EP4646797A1 - Methods, architectures, apparatuses and systems for codebook design for antenna array - Google Patents

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products are described for codebook design and precoder and/or precoding matrix indicator (PMI) feedback for near field beamforming and/or beamfocusing. For example, a wireless transmit/receive unit (WTRU) is configured to receive, from a network node, first information comprising any of: (1) distance information associated with an antenna array of the network node, wherein the antenna array comprises a plurality of antennas and/or antenna ports, and (2) a configuration of the antenna array; receive a channel state information configuration for PMI reporting; determine a Fresnel zone phase matrix based on the first information; determine a precoding matrix based on a combination of at least a far-field codebook and the Fresnel zone phase matrix; and send, to the network node, a PMI report based on the precoding matrix.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR CODEBOOK DESIGN FOR ANTENNA ARRAY CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application No.63/437,525 filed January 6, 2023, which is incorporated herein by reference in its entirety. BACKGROUND [0002] The present disclosure is generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems directed to codebook design, for example to methods, apparatus and systems to perform codebook design and precoder and/or precoding matrix indicator feedback for near field beamforming and/or beamfocusing. BRIEF DESCRIPTION OF THE DRAWINGS [0003] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the FIGs. indicate like elements, and wherein: [0004] FIG.1A is a system diagram illustrating an example communications system; [0005] FIG. 1B is a system diagram illustrating an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG.1A; [0006] FIG.1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG.1A; [0007] FIG.1D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG.1A; [0008] FIG. 2 is a diagram of supported antenna-port configurations, according to an embodiment; [0009] FIG.3 is a diagram of rotated orthogonal beams and orthogonal discrete Fourier transform (DFT) beams, according to an embodiment; [0010] FIG.4A depicts a far-field planar wave-channel model, according to an embodiment; [0011] FIG.4B depicts a near-field spherical wave-channel model, according to an embodiment; [0012] FIG. 5 is a diagram of a radiating aperture enclosed within a circle of diameter D, according to an embodiment; [0013] FIG.6A is a diagram of a large array/surface size transmission under a line of sight (LOS) scenario, according to an embodiment; [0014] FIG.6B is a diagram of a large array/surface size transmission under a non-LOS (NLOS) scenario, according to an embodiment; [0015] FIG.7 is a diagram of an antenna-array system with large numbers of horizontal antennas and vertical antennas, according to an embodiment; [0016] FIG.8 illustrates a channel state information (CSI) report maps to a sub-array aperture, according to an embodiment; [0017] FIG. 9 is a diagram of a minimum array aperture that satisfies the Fresnel zone criteria and of a maximum array aperture that satisfies the far-zone criteria for a given distance between a WTRU and the antenna array, according to an embodiment; [0018] FIG.10 is a diagram of a beam-focusing procedure for non-beam-formed or non-beam- focused CSI-RS, according to an embodiment; [0019] FIG. 11 is a flow diagram of a WTRU procedure for handling a CSI report group in a triggered aperiodic channel state information (AP-CSI) report, according to an embodiment; [0020] FIG.12 is a diagram illustrating a method implemented by a WTRU to perform codebook design and precoder and/or precoding matrix indicator feedback for near field beamforming and/or beamfocusing; and [0021] FIG.13 is a diagram illustrating a method implemented by a WTRU to perform precoder and/or precoding matrix indicator feedback for multiple CSI report. DETAILED DESCRIPTION [0022] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and/or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and/or inherently (collectively "provided") herein. Although various embodiments are described and/or claimed herein in which an apparatus, system, device, etc. and/or any element thereof carries out an operation, process, algorithm, function, etc. and/or any portion thereof, it is to be understood that any embodiments described and/or claimed herein assume that any apparatus, system, device, etc. and/or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and/or any portion thereof. [0023] Provided below are acronyms/abbreviations for terms and phrases commonly used in this application: AI Artificial Intelligence AOD Angle of Departure BFD-RS Beam Failure Detection-Reference Signal BFR Beam Failure Recovery BFRQ Beam Failure Recovery Request BLER Block Error Rate BFI Beam Failure Instance BM Beam Management CORESET Control Resource Set CRI CSI-RS Resource Index CSI Channel State Information CSI-RS Channel State Information-Reference Signal DCI Downlink Control Information DFT Discrete Fourier Transform DL Downlink EM Electro Magnetic GOB Grid of Beam GPS Global Positioning System GCS Generalized Cosine Similarity LTE Long Term Evolution L1-RSRP Layer 1-Reference Signal Received Power L1-SINR Layer 1-Signal to Interference-and-Noise Ratio LIS Large Intelligence Surface LOS Line of Sight SIMO Single Input Multiple Output SISO Single Input Single Output MIMO Multiple Input Multiple Output MISO Multiple Input Single Output ML Machine Learning MSE Mean Square Error NBI-RS New Beam Identification-Reference Signal NLOS Non-Line of Sight NW Network NZP Non-zero Power PDCCH Physical Downlink Control Channel PMI Precoder and/or Precoding Matrix Indicator PRACH Physical Random-Access Channel PSK Phase Shift Keying QCL Quasi- Colocation RD Rayleigh Distance RRC Radio Resource Control RS Reference Signal RSRP Reference Signal Received Power SD Spatial Domain SSB Synchronization Signal Block SSBRI SSB Resource Index SI System Information SRS Sounding Reference Signals TCI Transmission Configuration Indicator TRP Transmission and Reception Point TxRU Transceiver Units UE User Equipment UPA Uniform Planar Array ULA Uniform Linear Array WTRU Wireless Transmit-Receive Unit [0024] Example Communications System [0025] The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1D, where various elements of the network may utilize, perform, be arranged in accordance with and/or be adapted and/or configured for the methods, apparatuses and systems provided herein. [0026] FIG. 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single- carrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discreet Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block- filtered OFDM, filter bank multicarrier (FBMC), and the like. [0027] As shown in FIG. 1A, the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104/113, a core network (CN) 106/115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a "station" and/or a "STA", may be configured to transmit and/or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi- Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE. [0028] The communications systems 100 may also include a base station 114a and/or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d, e.g., to facilitate access to one or more communication networks, such as the CN 106/115, the Internet 110, and/or the networks 112. By way of example, the base stations 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB), a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements. [0029] The base station 114a may be part of the RAN 104/113, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and/or the base station 114b may be configured to transmit and/or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and/or receive signals in desired spatial directions. [0030] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT). [0031] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104/113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA). [0032] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/or LTE-Advanced Pro (LTE-A Pro). [0033] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR). [0034] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and/or transmissions sent to/from multiple types of base stations (e.g., an eNB and a gNB). [0035] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like. [0036] The base station 114b in FIG.1A may be a wireless router, Home Node-B, Home eNode- B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish any of a small cell, picocell or femtocell. As shown in FIG.1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106/115. [0037] The RAN 104/113 may be in communication with the CN 106/115, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106/115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG.1A, it will be appreciated that the RAN 104/113 and/or the CN 106/115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104/113 or a different RAT. For example, in addition to being connected to the RAN 104/113, which may be utilizing an NR radio technology, the CN 106/115 may also be in communication with another RAN (not shown) employing any of a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology. [0038] The CN 106/115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and/or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and/or the internet protocol (IP) in the TCP/IP internet protocol suite. The networks 112 may include wired and/or wireless communications networks owned and/or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104/114 or a different RAT. [0039] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG.1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology. [0040] FIG.1B is a system diagram illustrating an example WTRU 102. As shown in FIG.1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and/or other elements/peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment. [0041] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While FIG.1B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, e.g., in an electronic package or chip. [0042] The transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in an embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In an embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit/receive element 122 may be configured to transmit and/or receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals. [0043] Although the transmit/receive element 122 is depicted in FIG.1B as a single element, the WTRU 102 may include any number of transmit/receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in an embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116. [0044] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example. [0045] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read- only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown). [0046] The processor 118 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like. [0047] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment. [0048] The processor 118 may further be coupled to other elements/peripherals 138, which may include one or more software and/or hardware modules/units that provide additional features, functionality and/or wired or wireless connectivity. For example, the elements/peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and/or augmented reality (VR/AR) device, an activity tracker, and the like. The elements/peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and/or a humidity sensor. [0049] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and/or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)). [0050] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106. [0051] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a. [0052] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and/or downlink (DL), and the like. As shown in FIG.1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface. [0053] The CN 106 shown in FIG.1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any one of these elements may be owned and/or operated by an entity other than the CN operator. [0054] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and/or WCDMA. [0055] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like. [0056] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. [0057] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. [0058] Although the WTRU is described in FIGs. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network. [0059] In representative embodiments, the other network 112 may be a WLAN. [0060] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a distribution system (DS) or another type of wired/wireless network that carries traffic into and/or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and/or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication. [0061] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier sense multiple access with collision avoidance (CSMA/CA) may be implemented, for example in in 802.11 systems. For CSMA/CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed/detected and/or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS. [0062] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel. [0063] Very high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse fast Fourier transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above-described operation for the 80+80 configuration may be reversed, and the combined data may be sent to a medium access control (MAC) layer, entity, etc. [0064] Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11af and 802.11ah relative to those used in 802.11n, and 802.11ac. 802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control/machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and/or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life). [0065] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and/or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes. Carrier sensing and/or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available. [0066] In the United States, the available frequency bands, which may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code. [0067] FIG.1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115. [0068] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and/or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and/or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and/or gNB 180c). [0069] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, OFDM symbol spacing and/or OFDM subcarrier spacing may vary for different transmissions, different cells, and/or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a varying number of OFDM symbols and/or lasting varying lengths of absolute time). [0070] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and/or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with/connect to gNBs 180a, 180b, 180c while also communicating with/connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and/or throughput for servicing WTRUs 102a, 102b, 102c. [0071] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and/or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG.1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface. [0072] The CN 115 shown in FIG. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and/or operated by an entity other than the CN operator. [0073] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b, e.g., to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and/or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP access technologies such as Wi- Fi. [0074] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like. [0075] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, e.g., to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi- homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like. [0076] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and/or wireless networks that are owned and/or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b. [0077] In view of FIGs.1A-1D, and the corresponding description of FIGs.1A-1D, one or more, or all, of the functions described herein with regard to any of: WTRUs 102a-d, base stations 114a- b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a- b, SMFs 183a-b, DNs 185a-b, and/or any other element(s)/device(s) described herein, may be performed by one or more emulation elements/devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and/or to simulate network and/or WTRU functions. [0078] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and/or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and/or deployed as part of a wired and/or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented/deployed as part of a wired and/or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and/or may performing testing using over-the-air wireless communications. [0079] The one or more emulation devices may perform the one or more, including all, functions while not being implemented/deployed as part of a wired and/or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and/or a non-deployed (e.g., testing) wired and/or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and/or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and/or receive data. [0080] In NR, for example, NR type I, II, and type II port selection codebook, CSI acquisition may be (e.g., mainly) based on a CS-PMI report. The precoder defined in NR is for the precoder and/or precoding matrix indicator (PMI) for a WTRU to estimate channel-state information (CSI). PMI can indicate a preferred precoder to use in codebook-based transmission, conditioned on the indicated transmission rank (RI). [0081] There may be at least two types of precoders supported in NR, one is type-I CSI and the other is type-II CSI, respectively. type-I CSI (standard resolution), optimized for single-user MIMO (SU-MIMO) transmission with a potentially large number of layers (up to 8 layers) per WTRU. type-II CSI (high resolution), optimized for multiple-user MIMO (MU-MIMO) transmission, with up to 2 layers per scheduled WTRU and an overall maximum number of 12 layers. Both type I and type II codebooks may be constructed from two-dimensional (2D) DFT based grids of beams and enable the CSI feedback of beam selection as well as phase shift keying (PSK) based co-phase combining between two polarizations. Type II codebook-based CSI feedback reports the wideband and subband amplitude information of the selected beams. [0082] Type-II codebook-based CSI feedback may report the wideband (WB) and/or subband (SB) amplitude information of the selected beams. Type-II codebooks can provide more accurate CSI so that better precoded MIMO transmission can be implemented by the network. [0083] The NR standard may be designed to adapt to different beam-forming architectures and deployment scenarios. In NR, beamforming is supported, and the number of supported (logical) antenna ports ^^ can be {4, 8, 16, 32} ports. The number of (logical) antenna ports can be mapped to different antenna-port configurations (i.e., ( ^^_^, ^^_ଶ)) in a single panel). For example, 32 ports (assuming dual polarization, the number of dual polarized CSI-RS ports ^^ ൌ 2 ^^_^ ^^_ଶ) can be mapped to antenna configurations with ( ^^_^, ^^_ଶ) = (16,1), (8,2) and (4, 4) as shown in FIG. 2, respectively, where FIG.2 is a diagram of supported antenna-port configurations of (N1, N2). [0084] The number of grid of beams (GOB) may use (e.g., be dependent on) ( ^^_^, ^^_ଶ) and ( ^^_^, ^^_ଶ), where ( ^^_^, ^^_ଶ) is the oversampling factor (or rotation factor) in NR types I and II codebook. ^^_^, ^^_ଶ is determined by the number of antenna ports in the horizontal and vertical dimensions. ^^_^, ^^_ଶ is the oversampling factor of each respective dimension, which may determine the beam granularity and the beam number. The network node (e.g., gNB) may send in a downlink CSI-RS reference signals (e.g., the number of antenna ports used is equal to ^^_^ ^^_^ ^^_ଶ for single panel, where ^^_^ ൌ 1 for non-polarized and ^^_^ ൌ 2 for dual-polarized cases) and the WTRU may measure the CSI-RS reference signals with RX antennas and computes the PMI matrix (grid of beams based on PMI). [0085] For type II codebooks, considering the given channel conditions and the number of beams, the function may compute the precoding matrices for all orthogonal beam groups. The function may use the orthogonal matching pursuit (OMP) algorithm to get the beam amplitude scaling and co-phasing values for all the beams in the orthogonal beam groups so that a linear combination of orthogonal beams approximates to an eigen vector of the channel. The function may report the two indices, set ^^_^ and ^^_ଶ, as are known. These indices may correspond to the precoding matrix, which gives a maximum SINR. [0086] The rotated beam may be equivalent to an oversampled DFT beam with oversampling factors ^^_^ and ^^_ଶ. The number of (beam) directions can be calculated as ^^_^ ^^_^ ^^_ଶ ^^_ଶ. For example, for ( ^^_^ ൌ 4, ^^_ଶ ൌ 4) and ( ^^_^=4, ^^_ଶ ൌ 4), total ^^_^ ^^_^ ^^_ଶ ^^_ଶ ൌ 256 GoB can be formed including 16 orthogonal DFT beams and 240 (= 256-16) rotated beams as shown in FIG. 3, which is a diagram of an example of rotated orthogonal beams and orthogonal DFT beams. [0087] An NR type II port selection codebook is used for beamformed CSI-RS, which can be used by the WTRU to feedback to the selected CSI-RS ports. The configured CSI-RS ports can be considered as a set of spatial domains (SD) basis based on the port selection codebook, and the WTRU determines a subset of the SD basis and reports back to the gNB or the network. A type II port selection codebook does not require a WTRU to derive spatial domain (SD) beams or to consider a 2D DFT basis as does a regular type II codebook. If the network “knows” partial downlink channel information, for example, the direction of a beam that is obtained through the uplink/downlink (UL/DL) reciprocity, then the WTRU can measure the beamformed CSI–RS. [0088] Type II port selection codebook enhancement and type II port selection codebook may be based on Rel. 15/16 type II port selection where angle(s) and delay(s) may be estimated at the gNB, for example, based on a sounding reference signal (SRS) by utilizing DL/UL reciprocity of angle and delay, and the remaining DL CSI (i.e., amplitude, phase combining coefficients) may be reported by the WTRU. [0089] Regarding Fresnel zone and Rayleigh distance, a large antenna array or surface improves the transmission- or reception-array gain, which is beneficial for enhancement of link budget; thus, a large antenna array, meta-surface, or large Intelligence surface (LIS) can become a key MIMO technology in wireless communication systems. Hereafter, the term “array” and “surface” are interchangeable. [0090] When the antenna-array size becomes comparable to the link distance, operating conditions fall within the Fresnel region in which near-field propagation takes place. In the Fresnel region, to model the propagation of the electromagnetic (EM) wavefronts accurately, the EM wavefronts are modeled as a spherical wave instead of a planar wave as shown in FIG.4, in which FIG.4A depicts a far-field planar wave-channel model and FIG.4B depicts a near-field spherical wave-channel model. [0091] When antenna-array aperture ^^ is much larger than ^^ (wavelength), the electromagnetic- propagation regime is pushed from the Fraunhofer far-field region toward the Fresnel near-field region, where ^^ is the smallest diameter of a circle that encloses the array aperture as shown in FIG.5, which illustrates a radiating aperture enclosed within a circle of diameter D. The Rayleigh distance ^^ is the demarcation boundary between the Fresnel zone and the far (Fraunhofer) zone. _{The Rayleigh distance ^^ is defined to be ^^ ൌ The larger the aperture of an antenna array,} the farther away is the far zone of an array. This distance ^^ becomes larger too when the wavelength ^^ is shorter or the frequency is higher. [0092] For the uniform linear array (ULA) or uniform planar array (UPA), the array aperture can be uniquely defined by its dimensions in terms of width and height. To be more specific, the array aperture of a UPA can be expressed as the number of antennas in the horizontal dimension, the number of antennas in the vertical dimension, and the antenna separation. For example, if a UPA has antennas in the horizontal dimension, ^^_ଶ antennas in vertical dimension and the separations are equal to a half wavelength, i.e., then the array width is equal to and the array height is equal to . Therefore, the smallest diameter ^^ of a circle that encloses the UPA మ ଶ_^^ேభ ^మ _ାேమ ^మ _{^ ഊ can be e to} ^{^} _^ ^ேభఒ _^ ^ଶ ^ ^^{ேమఒ ଶ} మ ^ ൌ ^ ^^^ଶ ^ ^^^ଶ and the Rayleig _{ଶ ଶ} h distance ^^ ൌ ^^^ଶ ^ ^^^ଶ. If the ^ఒ ^ _ଶ antenna separation is equal to a quarter of a wavelength, i.e.,_ସ, then the Rayleigh మ ଶ_^^ே ^{మ మ} _{ഊ భାேమ^} ర distance ^^ ൌ _ఒ ൌ ^ ଶ ^ ^^_^ ^ଶ ^ ^^_ଶ ^ଶ^. In short, for a UPA or a ULA, the Rayleigh distance ^^ can be uniquely determined by the number of antennas in the horizontal dimension, the number of antennas in the vertical dimension, and the antenna separation. [0093] Rayleigh distance ^^ is evaluated with various array apertures ^^ and carrier frequencies ( ^^_^) as shown in Table 1. A Fresnel near-field criterion is applicable at lower frequency ranges as well, and the Rayleigh distance can be up to several kilometers (km). Also, Rayleigh distance is proportional with the inverse of the wavelength when the array aperture is fixed. In practice, the Fresnel zone is more noticeable in the higher-frequency region, i.e., Rayleigh distance is larger in a higher-frequency region than in a lower-frequency region. [0094] From Table 1, with the increased array aperture and frequency, the near-field range can be several hundreds of meters. For example, for a 1-meter diameter array operating at 28 GHz, the near-field region extends to distances around 200 meters, dominating the typical outdoor deployment for millimeter-wave (mmWave) communication. Table 1 Rayleigh distance for different panel apertures [0095] The effective Rayleigh distance has been proposed to be a better demarcation boundary for far- and near-field than classical Rayleigh distance. The effective Rayleigh distance is less than the Rayleigh distance, and it is also related to the AOD direction, e.g., ^^. Since the effective Rayleigh distance is defined from the perspective of the array gain, which directly affects the transmission rate, the effective Rayleigh distance is a more accurate metric to determine the classical near-field range for practical communications. The effective Rayleigh distance is defined as: మ ^^_^^^ ൌ ^^^cos ^^^^ଶ ^^ ^ ^^ ^{ଶ^} ఒ , Eq. (1) where ^^ ൌ 0.367. [0096] From the effective Rayleigh distance, the classical Rayleigh distance (RD) is overestimated, thus the effective Rayleigh distance may be used for the accurate demarcation boundary for the far field and near field. However, the effective Rayleigh distance still has a same property as the classical Rayleigh distance, i.e., it is proportional with the inverse of the wavelength and the square of the array aperture. [0097] Regarding beam focusing, in near field criteria, the accurate spherical wave model is adopted for the channel model and the near field beamformed vector w^ ^^_^, ^^, ^^^ (or beam focusing) is dependent on information regarding the following parameters: the distance ^^_^ and the angle ^ ^^, ^^^. Therefore, the generated near-field beam focuses the signal energy around on the desired location, e.g., WTRU location with a spatial direction ^{^} ^^, ^^^{^}. In other words, a beam- focused beam focuses the beam energy only on a specific location in a spatial direction. Therefore, we call a beam-focused beam as a ‘spot beam’. [0098] Regarding codebook design considerations for the Fresnel zone, when the array or meta- surface dimension is increased and/or the link distance is reduced, near-field/Fresnel criteria may be valid. In this case, the conventional beamforming for far field often cannot ensure the array gain for near-field criteria because the classical far-field beamforming only considers elevation and azimuth angles. However, conventional beamforming does not consider the near-field beamforming, i.e., beam focusing with ternary parameters, i.e., the distance (e.g., the distance between WTRU and the center of the array/surface), elevation-, and azimuth-angles information. [0099] Existing NR type I and II codebooks for PMI reporting only consider the far-field criteria, which depend only on the elevation and azimuth angles. A PMI based on a grid of beams (GOB) may not work well using existing NR type I and II codebooks for PMI in the near-field region. A new codebook considering ternary parameters to perform beam focusing would enhance performance, or at least would avoid performance degradation, of larger antennas. [0100] Described below are beam-focusing methods for large antenna arrays, according to an embodiment. Such methods include codebook design and PMI feedback methods for near-field beamforming, and beam focusing. And such methods can be applied to, or otherwise can be used in conjunction with, advanced MIMO, MIMO revolution, ultra-massive MIMO, L1, L2/3, 3GPP Rel-19, and to other technologies and standards. [0101] Furthermore, a Fresnel zone codebook can be based on the NR type I/II codebook with a Fresnel zone phase matrix (or vector) such as described below. [0102] Moreover, the Fresnel zone codebook phase matrix (or vector) can be constructed based on the distance between the WTRU and the center of the array, the antenna (array) configuration, and/or AOD information. [0103] In addition, a beam-focusing procedure for both non-beamformed CSI-RS and beamformed CSI-RS can use a Fresnel zone codebook such as described below. [0104] Regarding the Fresnel zone codebook structure, for simplicity without losing generality, it may be assumed, that a WTRU may comprise a single antenna for reception and the network node (e.g., gNB) may comprise an ^^_^ ൈ ^^_ଶ-element uniform planar array (UPA). In this disclosure, this description starts with a single path first and is extended to multipaths for discussing the near- field-channel model. The near-field channel ℎ_^ at subcarrier ^^ for SISO-OFDM may be expressed as follows: where ^^ is the frequency at ^^^th subcarrier, c is the light speed ^{^௭భ,௭మ^} ^ , ^^_^ is the channel gain at subcarrier ^^ from the ^{^} ^^_^, ^^_ଶ ^{^th} network node (e.g., gNB) or transmit antenna and ^^_{௭భ,௭మ} represents the distance between the WTRU and the ^ ^^_^, ^^_ଶ^^th network node (e.g., gNB) antenna. [0105] Generally, the distance ^^_{௭భ,௭మ} between the WTRU and the network node (e.g., gNB) may be larger than the array aperture ^^ ൌ ^^{^} ^^_^ ^ଶ ^ ^^_ଶ ^{ଶ^ଶ}Δ, where Δ denotes inter-element distance (or antenna separation) for both horizontal and vertical directions. In a Fresnel approximation, the channel gain of the ^ ^^ ^{^ ^} ^, ^^_ଶ^^th element ^^ ^{௭భ,௭మ} ^ can be approximated to a value ^^_^ ൌ 0,1, … , ^^_^ െ 1 and ^^ ൌ 0,1, … , ^^ െ 1, where ^^ _ଶ denotes the distance from the WTRU to the center of the array or surface as shown in FIGs.7A and 7B, which are a diagram of a large array/surface size transmission under a Line of Sight (LOS) scenario and a non-LOS (NLOS) scenario, respectively. ^^_௧ is the antenna gain, ^^^ ^^, ^^^ is the power radiation pattern, and ^^ and ^^ denote the zenith/elevation and azimuth angles, i.e., angle of departure (AOD) with respect to the center of the array, respectively. [0106] The SISO-OFDM channel model given in Eq. (2) can be extended to a MISO-OFDM channel model. The Fresnel zone MISO-OFDM channel h_^ ∈ ℂ^{^భ^మൈ^} at the subcarrier ^^ can be written as: where ^∙^^{^} denotes a matrix transpose and ^^_{௭భ,௭మ} is the distance between the WTRU and the ^{^} _{^^^, ^^ଶ} ^{^th} _{transmit antenna location, i.e., the distance between the WTRU and} ^{^} _{^^^Δ, ^^ଶΔ} ^{^} _{in the} transmit antenna array. [0107] The WTRU location/coordinates may be denoted by ^ ^^, ^^, ^^^ ൌ ^{^} ^^_^ sin ^^ cos ^^ , ^^_^ sin ^^ sin ^^ , ^^_^ cos ^^^{^}, where ^^_^ represents the distance between the WTRU and the center of network node (e.g., gNB) antenna array, and the ^{^} ^^_^, ^^_ଶ ^{^th} (antenna) element coordinator denotes ^{^} ^^_^Δ, ^^_ଶΔ, 0^{^} as shown in FIGs.6A and 6B. The distance between the WTRU _{and the} ^{^} _{^^^, ^^ଶ} ^{^th} _{antenna element can be expressed as:} where ^^_^ ൌ sin ^^ cos ^^, and ^^_ଶ ൌ sin ^^ sin ^^. [0108] From the first-order Taylor series, √1 ^ ^^ ^ 1 ^ ^௫ ଶ, Eq. (4) can be simplified as [0109] From Eq. (4) and Eq. (6), the near-field MISO-OFDM channel h_^,^ ∈ ℂ^{^^ൈ^} in Eq. (3) can be rewritten as: ^{[0110] From Eq. (7) and Eq. (8), Eq. (3) can be rewritten as} h_{^ ൌ ^^^Φ^b^ ^^, ^^^ ⊗ c^ ^^, ^^^, Eq. (9)} where ⊗ denotes the Kronecker product, b^ ^^, ^^^ and c^ ^^, ^^^ are the far-field azimuth and elevation manifolds, respectively. Also, b^ ^^, ^^^ ∈ ℂ^{^భൈ^} and c^ ^^, ^^^ ∈ ℂ^{^మൈ^} can be expressed as ^follows: [0111] The array response vectors b^ ^^, ^^^ and c^ ^^, ^^^ are classical far-field (DFT) array response vectors. The classical DFT codebook such as NR type I or II, or other two-dimension DFT codebook can be reused. From Eq. (8), Φ_^ is a diagonal matrix which can be expressed as: ^{[0112] Or Eq. (9) can be presented as the following form:} h_{^ ൌ ^^^ ^^^ ⊙ a^ ^^, ^^^ Eq. (12), where a} ^{^} _{^^, ^^} ^{^} _{ൌ b} ^{^} _{^^, ^^} ^{^} _{⊗ c} ^{^} _{^^, ^^} ^{^} _{is the far-field array response, ^^^ ൌ} is the Fresnel zone phase vector and ⊙ is the Hadamard product or element-wise product. [0113] The near-field phase term can be approximated to be frequency dependent at least for subbands around ^^_^ because the approximation of is valid. In narrowband systems, i.e., ^^_^ ~ ^^_^ holds, where ^^_^ is the central frequency. Therefore, or ^^_^ can be simplified as Φ or ^^, e.g., [0114] The assumption ^^_^ ~ ^^_^ might not hold for a very wideband systems; thus, the codebook may be adjusted from Φ back [0115] According to embodiments, the Fresnel zone channel matrix (for a path) at a subcarrier ^^ can be factorized through two major matrices (from Eq. (9)): ^ The first matrix may be the Fresnel zone phase matrix Φ (or vector ^^) ^ ^{The second matrix may be the classical far-field-array-response vector a^ ^^, ^^^ ൌ} b_{^ ^^, ^^^ ⊗ c^ ^^, ^^^} [0116] According to embodiments, the following Fresnel zone codebook is proposed: ^ If an NR type I (SU-MIMO) or II (MU-MIMO) codebook is adopted for replacing the far-field-array-response vectors a^ ^^, ^^^, the NR type I/II codebook can be reused for the far-field matrix, i.e., a^ ^^, ^^^. The new proposed Fresnel zone codebook can be based on the enhancement of an NR type I or II codebook with a phase matrix expressed as follows: o ΦW, where W are NR type I or II codebook matrices and the Fresnel zone phase matrix Φ is a diagonal matrix. o If dual polarization is applied, then the codebook can be expressed as Φ^ഥW, where is a block diagonal matrix Φ^ഥ ൌ Note that the phase term for dual polarization already exists in the NR codebooks. Therefore, there is no need to adjust the polarization phase term for the Fresnel zone phase term. [0117] According to embodiments, a signaling method is proposed for the construction of the (e.g., type-I) Fresnel zone phase term Φ. The phase term Φ can be constructed based on the following parameters: ^ If the phase term in the phase matrix is based on the 1^st order of a Taylor series approximation, the phase term is (e.g., only) dependent on any of the following parameters: o the distance between the center of the transmit array and the WTRU (e.g., UE), or the distance between the transmit array and the cluster/scatter, i.e., ^^_^, o the size of antenna/antenna ports, i.e., uniform planar array, ^^_^, ^^_ଶ, o the antenna separation, i.e., Δ. [0118] The Fresnel zone phase matrix Φ may be a function of the antenna configuration and/or the distance between the center of the transmit array of network node (e.g., gNB) and the WTRU. If the Fresnel zone phase matrix Φ is based on a 1^st order Tylor series per Eq. (6), the Fresnel zone phase matrix Φ can be applied for WTRUs with the same distance between WTRU and network node (e.g., gNB). Therefore, a MU-MIMO scenario may be still valid. The codebook structure for a Fresnel zone codebook can be based on an existing NR codebook (e.g., type I or II) and/or the phase matrix Φ based on the antenna configuration like ^^_^, ^^_ଶ distance between the WTRU and the array center and/or antenna separation. For a MU-MIMO Fresnel zone codebook, a network node (e.g., gNB) may consider those WTRUs with the (almost) same distance. For example, if WTRU1 and WTRU2 are (almost) same with the distance to the array, the network node (e.g., gNB) may group WTRU1 and WTRU2 for MU-MIMO so the Fresnel zone matrix Φ can be broadcast to all WTRUs. The legacy PMI reporting mechanism may be reused. [0119] The precision of the near-field phase term in the phase matrix Φ can be further improved, e.g., SU-MIMO if the far field AOD, i.e., ^ ^^, ^^^ angular information can be signaled to the WTRU for the construction of the near-field codebook. For example, the 2^nd order Taylor series may be √ ^{௫ ௫మ} use, 1 ^ ^^ ^ 1 ^_ଶ െ _଼ for approximation of the near-field phase in Eq. (2). Eq. (2) can be expressed as [0120] The value ^^_^ ൌ sin ^^ cos ^^ and ^^_ଶ ൌ sin ^^ sin ^^ can be obtained from the far field criteria, which have ^^_^ ^ଶ ^ 1 and ^^_ଶ ^ଶ ^ 1. [0121] Based on Eq. (14), the phase shift between the ^{^} ^^_^, ^^_ଶ ^{^th} antenna element and the WTRU may use (e.g., not only dependent on) the distance between the WTRU and the center of the transmit array, and may use (e.g., also is dependent on) the AOD information. [0122] According to embodiments, the (e.g., type-II) near-field SU-MIMO codebook can be enhanced and reconstructed based on any of the following information, i.e., the WTRU can use the following near-field information to construct the codebook: ^ the distance between the center of the transmit array and the WTRU, i.e., ^^ (note: the distance ^^_^ is quantized for signaling), or the distance between the transmit array or the distance between the transmit array to cluster/scatter, ^ the size of the antenna/antenna ports, i.e., uniform planar array ^^_^, ^^_ଶ, ^ the antenna separation, i.e., Δ, ^ the angular AOD ^ ^^, ^^^ information, the angular information can be based on ^^_^, ^^_ଶ and the oversampling rate ^^_^, ^^_ଶ, this is because max ( ^^_^ ^^_^, ^^_ଶ ^^_ଶ) determines the number of beams. [0123] The network node (e.g., gNB) can keep track of distance to the WTRU as previously proposed in the above-described embodiments of the WTRU. The WTRU can track the distance information ( ^^_^) to be estimated at the WTRU, quantized, and may be reported to the NW, for example, as part of the CSI report. [0124] Eq. (2) can be applied to a non-LOS (NLOS) path case. When there is a NLOS path between the WTRU and the array or surface, Eq. (2) may be (e.g., still) valid, but the phase shift between the WTRU and the ^{^} ^^_^, ^^_ଶ ^{^th} antenna element may be equivalent to the distance between the scatterer and the center of the ^{^} ^^_^, ^^_ଶ ^{^th} antenna element. This is because the phase shift between the WTRU and the ^{^} ^^_^, ^^_ଶ ^{^th} antenna element NLOS path may use (e.g., is dependent only on) the distance between the scatter and the center of the ^{^} ^^_^, ^^_ଶ ^{^th} antenna element. [0125] The NR type I and II codebooks can support (e.g., only) antenna configurations up to ^^_^ ^^_ଶ ൌ 16, but the NR type I or II codebook can be scalable by the extension of ^^_^, ^^_ଶ. In practice, the number of transmit antennas ^^_^, ^^_ଶ in the near field could be very large as shown in FIG.7, which is a diagram of antenna-array systems with large numbers of horizontal antennas N1 and vertical antennas N₂, where N₁ = N₂ and the antenna separate may be λ_c/2. For example, with a side length equal to 0.5 meter in a square antenna array with half-wavelength separation, the array can have around 8600 antenna elements. Although an NR type I or II codebook can extend the ^^_^, ^^_ଶ (array width, height) value to a large number to support a large antenna array for transmission, scheduling a WTRU to perform CSI acquisition based on PMI may not be used (e.g., practical) in this case because it may consume a large CSI-RS resource overhead, i.e., ^^_^ ^^_^ ^^_ଶ ( ^^_^ ൌ 1 for non-polarization or 2 for dual polarization) CSI-RS ports and demanding high computational complexity especially when a WTRU may (e.g., needs to) select unconstrained beams on a large orthogonal-beam basis. The following methods for performing beam focusing based on NR PMI are described. The following methods may reduce the CSI-RS resource overhead and/or reduce the beam selection complexity. [0126] The following describes a beam-focusing method for non-beamformed CSI-RS and beamformed CSI-RS, according to an embodiment. [0127] The method may comprise any of the following stages. [0128] The first stage may be to seek the far-field beam direction, i.e., to determine the spatial direction of ^^, ^^ from CSI-PMI reporting. The network node (e.g., gNB) can use the feedback PMI to determine the weight coefficients for performing beam focusing. [0129] A CSI report group can be configured for a WTRU and there may be one or more multiple CSI reports in the group as further described herein. In one or more (e.g., each) separated CSI report in a CSI report group, the reporting type can be set to PMI. One or more (e.g., each) separate CSI-PMI report in a CSI report group can correspond to a sub-array in a large array, as shown in FIG.8, which may include CSI-report maps to a sub-array aperture. A smaller array aperture can reduce the Fresnel zone. If the distance between the WTRU and the center of the array is “known” to the network node (e.g., gNB), the network node (e.g., gNB) may determine the array aperture, thus Fresnel criteria can be avoided. The WTRU can generate the CSI-PMI report based on the far-field criteria, so the NR legacy CSI-PMI reporting mechanism still can be reused. [0130] If multiple CSI-PMI reports are configured in a CSI report group, the WTRU may take up those (configured) multiple (e.g., ^^) CSI reports (in the same CSI report group) from different sub-arrays in a large array as shown in FIG. 8. Since those sub-arrays are geographically close (note: not like CSI from different TRPs), those CSI may have high correlation, e.g., the spatial direction and/or path delay. The PMI feedback can be based on the differential PMI, e.g., feedback the 1^st report with NR regular PMI. The rest of the feedback can be based on the differential PMI with the 1^st PMI. This is because one or more (e.g., each) feedback CSI-PMI reporting may have high correlation in the spatial direction with the other CSI-PMI feedback reports, thus the differential PMI can reduce the signaling overhead for PMI reporting as described elsewhere herein. [0131] The second stage may be to refine the weight coefficients for beam focusing. Following is described supporting non-beamformed CSI-RS and beamformed CSI-RS scenarios: [0132] For non-beamformed CSI-RS: the network node (e.g., gNB) may signal the assistance _{information like the estimated distance ^} ^{^} _{^, antenna information ^^^, ^^ଶ and estimated AOD} information in the second stage for a WTRU to perform PMI feedback. The signaled parameters can assist the WTRU for the reconstruction for the Fresnel codebook for a non-beamformed case. The number of transmit antennas ^^_^, ^^_ଶ can be selected such that the array aperture satisfies the Fresnel zone criterion for minimum array aperture, as shown in FIG. 9, which is a diagram of a minimum array aperture that satisfies the Fresnel zone criteria and maximum array aperture that satisfies the far-zone criteria for a given distance between a WTRU and the antenna array. The distance and angular information could be indicated, e.g., as a part of a CSI trigger (e.g., for AP CSI), the information can be updated with MAC CE, or hybrid indicated by MAC CE and an AP CSI trigger, i.e., a set of combinations of distance/angle indicated in MAC CE while one distance/angle combo is indicated in an AP CSI trigger. Once the network node (e.g., gNB) receives the feedback from the WTRU, the network node (e.g., gNB) can readjust the transmit antenna aperture size for achieving improved array gain for data/physical downlink shared channel (PDSCH) transmission. The WTRU may feedback the refined estimated distance ^^{^}^ and PMI (based on the proposed codebook in the above described embodiments) to the network node (e.g., gNB). Once the network node (e.g., gNB) obtains the refined CSI information, the network node (e.g., gNB) may use the refined CSI information for performing beam focusing. [0133] For beam-formed/beam-focused CSI-RS: when CSI-RS is beam formed, the associated spatial domain (SD) beams may be selected transparent to the WTRU like a legacy NR type II port selection codebook mechanism. In the NR type II port-selection codebook, the codebook structure _{can be expressed as W^ ൌ QW^W} ^{^} _^W ^ୌ ^_{,^, where Q is a matrix containing 2D DFT vectors for a regular} type II codebook, W_^ is a block diagonal indication matrix for port selection, W_^,^ and W^{^} _^ capture DFT basis vectors for frequency domain (FD) compression and non-zero linear combination (LC) coefficients, respectively. In legacy NR, the selection of the Q matrix may be transparent to the WTRU. As described above, a Fresnel zone codebook can apply the phase matrix Φ to the NR type II port-selection codebook, thus, the enhancement of the NR type II port selection codebook can be expressed as W_^ ൌ ΦQW_^W^{^} _^W^ୌ ^_,^. Like the legacy NR port selection mechanism, the selection of ΦQ may be transparent to the WTRU. Based on Eq. (13), the phase matrix Φ may use (be dependent on) the distance and antenna configurations. The network node (e.g., gNB) can schedule multiple CSI port-selection reports in a CSI report group like in the stage one for far field CSI-PMI reports. One or more (e.g., each) CSI port-selection report can be associated with a distance, thus the WTRU can perform CSI port selection based on different distances and feedback the selected ports to the network node (e.g., gNB). The (e.g., explicit) feedback distance information or a “distance ID” (quantized distance codepoint) could be indicated with a CSI report ID, e.g., in a MAC CE and transmitted in a PUSCH. A network node (e.g., gNB) can select among the feedback from multiple CSI port-selection reports to further refine the beam-focusing weights for data transmission. Like the differential PMI feedback method proposed in stage one, the feedback of port selection can be also based on the differential feedback. E.g., the first feedback can be based on regular PMI feedback, but the rest of (port selection) PMI feedback can be based on the differential with the 1^st PMI feedback, thus the signaling overhead can be reduced. This is because each port-selection feedback may have high correlation with each other. The other alternative method for a beam-formed CSI-RS case is like the legacy NR for beam management, i.e., the network node (e.g., gNB) can schedule one or multiple CSI-RS resources and one or more (e.g., each) resource can be associated, for example, with a single or two CSI-RS ports. One or more (e.g., each) CSI-RS port can be associated with a distance for beam focusing, and a WTRU can measure the beam-focused CSI-RS and select the best CRI (or could select multiple best CRIs) based on either L1-RSRP and/or L1-SINR for the feedback. [0134] A beam-focusing procedure for non-beam-formed or non-beam-focused CSI-RS is summarized in FIG.10, according to an embodiment. [0135] The network node may trigger a CSI report group with Q CSI-PMI Reports: #1 …#Q (step 10.1). The WTRU may perform PMI for CSI Report #1…#Q in a CSI report group (step 10.2) and/or send feedback #1…#K {PMI1 ΔPMI2...ΔPMIQ}. Based on #1…#Q feedback CSI- PM, the network node may estimate full CSI from the multiple PMI feedback and other assist information like distance estimation; and/or may select a transmit antenna aperture for data transmission (step 10.3). The network node may send assistance information like distance, antenna configuration, AoD, etc. (step 10.4). The WTRU may reconstruct Fresnel zone phase matrix ɸ based on the assistance information (step 10.5). The network node may send CSI report -CSI-PMI for Fresnel zone (step 10.6). The WTRU may perform PMI feedback based on Fresnel zone codebook (step 10.7). The WTRU may send PMI feedback including refined distance estimation (step 10.8). The network node may start (e.g., PDSCH) transmission with determined beamformed/beamfocused beams (TCI state) (step 10.9). The network node may transmit beamformed/beamfocused PDSCH (step 10.10). [0136] Regarding CSI-PMI reporting groups, in legacy NR, the triggered multiple CSI-PMI reports may correspond to different TRPs where M-TRPs may be located at different geometrical locations. When the network node (e.g., gNB) triggers multiple CSI-PMI reports for sub-arrays in the same large array as shown in FIG.8 for (near-field) CSI acquisition, the CSI-PMI reports may have high correlation with each other, e.g., they may have similar spatial direction and path delays. To inform a WTRU that those CSI-PMI reports may be highly correlated, a CSI-PMI report group can be used to indicate correlated CSI-PMI reports. A CSI-PMI report group may have any of the following properties, according to an embodiment: ^ Multiple CSI-PMI reports can be configured in a CSI group. When different CSI-PMI reports are within the same group, a WTRU may determine that those CSI-PMI reports may be mapped to different sub-arrays as shown in FIG.8, or similar. For example, an aperiodic (AP)-CSI trigger state (e.g., an AP CSI report) may be triggered with multiple CSI reports and one or more of the CSI reports can be configured to the same group in this trigger. ^ The indication that CSI reports belong to a group can, for example, be accomplished via any of the following options: o The grouping indication can be indicated in a CSI-AperiodicTriggerState information element (IE), or similar, which configures one trigger state. An aperiodic trigger state can be configured to include up to ^^ CSI-PMI reports, and one or more (e.g., each) configured CSI report may be associated to a bit to indicate whether this CSI report belongs to the same group or not. For example, if an AP-CSI trigger state is triggered by a DCI (e.g., DCI format 0_1/0_2) and ^^ (^{e.g., ^^ ൌ 8) CSI reports are associated with this AP-CSI trigger state, then ^^ ൌ} 8 _{bits, e.g., bitmap = ‘1111000’ may be used to configure that there are ^^ = 4 CSI} reports within the same CSI report group, i.e., those for which bit = ‘1’ are included in the same group. o The grouping indication can be indicated in CSI-AssociatedReportConfigInfo IE, or similar. In this option, a ‘groupId’ can be introduced in the CSI- AssociatedReportConfigInfo to indicate the group ID in the report configuration. For example, if an AP-CSI trigger state is triggered by a DCI (e.g., DCI format 0_1/0_2) and ^^ (e.g., ^^ ൌ 8) CSI reports are associated with this AP-CSI trigger state, then ^^ CSI-AssociatedReportConfigInfo will be configured for one or more (e.g., each) CSI report and the group Id in ^^ CSI-AssociatedReportConfigInfo can signal a WTRU which CSI report belongs to a group by the group Id. o Another option is using a CSI-RS bundle. One or more (e.g., each) CSI-RS report can be configured with a CSI-RS resource set and a configured CSI-RS resource in the CSI-RS resource set can be bundled with other CSI-RS resources in the different CSI-RS report. For instance, a WTRU may be triggered with four CSI reports and four bundled CSI-RSs {CSI-RS #1, CSI-RS #2, CSI-RS #3, CSI-RS #4} (they could be in the same CSI-RS resource set or different CSI-RS resource sets) may be assigned to one or more (e.g., each) CSI report in this trigger, i.e., CSI-RS #1 may be configured for CSI report #1, CSI-RS #2 may be configured for CSI report #2, …, CSI-RS #4 may be configured for CSI report #4, and so on. Because one or more (e.g., each) bundled CSI-RS in this bundle may be associated with one or more (e.g., each) CSI-RS report, a WTRU can determine those triggered CSI reports are within the same CSI report group. A purpose for bundled CSI-RS may be to indicate to a WTRU that each CSI-RS in this bundle is being associated with a sub-array in a large array of a TRP. The WTRU can be informed that some configured CSI-RSs may be from the same array in a TRP but not from different TRPs. o RRC or DCI may indicate joint feedback for those CSI reports that are in the same group. For example, if an AP-CSI trigger state is triggered by a DCI (e.g., DCI format 0_1/0_2) and ^^ (e.g., ^^ ൌ 8) CSI reports may be associated with this AP-CSI trigger state and there may be ^^ = 4 CSI reports of the ^^ (e.g., ^^ ൌ 8) CSI reports that may be configured to be in the same group. If the differential PMI feedback is enabled for a CSI-PMI report group, the DCI can schedule PUSCH, which carries the 5 (in this example) CSI feedback reports, i.e., one CSI feedback report for the ^^ = 4 CSI reports in the group and another ^^ െ ^^ ൌ 4 CSI reports that do not belong to the same group. [0137] A CSI Report group can be applied for periodic CSI reporting or semi-persistent CSI reporting as well. [0138] The WTRU procedure for handling a CSI report group in a triggered AP CSI report is summarized in FIG.11, which is a flow diagram of a WTRU procedure for handling a CSI report group in a triggered AP-CSI report, according to an embodiment. [0139] Described in conjunction with the flow diagram of FIG.11 is a method of how a WTRU performs differential PMI for PMI reporting, according to an embodiment. For purposes of example, in the case where a WTRU is configured with a CSI report group and there are ^^ CSI- PMI reports in the group. One or more (e.g., each) CSI-PMI may have a CSI-RS resource (e.g., for channel measurement) for performing a PMI, which may be the same or different among the CSI reports in the group. The WTRU may have obtained/estimated H_^…H_ொ channel matrices, for example, based on the ^^ CSI-RS resources. [0140] A WTRU may compute a regular PMI (PMI1) based on H_^ , e.g., as in the legacy NR mechanism. A network node (e.g., gNB) may reconstruct H_^ based on PMI1, at least approximately. In some cases, the WTRU may select which of the Q channel matrices is used for computing the regular PMI. The WTRU may include an index of the channel used for the regular PMI, e.g., between 1 and Q, in the CSI report. [0141] The WTRU may compute a differential PMIq based on PMI1 and H_^, for example, such that the H_^ ( ^^ ൌ 2, … ^^^ to be reconstructed at the network node (e.g., gNB) is as close to H_^ as possible (given the fewer bits in differential PMIq). [0142] The nominal reconstruction method of H_^ from PMI1 and PMIq may be specified and used by the WTRU in selection of a PMIq. The differential PMIq for CSI report ^^ can be calculated using the following procedure. First calculate PMIq using regular PMIq. Second, the differential PMIq can be calculated by calculating the difference between PMI(q-1), i.e., the q-1-th PMI and PMIq, e.g., calculating the PMI difference between PMI(q-1) ^^_^ and ^^_ଶ values and the PMIq ^^_^ and ^^_ଶ values and report the difference of PMI, i.e., differential PMI1 and PMIq. The network node (e.g., gNB) can use the feedback differential PMIq and PMI1 to reconstruct H_^. The differential ^^_^ and ^^_ଶ values may be represented by fewer bits than the regular ^^_^ and ^^_ଶ values, which means that not all values of ^^_^ and ^^_ଶ can be fed back in the differential PMI. [0143] According to embodiments, a codebook subset restriction value can be used to reduce the bits for differential PMI. For example, if codebook subset restriction is given for differential calculation, then if the difference PMI value exceeds the codebook subset restriction value, use the codebook subset restriction as the difference value for differential PMIq. For example, the codebook for PMIq may be restricted to include (e.g., only) values that are adjacent or close to PMI1. [0144] In FIG.11, the WTRU procedure for handling a CSI report group is illustrated, according to an embodiment. [0145] A network node (e.g., gNB) may trigger an aperiodic CSI report, multiple CSI-PMI reports may be associated with this AP CSI report (step 1110). The network node (e.g., gNB) may indicate that the CSI-PMI reports belong to the same CSI report group. The WTRU (e.g., UE) may receive the triggered AP CSI report and may perform PMI report for one or more (e.g., each associated CSI-PMI report) (step 1120). When a WTRU is triggered by an AP-CSI report with multiple CSI-PMI Reports (step 1110), the WTRU can determine whether there is a grouping indication for those multiple CSI-PMI reports and determine whether those CSI-PMI reports are within the same group or not (step 1130). The WTRU can perform differential PMI for feedback for those CSI-PMI reports that are in the same CSI-PMI report group (step 1140). The WTRU may perform regular/legacy PMI for feedback for those CSI-PMI reports that may be not in the same CSI-PMI report group (step 1150). The WTRU may send feedback CSI reports to the network node, for example, via PUSCH (step 1160). [0146] According to certain embodiments, a Fresnel zone codebook can be based on the NR type I/II codebook with the proposed Fresnel zone phase matrix. The Fresnel zone phase term Φ may use (e.g., depends on) the antenna configuration and/or the distance between the center of the transmit array of the network node (e.g., gNB) and the WTRU. [0147] According to certain embodiments, the signaling method for the construction of the Fresnel zone codebook phase matrix Φ is described. The phase term Φ can be constructed based on any of the following parameters: ^ the distance between the center of the transmit array and the WTRU, i.e., ^^, ^ the size of antenna array, ^^_ଶ, and ^ the antenna separation, i.e., Δ or ^ the distance between the center of the transmit array and the WTRU, i.e., ^^, ^ the size of antenna array, i.e., ^^_ଶ, ^ the antenna separation, i.e., Δ, and ^ the angular ^ ^^, ^^^ information, the angular information can be based on ^^_^, ^^_ଶ and the oversampling rate ^^_^, ^^_ଶ.Max ( ^^_^ ^^_^, ^^_ଶ ^^_ଶ) may determine the number of beams, i.e., including the orthogonality and rotation of beams. [0148] According to certain embodiments, a beam-focusing procedure for non-beam-formed CSI-RS and beam-formed CSI-RS with proposed Fresnel zone codebook is as follows: ^ A first stage may be to seek the far-field beam direction, i.e., determining the spatial direction of ^^, ^^ from CSI-PMI reporting. The network node (e.g., gNB) can use the feedback PMI to determine the pre-coded weight coefficients for performing beam focusing. ^ A second stage may be to refine the pre-coded weight coefficients for beam focusing. This embodiment can support non-beamformed CSI-RS and beam-formed CSI-RS scenarios. [0149] According to certain embodiments, a WTRU can be informed about the correlated CSI reports by the of the correlated CSI reports in the CSI group report. [0150] FIG.12 is a flowchart illustrating a representative method 1200 implemented by a WTRU 102. Referring to FIG.12, the representative method 1200 may include, at block 1210, receiving, from a network node, first information comprising any of: (1) distance information associated with an antenna array of the network node, wherein the antenna array comprises a plurality of antennas and/or antenna ports, and (2) a configuration of the antenna array. At block 1220, the representative method 1200 may include receiving a CSI configuration for PMI reporting. At block 1230, the representative method 1200 may include determining a Fresnel zone phase matrix based on the first information. At block 1240, the representative method 1200 may include determining a precoding matrix based on a combination of at least a far-field codebook and the Fresnel zone phase matrix. At block 1250, the representative method 1200 may include sending, to the network node, a PMI report based on the precoding matrix. [0151] According to certain embodiments, the at least far-field codebook may comprise/use a NR type I codebook and/or a NR type II codebook. [0152] According to certain embodiments, the configuration of antennas may comprise any of a size of one or more antennas of the antenna array, one or more distances between two antennas of the plurality of antennas. [0153] According to certain embodiments, the first information may comprise any of: angular information, a quantized angle of departure (AOD) information and quantized angle of arrival (AOA) information, and wherein the Fresnel zone phase matrix is determined using any of: the angular information, the quantized AOD and quantized AOA. [0154] According to certain embodiments, the WTRU may be configured with a CSI report group, wherein the CSI report group comprises one or more CSI reports, and the representative method 1200 may previously comprise: determining a PMI report for each of the one or more CSI reports of the report group, and sending, to the network node, the PMI report for each of the one or more CSI reports, and wherein the first information is based on the sent PMI report for each of the one or more CSI reports. [0155] According to certain embodiments, each of the one or more CSI reports of the report group may be associated to a sub-array of the antenna array. [0156] According to certain embodiments, the distance information may comprise any of a distance between the WTRU and the antenna array of the network node, a distance between the WTRU and a center of the antenna array of the network node, and a distance between a cluster/scatter and the antenna array. [0157] According to certain embodiments, the representative method 1200 may further comprise: receiving, from the network node, a trigger message and wherein sending, to the network node, the PMI report for each of the one or more CSI reports, is responsive to the trigger message. [0158] FIG.13 is a flowchart illustrating a representative method 1300 implemented by a WTRU 102. Referring to FIG.13, the representative method 1300 may include, at block 1310, obtaining configuration information indicating a CSI report group, wherein the CSI report group comprises one or more CSI reports. At block 1320, the representative method 1300 may include determining a PMI report for each of the one or more CSI reports of the report group. At block 1330, the representative method 1300 may include sending, to the network node, the PMI report for each of the one or more CSI reports. [0159] According to certain embodiments, each of the one or more CSI reports of the report group may be associated to a sub-array of the antenna array. [0160] According to certain embodiments, the representative method 1300 may further comprise: receiving, from the network node, a trigger message and wherein sending, to the network node, the PMI report for each of the one or more CSI reports, is responsive to the trigger message. [0161] According to certain embodiments, determining a PMI report for each of the one or more CSI reports of the report group may comprise performing differential PMI. [0162] Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems. [0163] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of infrared capable devices, i.e., infrared emitters and receivers. However, the embodiments discussed are not limited to these systems but may be applied to other systems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves. [0164] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, single image and/or multiple images displayed over a time basis. As another example, when referred to herein, the terms "user equipment" and its abbreviation "UE", the term "remote" and/or the terms "head mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and/or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless-capable and/or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU; (iii) a wireless-capable and/or wired-capable device configured with less than all structures and functionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs.1A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience. [0165] In addition, the methods provided herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer. [0166] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments that can be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery and the like, providing any appropriate voltage. [0167] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed." [0168] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods. [0169] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory (RAM)) or non-volatile (e.g., Read-Only Memory (ROM)) mass storage system readable by the CPU. The computer readable medium may include cooperating or interconnected computer readable medium, which exist exclusively on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods. [0170] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and/or any other computing device. [0171] There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and/or systems and/or other technologies described herein may be effected (e.g., hardware, software, and/or firmware), and the preferred vehicle may vary with the context in which the processes and/or systems and/or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and/or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and/or firmware. [0172] The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples include one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples may be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and/or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.). [0173] Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and/or processes into data processing systems. That is, at least a portion of the devices and/or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and/or control systems including feedback loops and control motors (e.g., feedback for sensing position and/or velocity, control motors for moving and/or adjusting components and/or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems. [0174] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components and/or wirelessly interactable and/or wirelessly interacting components and/or logically interacting and/or logically interactable components. [0175] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. [0176] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and/or the descriptions herein may include usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of" followed by a listing of a plurality of items and/or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and/or "any combination of multiples of" the items and/or the categories of items, individually or in conjunction with other items and/or other categories of items. Moreover, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero. And the term "multiple", as used herein, is intended to be synonymous with "a plurality". [0177] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. [0178] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. [0179] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. §112, ¶ 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

Claims

CLAIMS What is claimed is: 1. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising: receiving, from a network node, first information comprising any of: (1) distance information associated with an antenna array of the network node, wherein the antenna array comprises a plurality of antennas and/or antenna ports, and (2) a configuration of the antenna array; receiving a channel state information (CSI) configuration for precoder and/or precoding matrix indicator (PMI) reporting; determining a Fresnel zone phase matrix based on the first information; determining a precoding matrix based on a combination of at least a far-field codebook and the Fresnel zone phase matrix; and sending, to the network node, a PMI report based on the precoding matrix.

2. The method of claim 1 wherein the at least far-field codebook comprises a new radio (NR) type I codebook and/or a NR type II codebook.

3. The method of any of claims 1-2, wherein the configuration of the antenna array comprises any of: a size of one or more antennas of the antenna array; and one or more distances between two antennas of the plurality of antennas.

4. The method of any of claims 1-3, wherein the first information comprises any of: angular information, a quantized angle of departure (AOD) information and quantized angle of arrival (AOA) information, and wherein the Fresnel zone phase matrix is determined using any of: the angular information, the quantized AOD and quantized AOA.

5. The method of any of claims 1-4, wherein the WTRU is configured with a CSI report group, wherein the CSI report group comprises one or more CSI reports, and wherein the PMI report is a first PMI report, and the method comprising: determining one or more second PMI reports for the one or more CSI reports, respectively; and sending the one or more second PMI reports to the network node, wherein the first information is based on the one or more second PMI reports.

6. The method of claim 5, wherein each of the one or more CSI reports is associated to a sub- array of the antenna array.

7. The method of any of claims 5-7, comprising: receiving, from the network node, a trigger message, wherein sending, to the network node, the one or more second PMI reports is responsive to the trigger message.

8. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising: obtaining configuration information indicating a channel state information (CSI) report group, wherein the CSI report group comprises one or more CSI reports; determining one or more precoding matrix indicator (PMI) reports for the one or more CSI reports, respectively; and sending the one or more PMI reports to the network node.

9. The method of claim 8, wherein each of the one or more CSI reports is associated to a sub- array of the antenna array.

10. The method of any of claims 8-9, comprising: receiving, from the network node, a trigger message, wherein sending the one or more PMI reports to the network node comprises sending the one or more PMI reports to the network node responsive to the trigger message.

11. The method of any of claims 8-10, wherein determining the one or more PMI reports comprises determining a differential PMI.

12. A wireless transmit/receive unit (WTRU) comprising circuitry, including a transmitter, a receiver, a processor and memory, the WTRU configured to: receive, from a network node, first information comprising any of: (1) distance information associated with an antenna array of the network node, wherein the antenna array comprises a plurality of antennas and/or antenna ports, and (2) a configuration of the antenna array; receive a channel state information (CSI) configuration for precoding matrix indicator (PMI) reporting; determine a Fresnel zone phase matrix based on the first information; determine a precoding matrix based on a combination of at least a far-field codebook and the Fresnel zone phase matrix; and send, to the network node, a PMI report based on the precoding matrix.

13. The WTRU of claim 12 wherein the at least far-field codebook comprises a new radio (NR) type I codebook and/or a NR type II codebook.

14. The WTRU of any of claims 12-13, wherein the configuration of the antenna array comprises any of: a size of one or more antennas of the antenna array; and one or more distances between two antennas of the plurality of antennas.

15. The WTRU of any of claims 12-14, wherein the first information comprises any of: angular information, a quantized angle of departure (AOD) information and quantized angle of arrival (AOA) information, and wherein the Fresnel zone phase matrix is determined using any of: the angular information, the quantized AOD and quantized AOA.

16. The WTRU of any of claims 12-15, wherein the WTRU is configured with a CSI report group, wherein the CSI report group comprises one or more CSI reports, wherein the PMI report is a first PMI report, and wherein the WTRU is configured to: determine one or more second PMI reports for the one or more CSI reports, respectively; and send the one or more second PMI reports to the network node, wherein the first information is based on the one or more second PMI reports.

17. The WTRU of claim 16, wherein each of the one or more CSI reports is associated to a sub-array of the antenna array.

18. The WTRU of any of claims 16-17, configured to receive, from the network node, a trigger message, wherein the WTRU being configured to send the one or more second PMI reports to the network node comprises the WTRU being configured to send the one or more second PMI reports responsive to the trigger message.

19. A wireless transmit/receive unit (WTRU) comprising circuitry, including a transmitter, a receiver, a processor and memory, the WTRU configured to: obtain configuration information indicating a channel state information (CSI) report group, wherein the CSI report group comprises one or more CSI reports; determine one or more precoder and/or precoding matrix indicator (PMI) reports for the one or more CSI reports, respectively; and send the one or more PMI reports to the network node.

20. The WTRU of claim 19, wherein each of the one or more CSI reports is associated to a sub-array of the antenna array.

21. The WTRU of any of claims 19-20, wherein the WTRU is configured to receive, from the network node, a trigger message, and wherein the WTRU being configured to send the one or more PMI reports to the network node comprises the WTRU being configured to send the one or more PMI reports responsive to the trigger message. 21. The WTRU of any of claims 19-21, wherein the WTRU being configured to determine the one or more PMI reports comprises the WTRU being configured to determine a differential PMI.

22. The method of any of claims 1-11 or the WTRU of any of claims 12-21, wherein the distance information comprises any of: a distance between the WTRU and the antenna array, a distance between the WTRU and a center of the antenna array, and a distance between a cluster or a scatter and the antenna array.