Codebook subset restrictions for enhanced type II channel state information reporting

Abstract

The present disclosure relates to codebook subset restrictions for enhanced type II channel state information reporting. A base station may send an indication of a codebook subset restriction (CBSR) to a device, the indication including at least a frequency-based restriction. The device may receive the indication of the CBSR and may transmit channel state information (CSI) to the base station based on the received indication of the CBSR. The indication of the CBSR may also include space-based restrictions, and depending on the base station configuration, the device may report CSI based on a subset of frequency bases in addition to the space bases. The indication of the CBSR may include separately configured maximum allowed amplitudes for weighting coefficients for the space base and the frequency base, wherein the weighting coefficients are associated with column vectors of a precoding matrix used by the base station and the device. The number of frequency bases and frequency compression units may be determined based on the number of different standards, such as the number of antennas, the number of subbands, etc.

Description

[0001] This application is a divisional application of the invention patent application with application number 2019100118336.3, filed on January 9, 2019, and the invention name “Codebook subset restriction for enhanced type II channel state information reporting”. Technical Field

[0002] The present patent application relates to wireless communications, and more particularly to channel state information reporting during wireless cellular communications, such as during 5G-NR communications.

[0003] Related technical description

[0004] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smartphones and tablets have become increasingly sophisticated. In addition to supporting phone calls, many mobile devices (i.e., user equipment devices or UEs) now also provide access to the Internet, email, text messaging, and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these capabilities. In addition, there are many different wireless communication technologies and standards. Some examples of wireless communication standards include GSM, UMTS (WCDMA, TDS-CDMA), LTE, LTE Advanced (LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX), BLUETOOTH ™ The next telecommunications standard beyond the current International Mobile Telecommunications Advanced (IMT-Advanced) standard is known as the fifth generation mobile network or fifth generation wireless system, referred to as 3GPP NR (also known as 5G-NR for 5G New Radio, or simply NR). NR provides higher capacity for a higher density of mobile broadband users while supporting device-to-device, ultra-reliable, and massive machine-to-machine communications, as well as lower latency and reduced battery consumption than the current LTE standard.

[0005] In general, wireless communication technologies such as cellular communication technologies are generally designed to provide mobile communication capabilities to wireless devices. The introduction of an ever-increasing number of features and functions in wireless communication devices has created a continuous demand for improved wireless communications as well as improved wireless communication devices. In particular, it is very important to ensure the accuracy of transmitted and received signals. A UE, which may be a mobile phone or smart phone, a portable gaming device, a communication system / device housed in or carried by a transport vehicle (e.g., a car, bus, train, truck, motorcycle, etc.), a laptop, a wearable device, a PDA, a tablet computer, a portable internet device, a music player, a data storage device or other handheld device, is typically powered by a portable power source (e.g., a battery) and may have multiple radio interfaces that enable support of various wireless communication standards (LTE, LTE-A, 5G-NR, Wi-Fi, BLUETOOTH, etc.). ™ There are currently multiple radio access technologies (RATs) defined by the IEEE 802.11ac, ...

[0006] Many wireless communication standards provide for the use of known signals (e.g., pilot or reference signals) for various purposes, such as synchronization, measurement, equalization, and control. For example, in cellular wireless communications, a reference signal (RS) is a special signal that exists only at the physical layer and does not convey any specific information, but rather provides a reference point for downlink power. When a wireless communication device or mobile equipment (UE) attempts to determine downlink power (e.g., the power of a signal from a base station such as an eNB for LTE and a gNB for NR), it measures the power of the reference signal and uses it to determine the downlink cell power. Reference signals also help receivers demodulate received signals. Because the reference signal includes data known to both the transmitter and receiver, the receiver can use it to determine / identify various characteristics of the communication channel. This is often referred to as "channel estimation" and is a key component of many high-end wireless communications, such as LTE and 5G-NR. The known channel properties of a communication link in wireless communications are called channel state information (CSI), which provides information indicating the combined effects of scattering, fading, and power loss with distance. CSI enables transmission to adapt to current channel conditions, which is crucial for achieving reliable communication at high data rates in multi-antenna systems.

[0007] Typically, multi-antenna systems use precoding to improve communications. Precoding is an extension of beamforming to support multi-stream (or multi-layer) transmission for multi-antenna wireless communications, and is used to control differences in signal properties between individual signals transmitted from multiple antennas by modifying the signal transmitted from each antenna according to a precoding matrix. In one sense, precoding can be considered a process of cross-coupling signals (in a closed-loop operation) prior to transmission to equalize the demodulation performance of the layers. The precoding matrix is ​​typically selected from a codebook that defines multiple precoding matrix candidates, and the precoding matrix candidate is typically selected based on any of a number of different factors, such as the current system configuration, the communication environment, and / or feedback information from a receiver, such as a mobile device (UE) receiving one or more of the transmitted signals, according to the desired performance level.

[0008] The feedback information is used to select precoding matrix candidates by defining the same codebook at the transmitter (which can be a base station) and the receiver (which can be a mobile device or UE), and using the feedback information from the receiver as an indication of the preferred precoding matrix. In such cases, the feedback information includes a so-called precoding matrix index (PMI), which can be based on properties of the signal received at the receiver.

[0009] For example, the receiver may determine that the received signal has a relatively low signal-to-noise ratio (SNR) and may therefore transmit a PMI that will replace the current precoding matrix with a new precoding matrix to improve the signal-to-noise ratio (SNR).

[0010] In some cases, it may be necessary to restrict the set of precoding matrix candidates that can be selected from the codebook. For example, the network can prevent the receiver from selecting some precoding matrix candidates while allowing it to select others. This is often referred to as codebook subset restriction, or CBSR for short. CBSR may involve the transmission of a CBSR bitmap from the transmitter (e.g., base station) to the receiver (e.g., user equipment). The CBSR bitmap typically includes a bit corresponding to each precoding matrix in the codebook, where the value of each bit (e.g., "0" or "1") indicates to the receiver whether the receiver is restricted from considering the corresponding precoding matrix candidate as a preferred precoding candidate requested from the base station. One disadvantage of CBSR is increased signaling overhead. For example, in some systems, the CBSR bitmap may contain a high number of bits (e.g., 64) per channel, requiring the transmitting device to transmit a relatively large amount of information to implement CBSR for all its channels.

[0011] Other corresponding problems associated with the prior art will become apparent to those skilled in the art after comparing such prior art with the disclosed embodiments described herein. Summary of the Invention

[0012] In particular, embodiments of methods and processes for utilizing codebook subset restriction (CBSR) based on both spatial and frequency considerations for enhanced channel state information (CSI) reporting during wireless communications, such as during 5G-NR communications, in various devices, such as wireless communication devices, are provided herein. Embodiments of a wireless communication system are further presented herein, including wireless communication devices (UEs) and / or base stations and access points (APs) communicating with each other within the wireless communication system.

[0013] Note that the techniques described herein may be implemented in and / or used with a number of different types of devices, including but not limited to base stations, access points, cellular telephones, portable media players, tablets, wearable devices, and various other computing devices.

[0014] This summary is intended to provide a brief overview of some of the subject matter described in this document. It should be understood, therefore, that the foregoing features are merely examples and should not be construed as narrowing the scope or essence of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, accompanying drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 An exemplary (and simplified) wireless communication system according to some embodiments is shown;

[0016] Figure 2 illustrates an exemplary base station in communication with an exemplary wireless user equipment (UE) device according to some embodiments;

[0017] Figure 3 shows an exemplary block diagram of a UE according to some embodiments;

[0018] Figure 4 shows an exemplary block diagram of a base station according to some embodiments;

[0019] Figure 5 shows an exemplary simplified block diagram illustrating a cellular controller according to some embodiments;

[0020] Figure 6 shows an example diagram illustrating a precoding structure associated with Type II CSI reporting according to the prior art;

[0021] Figure 7 shows an example diagram of a reporting structure used by a UE to report back to a base station according to the prior art;

[0022] Figure 8shows an example diagram illustrating a CBSR associated with Type II CSI reporting according to the prior art;

[0023] Figure 9 shows an example diagram illustrating improved CBSR associated with Type II CSI reporting according to some embodiments;

[0024] Figure 10 shows a plot illustrating one example of separate space-based and frequency-based restrictions for improved CBSR according to some embodiments;

[0025] Figure 11 shows a plot illustrating one example of joint spatial frequency limiting for improved CBSR according to some embodiments;

[0026] Figure 12 shows a drawing of an exemplary precoder structure with frequency compression for improved CBSR according to some embodiments;

[0027] Figure 13 shows a drawing illustrating an example of a PMI frequency compression unit configuration for improved CBSR according to some embodiments; and

[0028] Figure 14 A table showing exemplary index values ​​for determining frequency bases corresponding to all considered sub-bands for improved CBSR according to some embodiments is shown.

[0029] While the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. However, it should be understood that the drawings and detailed description thereof are not intended to limit the invention to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0030] Acronyms

[0031] Various acronyms are used throughout this application. The definitions of the most prominent acronyms used that may appear throughout this application are as follows:

[0032] • AMR: Adaptive Multi-Rate

[0033] •AP: Access Point

[0034] •APN: Access Point Name

[0035] •APR: Application Processor

[0036] •AS: Access layer

[0037] •BS: Base Station

[0038] • BSR: Buffer Size Report

[0039] •BSSID: Basic Service Set Identifier

[0040] • CBRS: Citizens Broadband Radio Service

[0041] • CBSD: Citizens Broadband Radio Service Device

[0042] •CBSR: Codebook Subset Restriction

[0043] •CCA: Clear Channel Assessment

[0044] • CMR: Change Schema Request

[0045] •CS: Circuit Switched

[0046] • CSI: Channel State Information

[0047] •DL: Downlink (from BS to UE)

[0048] •DSDS: Dual SIM Dual Standby

[0049] •DYN: Dynamic

[0050] •EDCF: Enhanced Distributed Coordination Function

[0051] •FDD: Frequency Division Duplex

[0052] •FO: First-order state

[0053] • FT: Frame type

[0054] •GAA: General Authorisation Access

[0055] •GPRS: General Packet Radio Service

[0056] •GSM: Global System for Mobile Communications

[0057] •GTP: GPRS Tunneling Protocol

[0058] •IMS: Internet Protocol Multimedia Subsystem

[0059] •IP: Internet Protocol

[0060] •IR: Initialization and refresh status

[0061] •KPI: Key Performance Indicator

[0062] •LAN: Local Area Network

[0063] •LBT: Listen before speaking

[0064] •LQM: Link Quality Metric

[0065] •LTE: Long Term Evolution

[0066] • MIMO: Multiple Input Multiple Output

[0067] •MNO: Mobile Network Operator

[0068] •MU: Multi-User

[0069] •NAS: Non-Access Layer

[0070] •NB: Narrow Band

[0071] •OOS: Out of sync

[0072] •PAL: Priority Access Licensor

[0073] •PDCP: Packet Data Convergence Protocol

[0074] •PDN: Packet Data Network

[0075] •PDU: Protocol Data Unit

[0076] •PGW: PDN Gateway

[0077] •PLMN: Public Land Mobile Network

[0078] •PSD: Power Spectral Density

[0079] •PSS: Primary Synchronization Signal

[0080] •PT: Payload Type

[0081] • QBSS: Basic Service Set with Quality of Service Enhancement

[0082] •QI: Quality Indicator

[0083] •RAN: Radio Access Network

[0084] • RAT: Radio Access Technology

[0085] •RF: Radio Frequency

[0086] •ROHC: Robust Header Compression

[0087] •RRC: Radio Resource Control

[0088] •RTP: Real-time Transport Protocol

[0089] •RTT: Round Trip Time

[0090] •RX: Receive

[0091] •SAS: Spectrum Allocation Server

[0092] •SI: System Information

[0093] •SID: System Identification Number

[0094] •SIM: Subscriber Identity Module

[0095] •SGW: Serving Gateway

[0096] •SMB: Small and medium-sized business

[0097] •SSS: Secondary synchronization signal

[0098] •TBS: Transport Block Size

[0099] • TCP: Transmission Control Protocol

[0100] •TDD: Time Division Duplex

[0101] •TX: Transmit

[0102] •UE: User Equipment

[0103] •UI: User Interface

[0104] •UL: Uplink (from UE to BS)

[0105] •UMTS: Universal Mobile Telecommunications System

[0106] • USIM: UMTS Subscriber Identity Module

[0107] •WB: Broadband

[0108] • Wi-Fi: A wireless local area network (WLAN) RAT based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard

[0109] •WLAN: Wireless Local Area Network

[0110] the term

[0111] The following is a glossary of terms that will appear in this application:

[0112] Memory medium - Any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROMs, floppy disks, or tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media, such as hard drives or optical storage devices; registers, or other similar types of memory elements. Memory media may also include other types of memory or a combination thereof. Furthermore, a memory medium may be located in a first computer system executing a program, or in a different second computer system connected to the first computer system via a network, such as the Internet. In the latter example, the second computer system may provide program instructions to the first computer system for execution. The term "memory medium" may include two or more memory media that may reside in different locations, such as in different computer systems connected via a network. A memory medium may store program instructions (e.g., represented as a computer program) that are executable by one or more processors.

[0113] Carrier Medium—storage media as described above, and physical transmission media such as a bus, network, and / or other physical transmission media that transport signals such as electrical, electromagnetic, or digital signals.

[0114] Programmable hardware elements—a broad range of hardware devices consisting of multiple programmable function blocks connected via programmable interconnects. Examples include FPGAs (field programmable gate arrays), PLDs (programmable logic devices), FPOAs (field programmable object arrays), and CPLDs (complex PLDs). Programmable function blocks can range in granularity (combinational logic units or lookup tables) to coarse granularity (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "configurable logic units."

[0115] Computer system (or computer) – Any of various types of computing or processing systems, including a personal computer system (PC), mainframe computer system, workstation, network appliance, internet appliance, personal digital assistant (PDA), television system, grid computing system, or other devices or combinations of devices. In general, the term "computer system" can be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0116] User Equipment (UE) (or "UE device") – Any of various types of computer system devices that perform wireless communications. Also known as wireless communication devices, many of which may be mobile and / or portable. Examples of UE devices include mobile phones or smartphones (e.g., iPhones). ™, based on Android ™ phones) and tablets such as iPads ™ 、Samsung Galaxy ™ etc., gaming devices (such as Sony PlayStation ™ , Microsoft XBox ™ etc.), portable gaming devices (e.g., Nintendo DS ™ PlayStation Portable ™ 、Gameboy Advance ™ iPod ™ ), laptops, wearable devices (e.g., Apple Watch ™ , Google Glass ™ ), PDAs, portable internet devices, music players, data storage devices or other handheld devices, etc. Various other types of devices may include Wi-Fi communication capabilities or both cellular and Wi-Fi communication capabilities and / or other wireless communication capabilities (e.g., via short-range radio access technologies (SRATs) such as BLUETOOTH ™ In general, the term "UE" or "UE device" can be broadly defined to cover any electronic, computing and / or telecommunication equipment (or combination of equipment) capable of wireless communication and which may also be portable / mobile.

[0117] Wireless device (or wireless communication device) – Any of various types of computer system devices that perform wireless communications using WLAN communications, SRAT communications, Wi-Fi communications, etc. As used herein, the term "wireless device" can refer to a UE device as defined above or a fixed device such as a fixed wireless client or a wireless base station. For example, a wireless device can be a wireless station of any type of 802.11 system, such as an access point (AP) or a client station (UE), or a wireless station of any type of cellular communication system that communicates according to a cellular radio access technology (e.g., LTE, CDMA, GSM), such as a base station or a cellular phone.

[0118] Communication Device – Any of various types of computer systems or devices that perform communication, either wired or wireless. A communication device may be portable (or mobile), or fixed or stationary. A wireless device is an example of a communication device. A UE is another example of a communication device.

[0119] Base Station (BS) - The term "base station" has the full breadth of its ordinary meaning and includes at least a wireless communication station that is installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0120] Processing element - refers to any element or combination of elements that is capable of performing one or more functions in a device (e.g., in a user equipment device or in a cellular network device) and / or enables the user equipment device or cellular network device to perform one or more functions. A processing element may include, for example, a processor and associated memory, portions or circuits of individual processor cores, entire processor cores, processor arrays, circuits such as ASICs (application-specific integrated circuits), programmable hardware elements such as field-programmable gate arrays (FPGAs), and any combination thereof.

[0121] Channel - the medium used to transmit information from a sender (transmitter) to a receiver. It should be noted that since the characteristics of the term "channel" can vary depending on different wireless protocols, the term "channel" as used herein may be considered to be used in a manner consistent with the standard for the type of device to which the term is used. In some standards, the channel width may be variable (e.g., depending on device capabilities, frequency band conditions, etc.). For example, LTE may support scalable channel bandwidths from 1.4 MHz to 20 MHz. In contrast, a WLAN channel may be 22 MHz wide, while a Bluetooth channel may be 1 MHz wide. Other protocols and standards may include different definitions of channels. Furthermore, some standards may define and use multiple types of channels, such as different channels for uplink or downlink and / or different channels for different purposes such as data, control information, etc.

[0122] Frequency band – The term “frequency band” has the full breadth of its ordinary meaning and includes at least a segment of the spectrum (eg, radio frequency spectrum) in which channels are used or set aside for the same purpose.

[0123] Wi-Fi - The term "Wi-Fi" has the full scope of its ordinary meaning and includes at least wireless communication networks, or RATs, that are served by wireless LAN (WLAN) access points and provide connectivity to the Internet through those access points. Most modern Wi-Fi networks (or WLAN networks) are based on the IEEE 802.11 standard and are marketed under the "Wi-Fi" name. Wi-Fi (WLAN) networks are distinct from cellular networks.

[0124] Automatic – refers to an action or operation performed by a computer system (e.g., software executed by the computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without requiring user input to directly specify or execute the action or operation. Thus, the term "automatic" contrasts with manual execution or specification of an action by a user, where the user provides input to directly execute the action. An automatic process may be initiated by user input, but the subsequent actions performed "automatically" are not specified by the user, that is, they are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting checkboxes, selecting radios, etc.) is not manually filling out the form, even though the computer system must update the form in response to the user's actions. The form can be automatically filled out by a computer system, where the computer system (e.g., software executing on the computer system) analyzes the form's fields and fills the form without requiring any user input to specify the answers to the fields. As indicated above, a user can invoke the automatic filling of a form without participating in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields; they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions that a user has taken.

[0125] About – refers to a value that is close to the correct or exact value. For example, about can refer to a value that is within 1% to 10% of the exact (or desired) value. However, it should be noted that the actual threshold (or tolerance) may depend on the application. For example, in some embodiments, "about" can mean within 0.1% of some specified or desired value, while in various other embodiments, the threshold may be, for example, 2%, 3%, 5%, etc., depending on the desires or requirements of a particular application.

[0126] Concurrency refers to parallel execution or implementation, where tasks, processes, or programs are executed in an at least partially overlapping manner. For example, concurrency can be achieved using "strong" or strict parallelism, where tasks are executed (at least partially) in parallel on corresponding computing elements, or using "weak parallelism," where tasks are executed in an interleaved manner (e.g., by time-multiplexing of execution threads).

[0127] Station (STA) - The term "station" herein refers to any device capable of wireless communication (e.g., using the 802.11 protocol). A station can be a laptop, desktop PC, PDA, access point, or Wi-Fi phone, or any other type of device similar to a UE. A STA can be fixed, mobile, portable, or wearable. Generally speaking, in wireless networking terminology, the term "station" (STA) broadly encompasses any device capable of wireless communication, and the terms "station (STA), wireless client (UE), and node (BS)" are often used interchangeably.

[0128] Configured to - Various components may be described as being "configured to" perform one or more tasks. In such contexts, "configured to" is a broad term that generally means "having the structure" to perform one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, "configured to" can be a broad term that generally means "having the circuitry" to perform one or more tasks during operation. Thus, the component can be configured to perform a task even when the component is not currently turned on. Generally, the circuitry that forms the structure corresponding to "configured to" may include hardware circuitry.

[0129] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to." Representing a component as being configured to perform one or more tasks expressly does not invoke the sixth paragraph of 35 USC § 112 for that component.

[0130] Figure 1 and Figure 2 -Exemplary Communication System

[0131] Figure 1 An exemplary (and simplified) wireless communication system according to some embodiments is shown. Note that Figure 1 The system is merely one example of one possible system, and embodiments may be implemented in any of a variety of systems as desired.

[0132] As shown, an exemplary wireless communication system includes a base station 102 that communicates with one or more user equipment 106A, 106B, etc., through 106N via a transmission medium. Each user equipment may be referred to herein as a "user equipment" (UE) or a UE device. Therefore, user equipment 106 is referred to as a UE or a UE device. According to various embodiments disclosed herein, during wireless communication, such as during 5G-NR communication, each of the UE devices may utilize codebook subset restriction (CBSR) for enhanced channel state information (CSI) reporting based on both spatial and frequency considerations.

[0133] Base station 102 may be a base transceiver station (BTS) or a cell site and may include hardware that enables wireless communication with UEs 106A through 106N. Base station 102 may also be configured to communicate with network 100, such as a cellular service provider's core network, telecommunications networks such as the Public Switched Telephone Network (PSTN) and / or the Internet, neutral hosts, or various CBRS (Citizens Broadband Radio Service) deployments, among other possibilities. Thus, base station 102 may facilitate communication between user devices and / or between user devices and network 100. The communication area (or coverage area) of a base station may be referred to as a "cell." It should also be noted that "cell" may also refer to a logical designation for a given coverage area at a given frequency. Generally, any independent cellular wireless coverage area may be referred to as a "cell." In such a case, a base station may be located at a specific intersection of three cells. In this uniform topology, a base station may serve three 120-degree beamwidth areas, referred to as cells. Furthermore, for carrier aggregation, small cells, relays, and the like may also represent cells. Thus, particularly in carrier aggregation, there may be primary and secondary cells that may serve at least partially overlapping coverage areas, but on different respective frequencies. For example, a base station may serve any number of cells, and the cells served by a base station may or may not be collocated (e.g., a remote radio head). Also as used herein, with respect to a UE, a base station may sometimes be considered to represent a network, in the context of considering both uplink and downlink communications of the UE. Thus, a UE communicating with one or more base stations in a network may also be interpreted as a UE communicating with the network, and may also be considered to be at least a portion of the UE's communications on or through the network.

[0134] Base station 102A and user equipment may be configured to communicate over a transmission medium utilizing any of a variety of radio access technologies (RATs), also referred to as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA), LTE, LTE-Advanced (LTE-A), LAA / LTE-U, 5G-NR (abbreviated as NR), 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, WiMAX, and the like. It is noted that if base station 102A is implemented in the context of LTE, it may alternatively be referred to as an "eNodeB" or "eNB." It is noted that if base station 102A is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB." In some embodiments, as described herein, base station 102 may communicate with a UE that utilizes codebook subset restrictions for enhanced channel state information reporting based on both spatial and frequency considerations during wireless communications, such as during 5G-NR communications. Depending on a given application or specific considerations, some different RATs may be functionally grouped according to their overall defining characteristics for convenience. For example, all cellular RATs may be collectively considered to represent a first (form / type) RAT, while Wi-Fi communications may be considered to represent a second RAT. In other cases, individual cellular RATs may be individually considered distinct RATs. For example, when distinguishing between cellular and Wi-Fi communications, "first RAT" may collectively refer to all considered cellular RATs, while "second RAT" may refer to Wi-Fi. Similarly, different forms of Wi-Fi communications (e.g., over 2.4 GHz versus over 5 GHz) may be considered to correspond to different RATs, where applicable. Furthermore, cellular communications performed according to a given RAT (e.g., LTE or NR) may be distinguished from one another based on the spectrum in which those communications occur. For example, LTE or NR communications may be performed on both primary licensed spectrum and secondary spectrum, such as unlicensed spectrum. Overall, the use of various terms and expressions will always be clearly noted in relation to and within the context of the various applications / implementations being considered.

[0135] As shown, base station 102A may also be configured to communicate with network 100 (e.g., a cellular service provider's core network, a telecommunications network such as the Public Switched Telephone Network (PSTN), and / or the Internet, among other possibilities). Thus, base station 102A may facilitate communications between user devices and / or between user devices and network 100. In particular, cellular base station 102A may provide UE 106 with various communication capabilities, such as voice, SMS, and / or data services.

[0136] Base station 102A and other similar base stations operating according to the same or different cellular communication standards (such as base stations 102B...102N) can thus be provided as a network of cells that can provide continuous or nearly continuous overlapping service to UEs 106A-N and similar devices over a geographic area via one or more cellular communication standards.

[0137] Thus, although base station 102A may function as Figure 1 106A-N, each UE 106 may also be capable of receiving signals from (and possibly within communication range of) one or more other cells (which may be provided by base stations 102B-N and / or any other base stations), which may be referred to as "neighboring cells." Such cells may also be capable of facilitating communications between user devices and / or between user devices and network 100. Such cells may include "macro" cells, "micro" cells, "pico" cells, and / or cells of any other variety of granularity of service area size. For example, in Figure 1 The base stations 102A-B shown in FIG may be macro cells, while the base station 102N may be a micro cell. Other configurations are also possible.

[0138] In some embodiments, base station 102A may be a next-generation base station, such as a 5G New Radio (5G NR) base station or "gNB." In some embodiments, a gNB may be connected to a legacy evolved packet core (EPC) network and / or to an NR core (NRC) network. Furthermore, a gNB cell may include one or more transmission and reception points (TRPs). Furthermore, a UE capable of operating in accordance with 5G NR may be connected to one or more TRPs within one or more gNBs.

[0139] As described above, the UE 106 may be capable of communicating using multiple wireless communication standards. For example, the UE 106 may be configured to communicate using any or all of the 3GPP cellular communication standards (such as LTE or NR) or 3GPP2 cellular communication standards (such as a cellular communication standard in the CDMA2000 family of cellular communication standards). The base station 102 and other similar base stations operating according to the same or different cellular communication standards may thus be provided as one or more cell networks that may provide continuous or nearly continuous overlapping service to the UE 106 and similar devices over a wide geographic area via one or more cellular communication standards.

[0140] UE 106 may also or alternatively be configured to use WLAN, BLUETOOTH ™ 、BLUETOOTH ™The UE 106 may communicate with the network 100 via one or more base stations or other devices, stations, or any other apparatus not explicitly shown but considered to be part of the network 100. Therefore, a UE 106 communicating with the network may be interpreted as the UE 106 communicating with one or more network nodes considered to be part of the network, and may interact with the UE 106 to communicate with the UE 106 and, in some cases, influence at least some communication parameters and / or the use of communication resources of the UE 106.

[0141] In addition, for example Figure 1 As shown in FIG, at least some UEs (e.g., UE 106D and 106E) may represent vehicles that communicate with each other and with base station 102, for example, via cellular communications such as 3GPP LTE and / or 5G-NR communications. Additionally, UE 106F may similarly represent pedestrians that are communicating and / or interacting with the vehicles represented by UEs 106D and 106E. Figure 1 Other aspects of vehicles communicating in the network illustrated in , for example in the context of vehicle-to-everything (V2X) communications, such as specified by 3GPP TS 22.185 V 14.3.0, etc.

[0142] Figure 2 An exemplary user device 106 (e.g., one of devices 106-A through 106-N) is shown communicating with a base station 102 and an access point 112 according to some embodiments. The UE 106 may be a device having both cellular and non-cellular communication capabilities (e.g., BLUETOOTH ™, Wi-Fi, etc.), such as a mobile phone, handheld device, computer or tablet, or virtually any type of wireless device. UE 106 may include a processor configured to execute program instructions stored in a memory. UE 106 may perform any of the method implementations described herein by executing such stored instructions. Alternatively or in addition, UE 106 may include programmable hardware elements, such as an FPGA (field programmable gate array) configured to perform any of the method implementations described herein or any portion of any of the method implementations described herein. UE 106 may be configured to communicate using any of a plurality of wireless communication protocols. For example, UE 106 may be configured to communicate using two or more of CDMA 2000, LTE, LTE-A, NR, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0143] The UE 106 may include one or more antennas for communicating in accordance with one or more RAT standards using one or more wireless communication protocols. In some embodiments, the UE 106 may share one or more portions of a receive chain and / or transmit chain between multiple wireless communication standards; the shared radio may include a single antenna, or may include multiple antennas for performing wireless communication (e.g., for MIMO). Alternatively, the UE 106 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radios) for each wireless communication protocol with which it is configured to communicate. As another alternative, the UE 106 may include one or more radios shared between multiple wireless communication protocols, as well as one or more radios used exclusively by a single wireless communication protocol. For example, the UE 106 may include a shared radio for communicating using either LTE or CDMA2000 1xRTT or NR, as well as a shared radio for communicating using Wi-Fi and BLUETOOTH. ™ Independent radio components for each of the two devices to communicate. Other configurations are also possible.

[0144] Figure 3 —Exemplary UE

[0145] Figure 3A block diagram of an exemplary UE 106 according to some embodiments is shown. As shown, UE 106 may include a system on a chip (SOC) 300, which may include components for various purposes. For example, as shown, SOC 300 may include one or more processors 302 that may execute program instructions for UE 106 and display circuitry 304 that may perform graphics processing and provide display signals to a display 360. One or more processors 302 may also be coupled to a memory management unit (MMU) 340, and / or other circuits or devices (such as display circuitry 304, radio circuitry 330, connector I / F 320, and / or display 360). The MMU may be configured to receive addresses from the one or more processors 302 and translate those addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310). MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of one or more processors 302.

[0146] As shown, SOC 300 may be coupled to various other circuits of UE 106. For example, UE 106 may include various types of memory (e.g., including NAND flash memory 310), a connector interface 320 (e.g., for coupling to a computer system), a display 360, and wireless communication circuitry (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH, etc.). ™ , Wi-Fi, GPS, etc.). The UE device 106 may include at least one antenna (e.g., 335a), and may include multiple antennas (e.g., as shown by antennas 335a and 335b), for performing wireless communications with base stations and / or other devices. Antennas 335a and 335b are shown as examples, and the UE device 106 may include fewer or more antennas. Generally speaking, the one or more antennas are collectively referred to as one or more antennas 335. For example, the UE device 106 may use one or more antennas 335 to perform wireless communications with the radio circuit 330. As described above, in some embodiments, the UE may be configured to perform wireless communications using multiple wireless communication standards.

[0147] As further described herein, the UE 106 (and / or the base station 102) may include hardware and software components for implementing at least a method of the UE 106 that uses codebook subset restrictions based on both spatial and frequency considerations for enhanced channel state information reporting during wireless communication, such as during 5G-NR communication, for example, as further detailed herein. The one or more processors 302 of the UE device 106 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the one or more processors 302 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). Furthermore, according to various embodiments disclosed herein, the one or more processors 302 may be coupled to, for example, a processor. Figure 3 Other components are shown and / or may interoperate with the other components to use codebook subset restriction (CBSR) for enhanced channel state information (CSI) reporting based on both spatial and frequency considerations during wireless communications, such as during 5G-NR communications. The one or more processors 302 may also implement various other applications and / or end-user applications running on the UE 106.

[0148] In some embodiments, the radio circuitry 330 may include separate controllers dedicated to controlling communications for various corresponding RAT standards. Figure 3 As shown, the radio circuit 330 may include a Wi-Fi controller 356, a cellular controller (eg, LTE and / or NR controller) 352, and a BLUETOOTH controller. ™ Controller 354, and in at least some embodiments, one or more or all of these controllers may be implemented as respective integrated circuits (ICs or chips) that communicate with each other and with SOC 300 (more specifically, with one or more processors 302). For example, Wi-Fi controller 356 may communicate with cellular controller 352 via a cell-ISM link or WCI interface, and / or BLUETOOTH ™ The controller 354 may communicate with the cellular controller 352 via a cell-ISM link, etc. Although three separate controllers are shown within the radio circuit 330, other embodiments have fewer or more similar controllers for various different RATs that may be implemented in the UE device 106. For example, at least one exemplary block diagram illustrating some embodiments of the cellular controller 352 is provided in Figure 5 , as further described below.

[0149] Figure 4 —Exemplary Base Station

[0150] Figure 4 1 shows a block diagram of an exemplary base station 102 according to some embodiments. Note that Figure 4 The base station 102 is only one example of a possible base station. As shown, the base station 102 may include one or more processors 404 that may execute program instructions for the base station 102. The one or more processors 404 may also be coupled to a memory management unit (MMU) 440 (which may be configured to receive addresses from the one or more processors 404 and translate these addresses into locations in memory (e.g., memory 460 and read-only memory (ROM) 450)) or other circuits or devices.

[0151] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to the telephone network as described above. Figure 1 and Figure 2 The network port 470 may be configured to connect to a plurality of devices, such as the UE device 106, connected to the telephone network described in the embodiment of the present invention. The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices, such as the UE device 106. In some cases, the network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0152] Base station 102 may include at least one antenna 434, and possibly multiple antennas. At least one antenna 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with UE device 106 via radio 430. Antenna 434 communicates with radio 430 via communication chain 432. Communication chain 432 may be a receive chain, a transmit chain, or both. Radio 430 may be designed to communicate via various wireless telecommunication standards, including but not limited to LTE, LTE-A, 5G-NR (or simply NR), WCDMA, CDMA2000, and the like. One or more processors 404 of base station 102 may be configured to implement some or all of the methods described herein, for example, by executing program instructions stored on a storage medium (e.g., a non-transitory computer-readable storage medium) for base station 102 to communicate with a UE device. The UE device may utilize codebook subset restrictions based on both spatial and frequency considerations for enhanced channel state information reporting during wireless communications, such as 5G-NR communications. Alternatively, one or more processors 404 may be configured as programmable hardware elements such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit), or a combination thereof. In the case of certain RATs (e.g., Wi-Fi), base station 102 may be designed as an access point (AP), in which case network port 470 may be implemented to provide access to a wide area network and / or one or more local area networks, for example, it may include at least one Ethernet port, and radio 430 may be designed to communicate in accordance with the Wi-Fi standard. Base station 102 may operate in accordance with various methods and embodiments disclosed herein for communicating with a UE device that utilizes codebook subset restrictions based on both spatial and frequency considerations for enhanced channel state information reporting during wireless communications, such as during 5G-NR communications.

[0153] Figure 5 —Exemplary Cellular Controller

[0154] Figure 5 An exemplary simplified block diagram of an exemplary cellular controller 352 according to some embodiments is shown. Note that Figure 5The block diagram of the cellular controller 352 is merely one example of one possible cellular controller; other circuits, such as circuits that include or are coupled to sufficient antennas for different RATs to perform uplink activities using separate antennas, or circuits that include or are coupled to fewer antennas, such as circuits that can be shared between multiple RATs, are also possible. According to some embodiments, the cellular controller 352 may be included in a communication device such as the communication device 106 described above. As described above, the communication device 106 may be a user equipment (UE) device, a mobile device or mobile station, a wireless device or wireless station, a desktop computer or computing device, a mobile computing device (e.g., a laptop, notebook, or portable computing device), a tablet computer, and / or a combination of devices, among other devices.

[0155] The cellular controller 352 may be coupled (e.g., communicatively; directly or indirectly) to one or more antennas, such as antennas 335a-b and 336 as shown. In some embodiments, the cellular controller 352 may include dedicated receive chains (including and / or coupled (e.g., communicatively; directly or indirectly) to dedicated processors and / or radio components) for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, Figure 5 As shown, the cellular controller 352 may include a first modem 510 and a second modem 520. The first modem 510 may be configured for communication according to a first RAT (e.g., such as LTE or LTE-A), and the second modem 520 may be configured for communication according to a second RAT (e.g., such as 5G NR).

[0156] As shown, the first modem 510 may include one or more processors 512 and a memory 516 in communication with the processor 512. The modem 510 may communicate with a radio frequency (RF) front end 530. The RF front end 530 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 530 may include receive circuitry (RX) 532 and transmit circuitry (TX) 534. In some embodiments, the receive circuitry 532 may communicate with a downlink (DL) front end 550, which may include circuitry for receiving radio signals via antenna 335a.

[0157] Similarly, the second modem 520 may include one or more processors 522 and a memory 526 in communication with the processor 522. The modem 520 may communicate with an RF front end 540. The RF front end 540 may include circuitry for transmitting and receiving radio signals. For example, the RF front end 540 may include receive circuitry 542 and transmit circuitry 544. In some embodiments, the receive circuitry 542 may communicate with a DL front end 560, which may include circuitry for receiving radio signals via the antenna 335b.

[0158] In some embodiments, the switch 570 can couple the transmit circuitry 534 to an uplink (UL) front end 572. Furthermore, the switch 570 can couple the transmit circuitry 544 to the UL front end 572. The UL front end 572 can include circuitry for transmitting radio signals via the antenna 336. Thus, when the cellular controller 352 receives an instruction to transmit according to a first RAT (e.g., via a transmission chain including the transmit circuitry 534 and the UL front end 572), the switch 570 can be switched to a first state that allows the first modem 510 to transmit signals according to the first RAT (e.g., via a transmission chain including the transmit circuitry 534 and the UL front end 572). Similarly, when the cellular controller 352 receives an instruction to transmit according to a second RAT (e.g., via a transmission chain including the transmit circuitry 544 and the UL front end 572), the switch 570 can be switched to a second state that allows the second modem 520 to transmit signals according to the second RAT (e.g., via a transmission chain including the transmit circuitry 544 and the UL front end 572).

[0159] As described herein, the first modem 510 and / or the second modem 520 may include hardware and software components for implementing any of the various features and techniques described herein. For example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium), the processors 512 and 522 may be configured to implement some or all of the features described herein. Alternatively (or additionally), the processors 512 and 522 may be configured as programmable hardware elements, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). Alternatively (or additionally), in combination with one or more of the other components 530, 532, 534, 540, 542, 544, 550, 570, 572, 335, and 336, the processors 512 and 522 may be configured to implement some or all of the features described herein.

[0160] Furthermore, as described herein, processors 512, 522 may include one or more processing elements. Thus, processors 512, 522 may include one or more integrated circuits (ICs) configured to perform the functions of processors 512, 522. Furthermore, each integrated circuit may include circuitry (e.g., a first circuit, a second circuit, etc.) configured to perform the functions of processors 512, 522.

[0161] In some embodiments, the cellular controller 352 may include only one transmit / receive chain. For example, the cellular controller 352 may not include the modem 520, the RF front end 540, the DL front end 560, and / or the antenna 335b. As another example, the cellular controller 352 may not include the modem 510, the RF front end 530, the DL front end 550, and / or the antenna 335a. In some embodiments, the cellular controller 352 may not include the switch 570, and the RF front end 530 or the RF front end 540 may communicate with the UL front end 572, for example, directly.

[0162] Codebook Subset Restriction (CBSR) and Channel State Information (CSI) Reporting

[0163] As previously mentioned, CBSR is used to restrict the precoding matrix candidates that a UE can consider for CSI reporting. That is, a UE can be configured so that some precoder candidates are not considered for CSI reporting and, therefore, not requested from the base station. Generally speaking, for a Multi-User Multiple Input Multiple Output (MU-MIMO) system, a base station (e.g., a gNB) can force multiple UEs (e.g., two UEs) to report their precoding matrices, or precoding matrix candidates, in mutually orthogonal directions. For example, the gNB may request the first UE to report the precoder formed by beams 0 and 1, and the second UE to report the precoder formed by beams 2 and 3. To reduce the UE's CSI computation complexity, the gNB can remove certain unlikely beams based on uplink measurements, thereby allowing the UE to avoid having to test precoders formed by those beams removed from consideration. In other words, to reduce computational complexity, the gNB can restrict the UE to a narrow search space based on uplink measurements, so that the UE does not have to consider the entire codebook.

[0164] In 3GPP New Radio (NR or 5G-NR) systems, two types of codebooks, Type I and Type II, have been standardized for CSI feedback in support of advanced MIMO operations. Both codebook types consist of a beam grid based on a two-dimensional (2D) digital Fourier transform (DFT), enabling CSI feedback based on beam selection and phase-shift keying (PSK)-based in-phase combining between two polarizations. Type II codebook-based CSI feedback also reports wideband and subband amplitude information for the selected beam, allowing for more accurate CSI. This, in turn, provides improved precoded MIMO transmission over the network.

[0165] Figure 6An example diagram of a precoding structure associated with Type II CSI reporting according to the prior art is shown. CSI may be reported to a base station (gNB) to indicate which precoding is preferred by the UE. As mentioned above, there are two types of codebooks for CSI reporting, or in other words, two types of CSI reporting, namely Type I and Type II. In Type II reporting, a precoding matrix is ​​reported for each frequency band and is represented by a linear combination of a set of a specified number (L) of DFT vectors representing each column. Figure 6 As shown, there may be a specified number (N3) of subbands, each with a corresponding precoding matrix W. Each precoding matrix consists of two columns w 1 and w 2 . Each column corresponds to the precoding vector of one layer. For each layer, the precoding vector can be further divided into two parts, namely the first polarization and the second polarization. The L DFT vector is common to all subbands and is used for subband-specific combining. Specifically, each column vector is a weighted sum of a specified number (L) of vectors. The weighting (or combining) coefficients of the combining / combining weights are in Figure 6 In the equation, c0, c1 and c2 are represented. Figure 6 In the example shown in , v0, v1, and v2 represent three DFT vectors. The UE reports to the gNB which three DFT vectors are preferred.

[0166] Figure 7 The following diagram shows an example of a reporting structure used by a UE to report back to a base station (e.g., to a gNB) according to the prior art. Each subband has its own corresponding set of combining coefficients, and ultimately the UE needs to report all combining coefficients. When considering UE reporting, the Class II overhead is dominated by the subband combining coefficients. Figure 7 The information shown has a total of 2L× N3 entries, one (1) bit for amplitude, and three (3) bits for phase. In the worst case, there may be 19 subbands, 32 transmit (TX) ports, and a CSI payload size of over 1000 bits. Therefore, reducing the Type II CSI overhead would be beneficial.

[0167] Figure 8 An example diagram illustrating CBSR associated with Type II CSI reporting according to the prior art is shown. Figure 8This provides an indication of how to configure the CBSR. In general, a bit sequence is provided to the UE. This bit sequence consists of two parts, each of which indicates the maximum allowed amplitude for a DFT beam. Therefore, all O1O2 beam groups are classified into two categories: restricted or unrestricted. For the basis in the unrestricted beam group, the wideband amplitude is unrestricted (e.g., it can have eight different values). For the basis in the restricted beam group, the maximum allowed wideband amplitude is configured (e.g., it can have four different values). That is, the restriction is spatially based. Four spatially based groups are selected, and the maximum wideband amplitude for each beam in the corresponding basis group is restricted.

[0168] like Figure 8 As indicated, there are two antennas in the vertical dimension (number of antennas [N1] = 2) and two antennas in the horizontal dimension (number of antennas [N2] = 2), resulting in 16 beam groups (BGs). The base station (e.g. gNB) selects four (4) of the 16 beam groups for consideration. In the example shown, BG 1, BG 5, BG 8 and BG 10 are selected. The selection of these four beam groups is indicated by the first bit sequence B1. For each beam group, the gNB additionally sends a short sequence of eight (8) bits to the UE. The eight bits are divided into four groups, each corresponding to one beam in this group. These four groups are Figure 8 Displayed as B2 (0) 、B2 (1) 、B2 (2) and B2 (3) , which can indicate four different maximum amplitude levels. There are four beams in each group, and each beam can indicate the maximum allowed power that the UE can consider in reporting CSI. This can control the maximum amplitude of the spatial beam. Therefore, if Figure 8 As shown, the CBSR restricts beam groups 1, 5, 8, and 10, where each group consists of an N1N2 basis, where a maximum wideband amplitude is configured for each beam in each restricted beam group.

[0169] Figure 9 An example diagram illustrating improved CBSR associated with Type II CSI reporting according to some embodiments is shown. As previously mentioned, overhead may consume a significant amount of uplink code bandwidth. In some embodiments, frequency compression of the combined (or weighted) coefficients may be introduced to reduce overhead. Thus, in addition to the spatial basis considerations (described previously), the frequency basis may also be considered. If the channel frequency selectivity is low, adjacent coefficients may exhibit similarity. For example, is correlated. That is, the combined coefficients across frequencies may have some correlation (they may be correlated across frequencies). If this correlation is extracted to enable decorrelation, then it can be done by a small set of frequency bases W f Therefore, the coefficients can be presented by compressing the combined coefficients in the frequency dimension ( ) to reduce overhead. Each coefficient can then be represented by an M basis, where M < N3. This allows the UE to report a small number of combining coefficients while also reporting the frequency basis to allow the gNB to reconstruct the first subband combining coefficients. Therefore, the coding vector can be presented not only in the spatial dimension but also in the frequency dimension. Figure 9 As shown, w l represents the spatial basis, and w f represents the frequency basis. Therefore, a new CBSR can be designed where the codebook can be constrained based on frequency in addition to spatial constraints. After decorrelation, the wideband amplitude may no longer be applicable.

[0170] Based on the above, different spatial and frequency restrictions can be implemented for CBSR. Therefore, the UE can now receive indications of codebook subset restrictions based on both space and frequency. In other words, CBSR can be performed based on both space and frequency. Therefore, in addition to restrictions based on the spatial basis configured by the gNB, UE CSI reporting can also be restricted based on a subset of the frequency basis configured per gNB. In some implementations, the maximum allowed amplitude can be configured separately for the spatial basis and the frequency basis, resulting in separate maximum allowed amplitudes based on spatial considerations and separate maximum allowed amplitudes based on frequency considerations. The maximum allowed amplitude can be layer-specific, meaning each layer can be configured with a different maximum allowed amplitude for different ranks. At least three different combinations of spatial / frequency basis considerations can be implemented. In a first implementation, the UE can be configured with restricted spatial basis-related amplitudes and unrestricted frequency basis-related amplitudes. In a second implementation, the UE can be configured with restricted frequency basis-related amplitudes and unrestricted spatial basis-related amplitudes. Finally, in a third implementation, the UE can be configured with both restricted spatial basis-related amplitudes and restricted frequency basis-related amplitudes.

[0171] Separate space and frequency limits

[0172] As mentioned above, in some embodiments, the maximum allowed amplitude for the spatial basis and the maximum allowed amplitude for the frequency basis can be configured. This can be implemented in a variety of different embodiments, which can be grouped into three different alternatives. In the first alternative, the amplitude of each coefficient can be given by the following formula The at most three components of the representation are:

[0173] • Spatial basis correlation amplitude ( );

[0174] • Frequency base related amplitude ( );and

[0175] • Depends on the amplitude of both the spatial basis and the frequency basis ( );

[0176] in( )and( ) shall not exceed one or more configured maximum allowed values, respectively. In a second alternative, the amplitude of each coefficient may be represented by a single component P i,m,l Indicates that P i,m,l The maximum allowed value configured for the corresponding spatial basis should not be exceeded, and the maximum allowed value configured for the corresponding frequency basis should also not be exceeded. In a third alternative, the amplitude of each coefficient can be represented by a single component P i,m,l Indicates that P i,m,l The product of the maximum allowed values ​​configured for the corresponding spatial basis and frequency basis should not be exceeded.

[0177] Figure 10 A plot illustrating one example of separate space-based and frequency-based restrictions according to some embodiments is shown. Figure 10 In the implementation scheme illustrated in , the gNB can provide a 2-bit indication to the UE for each frequency component. That is, for each frequency base (FC), a 2-bit amplitude limit can be configured. When the amplitude is set to zero for a given frequency component, the given frequency component is completely limited. In other words, the given frequency component can be ignored for CSI (or PMI) reporting by the UE. Figure 10 As shown, for FC 0 the amplitude is limited to 1, for FC 2 the amplitude is limited to ½, and FC 1 and FC 3 are completely limited to CSI reporting. Figure 10 In the bottom graph of , the frequency basis limits are indicated on the vertical axis and the space basis limits are indicated on the horizontal axis. Figures 6 to 9 , beam groups 1, 5, 8, and 10 are restricted based on space.

[0178] Joint spatial frequency limit

[0179] Figure 11 A plot illustrating one example of joint spatial frequency limiting according to some embodiments is shown. Figure 11 As shown, the UE can be restricted from reporting a subset of spatial and frequency basis combinations based on the gNB configuration. In this case, the UE can be configured with a subset of spatial basis groups, where a set of frequency basis restrictions is configured for each spatial basis group. When the frequency basis is restricted, CSI reports with the associated spatial basis may not be considered (by the UE). For each spatial basis group, a maximum allowed amplitude can be configured for each basis in the group. In other words, the maximum allowed amplitude can be indicated for each combination. For each beam group, the frequency component to be used can also be indicated. The maximum amplitude still follows the beam group configuration.

[0180] exist Figure 11In the example shown, for each restricted spatial beam group, a specific frequency basis restriction is configured. On the other hand, for an unrestricted spatial basis group, the frequency basis is not restricted. Figure 10 In contrast to the example shown in , where frequency bases 1 and 3 are fully restricted (without considering the spatial basis), in Figure 11 In the example of FIG, spatially unrestricted beam groups 0 and 15 are not frequency restricted. However, as indicated by the corresponding frequency base restrictions for each spatially restricted beam group (1, 5, 8, and 10), each spatially restricted beam group may also have a frequency base restriction applied as shown.

[0181] In some embodiments, frequency-based restrictions and space-based restrictions may not be applied simultaneously. That is, depending on certain parameters, restrictions may be space-based or frequency-based. For example, the applicability of space / frequency restrictions may depend on the space / frequency granularity. Considering the number of transmission ports or antennas (N 1, For example, for CBSR, a smaller number of antennas (e.g., N1 and N2 are both equal to or less than 4) may indicate wider spatial beams and fewer PMI assumptions, for which spatial-based restriction may be less effective and, therefore, frequency-based restriction may be preferred. Therefore, in some embodiments, for CBSR, frequency-based restriction, but not spatial-based restriction, may be provided by the gNB to the UE. On the other hand, a larger number of antennas (e.g., N1 and N2 are both equal to or greater than 8) may suggest narrower spatial beams and more PMI assumptions, for which each spatial beam may correspond to a single frequency basis, and thus spatial-based restriction may be sufficient. Therefore, in some embodiments, for CBSR, spatial-based restriction, but not frequency-based restriction, may be provided by the gNB to the UE. Therefore, frequency-based restriction may be supported for certain combinations of (N1, N2), and the configuration of frequency-based restriction may be based at least in part on the values ​​of (N1, N2).

[0182] Configure the number of frequency bases for enhanced Type II CSI reporting

[0183] Reference again Figures 6 to 9 As previously mentioned, in some embodiments, the frequency basis may be beam-specific. For example, frequency basis may be considered for different polarizations and different spatial beams. Figure 12 A drawing showing an exemplary precoder structure with frequency compression according to some embodiments. Figure 12 The formula in represents the aggregated precoding vector of the nth layer. Figure 12 As shown, v0 represents a first spatial beam of a first polarization having a corresponding frequency basis M0. A second spatial beam v1 of the first polarization may have a smaller corresponding frequency basis M1. When determining the corresponding values ​​of M0, M1, M2, and M3, a value M may be obtained, which represents (corresponds to) the size of the W2 matrix.

[0184] For the i-th space basis, each combination coefficient is M i Linear combination of frequency bases. That is, for each spatial basis, each combination coefficient is a linear combination of the corresponding values ​​of M (denoted as M i ). M i The value of can be selected by the UE and reported in the CSI, or it can be configured by the gNB via higher layer signaling. In some embodiments, referred to as explicit configuration, the gNB can configure this value via dedicated Radio Resource Control (RRC) signaling. In some embodiments, referred to as implicit configuration, the value can be derived from some other RRC parameters based on specified predefined rules.

[0185] In a first implementation, the value of M can be a function of the number of ports in both dimensions (vertical and horizontal). i The value of may be a function of (N1, N2). Larger values ​​of N1 and N2 (eg, again, equal to or greater than 8) may result in narrower spatial beams, and thus smaller values ​​of Mi may be sufficient.

[0186] In a second specific implementation, the frequency size may be considered. Here, the UE may need to report a large number of subbands. i The value of M can be a function of N3. Large N3 values ​​may result in more resolvable paths, so large M i A value of M may be preferred. For example, i = f2 (N3).

[0187] In a third implementation, both spatial and frequency considerations may be considered. In this case, M i The value of can be a function of (N1, N2, N3), and the spatiotemporal granularity can be considered jointly. For example, M i = f3 (max (N1,N2), N3).

[0188] Configuring PMI frequency compression unit for enhanced NR Type II CSI

[0189] See again Figure 9 , can be considered to determine the length of the frequency base. In practice, this leads to determining how to choose W f The size of the matrix. It should be noted that there is a clear relationship between the frequency and time domains (Fourier transform), which allows the use of Fast Fourier Transform (FFT). For example, if the UE is required to report CSI for a specified number (e.g., 5) subbands, then W fThe columns may have the same number of entries (5 in this case). The value for each subband may be obtained. In the proposed system, the range of resource blocks (RBs) may be from 1 to 275 (as an example of a wider range). Therefore, FFT may be supported for this range. The number of CSI frequency cells may be related to W f to establish a relationship / link between the dimensions and the FFT size.

[0190] The frequency basis in Wf can be a subset of the DFT vectors. Therefore, the size of the frequency basis can be equal to the number of CSI frequency bins (e.g., the number of subbands indicated in the CSI reporting band). According to current 3GPP specifications, the number of subbands can be any integer within a specified range, such as 1 to 19. For finer PMI frequency bins, the size of the frequency basis can vary over a wider range, for example, from 1 to several hundred. As mentioned above, frequency compression can be achieved using the FFT. For ease of implementation, the size of the frequency basis (e.g., the FFT size) can be carefully selected.

[0191] Based on the above, a new size labeled N"3 can be introduced. N'3 can be specified to be smaller than the FFT size, which is W represented by N"3. f The size of each column of the matrix. Therefore, for the FFT implementation, the size of the frequency base can be N"3 = 2 i 3 j 5 k Definition. The values ​​of i, j, k may be chosen such that N”3 is the smallest integer greater than N’3, where N’3 is the maximum number of PMI FD compression units in a given bandwidth part (BWP) or a given component carrier (CC). N3 is then the number of PMI FD compression units to report and may be smaller than N’3. For example, the gNB may disable some subbands by setting the corresponding bits to “0” in the CSI reporting band. Therefore, the following inequality may be observed: N”3 ≥ N’3 ≥ N3.

[0192] Figure 13 A drawing illustrating an example of a PMI frequency compression unit configuration according to some embodiments is shown. Figure 12 As shown, the BWP contains N'3 = 7 (7) subbands. The value in the CSI reporting band = 1011011, i.e., the UE is requested to report CSI on subbands 0, 2, 3, 5, and 6, which means N3 = 5. The frequency basis dimension is then N"3 = 8. Figure 14 A table showing exemplary corresponding values ​​of i, j, k, and N″3 for all values ​​of N3 from 1 to 19 is shown.

[0193] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0194] Embodiments of the present invention may be implemented in any of a variety of forms. For example, in some embodiments, the present invention may be implemented as a computer-implemented method, a computer-readable storage medium, or a computer system. In other embodiments, the present invention may be implemented using one or more custom-designed hardware devices such as ASICs. In other embodiments, the present invention may be implemented using one or more programmable hardware elements such as FPGAs.

[0195] In some embodiments, a non-transitory computer-readable storage medium (e.g., a non-transitory memory element) may be configured such that it stores program instructions and / or data, wherein the program instructions, if executed by a computer system, cause the computer system to perform a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets.

[0196] In some embodiments, a device (e.g., a UE) may be configured to include a processor (or a group of processors) and a memory medium (or a memory element), wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets). The device may be implemented in any of various forms.

[0197] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A method for transmitting channel state information (CSI), the method comprising: Obtain a value M of a size of a frequency basis matrix for enhancing CSI feedback; wherein the enhanced CSI feedback is for a specific number S of frequency subbands and includes information corresponding to a coefficient matrix having a size of 2L times M; where L is the number of beams associated with the CSI feedback; wherein M is a result of compression of the number of frequency cells N3, and the number of frequency cells N3 indicates the total number of frequency cells to be reported; and wherein N3 is based on S; and wherein M is less than S; and The enhanced CSI feedback is sent to a base station.

2. The method according to claim 1, further comprising: M is obtained by deriving it from other parameters based on higher layer signaling from the base station.

3. The method according to claim 1, further comprising: Get N3, where N3 is greater than S. The method of claim 1 , wherein S is the number of frequency subbands indicated in the CSI reporting band.

5. The method according to claim 1, further comprising: Get N3, where N3 is equal to S. The method according to claim 1 , wherein the compression of N3 is achieved by fast Fourier transform.

7. The method according to claim 1, in, For each of the multiple spatial bases of the enhanced CSI feedback, the corresponding combining coefficient of the spatial base is based on the value M i A linear combination of .

8. A device for wireless communication, the device comprising: A processing circuit configured to perform the method according to any one of claims 1 to 7.

9. An electronic device comprising: a radio circuit configured to enable wireless communication of the electronic device; and A processing circuit is communicatively coupled to the radio circuit and is configured to interoperate with the radio circuit to perform the method according to any one of claims 1 to 7.

10. A non-transitory computer-readable medium storing instructions, which, when executed, cause an electronic device to perform the method according to any one of claims 1 to 7.

11. A method for receiving channel state information, the method comprising: Providing signaling to the electronic device for obtaining a value M of a size of a frequency base matrix for enhanced CSI feedback; wherein the enhanced CSI feedback is for a specific number S of frequency subbands and includes information corresponding to a coefficient matrix having a size of 2L times M; where L is the number of beams associated with the CSI feedback; wherein M is a result of compression of the number of frequency cells N3, and the number of frequency cells N3 indicates the total number of frequency cells to be reported; and wherein N3 is based on S; and wherein M is less than S; and The enhanced CSI feedback is received from the electronic device.

12. The method according to claim 11, wherein Obtaining M includes deriving M from other parameters based on the signaling, wherein the signaling includes higher layer signaling.

13. The method according to claim 11, further comprising: Get N3, where N3 is greater than S. The method of claim 11 , wherein S is the number of frequency subbands indicated in the CSI reporting band.

15. The method according to claim 11, further comprising: Get N3, where N3 is equal to S.

16. The method of claim 11, wherein the compression of N3 is achieved by fast Fourier transform.

17. The method according to claim 11, further comprising: in, For each of the multiple spatial bases of the enhanced CSI feedback, the corresponding combining coefficient of the spatial base is based on the value M i A linear combination of .

18. A device for wireless communication, the device comprising: A processing circuit configured to perform the method according to any one of claims 11 to 17.

19. A base station, comprising: radio circuitry configured to enable wireless communication of the base station; and A processing circuit communicatively coupled to the radio circuit and configured to interoperate with the radio circuit to perform the method according to any one of claims 11 to 17.

20. A non-transitory computer readable medium storing instructions which, when executed, cause a base station to perform the method according to any one of claims 11 to 17.

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