-chip memory 1506'. In some aspects, device 1504 may also include a Bluetooth module 1512, a WLAN module 1514, an SPS module 1516 (e.g., a GNSS module), one or more sensor modules 1518 (e.g., a barometric pressure sensor / altimeter; motion sensors such as an inertial measurement unit (IMU), gyroscope, and / or accelerometer; light detection and ranging (LIDAR), radio-assisted detection and ranging (RADAR), sound navigation and ranging (SONAR), magnetometer, audio, and / or other technologies for positioning), an additional memory module 1526, a power supply 1530, and / or a camera 1532. Bluetooth module 1512, WLAN module 1514, and SPS module 1516 may include an on-chip transceiver (TRX) (or in some cases, only a receiver (RX)). Bluetooth module 1512, WLAN module 1514, and SPS module 1516 may include their own dedicated antennas and / or communicate using antenna 1580. Cellular baseband processor 1524 communicates with UE 104 and / or RU associated with network entity 1502 via transceiver 1522 through one or more antennas 1580. Cellular baseband processor 1524 and application processor 1506 may each include computer-readable media / memory 1524', 1506'. Additional memory module 1526 may also be considered computer-readable media / memory. Each computer-readable media / memory 1524', 1506', 1526 may be non-transitory. Cellular baseband processor 1524 and application processor 1506 are each responsible for general processing, including the execution of software stored on the computer-readable media / memory. When executed by cellular baseband processor 1524 / application processor 1506, the software causes cellular baseband processor 1524 / application processor 1506 to perform the various functions described above. Cellular baseband processor 1524 and application processor 1506 are configured to perform the various functions described above based at least in part on information stored in memory.That is, the cellular baseband processor 1524 and application processor 1506 can be configured to perform a first subset of the various functions described above without information stored in memory, and can be configured to perform a second subset of the various functions described above based on information stored in memory. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 1524 / application processor 1506 during software execution. The cellular baseband processor 1524 / application processor 1506 can be a component of the UE 350 and can include at least one of a memory 360 and / or at least one of a TX processor 368, an RX processor 356, and a controller / processor 359. In one configuration, the device 1504 can be at least one processor chip (modem and / or application) and includes only the cellular baseband processor 1524 and / or application processor 1506, while in another configuration, the device 1504 can be the entire UE (e.g., see below). Figure 3 The UE 350 includes an additional module of the device 1504.

[0185] As discussed above, component 198 can be configured to receive a reference signal from a reconfigurable smart surface (RIS) via a reflection channel, wherein the reflection channel is based on a sparse metaelement array of the RIS and the reference signal is reflected from a network node via a source channel. Component 198 can also be configured to obtain the reflection coefficient of the reflection channel based on measurements of the sparse metaelement array codebook and the reflection channel. Component 198 can also be configured to provide an indication of the reflection coefficient of the reflection channel to at least one of the RIS or the network node. Component 198 can be configured to receive a configuration indicating the sparse metaelement array codebook from the network node. Component 198 can be configured to receive a resource and report configuration indicating at least one of a resource associated with the reference signal or a report associated with the reflection coefficient from the network node. Component 198 can also be configured to perform a combination Figure 11 , Figure 12 , Figure 13 , Figure 14 Any aspect described in the flowchart of any of the above and / or by the UE for any aspect Figures 4 to 10Any aspect of the process / algorithm executed by any of the processors. Component 198 may be within cellular baseband processor 1524, application processor 1506, or both cellular baseband processor 1524 and application processor 1506. Component 198 may be one or more hardware components specifically configured to execute the stated process / algorithm, implemented by one or more processors configured to execute the stated process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination thereof. When multiple processors are implemented, the multiple processors may execute the stated process / algorithm individually or in combination. As shown, device 1504 may include a variety of components configured for various functions. In one configuration, device 1504 (and specifically cellular baseband processor 1524 and / or application processor 1506) may include components for receiving a reference signal from the RIS via a reflection channel, wherein the reflection channel is based on a sparse meta-element array of the RIS and the reference signal is reflected from a network node via a source channel. In this configuration, device 1504 (and specifically cellular baseband processor 1524 and / or application processor 1506) may include components for obtaining the reflection coefficient of the reflection channel based on measurements of the sparse meta-element array codebook and the reflection channel. In this configuration, device 1504 (and specifically cellular baseband processor 1524 and / or application processor 1506) may include components for providing an indication of the reflection coefficient of the reflection channel to at least one of the RIS or network nodes. In one configuration, device 1504 (and specifically cellular baseband processor 1524 and / or application processor 1506) may include components for receiving a configuration indicating the sparse meta-element array codebook from the network node. In one configuration, device 1504 (and specifically cellular baseband processor 1524 and / or application processor 1506) may include components for receiving a resource and report configuration indicating at least one of resources associated with a reference signal or reports associated with the reflection coefficient from the network node. These components may be components 198 of device 1504 configured to perform the functions described therein. As described above, device 1504 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Thus, in one configuration, these components may be the TX processor 368, the RX processor 356, and / or the controller / processor 359 configured to perform the functions described therein.

[0186] Figure 16Figure 1600 illustrates an example of a hardware implementation for network entity 1602. Network entity 1602 may be a BS, a component of a BS, or implement BS functionality. Network entity 1602 may include at least one of CU 1610, DU 1630, or RU 1640. For example, depending on the layer functionality processed by component 199, network entity 1602 may include: CU 1610; both CU 1610 and DU 1630; each of CU 1610, DU 1630, and RU 1640; DU 1630; both DU 1630 and RU 1640; or RU 1640. CU 1610 may include at least one CU processor 1612. CU processor 1612 may include on-chip memory 1612'. In some aspects, CU 1610 may also include an additional memory module 1614 and a communication interface 1618. CU 1610 communicates with DU 1630 via a midhaul link such as an F1 interface. DU 1630 may include at least one DU processor 1632. DU processor 1632 may include on-chip memory 1632'. In some aspects, DU 1630 may also include an additional memory module 1634 and a communication interface 1638. DU 1630 communicates with RU 1640 via a fronthaul link. RU 1640 may include at least one RU processor 1642. RU processor 1642 may include on-chip memory 1642'. In some aspects, RU 1640 may also include an additional memory module 1644, one or more transceivers 1646, an antenna 1680, and a communication interface 1648. RU 1640 communicates with UE 104. On-chip memories 1612', 1632', 1642' and additional memory modules 1614, 1634, 1644 may each be considered as computer-readable media / memory. Each computer-readable medium / memory can be non-transitory. Each of processors 1612, 1632, and 1642 is responsible for general processing, including executing software stored on the computer-readable medium / memory. When executed by the corresponding processor, the software causes that processor to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the processor while executing the software.

[0187] As discussed above, component 199 can be configured to provide a reference signal on the source channel to a user equipment (UE) via reflection on a reflection channel of a RIS-based sparse meta-element array. Component 199 can also be configured to receive from the UE an indication of the reflection coefficients of the reflection channel, wherein the reflection coefficients of the reflection channel are based on the sparse meta-element array codebook and measurements of the reflection channel. Component 199 can also be configured to configure the RIS using the reflection coefficients of the reflection channel. Component 199 can be configured to receive from the RIS a parameter indication of a RIS sparse array parameter set, wherein the parameter indication of the RIS sparse array parameter set includes at least one of horizontal configuration parameters or vertical configuration parameters. Component 199 can be configured to configure the UE using a configuration indicating the sparse meta-element array codebook based on the parameter indication of the RIS sparse array parameter set. Component 199 can be configured to configure the UE using a resource and report configuration indicating at least one of resources associated with the reference signal or reports associated with the reflection coefficients. Component 199 can also be configured to perform a combination... Figure 11 , Figure 12 , Figure 13 , Figure 14 Any aspect described in the flowchart of any of the above and / or by network nodes, base stations, gNBs, etc. Figures 4 to 10Any aspect of the process / algorithm executed by any of the components. Component 199 may be located within one or more processors of one or more of CU 1610, DU 1630, and RU 1640. Component 199 may be one or more hardware components specifically configured to execute the stated process / algorithm, implemented by one or more processors configured to execute the stated process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination thereof. When multiple processors are implemented, the multiple processors may execute the stated process / algorithm individually or in combination. Network entity 1602 may include a variety of components configured for various functions. In one configuration, network entity 1602 may include components for providing a reference signal on the source channel to the user equipment UE via reflection on a reflection channel of a RIS-based sparse meta-element array. In this configuration, network entity 1602 may include components for receiving from the UE an indication of the reflection coefficients of the reflection channel, wherein the reflection coefficients of the reflection channel are based on the sparse meta-element array codebook and measurements of the reflection channel. In this configuration, network entity 1602 may include components for configuring the RIS using reflection coefficients of the reflection channel. In one configuration, network entity 1602 may include components for receiving parameter indications for a set of RIS sparse array parameters from the RIS, wherein the parameter indications for the set of RIS sparse array parameters include at least one of horizontal configuration parameters or vertical configuration parameters. In one configuration, network entity 1602 may include components for configuring the UE using a configuration indicating a sparse superelement array codebook based on the parameter indications for the set of RIS sparse array parameters. In one configuration, network entity 1602 may include components for configuring the UE using a resource and reporting configuration indicating at least one of resources associated with a reference signal or reports associated with reflection coefficients. These components may be components 199 of network entity 1602 configured to perform the functions described by these components. As described above, network entity 1602 may include a TX processor 316, an RX processor 370, and a controller / processor 375. Therefore, in one configuration, these components may be a TX processor 316, an RX processor 370, and / or a controller / processor 375 configured to perform the functions described therein.

[0188] Network nodes and UEs in wireless communication networks can communicate in various spatial configurations to account for UE mobility and obstacles or obstructions in the environment. An example device or system that can be used in communication environments with obstacles or obstructions is a Resonant Array of Elements (RIS) that may include a surface with a large number of densely placed, reconfigurable meta-elements that can reflect or refract electromagnetic waves in a target direction. The RIS can be configured to reflect, transmit (e.g., refract), or be configured to transmit and reflect simultaneously. The RIS can provide low-cost and low-power communication options based on, for example, a combination of positive intrinsic-negative / varactor diodes and a lack of radiated power (e.g., the RIS control can use power, but the meta-elements may not transmit power). However, the RIS configuration can be based on a uniform array of meta-elements, such as a uniform linear array ULA or UPA. In the high-frequency spectrum (e.g., frequency ranges specified as FR2, THz, etc.), given a half-wavelength spacing and RIS surface size, small wavelengths can result in a large number of ULA / UPA meta-elements. This, in turn, leads to higher hardware costs (e.g., the more meta-elements placed on the surface, the higher the hardware cost) and higher power consumption (e.g., the control circuitry of the meta-elements consumes power). Additionally, if the inter-element spacing is greater than half the wavelength of the reflected signal, aliasing and associated ambiguity in the sensing results may occur. Furthermore, when using a smaller RIS surface size, the beamwidth increases accordingly, and therefore the spatial resolution decreases.

[0189] This paper describes aspects of a reflection codebook for a RIS with a sparse meta-element array, where a UE can be configured with a sparse meta-element array codebook for the RIS. The UE can receive a reflection reference signal, which can be initiated by a network node and reflected by the RIS; and measure the reflection channel on which the reflection reference signal is received from the RIS. Based on the configured sparse meta-element array codebook for the RIS and the measurements, the UE can obtain reflection coefficients, which can be provided / reported to the RIS / network node to optimize the sparse meta-element array of the RIS. The aspects provide spatial resolution for the RIS at a lower cost and power than ULA / UPA implementations by utilizing the sparse meta-element array. The aspects also optimize the sparse meta-element array of the RIS for channel gain and throughput by providing a more accurate codebook-based reflection coefficient reporting scheme for the RIS via matching the RIS reflection coefficients with the utilized radio channels. The aspects further improve implementation flexibility by utilizing codebooks for nested and coprime sparse meta-element arrays on the sub-surfaces of the RIS, while still optimizing the RIS configuration.

[0190] It should be understood that the specific order or hierarchy of the boxes in the disclosed process / flowcharts is merely an example of the exemplary method. It should be understood that the specific order or hierarchy of the boxes in the process / flowcharts may be rearranged based on design preferences. Furthermore, some boxes may be combined or omitted. The appended method claims present the elements of various boxes in a sample order, but are not limited to the given specific order or hierarchy.

[0191] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not limited to the aspects described herein but should be given the full scope consistent with the language of the claims. Unless specifically stated otherwise, references to elements in the singular form do not mean “one and only one” but rather “one or more.” Terms such as “if,” “when,” and “simultaneously” do not imply a direct temporal relationship or reaction. That is, these phrases, such as “when,” do not imply an immediate action in response to the occurrence of an action or during the occurrence of an action, but simply suggest that if a condition is met, then the action will occur, without requiring a specific or immediate time limit for the occurrence of the action. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or superior to other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "one or more of A, B, and C", and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, wherein any such combination may contain one or more members of A, B, or C. A set should be interpreted as a collection of elements in which the number of elements is one or more. Therefore, for a set of X, X will include one or more elements. When at least one processor is configured to execute a set of functions, the at least one processor is configured to execute the set of functions individually or in any combination. Therefore, each processor in at least one processor can be configured to perform a specific subset of the set of functions, wherein the subset is the complete set, a suitable subset of the set, or an empty subset of the set. A processor may be referred to as a processor circuit. A memory / memory module may be referred to as a memory circuit. If a first device receives data from or sends data to a second device, data can be received / sent directly between the first and second devices, or indirectly between the first and second devices through a set of devices. A device configured to "output" or "provide" data (such as transmission, signaling, or messaging) may, for example, transmit data using a transceiver, or may transmit the data to the device that sent the data.A device configured to "acquire" data (such as, transmit, signal, or message) may, for example, receive the data using a transceiver, or may obtain the data from a device receiving the data. Information stored in memory includes instructions and / or data. All structural and functional equivalents of the elements throughout the various aspects described herein that are known to those skilled in the art or will later be known are expressly incorporated herein by reference and are covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is explicitly recited in the claims. The words "module," "mechanism," "element," "device," etc., cannot replace the word "component." Therefore, no claim element will be construed as a functional component unless the element is explicitly recited using the phrase "component for..."

[0192] As used in this article, the phrase “based on” should not be interpreted as referring to a closed set of information, one or more conditions, one or more factors, etc. In other words, the phrase “based on A” (where “A” can be information, conditions, factors, etc.) should be interpreted as “based on at least A”, unless otherwise stated otherwise.

[0193] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein without limitation.

[0194] Aspect 1 is a method for wireless communication at a user equipment (UE), the method comprising: receiving a reference signal from a reconfigurable smart surface (RIS) via a reflection channel, wherein the reflection channel is based on a sparse metaelement array of the RIS and the reference signal being reflected from a network node via a source channel; obtaining a reflection coefficient of the reflection channel based on a codebook of the sparse metaelement array and measurements of the reflection channel; and providing an indication of the reflection coefficient of the reflection channel to at least one of the RIS or the network node.

[0195] Aspect 2 is the method according to aspect 1, the method further comprising: receiving from the network node a configuration indicating the sparse superelement array codebook; wherein obtaining the reflection coefficient includes estimating the channel matrix of the reflection channel based on the measurement results of the reflection channel.

[0196] Aspect 3 is the method according to any one of Aspects 1 and 2, wherein the sparse superelement array codebook is based on a horizontal split configuration and a vertical split configuration of the sparse superelement array of the RIS, wherein the horizontal split configuration and the vertical split configuration are each associated with at least two sub-surface portions having a corresponding uniform superelement array.

[0197] Aspect 4 is the method according to aspect 3, wherein the sparse superelement array of the RIS is a nested sparse superelement array or a coprime sparse superelement array.

[0198] Aspect 5 is the method according to aspect 3, wherein the horizontal splitting configuration and the vertical splitting configuration of the sparse metaelement array of the RIS respectively include a first sub-surface portion having a first uniform metaelement array and a second sub-surface portion having a second uniform metaelement array different from the first uniform metaelement array.

[0199] Aspect 6 is the method according to aspect 5, wherein the reflection coefficient of the reflection channel includes at least a first codeword of a first codebook associated with the first sub-surface portion and a second codeword of a second codebook associated with the second sub-surface portion.

[0200] Aspect 7 is the method of claim 6, wherein the first codebook associated with the first sub-surface portion is a first horizontal sub-codebook and the second codebook associated with the second sub-surface portion is a second horizontal sub-codebook, the first horizontal sub-codebook and the second horizontal sub-codebook each being associated with a horizontal configuration parameter for the horizontal split configuration; or wherein the first codebook associated with the first sub-surface portion is a first vertical sub-codebook and the second codebook associated with the second sub-surface portion is a second vertical sub-codebook, the first vertical sub-codebook and the second vertical sub-codebook each being associated with a vertical configuration parameter for the vertical split configuration.

[0201] Aspect 8 is the method according to aspect 5, wherein, for the horizontal split configuration, the first sub-surface portion includes a first number of columns, wherein each first sub-surface row on the first number of columns is a first uniform array of the first uniform superelement array; wherein the second sub-surface portion includes a second number of columns, wherein each second sub-surface row on the second number of columns is a second uniform array of the second uniform superelement array.

[0202] Aspect 9 is the method according to aspect 5, wherein, for the vertically split configuration, the first sub-surface portion includes a first number of rows, wherein each first sub-surface column on the first number of rows is a first uniform array of the first uniform superelement array; wherein the second sub-surface portion includes a second number of rows, wherein each second sub-surface column on the second number of rows is a second uniform array of the second uniform superelement array.

[0203] Aspect 10 is the method according to aspect 5, wherein providing the indication of the reflection coefficients of the reflection channel comprises: providing an integration indication of an integral coefficient set for the first sub-surface portion and the second sub-surface portion, wherein the integration indication of the integral coefficient set is associated with the phase coherence of the beamforming gain between the first sub-surface portion and the second sub-surface portion.

[0204] Aspect 11 is the method according to aspect 10, wherein the indication of the reflection coefficients of the reflection channel includes an index set associated with a first selected set of codewords of the sparse superelement array codebook and zero or more first associated quantization magnitudes and phases for the set of integral coefficients.

[0205] Aspect 12 is the method according to aspect 10, wherein the indication of the reflection coefficients of the reflection channel includes an index set associated with a second selected set of codewords of the sparse superelement array codebook, zero or more values ​​associated with the second selected set of codewords of the sparse superelement array codebook, and zero or more second associated quantization amplitudes and phases for the set of integral coefficients, wherein the maximum number of selected codewords associated with the second selected set of codewords is greater than one.

[0206] Aspect 13 is the method according to aspect 10, wherein providing the integration indication for the set of integration coefficients includes: providing a channel matrix indication for the estimated channel matrix of the reflection channel.

[0207] Aspect 14 is a method according to any one of aspects 1 to 13, wherein the reference signal includes a channel state information (CSI) reference signal; wherein providing the indication of the reflection coefficient of the reflection channel comprises using at least one of a configured channel state information resource or a configured set of auxiliary reflection coefficients to provide the indication of the reflection coefficient of the reflection channel as a CSI.

[0208] Aspect 15 is a method for wireless communication at a network node, the method comprising: providing a reference signal on a source channel to a user equipment (UE) via reflection on a reflection channel of a sparse meta-element array based on a reconfigurable smart surface (RIS); receiving from the UE an indication of the reflection coefficient of the reflection channel, wherein the reflection coefficient of the reflection channel is based on a sparse meta-element array codebook and measurements of the reflection channel; and configuring the RIS with the reflection coefficient of the reflection channel.

[0209] Aspect 16 is the method according to aspect 15, wherein the sparse superelement array codebook is based on a horizontal split configuration and a vertical split configuration of the sparse superelement array of the RIS, wherein the horizontal split configuration and the vertical split configuration are each associated with at least two sub-surface portions having a corresponding uniform superelement array, the method further comprising: receiving from the RIS a parameter indication of a RIS sparse array parameter set, wherein the parameter indication of the RIS sparse array parameter set includes at least one of a horizontal configuration parameter or a vertical configuration parameter; and configuring the UE with a configuration indicating the sparse superelement array codebook based on the parameter indication of the RIS sparse array parameter set.

[0210] Aspect 17 is the method according to aspect 16, wherein at least one of the horizontal configuration parameters or the vertical configuration parameters includes at least one of the following: nested array type indicator, array element number, coprime array type indicator, or coprime array parameter set.

[0211] Aspect 18 is the method according to aspect 17, wherein the sparse superelement array of the RIS is a nested sparse superelement array or a coprime sparse superelement array.

[0212] Aspect 19 is the method according to aspect 17, wherein the horizontal splitting configuration and the vertical splitting configuration of the sparse metaelement array of the RIS respectively include a first sub-surface portion having a first uniform metaelement array and a second sub-surface portion having a second uniform metaelement array different from the first uniform metaelement array.

[0213] Aspect 20 is the method according to aspect 19, wherein the reflection coefficient of the reflection channel includes at least a first codeword of a first codebook associated with the first sub-surface portion and a second codeword of a second codebook associated with the second sub-surface portion.

[0214] Aspect 21 is the method according to aspect 20, wherein the first codebook associated with the first sub-surface portion is a first horizontal sub-codebook and the second codebook associated with the second sub-surface portion is a second horizontal sub-codebook, the first horizontal sub-codebook and the second horizontal sub-codebook each being associated with the horizontal configuration parameter for the horizontal split configuration; or wherein the first codebook associated with the first sub-surface portion is a first vertical sub-codebook and the second codebook associated with the second sub-surface portion is a second vertical sub-codebook, the first vertical sub-codebook and the second vertical sub-codebook each being associated with the vertical configuration parameter for the vertical split configuration.

[0215] Aspect 22 is the method according to aspect 19, wherein, for the horizontal split configuration, the first sub-surface portion includes a first number of columns, wherein each first sub-surface row on the first number of columns is a first uniform array of the first uniform superelement array; wherein the second sub-surface portion includes a second number of columns, wherein each second sub-surface row on the second number of columns is a second uniform array of the second uniform superelement array.

[0216] Aspect 23 is the method according to aspect 19, wherein, for the vertically split configuration, the first sub-surface portion includes a first number of rows, wherein each first sub-surface column on the first number of rows is a first uniform array of the first uniform metaelement array; wherein the second sub-surface portion includes a second number of rows, wherein each second sub-surface column on the second number of rows is a second uniform array of the second uniform metaelement array.

[0217] Aspect 24 is the method according to aspect 19, wherein receiving the indication of the reflection coefficients of the reflection channel comprises: receiving an integration indication of an integral coefficient set for the first sub-surface portion and the second sub-surface portion, wherein the integration indication of the integral coefficient set is associated with the phase coherence of the beamforming gain between the first sub-surface portion and the second sub-surface portion.

[0218] Aspect 25 is the method according to aspect 24, wherein the indication of the reflection coefficients of the reflection channel includes an index set associated with a first selected set of codewords of the sparse superelement array codebook and zero or more first associated quantization magnitudes and phases for the set of integral coefficients.

[0219] Aspect 26 is the method according to aspect 24, wherein the indication of the reflection coefficients of the reflection channel includes an index set associated with a second selected set of codewords of the sparse superelement array codebook, zero or more values ​​associated with the second selected set of codewords of the sparse superelement array codebook, and zero or more second associated quantization amplitudes and phases for the set of integral coefficients, wherein the maximum number of selected codewords associated with the second selected set of codewords is greater than one.

[0220] Aspect 27 is the method according to aspect 24, wherein receiving the integration indication for the set of integration coefficients includes: receiving a channel matrix indication for the estimated channel matrix of the reflection channel.

[0221] Aspect 28 is a method according to any one of aspects 15 to 27, wherein the reference signal includes a channel state information (CSI) reference signal; wherein receiving the indication of the reflection coefficient of the reflection channel includes receiving the indication of the reflection coefficient of the reflection channel as a CSI using at least one of a configured channel state information resource or a configured set of auxiliary reflection coefficients.

[0222] Aspect 29 is an apparatus for wireless communication at a user equipment (UE), the apparatus comprising: at least one memory; and at least one processor coupled to said at least one memory, said at least one processor being configured individually or in any combination to perform the method according to any one of aspects 1 to 14.

[0223] Aspect 30 is an apparatus for wireless communication at a user equipment (UE), the apparatus comprising components for performing each step of the method according to any one of aspects 1 to 14.

[0224] Aspect 31 is an apparatus according to any one of aspects 29 and 30, the apparatus further comprising a transceiver configured to receive or transmit in association with the method according to any one of aspects 1 to 14.

[0225] Aspect 32 is a computer-readable medium (e.g., a non-transitory computer-readable medium) that stores computer-executable code at a user equipment (UE), the code causing the at least one processor to perform the method according to any one of aspects 1 to 14 when executed by at least one processor.

[0226] Aspect 33 is an apparatus for wireless communication at a network node, the apparatus comprising: at least one memory; and at least one processor coupled to said at least one memory, said at least one processor being configured individually or in any combination to perform the method according to any one of aspects 15 to 28.

[0227] Aspect 34 is an apparatus for wireless communication at a network node, the apparatus comprising components for performing each step of the method according to any one of aspects 15 to 28.

[0228] Aspect 35 is an apparatus according to any one of aspects 33 and 34, the apparatus further comprising a transceiver configured to receive or transmit in association with the method according to any one of aspects 15 to 28.

[0229] Aspect 36 is a computer-readable medium (e.g., a non-transitory computer-readable medium) that stores computer-executable code at a network node, the code causing the at least one processor to perform the method according to any one of aspects 15 to 28 when executed by at least one processor.

Claims

1. An apparatus for wireless communication at a user equipment (UE), the apparatus comprising: At least one memory; and At least one processor coupled to the at least one memory, and based at least in part on information stored in the at least one memory, the at least one processor is configured individually or in any combination as follows: A reference signal is received from a reconfigurable smart surface (RIS) via a reflection channel, wherein the reflection channel is based on a sparse meta-element array of the RIS and the reference signal is reflected from a network node via a source channel; The reflection coefficient of the reflection channel is obtained based on the sparse metaelement array codebook and the measurement results of the reflection channel. as well as Provide an indication of the reflection coefficient of the reflection channel for at least one of the RIS or the network node.

2. The apparatus of claim 1, wherein the at least one processor is further configured, alone or in any combination, to: Receive configuration instructions for the sparse superelement array codebook from the network node; In order to obtain the reflection coefficient, the at least one processor is configured individually or in any combination to estimate the channel matrix of the reflection channel based on the measurement results of the reflection channel.

3. The apparatus of claim 1, wherein the sparse superelement array codebook is based on a horizontal and vertical split configuration of the sparse superelement array of the RIS, wherein each of the horizontal and vertical split configurations is associated with at least two sub-surface portions having a corresponding uniform superelement array.

4. The apparatus of claim 3, wherein the sparse superelement array of the RIS is a nested sparse superelement array or a coprime sparse superelement array.

5. The apparatus of claim 3, wherein the horizontal splitting configuration and the vertical splitting configuration of the sparse metaelement array of the RIS each include a first sub-surface portion having a first uniform metaelement array and a second sub-surface portion having a second uniform metaelement array different from the first uniform metaelement array.

6. The apparatus of claim 5, wherein the reflection coefficient of the reflection channel comprises at least a first codeword of a first codebook associated with the first sub-surface portion and a second codeword of a second codebook associated with the second sub-surface portion.

7. The apparatus of claim 6, wherein the first codebook associated with the first sub-surface portion is a first horizontal sub-codebook and the second codebook associated with the second sub-surface portion is a second horizontal sub-codebook, the first horizontal sub-codebook and the second horizontal sub-codebook each being associated with a horizontal configuration parameter for the horizontal split configuration; or The first codebook associated with the first sub-surface portion is a first vertical sub-codebook, and the second codebook associated with the second sub-surface portion is a second vertical sub-codebook. The first vertical sub-codebook and the second vertical sub-codebook are each associated with vertical configuration parameters for the vertical split configuration.

8. The apparatus according to claim 5, wherein, For the horizontally split configuration, the first sub-surface portion includes a first number of columns, wherein each first sub-surface row on the first number of columns is a first uniform array of the first uniform superelement array; The second sub-surface portion includes a second number of columns, wherein each second sub-surface row on the second number of columns is a second uniform array of the second uniform super-element array.

9. The apparatus according to claim 5, wherein, For the vertically split configuration, the first sub-surface portion includes a first number of rows, wherein each first sub-surface column on the first number of rows is a first uniform array of the first uniform meta-element array; The second sub-surface portion includes a second number of rows, wherein each second sub-surface column on the second number of rows is a second uniform array of the second uniform superelement array.

10. The apparatus of claim 5, wherein, in order to provide the indication of the reflection coefficient of the reflection channel, the at least one processor is configured individually or in any combination to: An integration indication is provided for the set of integration coefficients for the first sub-surface portion and the second sub-surface portion, wherein the integration indication for the set of integration coefficients is associated with the phase coherence of the beamforming gain between the first sub-surface portion and the second sub-surface portion.

11. The apparatus of claim 10, wherein the indication of the reflection coefficients of the reflection channel comprises an index set associated with a first selected set of codewords of the sparse superelement array codebook and zero or more first associated quantization magnitudes and phases for the set of integral coefficients.

12. The apparatus of claim 10, wherein the indication of the reflection coefficients of the reflection channel comprises an index set associated with a second selected set of codewords of the sparse superelement array codebook, zero or more values ​​associated with the second selected set of codewords of the sparse superelement array codebook, and zero or more second associated quantization amplitudes and phases for the set of integral coefficients, wherein the maximum number of selected codewords associated with the second selected set of codewords is greater than one.

13. The apparatus of claim 10, wherein, in order to provide the integration indication of the set of integration coefficients, the at least one processor is configured individually or in any combination to: Provides a channel matrix indication of the estimated channel matrix for the reflected channel.

14. The apparatus of claim 1, further comprising a transceiver coupled to the at least one processor, wherein the reference signal includes a channel state information (CSI) reference signal; In order to provide the indication of the reflection coefficients of the reflection channel, the at least one processor is configured individually or in any combination to provide the indication of the reflection coefficients of the reflection channel as a CSI via the transceiver using at least one of a configured channel state information resource or a configured set of auxiliary reflection coefficients.

15. An apparatus for wireless communication at a network node, the apparatus comprising: At least one memory; and At least one processor coupled to the at least one memory, and based at least in part on information stored in the at least one memory, the at least one processor is configured individually or in any combination as follows: A reference signal on the source channel is provided to the user equipment (UE) via reflection on the reflection channel of a sparse meta-element array based on a reconfigurable smart surface (RIS); The UE receives an indication of the reflection coefficient of the reflection channel, wherein the reflection coefficient of the reflection channel is based on a sparse superelement array codebook and a measurement of the reflection channel; as well as The RIS is configured using the reflection coefficient of the reflection channel.

16. The apparatus of claim 15, wherein the sparse metaelement array codebook is based on a horizontal and vertical split configuration of the sparse metaelement array of the RIS, wherein each of the horizontal and vertical split configurations is associated with at least two sub-surface portions having a corresponding uniform metaelement array, wherein the at least one processor is further configured individually or in any combination to: Receive parameter indications for a set of RIS sparse array parameters from the RIS, wherein the parameter indications for the set of RIS sparse array parameters include at least one of horizontal configuration parameters or vertical configuration parameters; and The UE is configured based on the parameter indications of the RIS sparse array parameter set, which instruct the configuration of the sparse superelement array codebook.

17. The apparatus of claim 16, wherein at least one of the horizontal configuration parameters or the vertical configuration parameters includes at least one of the following: a nested array type indicator, an array element number, a coprime array type indicator, or a coprime array parameter set.

18. The apparatus of claim 17, wherein the sparse superelement array of the RIS is a nested sparse superelement array or a coprime sparse superelement array.

19. The apparatus of claim 17, wherein the horizontal splitting configuration and the vertical splitting configuration of the sparse metaelement array of the RIS each include a first sub-surface portion having a first uniform metaelement array and a second sub-surface portion having a second uniform metaelement array different from the first uniform metaelement array.

20. The apparatus of claim 19, wherein the reflection coefficient of the reflection channel comprises at least a first codeword of a first codebook associated with the first sub-surface portion and a second codeword of a second codebook associated with the second sub-surface portion.

21. The apparatus of claim 20, wherein the first codebook associated with the first sub-surface portion is a first horizontal sub-codebook and the second codebook associated with the second sub-surface portion is a second horizontal sub-codebook, the first horizontal sub-codebook and the second horizontal sub-codebook each being associated with the horizontal configuration parameters for the horizontal split configuration; or The first codebook associated with the first sub-surface portion is a first vertical sub-codebook, and the second codebook associated with the second sub-surface portion is a second vertical sub-codebook. The first vertical sub-codebook and the second vertical sub-codebook are each associated with the vertical configuration parameters for the vertical split configuration.

22. The apparatus according to claim 19, wherein, For the horizontally split configuration, the first sub-surface portion includes a first number of columns, wherein each first sub-surface row on the first number of columns is a first uniform array of the first uniform superelement array; The second sub-surface portion includes a second number of columns, wherein each second sub-surface row on the second number of columns is a second uniform array of the second uniform super-element array.

23. The apparatus according to claim 19, wherein, For the vertically split configuration, the first sub-surface portion includes a first number of rows, wherein each first sub-surface column on the first number of rows is a first uniform array of the first uniform meta-element array; The second sub-surface portion includes a second number of rows, wherein each second sub-surface column on the second number of rows is a second uniform array of the second uniform superelement array.

24. The apparatus of claim 19, wherein, in order to receive the indication of the reflection coefficient of the reflection channel, the at least one processor is configured individually or in any combination to: Receive an integration indication for a set of integration coefficients for the first sub-surface portion and the second sub-surface portion, wherein the integration indication for the set of integration coefficients is associated with the phase coherence of the beamforming gain between the first sub-surface portion and the second sub-surface portion.

25. The apparatus of claim 24, wherein the indication of the reflection coefficients of the reflection channel comprises an index set associated with a first selected set of codewords of the sparse superelement array codebook and zero or more first associated quantization magnitudes and phases for the set of integral coefficients.

26. The apparatus of claim 24, wherein the indication of the reflection coefficients of the reflection channel comprises an index set associated with a second selected set of codewords of the sparse superelement array codebook, zero or more values ​​associated with the second selected set of codewords of the sparse superelement array codebook, and zero or more second associated quantization amplitudes and phases for the set of integral coefficients, wherein the maximum number of selected codewords associated with the second selected set of codewords is greater than one.

27. The apparatus of claim 24, wherein, in order to receive the integration indication for the set of integration coefficients, the at least one processor is configured individually or in any combination to: Receive a channel matrix indication of the estimated channel matrix of the reflected channel.

28. The apparatus of claim 15, wherein the reference signal includes a channel state information (CSI) reference signal; In order to receive the indication of the reflection coefficients of the reflection channel, the at least one processor is configured individually or in any combination to receive the indication of the reflection coefficients of the reflection channel as a CSI using at least one of a configured channel state information resource or a configured set of auxiliary reflection coefficients.

29. A method for conducting wireless communication at a user equipment (UE), the method comprising: A reference signal is received from a reconfigurable smart surface (RIS) via a reflection channel, wherein the reflection channel is based on a sparse meta-element array of the RIS and the reference signal is reflected from a network node via a source channel; The reflection coefficient of the reflection channel is obtained based on the sparse metaelement array codebook and the measurement results of the reflection channel. as well as Provide an indication of the reflection coefficient of the reflection channel for at least one of the RIS or the network node.

30. A method for wireless communication at a network node, the method comprising: A reference signal on the source channel is provided to the user equipment (UE) via reflection on the reflection channel of a sparse meta-element array based on a reconfigurable smart surface (RIS); The UE receives an indication of the reflection coefficient of the reflection channel, wherein the reflection coefficient of the reflection channel is based on a sparse superelement array codebook and a measurement of the reflection channel; as well as The RIS is configured using the reflection coefficient of the reflection channel.

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