WO2018084898A1

WO2018084898A1 - Evolved node-b (enb), user equipment (ue) and methods for codebook generation for multi-panel antenna arrangements

Info

Publication number: WO2018084898A1
Application number: PCT/US2017/038824
Authority: WO
Inventors: Alexei Davydov; Gregory Morozov; Victor SERGEEV; Wook Bong Lee
Original assignee: Intel Corporation
Priority date: 2016-11-02
Filing date: 2017-06-22
Publication date: 2018-05-11

Abstract

Embodiments of an Evolved Node-B (eNB), User Equipment (UE) and methods for communication are generally described herein. The eNB may generate, for beamformed transmission by an antenna array that comprises multiple panels of antenna elements, a multi-panel (MP) codeword that includes: for a horizontal polarization of the antenna elements of a first panel of the plurality: a predetermined single panel (SP) vector, for a vertical polarization of the antenna elements of the first panel: a product of the SP vector and a configurable polarization co-phase value; for horizontal polarizations of the antenna elements of the other panels of the plurality: products of the SP vector and configurable per-panel co-phase values; and for vertical polarizations of the antenna elements of the other panels of the plurality: products of the SP vector, the per-panel co-phase values, and the polarization co-phase value.

Description

EVOLVED NODE-B (ENB), USER EQUIPMENT (UE) AND METHODS FOR CODEBOOK GENERATION FOR MULTI-PANEL ANTENNA

ARRANGEMENTS

TECHNICAL FIELD [0001] This application claims the benefit of priority to United States Provisional Patent Application Serial No.62/416,277, filed November 2, 2016, which is incorporated herein by reference in its entirety. TECHNICAL FIELD [0002] Embodiments pertain to wireless communications. Some embodiments relate to wireless networks including 3GPP (Third Generation Partnership Project) networks, 3GPP LTE (Long Term Evolution) networks, and 3GPP LTE-A (LTE Advanced) networks, although the scope of the

embodiments is not limited in this respect. Some embodiments relate to beamforming. Some embodiments relate to reporting of channel state information (CSI).

BACKGROUND [0003] Base stations and mobile devices operating in a cellular network may exchange data and related control messages. Beamforming techniques may be used to provide directional transmission from the base station to a mobile device, in some cases. Such directional transmission may provide performance benefits in comparison to non-directional transmission, in some cases. For instance, a reduction in interference to other mobile devices, an increase in system capacity and/or other benefit may be realized. Accordingly, there is a general need for methods and systems to enable directional transmission in these and other scenarios.

BRIEF DESCRIPTION OF THE DRAWINGS [0004] FIG.1 is a functional diagram of a 3GPP network in accordance with some embodiments;

[0005] FIG.2 illustrates a block diagram of an example machine in accordance with some embodiments;

[0006] FIG.3 is a block diagram of an Evolved Node-B (eNB) in accordance with some embodiments;

[0007] FIG.4 is a block diagram of a User Equipment (UE) in accordance with some embodiments;

[0008] FIG.5 illustrates the operation of a method of communication in accordance with some embodiments;

[0009] FIG.6 illustrates the operation of another method of

communication in accordance with some embodiments;

[0010] FIG.7 illustrates an example antenna array in accordance with some embodiments; and

[0011] FIG.8 illustrates example vectors in accordance with some embodiments.

DETAILED DESCRIPTION [0012] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims. [0013] FIG.1 is a functional diagram of a 3GPP network in accordance with some embodiments. It should be noted that embodiments are not limited to the example 3GPP network shown in FIG.1, as other networks may be used in some embodiments. As an example, a Fifth Generation (5G) network may be used in some cases. As another example, a New Radio (NR) network may be used in some cases. As another example, a wireless local area network (WLAN) may be used in some cases. Embodiments are not limited to these example networks, however, as other networks may be used in some embodiments. In some embodiments, a network may include one or more components shown in FIG.1. Some embodiments may not necessarily include all components shown in FIG.1, and some embodiments may include additional components not shown in FIG.1.

[0014] The network 100 may comprise a radio access network (RAN) (e.g., as depicted, the E-UTRAN or evolved universal terrestrial radio access network) 101 and the core network 120 (e.g., shown as an evolved packet core (EPC)) coupled together through an S1 interface 115. For convenience and brevity sake, only a portion of the core network 120, as well as the RAN 101, is shown.

[0015] The core network 120 includes a mobility management entity (MME) 122, a serving gateway (serving GW) 124, and packet data network gateway (PDN GW) 126. The RAN 101 includes Evolved Node-B’s (eNBs) 104 (which may operate as base stations) for communicating with User Equipment (UE) 102. The eNBs 104 may include macro eNBs and low power (LP) eNBs.

[0016] In some embodiments, the eNB 104 may transmit signals (data, control and/or other) to the UE 102, and may receive signals (data, control and/or other) from the UE 102. These embodiments will be described in more detail below.

[0017] The MME 122 is similar in function to the control plane of legacy Serving GPRS Support Nodes (SGSN). The MME 122 manages mobility aspects in access such as gateway selection and tracking area list management. The serving GW 124 terminates the interface toward the RAN 101, and routes data packets between the RAN 101 and the core network 120. In addition, it may be a local mobility anchor point for inter-eNB handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement. The serving GW 124 and the MME 122 may be implemented in one physical node or separate physical nodes. The PDN GW 126 terminates an SGi interface toward the packet data network (PDN). The PDN GW 126 routes data packets between the EPC 120 and the external PDN, and may be a key node for policy enforcement and charging data collection. It may also provide an anchor point for mobility with non-LTE accesses. The external PDN can be any kind of IP network, as well as an IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the serving GW 124 may be implemented in one physical node or separated physical nodes.

[0018] The eNBs 104 (macro and micro) terminate the air interface protocol and may be the first point of contact for a UE 102. In some

embodiments, an eNB 104 may fulfill various logical functions for the RAN 101 including but not limited to RNC (radio network controller functions) such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In accordance with embodiments, UEs 102 may be configured to communicate Orthogonal Frequency Division Multiplexing (OFDM) communication signals with an eNB 104 over a multicarrier communication channel in accordance with an Orthogonal Frequency Division Multiple Access (OFDMA) communication technique. The OFDM signals may comprise a plurality of orthogonal subcarriers.

[0019] The S1 interface 115 is the interface that separates the RAN 101 and the EPC 120. It is split into two parts: the S1-U, which carries traffic data between the eNBs 104 and the serving GW 124, and the S1-MME, which is a signaling interface between the eNBs 104 and the MME 122. The X2 interface is the interface between eNBs 104. The X2 interface comprises two parts, the X2-C and X2-U. The X2-C is the control plane interface between the eNBs 104, while the X2-U is the user plane interface between the eNBs 104.

[0020] With cellular networks, LP cells are typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with very dense phone usage, such as train stations. As used herein, the term low power (LP) eNB refers to any suitable relatively low power eNB for implementing a narrower cell (narrower than a macro cell) such as a femtocell, a picocell, or a micro cell. Femtocell eNBs are typically provided by a mobile network operator to its residential or enterprise customers. A femtocell is typically the size of a residential gateway or smaller and generally connects to the user's broadband line. Once plugged in, the femtocell connects to the mobile operator's mobile network and provides extra coverage in a range of typically 30 to 50 meters for residential femtocells. Thus, a LP eNB might be a femtocell eNB since it is coupled through the PDN GW 126. Similarly, a picocell is a wireless communication system typically covering a small area, such as in-building (offices, shopping malls, train stations, etc.), or more recently in-aircraft. A picocell eNB can generally connect through the X2 link to another eNB such as a macro eNB through its base station controller (BSC)

functionality. Thus, LP eNB may be implemented with a picocell eNB since it is coupled to a macro eNB via an X2 interface. Picocell eNBs or other LP eNBs may incorporate some or all functionality of a macro eNB. In some cases, this may be referred to as an access point base station or enterprise femtocell.

[0021] In some embodiments, a downlink resource grid may be used for downlink transmissions from an eNB 104 to a UE 102, while uplink

transmission from the UE 102 to the eNB 104 may utilize similar techniques. The grid may be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid correspond to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element (RE). There are several different physical downlink channels that are conveyed using such resource blocks. With particular relevance to this disclosure, two of these physical downlink channels are the physical downlink shared channel and the physical down link control channel.

[0022] As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware. Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software.

[0023] FIG.2 illustrates a block diagram of an example machine in accordance with some embodiments. The machine 200 is an example machine upon which any one or more of the techniques and/or methodologies discussed herein may be performed. In alternative embodiments, the machine 200 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 200 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 200 may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environment. The machine 200 may be a UE 102, eNB 104, access point (AP), station (STA), mobile device, base station, personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a smart phone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[0024] Examples as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0025] Accordingly, the term“module” is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0026] The machine (e.g., computer system) 200 may include a hardware processor 202 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 204 and a static memory 206, some or all of which may communicate with each other via an interlink (e.g., bus) 208. The machine 200 may further include a display unit 210, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, input device 212 and UI navigation device 214 may be a touch screen display. The machine 200 may additionally include a storage device (e.g., drive unit) 216, a signal generation device 218 (e.g., a speaker), a network interface device 220, and one or more sensors 221, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine 200 may include an output controller 228, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc.).

[0027] The storage device 216 may include a machine readable medium 222 on which is stored one or more sets of data structures or instructions 224 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 224 may also reside, completely or at least partially, within the main memory 204, within static memory 206, or within the hardware processor 202 during execution thereof by the machine 200. In an example, one or any combination of the hardware processor 202, the main memory 204, the static memory 206, or the storage device 216 may constitute machine readable media. In some embodiments, the machine readable medium may be or may include a non-transitory computer-readable storage medium.

[0028] While the machine readable medium 222 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 224. The term“machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 200 and that cause the machine 200 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable

Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, machine readable media may include non-transitory machine readable media. In some examples, machine readable media may include machine readable media that is not a transitory propagating signal. [0029] The instructions 224 may further be transmitted or received over a communications network 226 using a transmission medium via the network interface device 220 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 226. In an example, the network interface device 220 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. In some examples, the network interface device 220 may wirelessly communicate using Multiple User MIMO techniques. The term“transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine 200, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

[0030] FIG.3 is a block diagram of an Evolved Node-B (eNB) in accordance with some embodiments. It should be noted that in some

embodiments, the eNB 300 may be a stationary non-mobile device. The eNB 300 may be suitable for use as an eNB 104 as depicted in FIG.1. The eNB 300 may include physical layer circuitry 302 and a transceiver 305, one or both of which may enable transmission and reception of signals to and from the UE 200, other eNBs, other UEs or other devices using one or more antennas 301. As an example, the physical layer circuitry 302 may perform various encoding and decoding functions that may include formation of baseband signals for transmission and decoding of received signals. As another example, the transceiver 305 may perform various transmission and reception functions such as conversion of signals between a baseband range and a Radio Frequency (RF) range. Accordingly, the physical layer circuitry 302 and the transceiver 305 may be separate components or may be part of a combined component. In addition, some of the described functionality related to transmission and reception of signals may be performed by a combination that may include one, any or all of the physical layer circuitry 302, the transceiver 305, and other components or layers. The eNB 300 may also include medium access control layer (MAC) circuitry 304 for controlling access to the wireless medium. The eNB 300 may also include processing circuitry 306 and memory 308 arranged to perform the operations described herein. The eNB 300 may also include one or more interfaces 310, which may enable communication with other components, including other eNBs 104 (FIG.1), components in the EPC 120 (FIG.1) or other network components. In addition, the interfaces 310 may enable communication with other components that may not be shown in FIG.1, including components external to the network. The interfaces 310 may be wired or wireless or a combination thereof. It should be noted that in some embodiments, an eNB or other base station may include some or all of the components shown in either FIG.2 or FIG.3 or both.

[0031] FIG.4 is a block diagram of a User Equipment (UE) in accordance with some embodiments. The UE 400 may be suitable for use as a UE 102 as depicted in FIG.1. In some embodiments, the UE 400 may include application circuitry 402, baseband circuitry 404, Radio Frequency (RF) circuitry 406, front-end module (FEM) circuitry 408 and one or more antennas 410, coupled together at least as shown. In some embodiments, other circuitry or arrangements may include one or more elements and/or components of the application circuitry 402, the baseband circuitry 404, the RF circuitry 406 and/or the FEM circuitry 408, and may also include other elements and/or components in some cases. As an example,“processing circuitry” may include one or more elements and/or components, some or all of which may be included in the application circuitry 402 and/or the baseband circuitry 404. As another example, a“transceiver” and/or“transceiver circuitry” may include one or more elements and/or components, some or all of which may be included in the RF circuitry 406 and/or the FEM circuitry 408. These examples are not limiting, however, as the processing circuitry, transceiver and/or the transceiver circuitry may also include other elements and/or components in some cases. It should be noted that in some embodiments, a UE or other mobile device may include some or all of the components shown in either FIG.2 or FIG.4 or both.

[0032] The application circuitry 402 may include one or more application processors. For example, the application circuitry 402 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors,

application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0033] The baseband circuitry 404 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 404 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 406 and to generate baseband signals for a transmit signal path of the RF circuitry 406. Baseband processing circuitry 404 may interface with the application circuitry 402 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 406. For example, in some embodiments, the baseband circuitry 404 may include a second generation (2G) baseband processor 404a, third generation (3G) baseband processor 404b, fourth generation (4G) baseband processor 404c, and/or other baseband processor(s) 404d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 404 (e.g., one or more of baseband processors 404a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 406. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 404 may include Fast-Fourier Transform (FFT), precoding, and/or constellation

mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 404 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0034] In some embodiments, the baseband circuitry 404 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 404e of the baseband circuitry 404 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 404f. The audio DSP(s) 404f may be include elements for

compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 404 and the application circuitry 402 may be implemented together such as, for example, on a system on a chip (SOC).

[0035] In some embodiments, the baseband circuitry 404 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 404 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 404 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[0036] RF circuitry 406 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 406 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 406 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 408 and provide baseband signals to the baseband circuitry 404. RF circuitry 406 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 404 and provide RF output signals to the FEM circuitry 408 for transmission.

[0037] In some embodiments, the RF circuitry 406 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 406 may include mixer circuitry 406a, amplifier circuitry 406b and filter circuitry 406c. The transmit signal path of the RF circuitry 406 may include filter circuitry 406c and mixer circuitry 406a. RF circuitry 406 may also include synthesizer circuitry 406d for synthesizing a frequency for use by the mixer circuitry 406a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 406a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 408 based on the synthesized frequency provided by synthesizer circuitry 406d. The amplifier circuitry 406b may be configured to amplify the down-converted signals and the filter circuitry 406c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 404 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 406a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. In some embodiments, the mixer circuitry 406a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 406d to generate RF output signals for the FEM circuitry 408. The baseband signals may be provided by the baseband circuitry 404 and may be filtered by filter circuitry 406c. The filter circuitry 406c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0038] In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a of the transmit signal path may include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion respectively. In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some

embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a of the transmit signal path may be configured for super- heterodyne operation.

[0039] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 406 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 404 may include a digital baseband interface to communicate with the RF circuitry 406. In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0040] In some embodiments, the synthesizer circuitry 406d may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 406d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. The synthesizer circuitry 406d may be configured to synthesize an output frequency for use by the mixer circuitry 406a of the RF circuitry 406 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 406d may be a fractional N/N+1 synthesizer. In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 404 or the applications processor 402 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look- up table based on a channel indicated by the applications processor 402.

[0041] Synthesizer circuitry 406d of the RF circuitry 406 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0042] In some embodiments, synthesizer circuitry 406d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 406 may include an IQ/polar converter.

[0043] FEM circuitry 408 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 410, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 406 for further processing. FEM circuitry 408 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 406 for transmission by one or more of the one or more antennas 410.

[0044] In some embodiments, the FEM circuitry 408 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 406). The transmit signal path of the FEM circuitry 408 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 406), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 410. In some embodiments, the UE 400 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.

[0045] The antennas 230, 301, 410 may comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, micro-strip antennas or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, the antennas 230, 301, 410 may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.

[0046] In some embodiments, the UE 400 and/or the eNB 300 and/or the machine 200 may be a mobile device and may be a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a wearable device such as a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that may receive and/or transmit information wirelessly. In some embodiments, the UE 400 and/or eNB 300 and/or the machine 200 may be configured to operate in accordance with 3GPP standards, although the scope of the embodiments is not limited in this respect. Mobile devices or other devices in some embodiments may be configured to operate according to other protocols or standards, including IEEE 802.11 or other IEEE standards. In some embodiments, the UE 400 and/or the eNB 300 and/or the machine 200 and/or other device may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0047] Although the UE 400, the eNB 300, and the machine 200 are each illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.

[0048] Embodiments may be implemented in one or a combination of hardware, firmware and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read- only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

[0049] It should be noted that in some embodiments, an apparatus used by the UE 400 and/or eNB 300 and/or machine 200 may include various components of the UE 400 and/or the eNB 300 and/or the machine 200 as shown in FIGs.2-4. Accordingly, techniques and operations described herein that refer to the UE 400 (or 102) may be applicable to an apparatus for a UE. In addition, techniques and operations described herein that refer to the eNB 300 (or 104) may be applicable to an apparatus for an eNB.

[0050] In accordance with some embodiments, the eNB 104 may generate, for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements, a multi-panel (MP) codeword that includes: for a horizontal polarization of the antenna elements of a first panel of the plurality: a predetermined single panel (SP) vector, for a vertical polarization of the antenna elements of the first panel: a product of the SP vector and a configurable polarization co-phase value, for horizontal polarizations of the antenna elements of the other panels of the plurality: products of the SP vector and configurable per-panel co-phase values, and for vertical polarizations of the antenna elements of the other panels of the plurality: products of the SP vector, the per-panel co-phase values, and the polarization co-phase value. These embodiments are described in more detail below.

[0051] FIG.5 illustrates the operation of a method of communication in accordance with some embodiments. It is important to note that embodiments of the method 500 may include additional or even fewer operations or processes in comparison to what is illustrated in FIG.5. In addition, embodiments of the method 500 are not limited to the chronological order that is shown in FIG.5. In describing the method 500, reference may be made to FIGs.1-4 and 6-8, although it is understood that the method 500 may be practiced with any other suitable systems, interfaces and components.

[0052] In some embodiments, an eNB 104 may perform one or more operations of the method 500, but embodiments are not limited to performance of the method 500 and/or operations of it by the eNB 104. In some

embodiments, the UE 102 may perform one or more operations of the method 500 (and/or similar operations). Accordingly, although references may be made to performance of one or more operations of the method 500 by the eNB 104 in descriptions herein, it is understood that the UE 102 may perform the same operation(s), similar operation(s) and/or reciprocal operation(s), in some embodiments. [0053] In addition, while the method 500 and other methods described herein may refer to eNBs 104 or UEs 102 operating in accordance with 3GPP standards, 5G standards and/or other standards, embodiments of those methods are not limited to just those eNBs 104 or UEs 102 and may also be practiced on other devices, such as a Wi-Fi access point (AP) or user station (STA). In addition, the method 500 and other methods described herein may be practiced by wireless devices configured to operate in other suitable types of wireless communication systems, including systems configured to operate according to various IEEE standards such as IEEE 802.11. The method 500 may also refer to an apparatus for a UE 102 and/or eNB 104 and/or other device described above.

[0054] It should also be noted that embodiments are not limited by references herein (such as in descriptions of the methods 500, 600, and/or other descriptions herein) to transmission, reception and/or exchanging of elements such as frames, messages, requests, indicators, signals or other elements. In some embodiments, such an element may be generated, encoded or otherwise processed by processing circuitry (such as by a baseband processor included in the processing circuitry) for transmission. The transmission may be performed by a transceiver or other component, in some cases. In some embodiments, such an element may be decoded, detected or otherwise processed by the processing circuitry (such as by the baseband processor). The element may be received by a transceiver or other component, in some cases. In some embodiments, the processing circuitry and the transceiver may be included in a same apparatus. The scope of embodiments is not limited in this respect, however, as the transceiver may be separate from the apparatus that comprises the processing circuitry, in some embodiments.

[0055] At operation 505, the eNB 104 may transmit one or more channel state information (CSI) reference signals (CSI-RS). In some embodiments, the CSI-RS may be mapped to one or more antenna elements of an antenna array. In some embodiments, the CSI-RS may be mapped to one or more antenna ports. In a non-limiting example, an antenna port may be mapped to one or more of the following: frequency resources (including but not limited to one or more resource elements (REs) and/or resource blocks (RBs)); time resources

(including but not limited to one or more symbol periods); one or more transmit antennas; one or more antenna elements; one or more antenna panels; an antenna array; and/or other resource(s).

[0056] In some embodiments, the eNB 104 may generate, for transmission by an antenna array, CSI-RS without precoding (such as precoding by a codeword), although the scope of embodiments is not limited in this respect. In some embodiments, precoding on the CSI-RS may be used.

[0057] At operation 510, the eNB 104 may receive one or more messages from the UE 102. The message(s) may include information, such as control information, that may be used by the eNB 104 for one or more operations, including but not limited to operations of the method 500. In some embodiments, the eNB 104 may receive one or more control messages from the UE 102, although embodiments are not limited to control messages. For instance, a data message from the UE 102 may include control information that the eNB 104 may use for one or more operations, including but not limited to operations of the method 500.

[0058] In some embodiments, the message(s) may include any suitable information related to communication between the UE 102 and the eNB 104, including but not limited to information related to an establishment of connectivity between the UE 102 and the eNB 104, information related to directional transmission by the eNB 104, information related to beamforming, information related to beamformed transmission by the eNB 104, information related to codebooks, information related to codewords (including but not limited to a selected codeword), information related to measurements (including but not limited to signal quality measurements) and/or other information.

[0059] It should be noted that embodiments are not limited to the chronological order shown in FIG.5. In some embodiments, one or more operations may be performed multiple times. As an example, multiple messages may be received separately. For instance, the eNB 104 may receive a first message, may perform a first operation after reception of the first message and may receive a second message after performance of the first operation. It should be noted that embodiments may not necessarily include all operations shown in FIG.5. [0060] At operation 515, the eNB 104 may generate a codebook of codewords. In some embodiments, the antenna array may include multiple panels of antenna elements, although the scope of embodiments is not limited in this respect. In some embodiments, the eNB 104 may generate a codebook of codewords for beamformed transmission by an antenna array that comprises multiple panels of antenna elements.

[0061] The codewords may be used for directional transmission of a signal by an antenna array of antenna elements. In a non-limiting example, a codeword may include scale values, the bit positions within the codeword may be mapped to the antenna elements, and the scale values may be used to scale the signal on the antenna elements. In another non-limiting example, a signal may be scaled based on a predetermined mapping between the antenna elements and positions within the codewords.

[0062] In some embodiments, the eNB 104 may determine the codewords to correspond to different transmit directions when the antenna elements of the antenna array are scaled by the scalar values of the different codewords. In some embodiments, the eNB 104 may generate the codewords for directional transmissions in different transmit directions.

[0063] In some embodiments, the eNB 104 may generate the codewords based at least partly on matrix products of a first matrix, a second matrix and a third matrix. In a non-limiting example, the codewords may be generated for an antenna array that comprises multiple panels. The first matrix (which may be referred to as“W1”) may comprise one or more candidate beamforming vectors for each panel. The candidate beamforming vectors may be based on a first Discrete Fourier Transform (DFT) based on an intra-panel row index and further based on a second DFT based on an intra-panel column index. In some embodiments, the candidate beamforming vectors may be based on a Kronecker product of the first DFT and the second DFT. The first DFT may be based on a first oversampling factor. The second DFT may be based on a second oversampling factor. The first and second oversampling factors may be different or may be the same.

[0064] The second matrix (which may be referred to as“W2”) may be configurable. The second matrix may comprise intra-panel scale vectors that are configurable to generate per-panel linear combinations of the candidate beamforming vectors. The third matrix (which may be referred to as“W3”) may be configurable. The third matrix may comprise at least one inter-panel scale vector that is configurable to scale the per-panel linear combinations of the beamforming vectors to generate the codewords. In some embodiments, the codewords may be generated as W1*W2*W3 for different realizations of W1 and/or W2 and/or W3.

[0065] Continuing the above example, in some embodiments, one or more candidate beamforming vectors may be used (and/or predetermined) for each panel. The first matrix may include the candidate beamforming vectors, and may also include vectors of zeros. The second matrix may include linear combination vectors (which may be referred to as intra-panel scale vectors) which may combine the candidate beamforming vectors. For instance, a linear combination vector for a particular panel may combine one or more of the candidate beamforming vectors of the particular panel. The linear combination may be performed by any suitable real values, imaginary values and/or complex values (which may or may not be predetermined).

[0066] Embodiments are not limited to combining by the second matrix, however. In some embodiments, selection may be used. For instance, for a particular panel, one of the candidate beamforming vectors of the particular panel may be selected. The selection may be performed by intra-panel scale vectors that are configurable to select one of the candidate beamforming vectors for inclusion in one of the per-panel linear combinations. For instance, the selection may be performed by usage of vectors that include: a non-zero value (including but not limited to a value of one) in a position that corresponds to the selected candidate beamforming vector, and values of zero in other positions.

[0067] The third matrix may include linear combination vectors (which may be referred to as inter-panel scale vectors) which may select, scale and/or combine the per-panel linear combinations. The linear combination may be performed by any suitable real values, imaginary values and/or complex values (which may or may not be predetermined). In a non-limiting example, a value in a first position may be based on a square root of a loading factor. A value in a second position may be based on a product of: a difference between one and the loading factor, and a complex exponential for which an argument is based on a co-phasing value. A value of zero may be included in other positions. In some embodiments, the inter-panel scale vectors may be configurable to select one or more of the panels for the beamforming by usage of vectors that include: a non- zero value in one or more positions that correspond to the selected panels, and values of zero in other positions.

[0068] In some embodiments, the candidate beamforming vectors may be of dimension equal to a number of antenna elements per panel. The intra- panel scale vectors may be of dimension equal to a number of candidate beamforming vectors per panel. The inter-panel scale vectors may be of dimension equal to a number of panels of the antenna array.

[0069] In some embodiments, the codewords may be of dimension equal to a product of the number of antenna elements per panel and the number of panels. Each codeword may include a concatenation of scaled vectors. Each scaled vector may correspond to one of the panels. The scaled vectors may be of dimension equal to the number of antenna elements per panel.

[0070] In some embodiments, one or more of the codewords may be of dimension equal to a product of the number of antenna elements per panel and the number of panels. One or more of the codewords may include a

concatenation of scaled vectors. One or more of the scaled vectors may correspond to one of the panels. One or more of the scaled vectors may be of dimension equal to the number of antenna elements per panel.

[0071] In a non-limiting example, the candidate beamforming vectors may be based at least partly on a sequence of complex exponentials. An argument of the sequence of complex exponentials may be based at least partly on a product that includes a configurable broadening factor and a sequence of antenna element indexes of the antenna array. The predetermined plurality of broadening factor values may be used in the first matrix to produce different beam-widths for the codebook, in some cases.

[0072] The above example may be extended in accordance with one or more of the following aspects, although the scope of embodiments is not limited in this respect. The product on which the argument of the sequence of complex exponentials is based may include a summation raised to a predetermined exponent. The summation may include a first term and a second term. The first term may be inversely proportional to a first product of two and a difference between a number of antenna elements and one. For a particular value of the antenna element index, the second term may be: directly proportional to a difference between the particular value of the antenna element index and a summation of one half of the number of antenna elements and one; and inversely proportional to a difference between the number of antenna elements and one. For instance, the first matrix may be based on elements such as those below: [0073]

[0074] It should be noted that embodiments are not limited by any of the above examples. For instance, other techniques and/or operations may be used to determine the codewords, including but not limited to the examples given below.

[0075] In some embodiments, a codebook of codewords may be generated for an antenna array of multiple two-dimensional panels of antenna elements. The codewords may be generated based on: a first DFT that is based on intra-panel row indexes of the antenna elements, a second DFT that is based on intra-panel column indexes of the antenna elements, and a third DFT that is based on panel indexes of the antenna elements.

[0076] In some embodiments, for a particular antenna element: the panel index of the particular antenna element may indicate the panel that comprises the particular antenna element, the intra-panel row index of the particular antenna element may indicate a row index within the panel that comprises the particular antenna element, and the intra-panel column index of the particular antenna element may indicate a column index within the panel that comprises the particular antenna element.

[0077] In some embodiments, the first DFT may be further based on a first oversampling parameter, and the second DFT may be further based on a second oversampling parameter. The first and second oversampling parameters may be the same, in some embodiments. The first and second oversampling parameters may be different, in some embodiments. [0078] In some embodiments, the codewords may include scalar values mapped to the antenna elements. The eNB 104 may generate the scalar values of the codewords that are mapped to each panel based on a Kronecker product of the first DFT and the second DFT.

[0079] In some embodiments, the eNB 104 may generate the codebook based on an arrangement of the antenna array that comprises multiple antenna panels in a rectangular grid of panels. The panel index of the third DFT may be a panel row index with respect to the rectangular grid of panels. The eNB 104 may generate the codebook of codewords further based on a fourth DFT that is based on a panel column index with respect to the rectangular grid of panels.

[0080] In some embodiments, the codewords may include scalar values mapped to the antenna elements. The eNB 104 may determine the scalar values of the codewords that are mapped to each panel based on a first Kronecker product of the first DFT and the second DFT. The eNB 104 may determine the scalar values of the codewords further based on a second Kronecker product of the third DFT and the fourth DFT.

[0081] In some embodiments, the codewords may include scalar values mapped to the antenna elements. The eNB 104 may determine a first Kronecker product between the first DFT and the second DFT. The eNB 104 may determine a second Kronecker product between the third DFT and the fourth DFT. The eNB 104 may determine the scalar values of the codewords based on a double Kronecker product, wherein: the first Kronecker product is applied within each panel, and the second Kronecker product is applied to the rectangular grid.

[0082] Returning to the method 500, at operation 520, the eNB 104 may select a codeword from the codebook. In some embodiments, operations 515 and 520 may be performed together (such as in one operation), although the scope of embodiments is not limited in this respect. In some embodiments, a codebook of codewords may be predetermined and may be included as part of a standard (such as a 3GPP standard and/or other standard). In such embodiments, the codebook may be stored in memory at the eNB 104 and/or UE 102.

Accordingly, in these and in some other embodiments, operation 515 may not necessarily be performed. In some embodiments, a codeword of the codebook may be selected and/or identified, and may be generated in response. For instance, one entity (eNB 104 or UE 102) may select a codeword and may indicate the selected codeword to the other entity. The other entity may generate the indicated codeword.

[0083] At operation 525, the eNB 104 may generate a signal for transmission by the antenna array. In some embodiments, the signal may be based at least partly on data, although the scope of embodiments is not limited in this respect. At operation 530, the eNB 104 may scale the signal. In some embodiments, the eNB 104 may scale the signal in accordance with the selected codeword, although the scope of embodiments is not limited in this respect. At operation 535, the eNB 104 may transmit the scaled signal.

[0084] In some embodiments, the eNB 104 may select one of the codewords to be used for directional transmissions in accordance with a beam- width, although the scope of embodiments is not limited in this respect. One or more factors may be used as part of the selection of the codeword, including but not limited to the examples below. In a non-limiting example, the eNB 104 may select the codeword based at least partly on a determined beam-width. A mapping between beam-width(s) and broadening factor(s) may be used, in some cases. A mapping between beam-widths and indexes of the codewords may be used, in some cases. For instance, a predetermined plurality of broadening factors may be used, and those broadening factors may be mapped to the indexes in a predetermined manner.

[0085] In another non-limiting example, one or more messages from the UE 102 may include information that the eNB 104 may use for the selection of the codeword. For instance, the eNB 104 may receive a message from the UE 102 that indicates a mobile velocity measurement of the UE 102. The eNB 104 may select the codeword based at least partly on the mobile velocity

measurement. In some embodiments, the eNB 104 may select the codeword further based at least partly on a predetermined mapping between the mobile velocity and the broadening factor. In some embodiments, the eNB 104 may select the codeword further based at least partly on a predetermined mapping between the mobile velocity and indexes of the codeword. For instance, a predetermined plurality of broadening factors may be used, and those broadening factors may be mapped to the indexes in a predetermined manner.

[0086] In another non-limiting example, the eNB 104 may receive a message from the UE 102 that may indicate the codeword to be used by the eNB 104. The message may be based at least partly on the CSI-RS, although the scope of embodiments is not limited in this respect. In another non-limiting example, the eNB 104 may receive a message from the UE that may indicate measurements (such as signal quality measurements and/or other) for the codewords. The measurements may be based at least partly on the CSI-RS, although the scope of embodiments is not limited in this respect. The eNB 104 may select the codewords based at least partly on the measurements. In a non- limiting example, the codeword that corresponds to a maximum signal quality (of the signal quality measurements of the message) may be selected. In another non-limiting example, a codeword for which the signal quality is greater than or equal to a predetermined threshold may be used.

[0087] The examples given above are not limiting, as the eNB 104 may use any suitable technique to select a codeword.

[0088] In some embodiments, the eNB 104 may generate a downlink signal based on downlink data. The eNB 104 may scale the downlink signal in accordance with the selected codeword (including but not limited to a codeword indicated in a message from the UE 102) for transmission by antenna elements of the antenna array. The signal may be scaled based on a predetermined mapping between the antenna elements and positions within the codewords.

[0089] In some embodiments, an apparatus of an eNB 104 may comprise memory. The memory may be configurable to store the codewords. The memory may store one or more other elements and the apparatus may use them for performance of one or more operations. In some embodiments, the apparatus of the eNB 104 may include a transceiver. The transceiver may be configurable to be coupled to the antenna array for directional transmissions. The transceiver may transmit and/or receive other signals, frames, PPDUs, messages and/or other elements. In some embodiments, the apparatus may include the antenna array, although the scope of embodiments is not limited in this respect. The apparatus may include processing circuitry, which may perform one or more operations (including but not limited to operation(s) of the method 500 and/or other methods described herein). The processing circuitry may include a baseband processor. The baseband circuitry and/or the processing circuitry may perform one or more operations described herein, including but not limited to generation of the codewords.

[0090] FIG.6 illustrates the operation of another method of

communication in accordance with some embodiments. As mentioned previously regarding the method 500, embodiments of the method 600 may include additional or even fewer operations or processes in comparison to what is illustrated in FIG.6 and embodiments of the method 600 are not limited to the chronological order that is shown in FIG.6. In describing the method 600, reference may be made to FIGs.1-5 and 7-8, although it is understood that the method 600 may be practiced with any other suitable systems, interfaces and components. In addition, embodiments of the method 600 may be applicable to UEs 102, eNBs 104, APs, STAs and/or other wireless or mobile devices. The method 600 may also be applicable to an apparatus for a UE 102, eNB 104 and/or other device described above.

[0091] In some embodiments, the UE 102 may perform one or more operations of the method 600, but embodiments are not limited to performance of the method 600 and/or operations of it by the UE 102. In some embodiments, the eNB 104 may perform one or more operations of the method 600 (and/or similar operations). Accordingly, although references may be made to performance of one or more operations of the method 600 by the UE 102 in descriptions herein, it is understood that the eNB 104 may perform one or more same operation(s), similar operation(s) and/or reciprocal operation(s), in some embodiments.

[0092] It should be noted that the method 600 may be practiced by the UE 102 and may include exchanging of elements, such as frames, signals, messages and/or other elements, with the eNB 104. Similarly, the method 500 may be practiced by an eNB 104 and may include exchanging of such elements with a UE 102. In some cases, operations and techniques described as part of the method 500 may be relevant to the method 600. In addition, embodiments of the method 600 may include one or more operations performed by the UE 102 that may be the same as, similar to or reciprocal to one or more operations described herein performed by the eNB 104 (including but not limited to operations of the method 500). As an example, an operation of the method 600 may be the same as or similar to an operation of the method 500. As another example, an operation of the method 500 may include a downlink transmission by the eNB that is similar to an uplink transmission by the UE 102 included in the method 600.

[0093] In addition, previous discussion of various techniques and concepts may be applicable to the method 600 in some cases, including beam- forming, directional transmission, codebooks, codewords, CSI, CSI-RS, and/or others.

[0094] At operation 605, the UE 102 may receive one or more CSI-RS from the eNB 104. At operation 610, the UE 102 determine CSI measurements (including but not limited to signal quality measurements) based on the CSI-RS. At operation 615, the UE 102 may generate a codebook of codewords. At operation 620, the UE 102 may select a codeword from the codebook. At operation 625, the UE 102 may transmit one or more messages to the eNB 104. The message(s) may include one or more of a codebook index to be used by the eNB 104, a codeword index to be used by the eNB 104, signal quality measurements, CSI, CSI measurements, mobile velocity of the UE 102 and/or other. At operation 630, the UE 102 may receive a signal from the eNB 104. In a non-limiting example, the signal may be a downlink data signal transmitted by the eNB 104 in accordance with a directional transmission based on one of the codewords of the codebook.

[0095] In some embodiments, the codebook of codewords may be generated for beamformed transmission by an antenna array that comprises multiple panels of antenna elements. The codewords may be generated based on matrix products of: a first matrix that comprises one or more candidate beamforming vectors for each panel, a configurable second matrix to generate per-panel linear combinations of the candidate beamforming vectors, and a configurable third matrix to scale the per-panel linear combinations of the beamforming vectors to generate the codewords. Signal quality measurements may be determined based on correlations of the codewords with received channel state information reference signals (CSI-RS). The UE 102 may transmit one or more uplink control messages that include information related to the signal quality measurements. In a non-limiting example, the UE 102 may select the codeword that corresponds to a highest value of the signal quality measurements. In another non-limiting example, the UE 102 may select a codeword for which the signal quality measurement is greater than or equal to a predetermined threshold. The UE 102 may encode the uplink control message(s) to indicate the selected codeword.

[0096] In some embodiments, the UE 102 may receive one or more downlink control messages from an eNB 104 that indicate one or more configuration parameters for a codebook of codewords to be used for downlink transmission by the eNB 104 on an antenna array of a rectangular grid of two- dimensional panels. The UE 102 may determine the codebook of codewords based on a first function of an intra-panel row index, a second function of an intra-panel column index, a third function of a panel row index, and a fourth function of a panel column index. The UE 102 may determine a plurality of signal quality measurements based on correlations of the codewords with CSI- RS received from the eNB 104. The UE 102 may transmit one or more uplink control messages that include information related to the signal quality measurements. In a non-limiting example, the UE 102 may select the codeword of maximum signal quality measurement in the plurality of signal quality measurements. In another non-limiting example, the UE 102 may select a codeword for which the signal quality measurement is greater than or equal to a predetermined threshold. The UE 102 may encode the uplink control message(s) to indicate the selected codeword.

[0097] It should be noted that references herein to an eNB 104 are not limiting. In some embodiments, one or more operations, methods and/or techniques (such as those described herein) may be practiced by a base station component (and/or other component), including but not limited to a Generation Node-B (gNB), a serving cell, a transmit receive point (TRP) and/or other. In some embodiments, the base station component may be configured to operate in accordance with a New Radio (NR) protocol and/or NR standard, although the scope of embodiments is not limited in this respect. In some embodiments, the base station component may be configured to operate in accordance with a Fifth Generation (5G) protocol and/or 5G standard, although the scope of

embodiments is not limited in this respect.

[0098] FIG.7 illustrates an example antenna array in accordance with some embodiments. FIG.8 illustrates example vectors in accordance with some embodiments. It should be noted that the examples shown in FIGs.7-8 may illustrate some or all of the concepts and techniques described herein in some cases, but embodiments are not limited by the examples. For instance, embodiments are not limited by the name, number, type, size, ordering, arrangement and/or other aspects of the matrixes, vectors, antennas, antenna elements, antenna arrays and/or other elements as shown in FIGs.7-8. Although some of the elements shown in the examples of FIGs.7-8 may be included in a 3GPP LTE standard and/or other standard, embodiments are not limited to usage of such elements that are included in standards.

[0099] Referring to FIG.7, the example antenna array 700 comprises multiple panels 710 arranged in a rectangular grid of Mg rows (denoted by 720) by Ng columns (denoted by 730). A spacing 722 between rows and a spacing 732 between columns may be the same in some embodiments, and may be configurable to be different in some embodiments. The panel 710 is shown in more detail comprising elements 716, which may include horizontal and vertical polarizations in some embodiments, as indicated by“/” and“\”. The elements 716 are arranged in a grid of a number of rows 712 by a number of columns 714.

[00100] Referring to FIG.8, the vector 810 may be a linear combination of vectors 812, 814, 816, in which a vector u1 is scaled by different complex exponentials. The vectors 820 and 830 may be determined in a similar manner.

[00101] A method to generate a precoding matrix is given below. In some embodiments, the precoding matrix may be based on a product of three matrices, W1*W2*W3. It should be noted that embodiments are not limited to the usage of three explicit matrices (such as W1, W2, and W3). In some embodiments, one or two matrices (such as any of W1, W2, W3 and/or other matrix) may be used. In some embodiments, a precoding matrix that may result from such a product (of any number of matrices) may be used, and may not necessarily be generated using the matrix product. For instance, a precoding matrix may be described as a result from one or more operations (including but not limited to any of those described below). However, the precoding matrix may be used, in some embodiments, without performance of one or more of those operations.

[00102] In the description below, the value M may be a number of antennas/port in a vertical direction per panel. The number N may be a number of antennas/port in a horizontal direction per panel. The number Mg may be a number of panels in a vertical direction. The number Ng may be a number of panels in a horizontal direction. The number dH may be a distance between antennas in a horizontal direction. The number dV may be a distance between antennas in a vertical direction. The number dg,H may be a distance between centers of panels in a horizontal direction. The number dg,V may be a distance between centers of panels in a vertical direction. In a non-uniform array, either or both of the following may be true: dg,H ^ dH·N, dg,V ^ dV·M.

[00103] In some embodiments, in addition to support of non-uniform array, various MIMO transmission schemes may be supported, such as high rank transmission, beam selection, beam diversity, coherent and non-coherent joint transmission, multiple beams, multiple TRPs, beam broadening and/or other(s).

[00104] In some embodiments, a codebook structure may support beam selection (both analog and digital), beam combining, coherent and non-coherent transmission, multi-TRP transmission, and/or beam broadening. A precoding matrix may be based on a product of three matrices, W1*W2*W3. The matrix W1 may comprise beamforming vectors for candidate beams. The beams may correspond to DFT vectors and/or other vectors (for instance, to support beam broadening). The matrix W2 may comprise vectors for beam selection and/or combining within antenna panels. The matrix W3 may be used for beam selection and/or power loading for analog beams. The matrix W3 may be used for co-phasing between different antenna panels/polarizations.

[00105] In some embodiments, a codebook structure that is the same as or similar to the one described below may be used. The codebook may be determined based on the matrix product of– [00106]

[00107] The matrix W1 may be of dimension equal to M·N x K·N, the matrix W2 may be of dimension equal to K·N x N, the matrix W3 may be of dimension equal to N x Ns. The matrix

may be an all-zero mztrix of dimension equal to M x K, M may be a number of antenna ports per panel per polarization, N may be (Number of antenna panel (=P) x polarization (=Po)) x (Number of Analog Beams=B), K may be a number of beams to select or combine, Ns may be a number of spatial streams

may be a beamforming vector for j-th panel, may be a linear combining vector

within k-th panel, may be a linear combining vector between panels

and/or polarizations. It should be noted that may represent digital

beamforming while different row blocks in W1 may represent different analog beamforming. Non-limiting examples are presented below.

[00108] In a non-limiting example,

may be a beamforming vector. In some cases, this vector may be similar to in LTE Class A or its

extension. The vector may be a Kronecker product of two DFT vectors, wherein l and m are indices of DFT vectors for the first and second dimensions, j is an index of panel/polarization/ analog beams, i is an index of potential beam, e.g. g^{rid of beams K = 4. Without a beam broadening function,}

_{may be the same as in LTE Class A. With a beam broadening} function,

may be the same as an adaptive beamwidth codebook structure.

[00109]

[00110] In some cases , and

otherwise is a beam broadening factor which may be set

differently for different dimension/polarization (index k), and different codebook index (index m). With beam selection function,

may include non-zero value only in i-th position.

[00111] The vector may be a linear combining vector, i.e.

b^{eam selection or combining within potential beams within panel. For selection,} _{^^ may include non-zero value(s) only in n-th position if n-th beam is selected} out of K candidate beams. For beam combining,

may include multiple non- zero values. The position of non-zero value(s) may represent selected beam(s). One or more of the non-zero value(s) may be complex valued to make combining of multiple beams. The may be selected within a predetermined

codebook set.

[00112] A non-limiting example of a candidate codebook set follows. For one non-zero value (such as in beam selection)– [00113]

[00114] For two non-zero values (such as in beam selection and beam combining)– [00115]

[00116] In some cases, may be a co-phasing value and may be a

power loading value. An example of co-phasing value can be

or As another example, may be

used for beam addition with equal power. Other non-zero values, such as 3, 4, … K, may be done similarly. In addition, a number of possible non-zero values may be configured, in some cases. [00117] In some cases, may be a linear combining vector, such

as in beam and panel selection, combining between panels and/or polarizations, and/or other operations. In some embodiments, a structure of

may be similar to although the scope of embodiments is not limited in this respect. The

may be based on LTE Class A codebook, which may be a Kronecker product of two DFT vectors, although the scope of embodiments is not limited in this respect. The vector

may be a beam selection vector, which may include only one non-zero value. In this case,

In addition,

[00118]

[00119] In case of rank-1 transmission, it becomes–

[00120]

[00121] In some cases,

may be a same value for all k, although the scope of embodiments is not limited in this respect.

[00122] In a non-limiting example,

(for instance, two polarizations, two potential beamforming, and two panels). There may be two candidate beam-formers per panel. Single rank transmission may be used. Also, beam selection within panel(s) may be used. The first beam may be selected (the first beam is applied in first half of ports). In addition,

[00123]

[00124] For single beam/direction for all panels and polarizations, then– [00125]

[00126] If all beams have a same power loading (ȕ=1), and same beamforming, then it becomes multiple co-phase value with single beamforming as follows– [00127]

[00128] In a non-limiting example

(for instance, two polarizations, two potential beamforming, and two panels). There are two candidates beam-formers per panel. Rank 2 transmission may be used. Also, beam selection within panel(s) may be used. The first beam may be selected (first beam is applied in first half of ports). Then–

[00129]

[00130] For single beam/direction for all panel and polarization, then– [00131]

[00132] If all have a same power loading then it becomes multiple

co-phase value–

[00133]

[00134] In case a single beam is selected, the may be orthogonal to

each other.

[00135] In some embodiments, a double Kronecker codebook structure may be used. A first Kronecker product may be used for beamforming on the panels of the NR antenna panel array and the second Kronecker product codebook may be used for co-phasing of the panels in two dimensions. The codebook may be formed based on matrix product(s) of W1*W2. The matrix W1 may be based on double Kronecker products. In a non-limiting example, a Kroneker product of two DFT vectors may be used. For instance, a Kronecker product of two DFT vectors

may be used, wherein:

[^00136]

^{oversampled DFT vector of length}

[^00137]

^{oversampled DFT vector of length}

[00138] The N1 and N2 may correspond to the number of antenna ports in the first and second dimension of the panel. The O1 and O2 may correspond to the DFT (beam) oversampling within the panel. co-phasing between panels may also be a Kronecker product of two DFT vector wherein:

[^00139]

^{s oversampled DFT vector of length}

^[00140]

^{is P2 oversampled DFT vector of length}

[00141] The Mg and Ng may correspond to the number of antenna panels in the first and second dimension of the panel. The P1 and P2 may correspond to the DFT co-phasing oversampling across the panels. In some embodiments, the parameter

1 and P2 may be higher layer configured for the UE 102, although the scope of embodiments is not limited in this respect. The overall beamforming matrix for an antenna array with cross- polarized antennas may be determined as–

[^00142]

[00143] The set of indexes m1y, m2y, m1x and m2x may determine the set of beams comprising a grid of beams. The codebook may comprise multiple partially overlapping or non-overlapping grids of beams. The actual set of the beam(s) from the selected grid of beams may be selected using W2 matrix. In a non-limiting example, the W2 matrix may have a similar structure as a similar W2 matrix of a legacy codebook (including but not limited to a codebook of one or more 3GPP standards). For instance, the matrix W2 may comprise selection vectors and the complex valued co-phasing element for different antenna polarizations. In some embodiments, the codebook may have a dual structure comprising the product of W1 by W2 matrix, wherein the W1 matrix may comprise a grid of beams and the W2 matrix may comprise vectors and/or values for operations such as beam selection, co-phasing across polarizations and/or other. In some embodiments, the structure of W1 previously described (and/or similar structure) may be used, although the scope of embodiments is not limited in this respect.

[00144] In some embodiments, operations such as beamforming, directional transmission, channel state information (CSI) reporting and/or other operations may be performed using a configurable codebook. The method may be performed by the UE 102, eNB 104 and/or other device. The eNB 104 may signal codebook configuration parameters to the UE 102, wherein the configuration parameters may correspond to a codebook with a double

Kronecker product structure. The UE 102 and/or eNB 104 and/or other device may generate codewords according to the indicated parameters of the codebook. Channel measurements may be performed at the UE 102 using reference signals transmitted by the eNB 104. The UE 102 may select a best codeword from the codebook using the channel measurements (such as selection of a codeword with highest signal quality measurement). The UE 102 may report an index of the selected codeword to the eNB 104 along with other CSI information. The double Kronecker product codebook may comprise a Kronecker product of two matrices.

[00145] In some embodiments, each matrix in the product may comprise Kronecker product of two DFT (Discrete Fourier Transform) vectors. In some embodiments, one or more parameters of the DFT vectors may be provided using higher layer signaling. In some embodiments, the parameter(s) may include the number of antenna ports in the panel in one of the dimensions and associated DFT oversampling. In some embodiments, the parameter(s) may include the number of antenna panels in the antenna array in one of the dimensions and associated DFT oversampling. In some embodiments, the reference signal may be Channel State Information reference signal (CSI-RS). In some embodiments, the number of antenna ports in the CSI-RS may correspond to the number of antenna ports in each panel multiplied by the number of panels.

[00146] In some embodiments, a precoding matrix may be based on a product of matrixes. For instance, the precoding matrix may be based on a product of W1*W3. For the product of three matrices W1*W2*W3 described herein, the W2 matrix may be an identity matrix (such as when K = 1, in which K is a number of beams of W1 to be selected), in which case the precoding matrix may be a product of W1*W3.

[00147] In some embodiments, a multi-panel (MP) codebook of MP codewords may be generated for an antenna array of multiple antenna panels. A single panel (SP) codebook of SP codewords may be used. For instance, an SP codeword may include scale values that are mapped to the antenna elements of one of the panels for transmission in accordance with a horizontal polarization. For convenience, this particular panel may be referred to as a“first panel,” but such references are not limiting. For instance, the first panel referred to may not necessarily be the panel that is furthest to the left of the antenna array, in the top row of the antenna array or any other panel that may be“first” in terms of counting or arrangement of the panels within the antenna array. In addition, the scale values may be mapped to the SP codeword for transmission in accordance with the horizontal polarization in the description herein, but this also is not limiting. In some embodiments, those scale values may be mapped to the first panel for transmission in accordance with a vertical polarization, and techniques described herein may be applied accordingly.

[00148] It should be noted that the eNB 104 may perform one or more operations described herein, including generation of one or more MP codewords. Embodiments are not limited to the eNB 104, however, as a UE 102 and/or other device may perform one or more of those operations, in some embodiments. Accordingly, references below to operation(s) performed by the eNB 104 are not limiting.

[00149] In some embodiments, the eNB 104 may generate, for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements, a multi-panel (MP) codeword that includes: for a horizontal polarization of the antenna elements of a first panel of the plurality: a predetermined single panel (SP) vector. The MP codeword may further include: for a vertical polarization of the antenna elements of the first panel: a product of the SP vector and a configurable polarization co-phase value. The MP codeword may further include: for horizontal polarizations of the antenna elements of the other panels of the plurality: products of the SP vector and configurable per- panel co-phase values. The MP codeword may further include: for vertical polarizations of the antenna elements of the other panels of the plurality:

products of the SP vector, the per-panel co-phase values, and the polarization co- phase value.

[00150] In a non-limiting example, the polarization co-phase value may be configurable as one of {1, j, -1, -j} (which may be equivalent to one, a square root of negative one, negative one, and a negative square root of negative one. The per-panel co-phase values may be configurable as one of: one, the square root of negative one, negative one, and the negative square root of negative one). Embodiments are not limited to the set of values (1, j, -1, -j) given above, as any suitable set may be used.

[00151] The products for the vertical polarizations of the antenna elements of the other panels may be based on products of: the polarization co-phase value, and the products for the horizontal polarizations of the antenna elements of the other panels. For instance, for a particular panel, a first vector (a product of a per-panel co-phase value of the particular panel) may be mapped to the antenna elements of the particular panel for horizontal polarization. A second vector (a product of the first vector and the polarization co-phase value) may be mapped to the antenna elements of the particular panel for vertical polarization.

[00152] In some embodiments, one or more operations may be used to generate multiple MP codewords, including but not limited to the operations described above. For instance, multiple SP codewords may be used. The same polarization co-phase value may be used to generate each of the MP codewords, although the scope of embodiments is not limited in this respect. In addition, the same per-panel co-phase values may be used to generate each of the MP codewords, although the scope of embodiments is not limited in this respect.

[00153] In some embodiments, the eNB 104 may generate the MP codeword(s) for panel configurations of the antenna elements in a first dimension of size equal to one and a second dimension of size greater than one (such as 1xN). One or more SP vectors may be based on DFT(s) of an antenna element index in the second dimension. The DFT(s) may be based on a predetermined oversampling factor. Example configurations include, but are not limited to: a configuration of the antenna array that includes two panels, a size of the second dimension equal to two, and an oversampling factor of four; a configuration of the antenna array that includes two panels, a size of the second dimension equal to four, and an oversampling factor of four; a configuration of the antenna array that includes four panels, a size of the second dimension equal to two, and an oversampling factor of four; a configuration of the antenna array that includes two panels, a size of the second dimension equal to eight, and an oversampling factor of four; and a configuration of the antenna array that includes four panels, a size of the second dimension equal to four, and an oversampling factor of four. One or more of the above (and in some cases, one or more additional configurations) may be supported.

[00154] In some embodiments, the eNB 104 may generate the MP codeword for panel configurations of the antenna elements in a first dimension of first size greater than one and a second dimension of second size greater than one. One or more SP vectors may be based on Kronecker product(s). For instance, a particular SP vector may be based on a first DFT of a first antenna element index in the first dimension and a second DFT of a second antenna element index in the second dimension. The first DFT may be based on a predetermined first oversampling factor. The second DFT may be based on a predetermined second oversampling factor. Example configurations include, but are not limited to: a configuration of the antenna array that includes two panels, a size of the first dimension equal to two, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four; a configuration of the antenna array that includes two panels, a size of the first dimension equal to four, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four; and a configuration of the antenna array that includes four panels, a size of the first dimension equal to two, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four. One or more of the above (and in some cases, one or more additional configurations) may be supported. For instance, one or more of the number of panels, the size of the first dimension, the size of the second dimension, the first oversampling factor and/or the second oversampling factor may be different from the above examples in other configuration(s).

[00155] In some embodiments, a multi-panel codebook may be determined based on a single-panel codebook. A non-limiting example of such is described below. The notation below may be based on 5G standard/protocol, a New Radio (NR) standard/protocol and/or other standard/protocol, in some embodiments. Embodiments are not limited by this notation.

[00156] An SP codeword may be denoted as below.

Generation of an MP codeword based on this SP codeword will be described below. It is understood that the technique for generation may be applied to other SP codewords, in some embodiments.

[^{00157] The MP codeword may be generated as}

^_{^ǡ^ǡ^ . The MP codeword may be normalized by and/or other factor,}

in some embodiments. In the abov

denotes the number of panels)

wherein ^ denotes rank). In addition, is a co-phasing coefficient (for

panels and polarizations).

[00158] For rank 1

is given below for two different modes (first mode and second mode). Other modes are possible.

[^{00159] For the first mode (Mode 1)}

[00160] For the second mode (Mode 2),

[00161] It should be noted that this generation of the MP codeword may be equivalent to and/or similar to one or more previously described techniques. For instance, recall the previous example in which all beams have a same power loading (ȕ=1), and same beamforming, then it becomes multiple co-phase value with single beamforming as follows– [00162]

[00163] For rank may be

defined in Type I SP codebook. The

may be given in the above rank 1 MP codebook for each mode except for

[00164] It should be noted that this generation of the codeword may be equivalent to and/or similar to one or more previously described techniques. For instance, recall the previous example in which all have a same power loading

then it becomes multiple co-phase value–

[00166] In Example 1, an apparatus of an Evolved Node-B (eNB) may comprise memory. The apparatus may further comprise processing circuitry. The processing circuitry may be configured to generate, for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements, a multi-panel (MP) codeword that includes: for a horizontal polarization of the antenna elements of a first panel of the plurality: a predetermined single panel (SP) vector, for a vertical polarization of the antenna elements of the first panel: a product of the SP vector and a configurable polarization co-phase value, for horizontal polarizations of the antenna elements of the other panels of the plurality: products of the SP vector and configurable per-panel co-phase values, and for vertical polarizations of the antenna elements of the other panels of the plurality: products of the SP vector, the per-panel co- phase values, and the polarization co-phase value.

[00167] In Example 2, the subject matter of Example 1, wherein the polarization co-phase value may be configurable as one of: one, a square root of negative one, negative one, and a negative square root of negative one, and the per-panel co-phase values are configurable as one of: one, the square root of negative one, negative one, and the negative square root of negative one.

[00168] In Example 3, the subject matter of one or any combination of Examples 1-2, wherein the products for the vertical polarizations of the antenna elements of the other panels are based on products of: the polarization co-phase value, and the products for the horizontal polarizations of the antenna elements of the other panels.

[00169] In Example 4, the subject matter of one or any combination of Examples 1-3, wherein the MP codeword is a first MP codeword. The processing circuitry may be further configured to generate an MP codebook of MP codewords that includes the first MP codeword and one or more other MP codewords. Each of the other codewords may be generated based on: another predetermined SP vector, another configurable polarization co-phase value, and other configurable per-panel co-phase values.

[00170] In Example 5, the subject matter of one or any combination of Examples 1-4, wherein the processing circuitry may be further configured to generate, for transmission by the antenna array, channel state information reference signals (CSI-RS) without precoding by the MP codewords. The processing circuitry may be further configured to decode a message from a User Equipment (UE) that indicates one of the MP codewords to be used for the beamformed transmission by the antenna array to transmit a downlink data signal to the UE.

[00171] In Example 6, the subject matter of one or any combination of Examples 1-5, wherein the processing circuitry may be further configured to generate the MP codeword for panel configurations of the antenna elements in a first dimension of size equal to one and a second dimension of size greater than one. The SP vector may be based on a Discrete Fourier Transform (DFT) of an antenna element index in the second dimension. The DFT may be based on a predetermined oversampling factor.

[00172] In Example 7, the subject matter of one or any combination of Examples 1-6, wherein the processing circuitry may be further configured to generate the MP codeword for one or more of: a configuration of the antenna array that includes two panels, a size of the second dimension equal to two, and an oversampling factor of four, a configuration of the antenna array that includes two panels, a size of the second dimension equal to four, and an oversampling factor of four, a configuration of the antenna array that includes four panels, a size of the second dimension equal to two, and an oversampling factor of four, a configuration of the antenna array that includes two panels, a size of the second dimension equal to eight, and an oversampling factor of four, a configuration of the antenna array that includes four panels, a size of the second dimension equal to four, and an oversampling factor of four.

[00173] In Example 8, the subject matter of one or any combination of Examples 1-7, wherein the processing circuitry may be further configured to generate the MP codeword for panel configurations of the antenna elements in a first dimension of first size greater than one and a second dimension of second size greater than one. The SP vector may be based on a Kronecker product of a first Discrete Fourier Transform (DFT) of a first antenna element index in the first dimension and a second DFT of a second antenna element index in the second dimension. The first DFT may be based on a predetermined first oversampling factor. The second DFT may be based on a predetermined second oversampling factor.

[00174] In Example 9, the subject matter of one or any combination of Examples 1-8, wherein the processing circuitry may be further configured to generate the MP codeword for one or more of: a configuration of the antenna array that includes two panels, a size of the first dimension equal to two, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four; a configuration of the antenna array that includes two panels, a size of the first dimension equal to four, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four; and a configuration of the antenna array that includes four panels, a size of the first dimension equal to two, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four.

[00175] In Example 10, the subject matter of one or any combination of Examples 1-9, wherein the processing circuitry may be further configured to store the MP codeword in the memory. The processing circuitry may be further configured to generate a signal based at least partly on data. The processing circuitry may be further configured to scale the signal by the MP codeword for transmission of the signal by the antenna array. The signal may be scaled in accordance with a predetermined mapping between the antenna elements and bit positions within the MP codeword.

[00176] In Example 11, the subject matter of one or any combination of Examples 1-10, wherein the apparatus may further include a transceiver coupled to the antenna array to transmit the signal.

[00177] In Example 12, the subject matter of one or any combination of Examples 1-11, wherein the apparatus may further comprise the antenna array. [00178] In Example 13, the subject matter of one or any combination of Examples 1-12, wherein the processing circuitry may include a baseband processor to generate the MP codeword.

[00179] In Example 14, a non-transitory computer-readable storage medium may store instructions for execution by one or more processors to perform operations for communication by a User Equipment (UE). The operations may configure the one or more processors to generate a multi-panel (MP) codebook of MP codewords for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements, the MP codewords generated based on: a plurality of single panel (SP) codewords for a horizontal polarization of the antenna elements of a first panel, products of the SP codewords and a configurable polarization co-phase value for a vertical polarization of the antenna elements of the first panel, products of the SP codewords and a plurality of per-panel co-phase values for horizontal polarizations of the antenna elements of the other panels of the plurality of panels, and products of the SP codewords, the polarization co-phase value, and a plurality of per-panel co-phase values for vertical polarizations of the antenna elements of the other panels of the plurality of panels. The operations may further configure the one or more processors to determine signal quality measurements based on correlations of the MP codewords with received channel state information reference signals (CSI-RS). The operations may further configure the one or more processors to encode, for transmission, an uplink control message that includes information related to the signal quality measurements.

[00180] In Example 15, the subject matter of Example 14, wherein the operations may further configure the one or more processors to select the MP codeword that corresponds to a highest value of the signal quality measurements. The operations may further configure the one or more processors to encode the uplink control message to indicate the selected MP codeword.

[00181] In Example 16, an apparatus of an Evolved Node-B (eNB) may comprise memory. The apparatus may further comprise processing circuitry. The processing circuitry may be configured to generate a codebook of codewords for beamformed transmission by an antenna array that comprises multiple panels of antenna elements. The codewords may be generated based on matrix products of: a first matrix that comprises one or more candidate beamforming vectors for each panel, wherein the candidate beamforming vectors are based on a first Discrete Fourier Transform (DFT) based on an intra-panel row index and further based on a second DFT based on an intra-panel column index; a configurable second matrix that comprises intra-panel scale vectors that are configurable to generate per-panel linear combinations of the candidate beamforming vectors; and a configurable third matrix that comprises at least one inter-panel scale vector that is configurable to scale the per-panel linear combinations of the beamforming vectors to generate the codewords.

[00182] In Example 17, the subject matter of Example 16, wherein the intra-panel scale vectors may be further configurable to select one of the candidate beamforming vectors for inclusion in one of the per-panel linear combinations. The selection may be performed by usage of vectors that include: a non-zero value in a position that corresponds to the selected candidate beamforming vector, and values of zero in other positions.

[00183] In Example 18, the subject matter of one or any combination of Examples 16-17, wherein at least one of the intra-panel scale vectors may include: a value in a first position that is based on a square root of a loading factor; a value in a second position that is based on a product of: a difference between one and the loading factor, and a complex exponential for which an argument is based on a co-phasing value; and a value of zero in other positions.

[00184] In Example 19, the subject matter of one or any combination of Examples 16-18, wherein the inter-panel scale vectors may be further configurable to select one or more of the panels for the beamforming by usage of vectors that include: a non-zero value in one or more positions that correspond to the selected panels, and values of zero in other positions.

[00185] In Example 20, the subject matter of one or any combination of Examples 16-19, wherein the candidate beamforming vectors may be based on a Kronecker product of the first DFT and the second DFT. The first DFT may be based on a first oversampling factor. The second DFT may be based on a second oversampling factor. [00186] In Example 21, the subject matter of one or any combination of Examples 16-20, wherein the candidate beamforming vectors may be of dimension equal to a number of antenna elements per panel. The intra-panel scale vectors may be of dimension equal to a number of candidate beamforming vectors per panel. The inter-panel scale vectors may be of dimension equal to a number of panels of the antenna array.

[00187] In Example 22, the subject matter of one or any combination of Examples 16-21, wherein the codewords may be of dimension equal to a product of the number of antenna elements per panel and the number of panels. Each codeword may include a concatenation of scaled vectors. Each scaled vector may correspond to one of the panels. The scaled vectors may be of dimension equal to the number of antenna elements per panel.

[00188] In Example 23, an apparatus of an Evolved Node-B (eNB) may comprise memory. The apparatus may further comprise processing circuitry. The processing circuitry may be configured to generate a codebook of codewords for an antenna array of multiple two-dimensional panels of antenna elements, the codewords generated based on: a first Discrete Fourier Transform (DFT) based on intra-panel row indexes of the antenna elements, a second DFT that is based on intra-panel column indexes of the antenna elements, and a third DFT that is based on panel indexes of the antenna elements.

[00189] In Example 24, the subject matter of Example 23, wherein for a particular antenna element: the panel index of the particular antenna element indicates the panel that comprises the particular antenna element, the intra-panel row index of the particular antenna element indicates a row index within the panel that comprises the particular antenna element, and the intra-panel column index of the particular antenna element indicates a column index within the panel that comprises the particular antenna element.

[00190] In Example 25, the subject matter of one or any combination of Examples 23-24, wherein the first DFT may be further based on a first oversampling parameter. The second DFT may be further based on a second oversampling parameter.

[00191] In Example 26, the subject matter of one or any combination of Examples 23-25, wherein the codewords may include scalar values mapped to the antenna elements. The processing circuitry may be further configured to generate the scalar values of the codewords that are mapped to each panel based on a Kronecker product of the first DFT and the second DFT.

[00192] In Example 27, the subject matter of one or any combination of Examples 23-26, wherein the processing circuitry may be further configured to generate the codebook based on an arrangement of the antenna array that comprises multiple antenna panels in a rectangular grid of panels. The panel index of the third DFT may be a panel row index with respect to the rectangular grid of panels. The processing circuitry may be further configured to generate the codebook of codewords based on a fourth DFT that is based on a panel column index with respect to the rectangular grid of panels.

[00193] In Example 28, the subject matter of one or any combination of Examples 23-27, wherein the codewords may include scalar values mapped to the antenna elements. The processing circuitry may be further configured to determine the scalar values of the codewords that are mapped to each panel based on a first Kronecker product of the first DFT and the second DFT. The processing circuitry may be further configured to determine the scalar values of the codewords further based on a second Kronecker product of the third DFT and the fourth DFT.

[00194] In Example 29, the subject matter of one or any combination of Examples 23-28, wherein the codewords may include scalar values mapped to the antenna elements. The processing circuitry may be further configured to determine a first Kronecker product between the first DFT and the second DFT. The processing circuitry may be further configured to determine a second Kronecker product between the third DFT and the fourth DFT. The processing circuitry may be further configured to determine the scalar values of the codewords based on a double Kronecker product. The first Kronecker product may be applied within each panel. The second Kronecker product may be applied to the rectangular grid.

[00195] In Example 30, an apparatus of a User Equipment (UE) may comprise means for generating a multi-panel (MP) codebook of MP codewords for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements. The MP codewords may be generated based on: a plurality of single panel (SP) codewords for a horizontal polarization of the antenna elements of a first panel; products of the SP codewords and a configurable polarization co-phase value for a vertical polarization of the antenna elements of the first panel; products of the SP codewords and a plurality of per-panel co-phase values for horizontal polarizations of the antenna elements of the other panels of the plurality of panels; and products of the SP codewords, the polarization co-phase value, and a plurality of per-panel co-phase values for vertical polarizations of the antenna elements of the other panels of the plurality of panels. The apparatus may further comprise means for determining signal quality measurements based on correlations of the MP codewords with received channel state information reference signals (CSI-RS). The apparatus may further comprise means for encoding, for transmission, an uplink control message that includes information related to the signal quality measurements.

[00196] In Example 31, the subject matter of Example 30, wherein the apparatus may further comprise means for selecting the MP codeword that corresponds to a highest value of the signal quality measurements. The apparatus may further comprise means for encoding the uplink control message to indicate the selected MP codeword.

[00197] The Abstract is provided to comply with 37 C.F.R. Section 1.72(b) requiring an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

Claims

What is claimed is: 1. An apparatus of an Evolved Node-B (eNB), the apparatus comprising: memory; and processing circuitry, configured to:

generate, for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements, a multi-panel (MP) codeword that includes:

for a horizontal polarization of the antenna elements of a first panel of the plurality: a predetermined single panel (SP) vector,

for a vertical polarization of the antenna elements of the first panel: a product of the SP vector and a configurable polarization co-phase value,

for horizontal polarizations of the antenna elements of the other panels of the plurality: products of the SP vector and configurable per-panel co-phase values, and

for vertical polarizations of the antenna elements of the other panels of the plurality: products of the SP vector, the per-panel co-phase values, and the polarization co-phase value.

2. The apparatus according to claim 1, wherein:

the polarization co-phase value is configurable as one of: one, a square root of negative one, negative one, and a negative square root of negative one, and

the per-panel co-phase values are configurable as one of: one, the square root of negative one, negative one, and the negative square root of negative one.

3. The apparatus according to claim 1, wherein:

the products for the vertical polarizations of the antenna elements of the other panels are based on products of:

the polarization co-phase value, and

the products for the horizontal polarizations of the antenna elements of the other panels.

4. The apparatus according to claim 1, wherein:

the MP codeword is a first MP codeword,

the processing circuitry is further configured to generate an MP codebook of MP codewords that includes the first MP codeword and one or more other MP codewords,

each of the other codewords is generated based on:

another predetermined SP vector, another configurable polarization co-phase value, and other configurable per-panel co-phase values.

5. The apparatus according to any of claims 1-4, the processing circuitry further configured to:

generate, for transmission by the antenna array, channel state information reference signals (CSI-RS) without precoding by the MP codewords; and

decode a message from a User Equipment (UE) that indicates one of the MP codewords to be used for the beamformed transmission by the antenna array to transmit a downlink data signal to the UE.

6. The apparatus according to claim 1, wherein:

the processing circuitry is further configured to generate the MP codeword for panel configurations of the antenna elements in a first dimension of size equal to one and a second dimension of size greater than one,

the SP vector is based on a Discrete Fourier Transform (DFT) of an antenna element index in the second dimension,

the DFT is based on a predetermined oversampling factor.

7. The apparatus according to any of claims 1 or 6, wherein:

the processing circuitry is further configured to generate the MP codeword for one or more of:

a configuration of the antenna array that includes two panels, a size of the second dimension equal to two, and an oversampling factor of four,

a configuration of the antenna array that includes two panels, a size of the second dimension equal to four, and an oversampling factor of four, a configuration of the antenna array that includes four panels, a size of the second dimension equal to two, and an oversampling factor of four,

a configuration of the antenna array that includes two panels, a size of the second dimension equal to eight, and an oversampling factor of four,

a configuration of the antenna array that includes four panels, a size of the second dimension equal to four, and an oversampling factor of four.

8. The apparatus according to claim 1, wherein:

the processing circuitry is further configured to generate the MP codeword for panel configurations of the antenna elements in a first dimension of first size greater than one and a second dimension of second size greater than one,

the SP vector is based on a Kronecker product of a first Discrete Fourier Transform (DFT) of a first antenna element index in the first dimension and a second DFT of a second antenna element index in the second dimension,

the first DFT is based on a predetermined first oversampling factor, and the second DFT is based on a predetermined second oversampling factor.

9. The apparatus according to any of claims 1 or 8, wherein:

a configuration of the antenna array that includes two panels, a size of the first dimension equal to two, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four,

a configuration of the antenna array that includes two panels, a size of the first dimension equal to four, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four, and

a configuration of the antenna array that includes four panels, a size of the first dimension equal to two, a size of the second dimension equal to two, a first oversampling factor of four, and a second oversampling factor of four.

10. The apparatus according to any of claims 1 - 3, the processing circuitry further configured to:

store the MP codeword in the memory;

generate a signal based at least partly on data; and

scale the signal by the MP codeword for transmission of the signal by the antenna array, the signal scaled in accordance with a predetermined mapping between the antenna elements and bit positions within the MP codeword.

11. The apparatus according to claim 10, wherein the apparatus further includes a transceiver coupled to the antenna array to transmit the signal.

12. The apparatus according to any of claims 1 - 3, wherein the apparatus further comprises the antenna array.

13. The apparatus according to any of claims 1 - 3, wherein the processing circuitry includes a baseband processor to generate the MP codeword.

14. A computer-readable storage medium that stores instructions for execution by one or more processors to perform operations for communication by a User Equipment (UE), the operations to configure the one or more processors to:

generate a multi-panel (MP) codebook of MP codewords for beamformed transmission by an antenna array that comprises a plurality of panels of antenna elements, the MP codewords generated based on:

a plurality of single panel (SP) codewords for a horizontal polarization of the antenna elements of a first panel,

products of the SP codewords and a configurable polarization co- phase value for a vertical polarization of the antenna elements of the first panel, products of the SP codewords and a plurality of per-panel co- phase values for horizontal polarizations of the antenna elements of the other panels of the plurality of panels, and products of the SP codewords, the polarization co-phase value, and a plurality of per-panel co-phase values for vertical polarizations of the antenna elements of the other panels of the plurality of panels; and

determine signal quality measurements based on correlations of the MP codewords with received channel state information reference signals (CSI-RS); and

encode, for transmission, an uplink control message that includes information related to the signal quality measurements.

15. The computer-readable storage medium according to claim 14, the operations to further configure the one or more processors to:

select the MP codeword that corresponds to a highest value of the signal quality measurements; and

encode the uplink control message to indicate the selected MP codeword.

16. An apparatus of an Evolved Node-B (eNB), the apparatus comprising: memory; and processing circuitry, configured to:

generate a codebook of codewords for beamformed transmission by an antenna array that comprises multiple panels of antenna elements, the codewords generated based on matrix products of:

a first matrix that comprises one or more candidate beamforming vectors for each panel, wherein the candidate beamforming vectors are based on a first Discrete Fourier Transform (DFT) based on an intra-panel row index and further based on a second DFT based on an intra-panel column index,

a configurable second matrix that comprises intra-panel scale vectors that are configurable to generate per-panel linear combinations of the candidate beamforming vectors, and

a configurable third matrix that comprises at least one inter-panel scale vector that is configurable to scale the per-panel linear combinations of the beamforming vectors to generate the codewords.

17. The apparatus according to claim 16, wherein: the intra-panel scale vectors are further configurable to select one of the candidate beamforming vectors for inclusion in one of the per-panel linear combinations, the selection by usage of vectors that include:

a non-zero value in a position that corresponds to the selected candidate beamforming vector, and

values of zero in other positions.

18. The apparatus according to claim 16, wherein at least one of the intra- panel scale vectors includes:

a value in a first position that is based on a square root of a loading factor,

a value in a second position that is based on a product of:

a difference between one and the loading factor, and a complex exponential for which an argument is based on a co- phasing value, and

a value of zero in other positions.

19. The apparatus according to claim 16, wherein:

the inter-panel scale vectors are further configurable to select one or more of the panels for the beamforming by usage of vectors that include:

a non-zero value in one or more positions that correspond to the selected panels, and

values of zero in other positions.

20. The apparatus according to claim 16, wherein:

the candidate beamforming vectors are based on a Kronecker product of the first DFT and the second DFT, and

the first DFT is based on a first oversampling factor,

the second DFT is based on a second oversampling factor.

21. The apparatus according to claim 16, wherein:

the candidate beamforming vectors are of dimension equal to a number of antenna elements per panel, the intra-panel scale vectors are of dimension equal to a number of candidate beamforming vectors per panel, and

the inter-panel scale vectors are of dimension equal to a number of panels of the antenna array.

22. The apparatus according to claim 21, wherein:

the codewords are of dimension equal to a product of the number of antenna elements per panel and the number of panels,

each codeword includes a concatenation of scaled vectors,

each scaled vector corresponds to one of the panels, and

the scaled vectors are of dimension equal to the number of antenna elements per panel.

23. An apparatus of an Evolved Node-B (eNB), the apparatus comprising: memory; and processing circuitry, configured to:

generate a codebook of codewords for an antenna array of multiple two- dimensional panels of antenna elements, the codewords generated based on:

a first Discrete Fourier Transform (DFT) based on intra-panel row indexes of the antenna elements,

a second DFT that is based on intra-panel column indexes of the antenna elements, and

a third DFT that is based on panel indexes of the antenna elements.

24. The apparatus according to claim 23, wherein:

for a particular antenna element:

the panel index of the particular antenna element indicates the panel that comprises the particular antenna element,

the intra-panel row index of the particular antenna element indicates a row index within the panel that comprises the particular antenna element, and the intra-panel column index of the particular antenna element indicates a column index within the panel that comprises the particular antenna element.

25. The apparatus according to claim 23, wherein:

the first DFT is further based on a first oversampling parameter, and the second DFT is further based on a second oversampling parameter.

26. The apparatus according to claim 23, wherein:

the codewords include scalar values mapped to the antenna elements, and the processing circuitry is further configured to:

generate the scalar values of the codewords that are mapped to each panel based on a Kronecker product of the first DFT and the second DFT.

27. The apparatus according to claim 23, wherein:

the processing circuitry is further configured to generate the codebook based on an arrangement of the antenna array that comprises multiple antenna panels in a rectangular grid of panels,

the panel index of the third DFT is a panel row index with respect to the rectangular grid of panels,

the processing circuitry is further configured to generate the codebook of codewords based on a fourth DFT that is based on a panel column index with respect to the rectangular grid of panels.

28. The apparatus according to claim 27, wherein:

determine the scalar values of the codewords that are mapped to each panel based on a first Kronecker product of the first DFT and the second DFT; and

determine the scalar values of the codewords further based on a second Kronecker product of the third DFT and the fourth DFT.

29. The apparatus according to claim 27, wherein:

determine a first Kronecker product between the first DFT and the second DFT;

determine a second Kronecker product between the third DFT and the fourth DFT; and

determine the scalar values of the codewords based on a double Kronecker product, wherein:

the first Kronecker product is applied within each panel, and

the second Kronecker product is applied to the rectangular grid.