Method and apparatus for type ii codebook

Abstract

This document discloses methods and apparatus for using enhanced Type II codebooks. According to embodiments of this disclosure, a user equipment (UE) may include: at least one memory; and at least one processor coupled to the at least one memory and configured such that the UE: receives configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of Channel State Information (CSI) Reference Signal (CSI-RS) ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; determines a precoding matrix indicator (PMI) based on either a second number of beams selected by the UE or beam groups associated with the codebook, each beam group having a scaled number of beams; and transmits a CSI report, wherein the CSI report includes the PMI.

Description

Technical Field

[0001] This disclosure relates to wireless communication, and more specifically to methods and apparatus for using Type II codebooks. Background Technology

[0002] A wireless communication system may include one or more network communication devices, such as base stations (BS), which may support wireless communication with one or more user communication devices, which may also be referred to as user equipment (UE) or other suitable terms. The wireless communication system may support wireless communication with one or more user communication devices by utilizing the resources of the wireless communication system (e.g., time resources (e.g., symbols, time slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like)). Furthermore, the wireless communication system may support wireless communication across a variety of radio access technologies, including third-generation (3G), fourth-generation (4G), fifth-generation (5G), and other suitable radio access technologies beyond 5G (e.g., sixth-generation (6G)). Summary of the Invention

[0003] The article “a” preceding an element is not limited and should be understood to refer to “at least one” or “one or more” of those elements. The terms “a,” “at least one,” “one or more,” and “at least one of one or more” are interchangeable. As used herein (including in the claims), “or” as used in a list of items (e.g., a list of items beginning with phrases such as “at least one of…” or “one or more of…” or “one or both of…”) indicates an inclusive list such that a list of at least one of, for example, A, B, or C represents A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase “based on” should not be construed as a reference to a closed set of conditions. For example, without departing from the scope of this disclosure, an example step described as “based on condition A” may be based on both condition A and condition B. In other words, as used herein, the phrase “based on” should be interpreted in the same manner as the phrase “at least partially based on.” Furthermore, as used herein (including in the claims), a “set” may comprise one or more elements.

[0004] Some embodiments of the methods and apparatus described herein may include a UE for wireless communication. The UE may include: at least one memory; and at least one processor coupled to the at least one memory and configured such that the UE: receives configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of Channel State Information (CSI) Reference Signal (CSI-RS) ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; determines a precoding matrix indicator (PMI) based on either a second number of beams selected by the UE or beam groups associated with the codebook, each beam group having a scaled number of beams; and transmits a CSI report, wherein the CSI report includes the PMI.

[0005] In some embodiments of the UE described herein, the PMI includes an indication of an index for indicating a second codebook parameter configuration, the second codebook parameter configuration including the second number of beams, frequency compression ratio, and non-zero coefficient compression ratio selected by the UE.

[0006] In some implementations of the UE described herein, the second codebook parameter configuration is selected by the UE from a plurality of predefined candidate codebook parameter configurations, wherein each predefined candidate codebook parameter configuration includes a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio.

[0007] In some implementations of the UE described herein, the second codebook parameter configuration is selected by the UE from a subset of multiple predefined candidate codebook parameter configurations, wherein each predefined candidate codebook parameter configuration includes a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio, and the subset is configured for the UE.

[0008] In some embodiments of the UE described herein, the PMI includes an indication of an index for indicating the second number of beams selected by the UE from a plurality of candidate beam numbers, wherein the PMI is determined based on the second number of beams selected by the UE, the first frequency compression ratio, and the first non-zero coefficient compression ratio.

[0009] In some embodiments of the UE described herein, each of the plurality of candidate beam numbers is within {2, 4, 6}.

[0010] In some embodiments of the UE described herein, the plurality of candidate beam numbers are predetermined integers in the range [2, L], where L is the first beam number.

[0011] In some embodiments of the UE described herein, when the first number of beams is 6, the first frequency compression ratio for 3-layer or 4-layer CSI reporting is half that for 1-layer or 2-layer CSI reporting, and the first non-zero coefficient compression ratio for 3-layer or 4-layer CSI reporting is the same as that for 1-layer or 2-layer CSI reporting.

[0012] In some embodiments of the UE described herein, the at least one processor is further configured to enable the UE to transmit capability information indicating whether the UE supports beam number selection or indicating the number of candidate beam numbers supported by the UE for beam number selection.

[0013] In some implementations of the UE described herein, the number of scaled beams per beam group is determined based on k1O1k2O2, where O1 is the horizontal oversampling factor of the antenna array having a first number of CSI-RS ports, and O2 is the vertical oversampling factor of the antenna array, k1 is the horizontal scaling factor, and k2 is the vertical scaling factor.

[0014] In some embodiments of the UE described herein, the PMI includes L beam groups indicating selection from N beam groups. The first codebook index of the unit digit, where L is the number of the first or second beams selected by the UE, and N is based on Determine that N1 is the number of antenna ports in each polarization direction in the horizontal direction of the antenna array, and N2 is the number of antenna ports in each polarization direction in the vertical direction of the antenna array.

[0015] In some embodiments of the UE described herein, the PMI includes an indication of selecting one beam from a beam group consisting of O beams. log2(O) The second codebook index of the unit digit, where O is the number of scaled beams per beam group.

[0016] In some implementations of the UE described herein, k1 and k2 have predefined values.

[0017] In some implementations of the UE described herein, when N2=1, k1=2 and k2=1, or k1=4 and k2=1; or when N2>1, k1=2 and k2=2, or k1=4 and k2=4.

[0018] In some embodiments of the UE described herein, the at least one processor is further configured to enable the UE to receive information indicating a second number of CSI-RS resources for CSI reporting using the first number of CSI-RS ports, wherein the second number of CSI-RS resources includes a third number of CSI-RS resources in the horizontal direction and a fourth number of CSI-RS resources in the vertical direction, k1 equals the third number and k2 equals the fourth number.

[0019] In some embodiments of the UE described herein, the at least one processor is further configured to enable the UE to receive information indicating the values ​​of k1 and k2.

[0020] In some implementations of the UE described herein, the information is either Radio Resource Control (RRC) signaling or Media Access Control (MAC) control element (CE).

[0021] Some embodiments of the methods and apparatus described herein may include a processor for wireless communication. The processor may include: at least one controller coupled to at least one memory and configured to: receive configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; determine a PMI based on either a second number of beams selected by the processor or beam groups associated with the codebook, each beam group having a scaled number of beams; and transmit a CSI report, wherein the CSI report includes the PMI.

[0022] Some embodiments of the methods and apparatus described herein may include a BS for wireless communication. The BS may include: at least one memory; and at least one processor coupled to the at least one memory and configured such that the BS: transmits configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; and receives CSI reports, wherein the CSI reports include a PMI based on either a second number of beams selected by the UE or beamgroups associated with the codebook, each beamgroup having a scaled number of beams.

[0023] Some embodiments of the methods and apparatus described herein may include a method performed by a UE. The method may include: receiving configuration information indicating a first codebook parameter configuration for using a codebook for CSI reporting with a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; determining a PMI based on either a second number of beams selected by the UE or beam groups associated with the codebook, each beam group having a scaled number of beams; and transmitting a CSI report, wherein the CSI report includes the PMI.

[0024] Some embodiments of the methods and apparatus described herein may include a method performed by a BS. The method may include: transmitting configuration information indicating a first codebook parameter configuration for using a codebook to report CSI using a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; and receiving a CSI report, wherein the CSI report includes a PMI based on either a second number of beams selected by the UE or beam groups associated with the codebook, each beam group having a scaled number of beams. Attached Figure Description

[0025] To illustrate the advantages and features of this application, the description of this application is presented with reference to specific embodiments illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of this application and should therefore not be construed as limiting its scope.

[0026] Figure 1 Examples of wireless communication systems according to aspects of this disclosure are described.

[0027] Figure 2 A flowchart illustrating an exemplary method performed by a UE according to aspects of this disclosure.

[0028] Figure 3 A flowchart illustrating an exemplary method performed by a BS according to aspects of this disclosure.

[0029] Figure 4 Examples of UEs based on aspects of this disclosure are described.

[0030] Figure 5 Examples of processors according to aspects of this disclosure are described.

[0031] Figure 6 Examples of BS based on aspects of this disclosure are described. Detailed Implementation

[0032] The detailed description of the accompanying drawings is intended to illustrate preferred embodiments of the present application and is not intended to represent the only form in which the present application may be practiced. It should be understood that the same or equivalent functionality may be achieved through different embodiments intended to be encompassed within the spirit and scope of the present application.

[0033] Although the operations are depicted in a specific order in the diagram, those skilled in the art will readily recognize that such operations need not be performed in the specific order shown or in a sequential manner, or that all the described operations need to be performed to achieve the desired result; sometimes one or more operations can be skipped. Furthermore, the diagram may schematically depict one or more instance processes in the form of a flowchart. However, other operations not depicted may be incorporated into the schematically illustrated instance processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the described operations. In some cases, multitasking and parallel processing may be advantageous.

[0034] Reference will now be made in detail to some embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architectures and new service scenarios (e.g., 3GPP Long Term Evolution (LTE) and Advanced LTE, 3GPP 5G New Radio (NR), Advanced 5G, 6G, etc.). It has been considered that all embodiments in this disclosure are applicable to similar technical problems as network architectures and new service scenarios evolve; furthermore, the terminology used in this disclosure may be changed without affecting the principles of this disclosure.

[0035] Aspects of this disclosure are described in the context of wireless communication systems.

[0036] Figure 1This section describes an example of a wireless communication system 100 according to aspects of this disclosure. The wireless communication system 100 may include one or more network equipment (NEs) (e.g., BSs) 102, one or more UEs 104, and a core network (CN) 106. The wireless communication system 100 may support various radio access technologies. In some embodiments, the wireless communication system 100 may be a 4G network, such as an LTE network or an advanced LTE (LTE-A) network. In some other embodiments, the wireless communication system 100 may be an NR network, such as a 5G network, an advanced 5G (5G-A) network, or a 5G ultra-wideband (5G-UWB) network. In other embodiments, the wireless communication system 100 may be a combination of 4G and 5G networks, or include other suitable radio access technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), and IEEE 802.20. The wireless communication system 100 may support radio access technologies beyond 5G, such as 6G. In addition, the wireless communication system 100 can support technologies such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or Code Division Multiple Access (CDMA).

[0037] One or more NEs 102 may be distributed across a geographical area to form a wireless communication system 100. One or more of the NEs 102 described herein may be, include, or be referred to as a network node, base station, network element, network function, network entity, radio access network (RAN), NodeB, eNodeB (eNB), next-generation NodeB (gNB), or other suitable terms. NEs 102 and UEs 104 may communicate via a communication link, which may be a wireless or wired connection. For example, NEs 102 and UEs 104 may perform wireless communication (e.g., receive signaling, transmit signaling) via a Uu interface.

[0038] NE 102 can provide a geographic coverage area, for which NE 102 can support services of one or more UE 104s within the geographic coverage area. For example, NE 102 and UE 104 can support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcasting, etc.) according to one or more radio access technologies. In some embodiments, NE 102 can be mobile, for example, a satellite associated with a non-terrestrial network (NTN). In some embodiments, different geographic coverage areas associated with the same or different radio access technologies may overlap, but different geographic coverage areas may be associated with different NE 102s.

[0039] One or more UEs 104 may be distributed across a geographical area of ​​the wireless communication system 100. UE 104 may include or be referred to as a remote unit, mobile device, wireless device, remote device, subscriber device, transmitter device, receiver device, or some other suitable term. In some embodiments, UE 104 may be referred to as a unit, station, terminal, or client, and other instances thereof. Alternatively or additionally, UE 104 may be referred to as an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a Machine Type Communication (MTC) device, and other instances thereof.

[0040] UE 104 may be able to support direct wireless communication with other UE 104s via a communication link. For example, UE 104 may support direct wireless communication with another UE 104 via a device-to-device (D2D) communication link. In some implementations (e.g., vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular V2X deployments), the communication link may be referred to as a side link. For example, UE 104 may support direct wireless communication with another UE 104 via a PC5 interface.

[0041] NE 102 may support communication with CN 106 or with another NE 102, or both. For example, NE 102 may interface with other NE 102 or CN 106 via one or more backhaul links (e.g., S1, N2, N2, or network interfaces). In some embodiments, NE 102 may communicate directly with each other. In some other embodiments, NE 102 may communicate indirectly with each other (e.g., via CN 106). In some embodiments, one or more NE 102 may include sub-components, such as access network entities, which may be instances of Access Node Controllers (ANCs). The ANC may communicate with one or more UEs 104 via one or more other access network transport entities (which may be referred to as radio heads, smart radio heads, or transmit-receive points (TRPs)).

[0042] CN 106 can support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. CN 106 can be an evolved packet core (EPC) or a 5G core (5GC), which may include control plane entities (e.g., Mobility Management Entity (MME), Access and Mobility Management Function (AMF)) that manage access and mobility, and user plane entities (e.g., Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)) that route or interconnect packets to external networks. In some implementations, the control plane entities may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signaling bearers, etc.) of one or more UEs 104 served by one or more NEs 102 associated with CN 106.

[0043] CN 106 can communicate with the packet data network via one or more backhaul links (e.g., via S1, N2, N2, or another network interface). The packet data network may contain an application server. In some implementations, one or more UEs 104 can communicate with the application server. UE 104 can establish a session (e.g., a Protocol Data Unit (PDU) session or the like) with CN 106 via NE 102. CN 106 can use the established session (e.g., an established PDU session) to route traffic (e.g., control information, data, and the like) between UE 104 and the application server. A PDU session may be an instance of a logical connection between UE 104 and CN 106 (e.g., one or more network functions of CN 106).

[0044] In the wireless communication system 100, NE 102 and UE 104 can use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some embodiments, NE 102 and UE 104 may support different resource structures. For example, NE 102 and UE 104 may support different frame structures. In some embodiments, such as in 4G, NE 102 and UE 104 may support a single frame structure. In some other embodiments, such as in 5G and other suitable radio access technologies, NE 102 and UE 104 may support various frame structures (e.g., multiple frame structures). NE 102 and UE 104 may support various frame structures based on one or more parameter sets.

[0045] The wireless communication system 100 may support one or more parameter sets, and the parameter sets may include subcarrier spacing and cyclic prefixes. A first parameter set (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a regular cyclic prefix. In some embodiments, the first parameter set (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one time slot per subframe. A second parameter set (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a regular cyclic prefix. A third parameter set (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a regular cyclic prefix or an extended cyclic prefix. A fourth parameter set (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a regular cyclic prefix. A fifth parameter set (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a regular cyclic prefix.

[0046] The time intervals of resources (e.g., communication resources) can be organized according to frames (also called radio frames). Each frame may have a certain duration, such as 10 milliseconds (ms). In some embodiments, each frame may contain multiple subframes. For example, each frame may contain 10 subframes, and each subframe may have a certain duration, such as 1 ms. In some embodiments, each frame may have the same duration. In some embodiments, each subframe of a frame may have the same duration.

[0047] Alternatively, the time intervals of resources (e.g., communication resources) can be organized according to time slots. For example, a subframe may contain a certain number (e.g., quantity) of time slots. The number of time slots in each subframe may also depend on one or more parameter sets supported in the wireless communication system 100. For example, the first, second, third, fourth, and fifth parameter sets (e.g., μ=0, μ=1, μ=2, μ=3, μ=4) associated with corresponding subcarrier intervals of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize one time slot per subframe, two time slots per subframe, four time slots per subframe, eight time slots per subframe, and 16 time slots per subframe, respectively. Each time slot may contain a certain number (e.g., quantity) of symbols (e.g., Orthogonal Frequency Division Multiplexing (OFDM) symbols). In some embodiments, the number (e.g., quantity) of time slots in a subframe may depend on the parameter set. For a conventional cyclic prefix, a time slot may contain 14 symbols. For an extended cyclic prefix (e.g., applicable to a 60 kHz subcarrier spacing), a time slot may contain 12 symbols. The relationship between the number of symbols per time slot for the regular cyclic prefix and the extended cyclic prefix, and between the number of time slots per subframe and the number of time slots per frame, may depend on the parameter set. It should be understood that references to the first parameter set (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and time slots.

[0048] In the wireless communication system 100, the electromagnetic (EM) spectrum can be divided into various categories, frequency bands, channels, etc., based on frequency or wavelength. For example, the wireless communication system 100 may support one or more operating frequency bands, such as frequency range identifiers FR1 (410 MHz to 7.125 GHz), FR2 (24.25 GHz to 52.6 GHz), FR3 (7.125 GHz to 24.25 GHz), FR4 (52.6 GHz to 114.25 GHz), FR4a or FR4-1 (52.6 GHz to 71 GHz), and FR5 (114.25 GHz to 300 GHz). In some embodiments, NE 102 and UE 104 may perform wireless communication on one or more of the operating frequency bands. In some embodiments, FR1 may be used by NE 102 and UE 104, as well as other equipment or devices, for cellular communication services (e.g., control information, data). In some implementations, FR2 can be used by NE 102 and UE 104, as well as other equipment or devices, for short-range, high data rate capabilities.

[0049] FR1 may be associated with one or more parameter sets (e.g., at least three parameter sets). For example, FR1 may be associated with: a first parameter set (e.g., μ=0) containing a 15 kHz subcarrier spacing; a second parameter set (e.g., μ=1) containing a 30 kHz subcarrier spacing; and a third parameter set (e.g., μ=2) containing a 60 kHz subcarrier spacing. FR2 may be associated with one or more parameter sets (e.g., at least two parameter sets). For example, FR2 may be associated with: a third parameter set (e.g., μ=2) containing a 60 kHz subcarrier spacing; and a fourth parameter set (e.g., μ=3) containing a 120 kHz subcarrier spacing.

[0050] With the development of communication technologies, there is a growing demand for enhancements to downlink multiple-input multiple-output (MIMO) using large antenna arrays for both FR1 and FR2, to meet the evolving needs of NR deployments, especially in the 7 GHz band. In existing 5G systems, CSI-RS ports are designed based on a maximum port number of 32. However, for large antenna arrays, a larger number of CSI-RS ports (e.g., more than 32 ports) can be used to further increase beamforming gain, thereby improving cell coverage and average / edge cell throughput, especially when the CSI-RS ports are implemented using all-digital ports. In this document, the terms "port," "CSI-RS port," "antenna port," and "CSI-RS antenna port" are used interchangeably.

[0051] Type II codebooks (e.g., the Type 2 codebook in 3GPP Release 15, the enhanced Type 2 (eType 2) codebook in 3GPP Release 16, or the eType 2 codebook for predicting PMI in 3GPP Release 18) can be used in multi-user multiple-input multiple-output (MU-MIMO) scenarios to provide more accurate CSI. Type II codebooks can be represented by PMI values ​​and can contain codewords (i.e., precoding matrices) corresponding to the PMI values. In existing 5G systems, Type II codebooks (e.g., Type 2 codebooks, eType 2 codebooks, or eType 2 codebooks for predicting PMI) are designed based on CSI-RS with 8, 12, 16, 24, or 32 ports and 1, 2, 3, or 4 layers. The PMI values ​​of the Type II codebook can contain codebook indices i1 and i2, which can further contain the following codebook indices for different rank indication (RI) values ​​(i.e., the number of layers, which can be represented as υ).

[0052] · ;

[0053] · .

[0054] The specific definitions of these codebook indexes can be found in 3GPP standard documents (e.g., TS 38.214).

[0055] For large antenna arrays with more than 32 ports, finer spatial granularity can be achieved to provide more accurate CSI. More accurate CSI enables higher gain and better interference suppression for MU-MIMO. However, the overhead of CSI reporting (which includes PMI values) increases due to the increased number of candidate beams used for selection and the larger number of selected beams for CSI reporting. Therefore, it is necessary to address how to reduce the overhead of CSI reporting using more than 32 ports based on Type II codebooks.

[0056] Embodiments of this disclosure provide solutions for Type II codebooks (e.g., Type 2 codebooks, or eType 2 codebooks, or eType 2 codebooks for predicting PMI) using more than 32 ports, which can reduce CSI reporting overhead. In some embodiments of this disclosure, dynamic beam selection schemes can be designed to reduce CSI reporting overhead. In some embodiments of this application, new beamgrouping schemes with scaled beamgroup numbers and scaled beam numbers per group can be designed to reduce CSI reporting overhead. More details will be described below in conjunction with the accompanying drawings.

[0057] According to some embodiments of this application, a Type II codebook for more than 32 ports (e.g., a Type 2 codebook, or an eType 2 codebook, or an eType 2 codebook for predicting PMI) can be derived based on an (N1,N2) configuration for a large antenna array with more than 32 antenna ports and a (O1,O2) configuration corresponding to or associated with the (N1,N2) configuration, where N1 is the number of antenna ports per polarization direction in the horizontal direction of the antenna array, N2 is the number of antenna ports per polarization direction in the vertical direction of the antenna array, O1 is the horizontal oversampling factor, and O2 is the vertical oversampling factor. The total number of antenna ports in the antenna array is 2N1N2.

[0058] In some embodiments, the BS may transmit the (N1, N2) configuration of its antenna array to the UE. The (O1, O2) configuration corresponding to or associated with the (N1, N2) configuration may be specified in 3GPP standard documents, and therefore the UE may derive the (O1, O2) configuration based on the (N1, N2) configuration. Alternatively or additionally, the BS may transmit the (N1, N2) configuration and the corresponding or associated (O1, O2) configuration to the UE.

[0059] In some instances, with an antenna array having 48 CSI-RS ports, the (N1,N2) configuration may include (6,4), (8,3), (12,2), or (24,1).

[0060] In some instances, with an antenna array having 64 CSI-RS ports, the (N1,N2) configuration may include (8,4), (16,2), or (32,1).

[0061] In some instances, with an antenna array having 72 CSI-RS ports, the (N1,N2) configuration may include (6,6), (12,3), (18,2), or (36,1).

[0062] In some instances, with an antenna array having 96 CSI-RS ports, the (N1,N2) configuration may include (8,6), (12,4), (16,3), (24,2), or (48,1).

[0063] In some instances, with an antenna array having 128 CSI-RS ports, the (N1,N2) configuration may include (8, 8), (16, 4), (32, 2), or (64, 1).

[0064] In some embodiments of this disclosure, when N2>1, the corresponding or associated (O1, O2) configuration may include (4,4), (4, 2), (2, 4), or (2, 2); when N2=1, the corresponding or associated (O1, O2) configuration may include (4, 1) or (2,1).

[0065] The above (N1,N2) and (O1,O2) configurations are provided for illustrative purposes only, and other configurations may be applied without departing from the spirit of this disclosure.

[0066] In existing 5G systems, it is also possible to base them on L, β, and p. υ The codebook parameters are configured to derive the eType2 codebook, where the L value indicates the number of beams, the β value indicates the non-zero coefficient compression ratio, and p... υ The values ​​indicate the frequency compression ratio. L, β, and p υ The value can be configured by the BS, for example via the higher-level parameter paramCombination as specified in the 3GPP standard documents.

[0067] Table 1 below illustrates the mapping from the values ​​indicated by paramCombination to the corresponding codebook parameter configurations, where each codebook parameter configuration may contain L, β, and p. υ The corresponding values ​​are shown in Table 1, which is the same as Table 5.2.2.2.5-1 in TS 38.214.

[0068] Table 1: L, β, and p υ Codebook parameter configuration

[0069]

[0070] According to the definition provided in TS 38.214, codebook index i 1,2 It can indicate L beam groups selected from N1N2 beam groups, where L is the number of beams included in, for example, a codebook parameter configuration configured by the BS. That is, i 1,2 ∈ and used to indicate i 1,2 The number of digits is As stated above, larger N1 and N2 values ​​can be introduced to support more than 32 (e.g., 48, 64, 72, 96, or 128) CSI-RS ports. Larger N1 and N2 values ​​are used to indicate i 1,2 The increased number of bits increases CSI reporting overhead.

[0071] Table 2 below illustrates the indications for different numbers of CSI-RS ports and different numbers of beams. 1,2 The number of exemplary bits.

[0072] Table 2: Indication for different numbers of CSI-RS ports and different numbers of beams 1,2 Number of digits

[0073]

[0074] Referring to Table 2, for CSI reporting using 64 CSI-RS ports, compared to the case with 4 beams, the number of beams used to indicate i is [missing information]. 1,2 The number of bits is reduced by 7, and compared to the case with 6 beams, the number of bits used to indicate i is reduced. 1,2 The number of bits is reduced by 11. For CSI reporting using 128 CSI-RS ports, with 2 beams, compared to 4 beams, the number of bits used to indicate i... 1,2 The number of bits is reduced by 9, and compared to the case with 6 beams, the number of bits used to indicate i is reduced. 1,2 The number of bits is reduced by 16.

[0075] Additionally, using a smaller number of beams (i.e., a smaller L value) can also reduce the CSI reporting overhead for other codebook indices.

[0076] For example, the precoding matrix W of a codebook (e.g., the eType2 codebook) can be expressed as: W1 is primarily used to reflect the broadband characteristics of the channel and contains beam selection information; It is a direct transfer function (DTF) matrix used to represent the basis of the transform domain derived from the frequency domain; It is a non-zero coefficient matrix of a linear combination. The dimension can be represented as 2L×M v The dimension can be reduced when a smaller L value is used. Furthermore, when a smaller L value is used, the maximum number of non-zero coefficients (i.e., K0, which is [value missing] in the case of one layer used for CSI reporting) is [value missing]. β2LM1 And in cases where more than one layer is used for CSI reporting, it is 2. β2LM1 This can be reduced. Therefore, when using a smaller L value, it is used to indicate i. 1,7,l The number of bits (of the bitmap indicating non-zero coefficients) used to indicate i 2,4,l The number of bits (indicating the magnitude of the non-zero coefficient) and the bits used to indicate i 2,5,l The number of bits (indicating the phase of non-zero coefficients) can be significantly reduced. Additionally, when using a smaller L value, the number of bits used to indicate i... 1,8,l The number of bits (of its strongest indicator coefficient) can also be significantly reduced.

[0077] In existing 5G systems, the number of beams (i.e., the L value) is configured semi-statically by higher-layer parameters. For large antenna arrays with increased candidate beams, a larger L value can be configured by the BS. As stated above, a larger L value can increase CSI reporting overhead. To reduce CSI reporting overhead, some embodiments of this disclosure propose a dynamic beam number selection scheme. In this scheme, the UE can select a number of beams (which may differ from the number of beams configured by the BS) and report it to the BS. The following embodiments provide several schemes regarding how the UE selects the number of beams.

[0078] Option 1

[0079] As stated above, the BS may transmit to the UE configuration information (e.g., paramCombination as specified in 3GPP standard documents) indicating the first codebook parameter configuration for CSI reporting using more than 32 CSI-RS ports. The first codebook parameter configuration may include a first number of beams (e.g., L value), a first frequency compression ratio (e.g., p...). υ The first non-zero coefficient compression ratio (e.g., β value) and the first non-zero coefficient compression ratio. However, in scheme 1, the UE may not use the first codebook parameter configuration to determine the PMI. Instead, the UE may select a codebook parameter configuration that is different from the first codebook parameter configuration. For example, the UE may select a codebook parameter configuration that includes a number of beams different from (e.g., smaller than) the number of beams configured by the BS. In some cases, the UE may select a codebook parameter configuration regardless of whether it receives a codebook parameter configuration configured by the BS.

[0080] According to some embodiments of Scheme 1, the UE can select a codebook parameter configuration from multiple predefined candidate codebook parameter configurations, where each predefined candidate codebook parameter configuration may include a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio. For example, the multiple predefined candidate codebook parameter configurations may be those codebook parameter configurations included in Table 1, which may be specified in 3GPP standard documents. The number of beams selected by the UE is the corresponding number of beams included in the selected codebook parameter configuration. The UE can determine the PMI corresponding to a codebook used for CSI reporting with more than 32 ports based on the selected codebook parameter configuration.

[0081] In such embodiments, the UE may report an index of the selected codebook parameter configuration. For example, the PMI reported by the UE may include an indication of the index of the selected codebook parameter configuration. For instance, if multiple predefined candidate codebook parameter configurations are the eight codebook parameter configurations in Table 1, the index of the selected codebook parameter configuration (i.e., the value of "paramCombination") may be one of 0 to 7, and therefore the PMI reported by the UE may include a 3-bit indication of any of the eight codebook parameter configurations in Table 1. In such embodiments, the number of beams selected by the UE may be indicated by the index of the selected codebook parameter configuration reported by the UE.

[0082] According to some other embodiments of Scheme 1, the BS can (e.g., via RRC signaling) configure a subset of multiple predefined candidate codebook parameter configurations for the UE, wherein each predefined candidate codebook parameter configuration may include a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio. For example, the BS may transmit configuration information indicating one or more indices of the multiple predefined candidate codebook parameter configurations. For example, the multiple predefined candidate codebook parameter configurations may be those codebook parameter configurations included in Table 1, which may be specified in the 3GPP standard document, and the BS may transmit configuration information indicating one or more indices (i.e., the value of "paramCombination") of the one or more codebook parameter configurations included in Table 1, such that the subset configured for the UE includes one or more codebook parameter configurations corresponding to the indicated indices.

[0083] The UE can select codebook parameter configurations from a subset configured by the BS. The number of beams selected by the UE is the corresponding number of beams included in the selected codebook parameter configuration. The UE can determine the PMI corresponding to a codebook used for CSI reporting with more than 32 ports based on the selected codebook parameter configuration.

[0084] In such embodiments, the UE may report the index of a selected codebook parameter configuration from a subset configured by the BS. For example, the PMI reported by the UE may include an indication of the index of the selected codebook parameter configuration. For instance, if the subset configured by the BS includes two codebook parameter configurations from Table 1, the index of the selected codebook parameter configuration may be 0 or 1, and therefore the PMI reported by the UE may include a 1-bit indication of either of the two codebook parameter configurations in the subset. As another example, if the subset configured by the BS includes four codebook parameter configurations from Table 1, the index of the selected codebook parameter configuration may be one of 0 to 3, and therefore the PMI reported by the UE may include a 2-bit indication of either of the four codebook parameter configurations in the subset. In such embodiments, the number of beams selected by the UE may be indicated by the index of the selected codebook parameter configuration reported by the UE.

[0085] Option 2

[0086] As stated above, the BS may transmit to the UE configuration information (e.g., paramCombination as specified in 3GPP standard documents) indicating the first codebook parameter configuration for CSI reporting using more than 32 CSI-RS ports. The first codebook parameter configuration may include a first number of beams (e.g., L value), a first frequency compression ratio (e.g., p...). υ The first non-zero coefficient compression ratio (e.g., β value) and the first non-zero coefficient compression ratio. However, in Scheme 2, the UE can determine the PMI corresponding to the codebook based on the number of beams selected by the UE from multiple candidate beam numbers, the first frequency compression ratio, and the first non-zero coefficient compression ratio. The selected beam number may differ from the first beam number configured by the BS. In some instances, the selected beam number may be less than the first beam number. In some instances, the selected beam number may be greater than the first beam number.

[0087] In some embodiments of scheme 2, the UE may report an index of the selected number of beams to the BS. For example, the PMI reported by the UE may include an indication of the index of the selected number of beams.

[0088] According to some embodiments of this application, each of the plurality of candidate beam numbers is within {2, 4, 6}.

[0089] According to some embodiments of this application, each of the plurality of candidate beam numbers is within {2, 4, 6} and less than or equal to the first beam number configured by the BS. For example, when the first beam number is 4, the plurality of candidate beam numbers can be 2 and 4, which can have indices 0 and 1 respectively. Then, the PMI reported by the UE can include a 1-bit indication for indicating any of the 2 candidate beam numbers. As another example, when the first beam number is 6, the plurality of candidate beam numbers can be {2, 4, 6}, which can have indices 0, 1, and 2 respectively. Then, the PMI reported by the UE can include a 2-bit indication for indicating any of the 3 candidate beam numbers.

[0090] According to some embodiments of this application, the number of the plurality of candidate beams may be a predetermined integer in the range of [2, L], where L is the first number of beams configured in the BS.

[0091] For example, when the first number of beams is 4, the number of candidate beams can be {2, 3, 4}, which can have indices 0, 1, and 2 respectively. Then, the PMI reported by the UE can include a 2-bit indication to indicate any of the 3 candidate beam numbers.

[0092] As another example, when the first number of beams is 6, the number of candidate beams can be {2, 3, 4, 6}, which can have indices 0, 1, 2, and 3 respectively. The PMI reported by the UE can then include a 2-bit indication to indicate any of the 4 candidate beam numbers. Alternatively, when the first number of beams is 6, the number of candidate beams can be {2, 3, 4, 5, 6}, which can have indices 0, 1, 2, 3, and 4 respectively. The PMI reported by the UE can then include a 3-bit indication to indicate any of the 5 candidate beam numbers.

[0093] In the examples illustrated in Table 1, when the number of beams is 6, there is no corresponding frequency compression ratio and non-zero coefficient compression ratio for Layer 3 or Layer 4 CSI reports. To support PMI determination for Layer 3 or Layer 4 CSI reports in scenarios where the BS is configured with 6 beams, or the UE selects 6 beams, or the BS is configured with 6 beams but the UE selects a non-6 beam number, it is necessary to define corresponding frequency compression ratios and non-zero coefficient compression ratios. According to some embodiments of this disclosure, when the number of beams is 6, the corresponding frequency compression ratio for Layer 3 or Layer 4 CSI reports can be half that for Layer 1 or Layer 2 CSI reports, and the corresponding non-zero coefficient compression ratio for Layer 3 or Layer 4 CSI reports can be the same as that for Layer 1 or Layer 2 CSI reports. Table 3 below illustrates examples of codebook parameter configurations including corresponding frequency compression ratios and non-zero coefficient compression ratios for Layer 3 or Layer 4 CSI reports for a beam number of 6.

[0094] Table 3: L, β, and p υ Codebook parameter configuration

[0095]

[0096] Based on the number of beams selected by the UE according to Scheme 1 or Scheme 2, and the frequency compression ratio and non-zero coefficient compression ratio associated with the number of beams selected by the UE, the UE can determine the PMI corresponding to the codebook used for CSI reporting with more than 32 ports, and transmit a CSI report containing the PMI to the BS. When using Scheme 1, the frequency compression ratio and non-zero coefficient compression ratio associated with the number of beams selected by the UE are those compression ratios included in the codebook parameter configuration selected by the UE. When using Scheme 2, the frequency compression ratio and non-zero coefficient compression ratio associated with the number of beams selected by the UE are those compression ratios included in the codebook parameter configuration configured by the BS.

[0097] In some embodiments, the UE may use the same formula specified in TS 38.214 to determine the PMI, but using the number of beams selected by the UE (e.g., expressed as: ) and the frequency compression ratio and non-zero coefficient compression ratio associated with the number of beams selected by the UE (e.g., expressed as respectively). and () as input.

[0098] For example, for each layer, the indicator i 1,7,l The number of bits in the bitmap (which indicates non-zero coefficients) can be changed to ,in υ is the level index, which can be 1, 2, 3 or 4.

[0099] As another example, used to indicate i 2,4,l The number of bits (indicating the magnitude of the non-zero coefficient) can be changed to And used to indicate i 2,5,l The number of bits (indicating the phase of non-zero coefficients) can be changed to ,in It is the maximum number of non-zero coefficients, which is [number] in the case of one layer used for CSI reporting. Or, in cases where more than one layer is used for CSI reporting, 2 .

[0100] As another example, used to indicate i 1,8,l The number of bits (indicating the strongest coefficient) can be changed when only one layer is used for CSI reporting. Or, in cases where more than one layer is used for CSI reporting, change to each layer as follows: .

[0101] As another example, it is used to indicate the initial position index i 1,5 The number of bits (used to select the frequency base, and only present when N3 > 19) can be changed to ,in υ is the level index, which can be 1, 2, 3 or 4.

[0102] As another example, used to indicate i 1,6 The number of bits (used to select the frequency base) can be changed for each layer of the total layers if N3≤19. Alternatively, if N3 > 19, then for each layer of the total layers, ,in υ is the level index, which can be 1, 2, 3 or 4.

[0103] To support beam number selection on the UE side, the UE needs to determine the appropriate beam number from multiple candidate beam numbers. This can increase the implementation complexity of the UE. Therefore, supporting beam number selection can be a new capability for the UE. In some embodiments of this disclosure, the UE can transmit capability information indicating whether the UE supports beam number selection. In some cases, since assuming a candidate beam number each time can introduce additional complexity, the UE can transmit capability information indicating the number of candidate beam numbers used for beam number selection supported by the UE. For example, in embodiment 2, if the multiple candidate beam numbers are {2, 3, 4, 6}, then the UE can transmit capability information indicating that the UE supports 4 candidate beam numbers for beam number selection. Based on the above capability information, the BS can enable CSI reporting with dynamic beam number selection only for UEs with this capability.

[0104] Although the selection of the number of beams on the UE side is described based on the eType2 codebook with more than 32 ports, due to L, β, and p υ The codebook parameter configuration is similar for both codebooks, but with different values, so it can also be used for eType2 codebooks that predict PMIs with more than 32 ports.

[0105] In existing 5G systems, for the eType 2 codebook, L beam groups are selected from N1N2 beam groups, where each beam group consists of O1O2 overlapping beams, and then one beam is selected from each selected beam group, such that L beams are selected for CSI reporting. The L selected beams can be determined by index i. 1,1 andi 1,2 Instructions, where i 1,1 = , Used to indicate i 1,1 The number of digits can be equal to Used to indicate i 1,2 The number of digits can be equal to .

[0106] For CSI reporting using more than 32 CSI-RS ports, larger values ​​for N1 and N2 can be used, which can increase CSI reporting overhead (e.g., for indicating i...). 1,2 (Number of bits). To reduce CSI reporting overhead, a new beamgrouping scheme with a scaled number of beam groups and a scaled number of beams per group can be introduced. The new beamgrouping scheme can be used with the number of beams configured by the BS, or it can be used in conjunction with the dynamic beam number selection according to the aforementioned scheme 1 or scheme 2 to further reduce CSI reporting overhead.

[0107] In the new beamgrouping scheme, the PMI corresponding to the codebook (e.g., eType2 codebook) can be determined based on the beamgrouping with a scaled number of beams per beamgroup.

[0108] The new beamgrouping scheme can be implemented by introducing a horizontal scaling factor (e.g., denoted as k1) and a vertical scaling factor (e.g., denoted as k2).

[0109] The number of scaled beams per beam group can be determined based on (e.g., equal to) k1O1k2O2, where O1 is the horizontal oversampling factor of the antenna array and O2 is the vertical oversampling factor of the antenna array. Thus, it can be determined based on (e.g., equal to) The number of beam groups is determined, where N1 is the number of antenna ports in each polarization direction in the horizontal direction of the antenna array, and N2 is the number of antenna ports in each polarization direction in the vertical direction of the antenna array.

[0110] To select L beams for CSI reporting (e.g., L could be the number of beams selected by the BS via higher-layer parameter configuration or by the UE using the method in Scheme 1 or Scheme 2), L beam groups can first be selected from N beam groups, where N is based on It is determined that a beam (e.g., an oversampled beam) can then be selected from each selected beam group consisting of O beams (e.g., oversampled beams), where O is the number of scaled beams in each beam group, which is determined based on k1O1k2O2.

[0111] The selection of L beams can be achieved by indexing i in the codebook. 1,1 andi 1,2 Instructions. i 1,2 ∈ It may also include L beam groups for indicating selection from N beam groups. Ones place. 1,1 It may include a beam selected from a beam group consisting of 0 beams. log2(O) Units digit. The selected beam can include both horizontal and vertical beam indices. For example, when O equals k1O1k2O2, ,in , , and i 1,1 It may include information for indicating a selected beam. log2(k1O1k2O2) Ones.

[0112] k1 and k2 can be determined in several ways.

[0113] According to some embodiments of this disclosure, k1 and k2 have predefined values. For example, when N2=1, k1=2 and k2=1, or k1=4 and k2=1. As another example, when N2>1, k1=2 and k2=2, or k1=4 and k2=4. In other instances, (k1, k2) may have other values, such as (4, 2), (2, 4), or (4, 1).

[0114] According to some embodiments of this disclosure, the BS may transmit information indicating the number of CSI-RS resources used for CSI reporting using more than 32 CSI-RS ports. The number of CSI-RS resources may include a first number of CSI-RS resources in the horizontal direction and a second number of CSI-RS resources in the vertical direction. In such embodiments, k1 may be equal to the first number, and k2 may be equal to the second number. In some embodiments, the information indicating the number of CSI-RS resources may be RRC signaling or MAC CE.

[0115] According to some embodiments of this disclosure, the BS can transmit information indicating the values ​​of k1 and k2. In some embodiments, the information may be RRC signaling or MAC CE. In some embodiments, the k1 or k2 value may be configured from {1, 2, 3, 4}. In some embodiments, a simple extension scheme may be used, where k1=1 and k2=1.

[0116] Table 4-1 below illustrates the methods used to indicate i when using traditional beamgrouping schemes or simple extension schemes. 1,1 andi 1,2 The total number of exemplary positions.

[0117] Table 4-1: Indication of i when using traditional beamgrouping schemes or simple extension schemes 1,1 andi 1,2 Total number of digits

[0118]

[0119] In the examples illustrated in Table 4-1, it is assumed that O1=4 and O2=4. For CSI reporting using 32 CSI-RS ports, a conventional beamgrouping scheme can be used. Taking a beam count of 2 as an example, used to indicate i... 1,1 The number of bits can be log2(O1O2) =4, and used to indicate i 1,2 The number of bits can be =7. Therefore, it is used to indicate i 1,1 andi 1,2 The total number of digits is 11.

[0120] For CSI reports using 64 CSI-RS ports, taking a beam count of 2 as an example, this is used to indicate i 1,1 The number of bits can be log2(O1O2) =4, and used to indicate i 1,2 The number of bits can be =9. Therefore, it is used to indicate i 1,1 andi 1,2 The total number of digits is 13.

[0121] For CSI reports using 128 CSI-RS ports, taking a beam count of 2 as an example, this is used to indicate i 1,1 The number of bits can be log2(O1O2) =4, and used to indicate i 1,2 The number of bits can be =11. Therefore, it is used to indicate i 1,1 andi 1,2 The total number of digits is 15.

[0122] Table 4-2 below illustrates the indications used when using the new beam grouping scheme. 1,1 andi 1,2 The exemplary total number of bits, where k1k2>1, also includes the case of using a conventional beamgrouping scheme for 32 CSI-RS ports for reference and comparison.

[0123] Table 4-2: Indication for i when using the new beam grouping scheme 1,1 andi 1,2 The total number of digits, where k1k2>1

[0124]

[0125]

[0126] In the examples illustrated in Table 4-2, assume O1=4 and O2=4.

[0127] For CSI reports using 64 CSI-RS ports, assuming k1=2 and k2=1, taking a beam count of 2 as an example, this is used to indicate i 1,1 The number of bits can be And used to indicate i 1,2 The number of bits can be =7. Therefore, it is used to indicate i 1,1 andi 1,2 The total number of digits is 12.

[0128] For CSI reports using 128 CSI-RS ports, assuming k1=4 and k2=1, and taking a beam count of 2 as an example, this is used to indicate i 1,1 The number of bits can be And used to indicate i 1,2 The number of bits can be =7. Therefore, it is used to indicate i 1,1 andi 1,2 The total number of digits is 13.

[0129] Comparing Table 4-2 with Table 4-1, it can be seen that when using the new beam grouping scheme, the indicator i is used... 1,1 andi 1,2 The total number of bits is less than that used for indicating i when using a conventional beam grouping scheme. 1,1 andi 1,2 The total number of bits, especially for the case of 6 selected beams and 128 CSI-RS ports. In this case, when k1=4 and k2=1, 12 bits are reduced.

[0130] Although the new beamforming scheme is described based on the eType2 codebook with more than 32 ports, it can also be used with Type2 codebooks with more than 32 ports because the beam selection schemes used for the two codebooks are similar.

[0131] Although the new beamgrouping scheme is described based on an eType2 codebook with more than 32 ports, it can also be used for eType2 codebooks with more than 32 ports for predictive PMI, since the beam selection schemes used for the two codebooks are similar.

[0132] Figure 2 A flowchart illustrating an exemplary method according to aspects of this disclosure. Figure 2 The operation of the method described herein can be performed by a UE as described herein (e.g., Figure 1 The UE (104) or other devices with similar functionality may execute this action. In some implementations, the UE may execute a set of instructions to control the functional elements of the UE to perform the described operation or function.

[0133] like Figure 2 As shown in the diagram, in step 202, the UE can retrieve data from the BS (e.g., Figure 1 The NE 102 (e.g., via RRC signaling) receives configuration information indicating a first codebook parameter configuration for using a first number of CSI-RS ports for CSI reporting, wherein the first number is greater than 32. The first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio.

[0134] In step 204, the UE may determine the PMI based on either a second number of beams selected by the UE or a beam grouping associated with a codebook, each beam group having a scaled number of beams. The PMI may include a codebook index as described in any of the foregoing embodiments.

[0135] In step 206, the UE may transmit a CSI report, wherein the CSI report contains a PMI.

[0136] According to some embodiments of this disclosure, the PMI may include an indication of an index for indicating a second codebook parameter configuration, the second codebook parameter configuration including the second number of beams, frequency compression ratio, and non-zero coefficient compression ratio selected by the UE.

[0137] In some embodiments, the second codebook parameter configuration may be selected by the UE from a plurality of predefined candidate codebook parameter configurations, wherein each predefined candidate codebook parameter configuration includes a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio.

[0138] In some embodiments, the second codebook parameter configuration may be selected by the UE from a subset of multiple predefined candidate codebook parameter configurations, wherein each predefined candidate codebook parameter configuration includes a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio. The subset may be configured by the BS for the UE. For example, the subset may be indicated by configuration information received in step 202, or by other configuration information (e.g., via other RRC signaling).

[0139] According to some embodiments of this disclosure, the PMI may include an indication of an index for indicating the number of second beams selected by the UE from a plurality of candidate beam numbers, wherein the PMI is determined based on the number of second beams selected by the UE, the first frequency compression ratio, and the first non-zero coefficient compression ratio.

[0140] In some embodiments of this disclosure, each of the plurality of candidate beam numbers is within {2, 4, 6}.

[0141] In some embodiments of this disclosure, the number of the plurality of candidate beams is a predetermined integer in the range of [2, L], where L is the number of the first beam.

[0142] According to some embodiments of this disclosure, when the first number of beams is 6, the first frequency compression ratio for 3-layer or 4-layer CSI reporting is half the first frequency compression ratio for 1-layer or 2-layer CSI reporting, and the first non-zero coefficient compression ratio for 3-layer or 4-layer CSI reporting is the same as the first non-zero coefficient compression ratio for 1-layer or 2-layer CSI reporting.

[0143] According to some embodiments of this disclosure, the UE may transmit to the BS capability information indicating whether the UE supports beam number selection or indicating the number of candidate beams supported by the UE for beam number selection.

[0144] According to some embodiments of this disclosure, the number of scaled beams in each beam group can be determined based on k1O1k2O2, where O1 is the horizontal oversampling factor of the antenna array having a first number of CSI-RS ports, and O2 is the vertical oversampling factor of the antenna array, k1 is the horizontal scaling factor, and k2 is the vertical scaling factor.

[0145] In some embodiments, the PMI may include L beam groups indicating selection from N beam groups. The first codebook index of the unit digit, where L is the number of the first or second beams selected by the UE, and N is based on Determine that N1 is the number of antenna ports in each polarization direction in the horizontal direction of the antenna array, and N2 is the number of antenna ports in each polarization direction in the vertical direction of the antenna array.

[0146] In some embodiments, the PMI may include a feature indicating selection from a beam group consisting of O beams. log2(O) The second codebook index of the unit digit, where O is the number of scaled beams per beam group.

[0147] In some embodiments, k1 and k2 have predefined values. For example, when N2=1, k1=2 and k2=1, or k1=4 and k2=1. As another example, when N2>1, k1=2 and k2=2, or k1=4 and k2=4.

[0148] In some embodiments, the UE may receive from the BS information indicating a second number of CSI-RS resources for CSI reporting using the first number of CSI-RS ports, wherein the second number of CSI-RS resources includes a third number of CSI-RS resources in the horizontal direction and a fourth number of CSI-RS resources in the vertical direction, k1 equals the third number, and k2 equals the fourth number. For example, the information may be RRC signaling or MAC CE.

[0149] In some embodiments, the UE may receive information indicating the values ​​of k1 and k2 from the BS. For example, the information may be RRC signaling or MAC CE.

[0150] Figure 3 A flowchart illustrating an exemplary method according to aspects of this disclosure. Figure 3 The operation of the methods described herein can be performed by BS (e.g., as described in this document). Figure 1 This can be performed by NE 102 or other devices with similar functionality. In some implementations, the BS can execute a set of instructions to control the functional elements of the BS to perform the described operations or functions.

[0151] like Figure 3 As shown in the diagram, in step 302, the BS can send a message to the UE (e.g., Figure 1 The UE 104 transmits configuration information for a first codebook parameter configuration for using a first number of CSI-RS ports for CSI reporting, wherein the first number is greater than 32. The first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio.

[0152] In step 304, the BS may receive a CSI report, wherein the CSI report contains a PMI based on either a second number of beams selected by the UE or a beam grouping associated with a codebook, each beam group having a scaled number of beams.

[0153] According to some embodiments of this disclosure, the BS may receive capability information from the UE indicating whether the UE supports beam number selection or indicating the number of candidate beams supported by the UE for beam number selection.

[0154] As in the foregoing embodiments (e.g., regarding...) Figure 2 All definitions and operations described in [the original text] relating to the first codebook parameter configuration, PMI, the number of second beams selected by the UE, and beamgrouping with scaled beam numbers per beam group, are also applicable here. Therefore, for simplicity, details are omitted.

[0155] Figure 4 An example of a UE 400 according to aspects of this disclosure is described. UE 400 may include at least one processor 402 and at least one memory 404. Additionally, UE 400 may also include one or more of at least one controller 406 or at least one transceiver 408. The processor 402, memory 404, controller 406, or transceiver 408, or various combinations thereof, or various components thereof, may be examples of components for performing the various aspects of this disclosure as described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, electrically).

[0156] Processor 402, memory 404, controller 406, or transceiver 408, or various combinations or components thereof, may be implemented in hardware (e.g., a circuit system). The hardware may include processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or other programmable logic devices, or any combination thereof, configured to or otherwise support components for performing the functions described in this disclosure.

[0157] Processor 402 may include intelligent hardware devices (e.g., a general-purpose processor, DSP, CPU, ASIC, FPGA, or any combination thereof). In some embodiments, processor 402 may be configured to operate memory 404. In some other embodiments, memory 404 may be integrated into processor 402. Processor 402 may be configured to execute computer-readable instructions stored in memory 404 to cause UE 400 to perform various functions of this disclosure.

[0158] Memory 404 may include volatile or non-volatile memory. Memory 404 may store computer-readable, computer-executable code containing instructions that, when executed by processor 402, cause UE 400 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as memory 404 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media, wherein the communication media includes any medium that facilitates the transfer of a computer program from one place to another. Non-transitory storage media may be any available medium accessible by a general-purpose or special-purpose computer.

[0159] In some embodiments, processor 402 and memory 404 coupled to processor 402 may be configured to cause UE 400 to perform one or more of the functions described herein (e.g., instructions stored in memory 404 are executed by processor 402). For example, processor 402 may support wireless communication at UE 400 according to examples disclosed herein. UE 400 may be configured to support components for performing the methods described in embodiments of this disclosure. In an embodiment, processor 402 may be configured to cause UE 400 to: receive configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; determine a PMI based on either a second number of beams selected by the UE or beam groups associated with the codebook, each beam group having a scaled number of beams; and transmit a CSI report, wherein the CSI report includes the PMI.

[0160] Controller 406 manages the input and output signals of UE 400. Controller 406 can also manage peripheral devices not integrated into UE 400. In some embodiments, controller 406 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some embodiments, controller 406 may be implemented as part of processor 402.

[0161] In some embodiments, UE 400 may include at least one transceiver 408. In other embodiments, UE 400 may have more than one transceiver 408. Transceiver 408 may represent a wireless transceiver. Transceiver 408 may include one or more receiver chains 410, one or more transmitter chains 412, or a combination thereof.

[0162] Receiver chain 410 may be configured to receive signals (e.g., control information, data, packets) via a wireless medium. For example, receiver chain 410 may include one or more antennas for receiving signals in the air or via a wireless medium. Receiver chain 410 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. Receiver chain 410 may include at least one demodulator configured to demodulate the received signal and obtain transmitted data by reversing the modulation technique applied during signal transmission. Receiver chain 410 may include at least one decoder for decoding the demodulated signal to receive transmitted data.

[0163] Transmitter chain 412 can be configured to generate and transmit signals (e.g., control information, data, packets). Transmitter chain 412 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase shift keying (PSK) or quadrature amplitude modulation (QAM). Transmitter chain 412 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. Transmitter chain 412 may also include one or more antennas for transmitting the amplified signal into the air or a wireless medium.

[0164] Figure 5 An example of a processor 500 according to aspects of this disclosure is described. Processor 500 may be an example of a processor configured to perform various operations according to the examples described herein. Processor 500 may include at least one controller 502 configured to perform various operations according to the examples described herein. Processor 500 may optionally include at least one memory 504, which may be, for example, a layer 1 (L1), layer 2 (L2), or layer 3 (L3) cache. Additionally or alternatively, processor 500 may optionally include one or more arithmetic logic units (ALUs) 506. One or more of these components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses).

[0165] Processor 500 may be a processor chipset and includes a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, and reading) according to the examples described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory native to the processor chipset (e.g., processor 500) or included in the processor chipset), or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase-change memory (PCM), and others).

[0166] Controller 502 can be configured to manage and coordinate various operations of processor 500 (e.g., signaling, receiving, acquiring, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, and reading) to enable processor 500 to support various operations according to the examples described herein. For example, controller 502 can operate as a control unit of processor 500, generating control signals that manage the operation of various components of processor 500. These control signals include enabling or disabling functional units, selecting data paths, initiating memory accesses, and coordinating operation timing.

[0167] Controller 502 may be configured to fetch (e.g., fetch, retrieve, receive) instructions from memory 504 and determine subsequent instructions to be executed to enable processor 500 to support various operations according to the examples described herein. Controller 502 may be configured to track the memory addresses of instructions associated with memory 504. Controller 502 may be configured to decode instructions to determine the operations to be performed and the operands involved. For example, controller 502 may be configured to interpret instructions and determine control signals to be output to other components of processor 500 to enable processor 500 to support various operations according to the examples described herein. Alternatively or additionally, controller 502 may be configured to manage data flow within processor 500. Controller 502 may be configured to control data transfers between registers, ALU, and other functional units of processor 500.

[0168] Memory 504 may include one or more caches (e.g., memory local to or included in processor 500, or other memory such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc.). In some embodiments, memory 504 may reside within or on the processor chipset (e.g., local to processor 500). In some other embodiments, memory 504 may reside outside the processor chipset (e.g., remotely from processor 500).

[0169] Memory 504 may store computer-readable, computer-executable code containing instructions that, when executed by processor 500, cause processor 500 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. Controller 502 and / or processor 500 may be configured to execute computer-readable instructions stored in memory 504 to cause processor 500 to perform various functions. For example, processor 500 and / or controller 502 may be coupled to or coupled to memory 504, and processor 500, controller 502, and memory 504 may be configured to perform the various functions described herein. In some instances, processor 500 may include multiple processors, and memory 504 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, and the processors and memories may be individually or collectively configured to perform the various functions described herein.

[0170] One or more ALUs 506 may be configured to support various operations according to the examples described herein. In some embodiments, one or more ALUs 506 may reside within or on a processor chipset (e.g., processor 500). In some other embodiments, one or more ALUs 506 may reside outside the processor chipset (e.g., processor 500). One or more ALUs 506 may perform one or more calculations on data, such as addition, subtraction, multiplication, and division. For example, one or more ALUs 506 may receive input operands and opcodes, the opcodes determining the operation to be performed. One or more ALUs 506 may be configured with various logic and arithmetic circuitry (including adders, subtractors, shifters, and logic gates) to process and manipulate data according to the operation. Alternatively, one or more ALU 506s may support logical operations such as AND, OR, XOR, NOR, and NAND, thereby enabling one or more ALU 506s to handle conditional operations, comparisons, and bitwise operations.

[0171] Processor 500 may support wireless communication according to examples disclosed herein. Processor 500 may be configured or operable to support components for performing the methods described in embodiments of this disclosure. In an embodiment, controller 502 may cause processor 500 to: receive configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; determine a PMI based on either a second number of beams selected by processor 500 or a beam group associated with the codebook, each beam group having a scaled number of beams; and transmit a CSI report, wherein the CSI report includes the PMI.

[0172] Figure 6 An example of BS 600 according to aspects of this disclosure is described. BS 600 may include at least one processor 602 and at least one memory 604. Additionally, BS 600 may also include one or more of at least one controller 606 or at least one transceiver 608. Processor 602, memory 604, controller 606, or transceiver 608, or various combinations thereof, or various components thereof, may be examples of components for performing the various aspects of this disclosure as described herein. These components may be coupled via one or more interfaces (e.g., operatively, communicatively, functionally, electronically, electrically).

[0173] Processor 602, memory 604, controller 606, or transceiver 608, or various combinations or components thereof, may be implemented in hardware (e.g., a circuit system). The hardware may include processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or other programmable logic devices, or any combination thereof, configured to or otherwise support components for performing the functions described in this disclosure.

[0174] Processor 602 may include intelligent hardware devices (e.g., a general-purpose processor, DSP, CPU, ASIC, FPGA, or any combination thereof). In some embodiments, processor 602 may be configured to operate memory 604. In some other embodiments, memory 604 may be integrated into processor 602. Processor 602 may be configured to execute computer-readable instructions stored in memory 604 to cause BS 600 to perform various functions of this disclosure.

[0175] Memory 604 may comprise volatile or non-volatile memory. Memory 604 may store computer-readable, computer-executable code containing instructions that, when executed by processor 602, cause BS 600 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as memory 604 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media, wherein the communication media includes any medium that facilitates the transfer of a computer program from one place to another. Non-transitory storage media may be any available medium accessible by a general-purpose or special-purpose computer.

[0176] In some implementations, processor 602 and memory 604 coupled to processor 602 may be configured to cause BS 600 to perform one or more of the functions described herein (e.g., processor 602 executing instructions stored in memory 604). For example, processor 602 may support wireless communication at BS 600 according to examples disclosed herein. BS 600 may be configured to support components for performing the methods described in embodiments of this disclosure. In an embodiment, processor 602 may be configured to cause BS 600 to: transmit configuration information indicating a first codebook parameter configuration for CSI reporting using a first number of CSI-RS ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio; and receive CSI reports, wherein the CSI reports include a PMI based on either a second number of beams selected by the UE or beamgroups associated with the codebook, each beamgroup having a scaled number of beams.

[0177] Controller 606 manages the input and output signals of BS 600. Controller 606 can also manage peripheral devices not integrated into BS 600. In some embodiments, controller 606 may utilize an operating system such as iOS®, ANDROID®, WINDOWS®, or other operating systems. In some embodiments, controller 606 may be implemented as part of processor 602.

[0178] In some embodiments, the BS 600 may include at least one transceiver 608. In other embodiments, the BS 600 may have more than one transceiver 608. The transceiver 608 may represent a wireless transceiver. The transceiver 608 may include one or more receiver chains 610, one or more transmitter chains 612, or a combination thereof.

[0179] Receiver chain 610 may be configured to receive signals (e.g., control information, data, packets) via a wireless medium. For example, receiver chain 610 may include one or more antennas for receiving signals in the air or via a wireless medium. Receiver chain 610 may include at least one amplifier (e.g., a low-noise amplifier (LNA)) configured to amplify the received signal. Receiver chain 610 may include at least one demodulator configured to demodulate the received signal and obtain transmitted data by reversing the modulation technique applied during signal transmission. Receiver chain 610 may include at least one decoder for decoding the demodulated signal to receive the transmitted data.

[0180] Transmitter chain 612 can be configured to generate and transmit signals (e.g., control information, data, packets). Transmitter chain 612 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques, such as amplitude modulation (AM), frequency modulation (FM), or digital modulation schemes like phase shift keying (PSK) or quadrature amplitude modulation (QAM). Transmitter chain 612 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over a wireless medium. Transmitter chain 612 may also include one or more antennas for transmitting the amplified signal into the air or a wireless medium.

[0181] The description herein is provided to enable those skilled in the art to make or use this disclosure. Those skilled in the art will understand that various modifications to this disclosure are possible, and that the general principles defined herein can be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE) for wireless communication, comprising: At least one memory; and At least one processor, coupled to and configured to enable the UE to: The receiver receives configuration information for a first codebook parameter configuration for a codebook used for CSI reporting with a first number of Channel State Information CSI Reference Signal (CSI-RS) ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio. The precoding matrix indicator PMI is determined based on either the second number of beams selected by the UE or the beam groups associated with the codebook, each beam group having a scaled number of beams. and Transmit a CSI report, wherein the CSI report contains the PMI.

2. The UE of claim 1, wherein the PMI includes an indication of an index for indicating a second codebook parameter configuration, the second codebook parameter configuration including the second number of beams, frequency compression ratio, and non-zero coefficient compression ratio selected by the UE.

3. The UE according to claim 2, wherein the second codebook parameter configuration is selected by the UE from a plurality of predefined candidate codebook parameter configurations, and each predefined candidate codebook parameter configuration includes a corresponding number of beams, a corresponding frequency compression ratio, and a corresponding non-zero coefficient compression ratio.

4. The UE according to claim 2, wherein the second codebook parameter configuration is selected by the UE from a subset of a plurality of predefined candidate codebook parameter configurations, each predefined candidate codebook parameter configuration including a corresponding number of beams, a corresponding frequency compression ratio and a corresponding non-zero coefficient compression ratio, and the subset is configured for the UE.

5. The UE of claim 1, wherein the PMI includes an indication of an index for indicating the number of second beams selected by the UE from a plurality of candidate beam numbers, wherein the PMI is determined based on the number of second beams selected by the UE, the first frequency compression ratio, and the first non-zero coefficient compression ratio.

6. The UE of claim 5, wherein each of the plurality of candidate beam numbers is within {2, 4, 6}.

7. The UE according to claim 5, wherein the number of the plurality of candidate beams is a predetermined integer in the range of [2, L], where L is the number of the first beams.

8. The UE according to claim 1, wherein when the first number of beams is 6, the first frequency compression ratio for 3-layer or 4-layer CSI reporting is half of the first frequency compression ratio for 1-layer or 2-layer CSI reporting, and the first non-zero coefficient compression ratio for 3-layer or 4-layer CSI reporting is the same as the first non-zero coefficient compression ratio for 1-layer or 2-layer CSI reporting.

9. The UE of claim 1, wherein the at least one processor is further configured to enable the UE to transmit capability information, the capability information indicating whether the UE supports beam number selection or indicating the number of candidate beam numbers supported by the UE for beam number selection.

10. The UE of claim 1, wherein the number of scaled beams per beam group is determined based on k1O1k2O2, where O1 is the horizontal oversampling factor of the antenna array having the first number of CSI-RS ports, and O2 is the vertical oversampling factor of the antenna array, k1 is the horizontal scaling factor, and k2 is the vertical scaling factor.

11. The UE of claim 10, wherein the PMI comprises L beam groups having indications of selection from N beam groups. The first codebook index of the unit digit, where L is the number of the first beam or the number of the second beam selected by the UE, and N is based on It is determined that N1 is the number of antenna ports in each polarization direction in the horizontal direction of the antenna array, and N2 is the number of antenna ports in each polarization direction in the vertical direction of the antenna array.

12. The UE of claim 10, wherein the PMI includes a function indicating selection from a beam group consisting of 0 beams. log2(O) The second codebook index is the unit digit, where O is the number of scaled beams per beam group.

13. The UE according to claim 10, wherein k1 and k2 have predefined values.

14. The UE according to claim 13, wherein: When N2=1, k1=2 and k2=1, or k1=4 and k2=1; or When N2>1, k1=2 and k2=2, or k1=4 and k2=4.

15. The UE of claim 10, wherein the at least one processor is further configured to enable the UE to receive information indicating a second number of CSI-RS resources for CSI reporting using the first number of CSI-RS ports, and the second number of CSI-RS resources includes a third number of CSI-RS resources in the horizontal direction and a fourth number of CSI-RS resources in the vertical direction, k1 being equal to the third number and k2 being equal to the fourth number.

16. The UE of claim 10, wherein the at least one processor is further configured to enable the UE to receive information indicating the values ​​of k1 and k2.

17. The UE according to claim 15 or 16, wherein the information is Radio Resource Control (RRC) signaling or Media Access Control (MAC) control element (CE).

18. A processor for wireless communication, comprising: At least one controller, coupled to at least one memory and configured to enable the processor to: The receiver receives configuration information for a first codebook parameter configuration for a codebook used for CSI reporting with a first number of Channel State Information CSI Reference Signal (CSI-RS) ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio. The precoding matrix indicator PMI is determined based on either a second number of beams selected by the processor or a beam grouping with a scaled number of beams per beam group associated with the codebook. and Transmit a CSI report, wherein the CSI report contains the PMI.

19. A base station (BS) for wireless communication, comprising: At least one memory; and At least one processor, coupled to the at least one memory and configured to enable the BS to: The transmission indication is configured with configuration information for a first codebook parameter configuration for a codebook used for CSI reporting using a first number of Channel State Information CSI Reference Signal (CSI-RS) ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio. and Receive a CSI report, wherein the CSI report contains a precoded matrix indicator (PMI) based on either a second number of beams selected by the user equipment (UE) or a beam group with a scaled number of beams per beam group associated with the codebook.

20. A method performed by a user equipment (UE), the method comprising: The receiver receives configuration information for a first codebook parameter configuration for a codebook used for CSI reporting with a first number of Channel State Information CSI Reference Signal (CSI-RS) ports, wherein the first number is greater than 32, and the first codebook parameter configuration includes a first number of beams, a first frequency compression ratio, and a first non-zero coefficient compression ratio. The precoding matrix indicator PMI is determined based on either the second number of beams selected by the UE or the beam groups associated with the codebook, each beam group having a scaled number of beams. and Transmit a CSI report, wherein the CSI report contains the PMI.

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