# US 2021/0175950 A1 · Beam combining based channel state information (csi) feedback > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0175950 A1 - Document ID: US20210175950A1 - Status: Published application - Kind: A1 - Application number: 17/259,117 - Filed: 2019-08-07 - Published: 2021-06-10 - Earliest claimed: 2018-08-10 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Victor SERGEEV; Alexei Vladimirovich DAVYDOV; Gregory ERMOLAEV; Dmitry DIKAREV - Web page: https://patentgrep.com/patent/US20210175950A1 ## CPC - H04B 7/0469: {taking special antenna structures, e.g. cross polarized antennas into account} - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0486: {taking channel rank into account} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0634: {Antenna weights or vector/matrix coefficients} - H04B: TRANSMISSION ## Abstract User equipment (UE) includes processing circuitry coupled to memory. To configure the UE for channel state information (CSI) reporting in a 5G network, the processing circuitry is to decode a radio resource control (RRC) configuration message, the RRC configuration message including first configuration information to configure determination of channel quality information (CQI), a rank indicator (RI), and a precoding matrix indicator (PMI) for the CSI reporting. Second configuration information is decoded to configure codebook parameters for a high spatial resolution codebook associated with the PMI. A precoding matrix is determined based on the first configuration information, where a number of coefficients in at least one coefficient vector of the precoding matrix is configured using the second configuration information. CSI is encoded for transmission to a base station, the CSI including the RI and the PMI associated with the determined precoding matrix. ## Claims ### Claim 1 An apparatus comprising: one or more processors, wherein to configure a user equipment (UE) for channel state information (CSI) reporting in a 5G network, the one or more processors are configured to: decode a radio resource control (RRC) configuration message, the RRC configuration message including first configuration information to configure determination of channel quality information (CQI), a rank indicator (RI), and a precoding matrix indicator (PMI) for the CSI reporting; decode second configuration information to configure codebook parameters for a high spatial resolution codebook associated with the PMI; determine a precoding matrix based on the first configuration information, wherein a number of coefficients in at least one coefficient vector of the precoding matrix is configured using the second configuration information; and encode CSI for transmission to a base station, the CSI including the RI and the PMI associated with the determined precoding matrix. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the one or more processors are configured to: perform a linear combination of mutually orthogonal discrete Fourier transform (DFT) beams to generate the precoding matrix. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein a number of the mutually orthogonal DFT beams is configured for each rank of a plurality of available precoding matrix ranks based on the first configuration information. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the second configuration information configures a maximum number of vector coefficients for a first transmission layer of a plurality of available transmission layers, and wherein the one or more processors are configured to: decode third configuration information configuring a maximum number of vector coefficients for a second transmission layer of the plurality of available transmission layers. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the one or more processors are configured to: determine the precoding matrix further based on the second and third configuration information, wherein a number of coefficients in the first transmission layer of the precoding matrix is configured using the second configuration information, and a number of coefficients in the second transmission layer of the precoding matrix is configured using the third configuration information. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the precoding matrix is a rank 2 precoding matrix and the second configuration information configures a maximum number of vector coefficients per transmission layer of a plurality of available transmission layers. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the precoding matrix is a rank 1 or rank 2 precoding matrix, and the second configuration information configures a maximum number of vector coefficients used within the precoding matrix. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the one or more processors are configured to: configure a subset of the coefficients in the at least one coefficient vector of the precoding matrix to a value of 0 based on the second configuration information. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the coefficients include one or more of the following: a quantization scheme of phase coefficients; a quantization scheme of sub-band amplitude coefficients; or a quantization scheme of wideband amplitude coefficients ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the precoding matrix is a rank 2 precoding matrix including a first subset of non-zero amplitude coefficients and a second subset of zero amplitude coefficients, and wherein a number of coefficients in each of the first and second subsets is based on the second configuration information. ### Claim 11 (depends on 1) The apparatus of claim 1, further comprising transceiver circuitry coupled to the one or more processors; and, one or more antennas coupled to the transceiver circuitry. ### Claim 12 An apparatus comprising: one or more processors configured to cause of a base station (BS) operating in a 5G network to: encode a radio resource control (RRC) configuration message, the RRC configuration message including first configuration information to configure determination of channel quality information (CQI), a rank indicator (RI), and a precoding matrix indicator (PMI) for channel state information (CSI) reporting by a user equipment (LIE); encode second configuration information for transmission to the UE, the second configuration information to configure codebook parameters for a high spatial resolution codebook associated with the PMI; and decode CSI received from the UE, the CSI including the RI and the PMI, wherein the PMI is based on a precoding matrix determined based on the first configuration information and a number of coefficients in at least one coefficient vector of the precoding matrix is configured using the second configuration information. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the second configuration information configures a maximum number of vector coefficients for a first transmission layer of a plurality of available transmission layers, and wherein the one or more processors further cause the BS to: encode third configuration information for transmission to the UE, the third configuration information configuring a maximum number of vector coefficients for a second transmission layer of the plurality of available transmission layers. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the precoding matrix is determined further based on the second and third configuration information, wherein a number of coefficients in the first transmission layer of the precoding matrix is configured using the second configuration information, and a number of coefficients in the second transmission layer of the precoding matrix is configured using the third configuration information. ### Claim 15 A user equipment (UE) comprising: one or more memory mediums storing program instructions; and one or more processors, the instructions to configure the one or more processors for performing channel state information (CSI) reporting in a 5G network and to cause the UE to: decode a radio resource control (RRC) configuration message, the RRC configuration message including first configuration information to configure determination of channel quality information (CQI), a rank indicator (RI), and a precoding matrix indicator (PMI) for the CSI reporting; decode second configuration information to configure codebook parameters for a high spatial resolution codebook associated with the PMI; determine a precoding matrix based on the first configuration information, wherein a number of coefficients in at least one coefficient vector of the precoding matrix is configured using the second configuration information; and encode CSI for transmission to a base station, the CSI including the RI and the PMI associated with the determined precoding matrix. ### Claim 16 (depends on 15) The UE of claim 15, wherein executing the instructions further cause the UE to: perform a linear combination of mutually orthogonal discrete Fourier transform (DFT) beams to generate the precoding matrix. ### Claim 17 (depends on 16) The UE of claim 16, wherein a number of the DFT beams is configured for each rank of a plurality of available precoding matrix ranks based on the first configuration information. ### Claim 18 (depends on 15) The UE of claim 15, wherein the second configuration information configures a maximum number of vector coefficients for a first transmission layer of a plurality of available transmission layers, and wherein executing the instructions further cause the UE decode third configuration information configuring a maximum number of vector coefficients for a second transmission layer of the plurality of available transmission layers. ### Claim 19 (depends on 18) The UE of claim 18, wherein executing the instructions further cause the UE to: determine the precoding matrix further based on the second and third configuration information, wherein a number of coefficients in the first transmission layer of the precoding matrix is configured using the second configuration information, and a number of coefficients in the second transmission layer of the precoding matrix is configured using the third configuration information. ### Claim 20 (depends on 15) The UE of claim 15, wherein the precoding matrix is a rank 2 precoding matrix and the second configuration information configures a maximum number of vector coefficients per transmission layer of a plurality of available transmission layers.