# US 11,909,466 B2 · Channel state information feedback in wireless communication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,466 B2 - Document ID: US11909466B2 - Status: Granted - Kind: B2 - Application number: 17/403,497 - Filed: 2021-08-16 - Published: 2021-12-02 - Granted: 2024-02-20 - Earliest claimed: 2019-02-15 - Assignees: Zte Corporation - Applicants: ZTE Corporation - Inventors: Hao Wu; Yong Li; Guozeng Zheng; Zhaohua Lu; Yu Ngok Li - Web page: https://patentgrep.com/patent/US11909466B2 ## CPC - H04B 7/0417: Feedback systems - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/063: {Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 7/0645: {Variable feedback} - H04B: TRANSMISSION ## Abstract Methods, systems, and devices for reducing channel state information feedback channel overhead by compressing coefficients of precoding vectors and reporting a subset of the compressed coefficients based on several parameters including network-signaled parameters. Some embodiments may be used in wireless communication embodiments in which channel state information from many layers and many frequency domain units need to be reported. ## Claims ### Claim 1 A method for wireless communication, comprising: generating, by a wireless device, a channel state information (CSI) feedback report, wherein a first part of the CSI feedback report includes a channel quality indicator (CQI), a rank indicator (RI), and an indication of a number of non-zero coefficients across a plurality of layers, wherein a second part of the CSI feedback report includes a precoding matrix indicator (PMI) determined based on a first plurality of L basis vectors, a second plurality of M basis vectors, and a number of non-zero coefficients for each layer of the plurality of layers, wherein the number of non-zero coefficients for each layer is smaller than or equal to K0 non-zero coefficients, wherein K0 is determined based on at least one of L or M, wherein L, M, and K0 are integers; and transmitting, by the wireless device, the CSI feedback report to a wireless node. ### Claim 2 (depends on 1) The method of claim 1, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 3 (depends on 1) The method of claim 1, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on a maximum number of layers. ### Claim 4 (depends on 3) The method of claim 3, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 5 (depends on 1) The method of claim 1, wherein a value of K0 for a layer of rank R is equal to the value of K0 for a layer of rank R0, wherein R>R0, and wherein R0 is greater than or equal to 1. ### Claim 6 (depends on 1) The method of claim 1, wherein at least one of L, M, or K0 is based on a network configuration parameter. ### Claim 7 A method for wireless communication, comprising: receiving, by a wireless node, a channel state information (CSI) feedback report from a wireless device, wherein a first part of the CSI feedback report includes a channel quality indicator (CQI), a rank indicator (RI), and an indication of a number of non-zero coefficients across a plurality of layers, wherein a second part of the CSI feedback report includes a precoding matrix indicator (PMI) determined based on a first plurality of L basis vectors, a second plurality of M basis vectors, and a number of non-zero coefficients for each layer of the plurality of layers, wherein the number of non-zero coefficients for each layer is smaller than or equal to K0 non-zero coefficients, wherein K0 is determined based on at least one of L or M, and wherein L, M, and K0 are integers. ### Claim 8 (depends on 7) The method of claim 7, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 9 (depends on 7) The method of claim 7, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on a maximum number of layers. ### Claim 10 (depends on 9) The method of claim 9, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 11 (depends on 7) The method of claim 7, wherein a value of K0 for a layer of rank R is equal to the value of K0 for a layer of rank R0, wherein R>R0, and wherein R0 is greater than or equal to 1. ### Claim 12 (depends on 7) The method of claim 7, wherein at least one of L, M, or K0 is based on a network configuration parameter. ### Claim 13 A device for wireless communication, comprising a processor configured to: generate a channel state information (CSI) feedback report, wherein a first part of the CSI feedback report includes a channel quality indicator (CQI), a rank indicator (RI), and an indication of a number of non-zero coefficients across a plurality of layers; wherein a second part of the CSI feedback report includes a precoding matrix indicator (PMI) indicating a precoding matrix determined based on a first plurality of L basis vectors, a second plurality of M basis vectors, and a number of non-zero coefficients for each layer of the plurality of layers, wherein the number of non-zero coefficients for each layer is smaller than or equal to K0 non-zero coefficients, wherein K0 is determined based on at least one of L or M, wherein L, M, and K0 are integers; and transmit the CSI feedback report to a wireless node. ### Claim 14 (depends on 13) The device of claim 13, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 15 (depends on 13) The device of claim 13, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on a maximum number of layers. ### Claim 16 (depends on 15) The device of claim 15, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 17 (depends on 13) The device of claim 13, wherein a value of K0 for a layer of rank R is equal to the value of K0 for a layer of rank R0, wherein R>R0, and wherein R0 is greater than or equal to 1. ### Claim 18 (depends on 13) The device of claim 13, wherein at least one of L, M, or K0 is based on a network configuration parameter. ### Claim 19 A device for wireless communication, comprising a processor configured to: receive a channel state information (CSI) feedback report from a wireless device, wherein a first part of the CSI feedback report includes a channel quality indicator (CQI), a rank indicator (RI), and an indication of a number of non-zero coefficients across a plurality of layers, and wherein a second part of the CSI feedback report includes a precoding matrix indicator (PMI) indicating a precoding matrix determined based on a first plurality of L basis vectors, a second plurality of M basis vectors, and a number of non-zero coefficients for each layer of the plurality of layers, wherein the number of non-zero coefficients for each layer is smaller than or equal to K0 non-zero coefficients, wherein K0 is determined based on at least one of L or M, and wherein L, M, and K0 are integers. ### Claim 20 (depends on 19) The device of claim 19, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 21 (depends on 19) The device of claim 19, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on a maximum number of layers. ### Claim 22 (depends on 21) The device of claim 21, wherein a bit width of the indication of the number of non-zero coefficients across the plurality of layers is based on K0. ### Claim 23 (depends on 19) The device of claim 19, wherein a value of K0 for a layer of rank R is equal to the value of K0 for a layer of rank R0, wherein R>R0, and wherein R0 is greater than or equal to 1. ### Claim 24 (depends on 19) The device of claim 19, wherein at least one of L, M, or K0 is based on a network configuration parameter.