# US 12,191,956 B2 · Channel state information feedback method and apparatus in wireless communications system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,956 B2 - Document ID: US12191956B2 - Status: Granted - Kind: B2 - Application number: 18/338,947 - Filed: 2023-06-21 - Published: 2023-12-28 - Granted: 2025-01-07 - Earliest claimed: 2018-01-12 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Yanchun Li - Web page: https://patentgrep.com/patent/US12191956B2 ## CPC - H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]} - H04B 7/0691: {using subgroups of transmit antennas} - H04B 7/0417: Feedback systems - H04B 7/0634: {Antenna weights or vector/matrix coefficients} - H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection} - H04B 17/336: Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] - H04L 1/0026: {Transmission of channel quality indication} - H04L 1/0028: {Formatting} - H04L 1/1614: {using bitmaps} - H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports} - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 72/542: using measured or perceived quality - H04W 84/12: WLAN [Wireless Local Area Networks] - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A channel state information transmission method, where a responder receives a channel measurement signal sent by an initiator by using one or more transmit antennas, and the responder sends a feedback frame to the initiator based on the channel measurement signal. The feedback frame includes information used to indicate a transmit antenna subset of the initiator and one or more channel state information blocks of a channel between the corresponding transmit antenna subset of the initiator and the responder, where the transmit antenna subset is determined from one or more transmit antennas by using which a channel measurement signal is sent. ## Claims ### Claim 1 A method, comprising: generating, by a responder, a multiple input multiple output (MIMO) beamforming (BF) feedback frame, wherein the MIMO BF feedback frame comprises information indicating a transmit antenna subset of an initiator and one or more channel state information blocks that represent channel state information between the transmit antenna subset of the initiator and one or more receive antennas of the responder, and wherein the transmit antenna subset of the initiator is determined based on one or more user mask fields of a MIMO spatial configuration frame sent by the initiator; and sending, by the responder, the MIMO BF feedback frame. ### Claim 2 (depends on 1) The method according to claim 1, wherein the one or more user mask fields have a one-to-one correspondence with one or more transmit antennas of the initiator, and bits in each user mask field have a one-to-one correspondence to responders. ### Claim 3 (depends on 1) The method according to claim 1, wherein the information indicating the transmit antenna subset is a transmit antenna mask field, and the transmit antenna mask field comprises a bitmap, and wherein each bit in the bitmap corresponds to a respective transmit antenna of one or more transmit antennas, and each bit in the bitmap indicates whether the corresponding transmit antenna is comprised in the transmit antenna subset. ### Claim 4 (depends on 3) The method according to claim 3, wherein for each bit of the bitmap: when a value of the respective bit is 1, it indicates that the corresponding transmit antenna is comprised in the transmit antenna subset; and when a value of the respective bit is 0, it indicates that the corresponding transmit antenna is not comprised in the transmit antenna subset. ### Claim 5 (depends on 1) The method according to claim 1, wherein the information indicating the transmit antenna subset comprises an antenna ID of each transmit antenna in the transmit antenna subset. ### Claim 6 (depends on 1) The method according to claim 1, wherein the MIMO BF feedback frame further comprises one or a combination of more of the following: a responder receive antenna ID corresponding to the transmit antenna subset, a transmit sector ID or an antenna weight vector (AWV) number corresponding to the transmit antenna subset, a spatial stream number corresponding to the transmit antenna subset, or a transmit sector CDOWN value corresponding to the transmit antenna subset; a feedback frame type identifier indicating a type of the MIMO BF feedback frame, wherein the type is a frequency-domain feedback type or a time-domain feedback type; a down-sampling rate Ng, indicating a down-sampling rate of the MIMO BF feedback frame; a number Nc of columns, indicating a number of columns of a channel state information matrix corresponding to the one or more channel state information blocks; a measurement dialog identifier, indicating a measurement dialog in which a channel measurement signal corresponding to the MIMO BF feedback frame is located; a signal strength or a signal-to-noise ratio (SNR), indicating a signal strength or a signal-to-noise ratio (SNR) of each column in the channel state information matrix; a channel state information feedback frame type identifier, indicating whether the one or more channel state information blocks are of a channel time-domain coefficient or a frequency-domain coefficient; a feedback compression type identifier, indicating that the one or more channel state information blocks use a frequency-domain compressed coefficient matrix or a frequency-domain non-compressed coefficient matrix; a codebook information field, indicating a number of quantization bits corresponding to a preset quantization mode used for a value in the one or more channel state information blocks; or a measurement channel frequency-domain identifier corresponding to the feedback, indicating channel bandwidth or a frequency-domain resource block corresponding to the one or more channel state information blocks. ### Claim 7 (depends on 1) The method according to claim 1, wherein the MIMO spatial configuration frame comprises a MIMO selection control element, and the one or more user mask fields are comprised in the MIMO selection control element. ### Claim 8 A method, comprising: sending, by an initiator, a multiple input multiple output (MIMO) spatial configuration frame, wherein the MIMO spatial configuration frame comprises one or more user mask fields; and receiving, by the initiator, a MIMO beamforming (BF) feedback frame, wherein the MIMO BF feedback frame comprises information indicating a transmit antenna subset of the initiator and one or more channel state information blocks that represent channel state information between the transmit antenna subset of the initiator and one or more receive antennas of a responder, and wherein the transmit antenna subset of the initiator is determined based on the one or more user mask fields of the MIMO spatial configuration frame. ### Claim 9 (depends on 8) The method according to claim 8, wherein the one or more user mask fields have a one-to-one correspondence with one or more transmit antennas of the initiator, and bits each one user mask field have a one-to-one correspondence to responders. ### Claim 10 (depends on 8) The method according to claim 8, wherein the MIMO spatial configuration frame comprises a MIMO selection control element, and the one or more user mask fields are comprised in the MIMO selection control element. ### Claim 11 (depends on 8) The method according to claim 8, wherein the information indicating the transmit antenna subset is a transmit antenna mask field, and the transmit antenna mask field comprises a bitmap, and wherein each bit in the bitmap corresponds to a respective transmit antenna of one or more transmit antennas, and each bit in the bitmap indicates whether the corresponding transmit antenna is comprised in the transmit antenna subset. ### Claim 12 (depends on 11) The method according to claim 11, wherein for each bit in the bitmap: when a value of the bit is 1, it indicates that the corresponding transmit antenna is comprised in the transmit antenna subset; and when a value of the bit is 0, it indicates that the corresponding transmit antenna is not comprised in the transmit antenna subset. ### Claim 13 (depends on 8) The method according to claim 8, wherein the information indicating the transmit antenna subset comprises an antenna ID of each transmit antenna in the transmit antenna subset. ### Claim 14 (depends on 8) The method according to claim 8, wherein the MIMO BF feedback frame further comprises one or a combination of more of the following: a responder receive antenna ID corresponding to the transmit antenna subset, a transmit sector ID or an antenna weight vector (AWV) number corresponding to the transmit antenna subset, a spatial stream number corresponding to the transmit antenna subset, or a transmit sector CDOWN value corresponding to the transmit antenna subset; a feedback frame type identifier, indicating a type of the MIMO BF feedback frame, and wherein the type is a frequency-domain feedback type or a time-domain feedback type; a down-sampling rate Ng, indicating a down-sampling rate of the MIMO BF feedback frame; a number Nc of columns, indicating a number of columns of a channel state information matrix corresponding to the one or more channel state information blocks; a measurement dialog identifier, indicating a measurement dialog in which a channel measurement signal corresponding to the MIMO BF feedback frame is located; a signal strength or a signal-to-noise ratio (SNR), indicating a signal strength or a signal-to-noise ratio (SNR) of each column in the channel state information matrix; a channel state information feedback frame type identifier, indicating whether the one or more channel state information blocks are of a channel time-domain coefficient or a frequency-domain coefficient; a feedback compression type identifier, indicating that the one or more channel state information blocks use a frequency-domain compressed coefficient matrix or a frequency-domain non-compressed coefficient matrix; a codebook information field, indicating a number of quantization bits corresponding to a preset quantization mode used for a value in the one or more channel state information blocks; and a measurement channel frequency-domain identifier corresponding to the feedback, indicating channel bandwidth or a frequency-domain resource block corresponding to the one or more channel state information blocks. ### Claim 15 A apparatus in a wireless communications system, the apparatus comprising: a processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, wherein the programming, when executed by the processor, instructing the apparatus to: generate a multiple input multiple output (MIMO) beamforming (BF) feedback frame, wherein the MIMO BF feedback frame comprises information indicating a transmit antenna subset of an initiator and one or more channel state information blocks that represent channel state information between the transmit antenna subset of the initiator and one or more receive antennas of a responder, and wherein the transmit antenna subset of the initiator is determined based on one or more user mask fields of a MIMO spatial configuration frame sent by the initiator; and sending, by the responder, the MIMO BF feedback frame. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the one or more user mask fields have a one-to-one correspondence with one or more transmit antennas of the initiator, and bits in each user mask field have a one-to-one correspondence to responders. ### Claim 17 (depends on 15) The apparatus according to claim 15, wherein the MIMO spatial configuration frame further comprises a MIMO selection control element, and the one or more user mask fields are comprised in the MIMO selection control element. ### Claim 18 (depends on 15) The apparatus according to claim 15, wherein the information that indicates the transmit antenna subset is a transmit antenna mask field, and the transmit antenna mask field comprises a bitmap, and wherein each bit in the bitmap corresponds to a respective transmit antenna of one or more transmit antennas, and each bit in the bitmap indicates whether the corresponding transmit antenna is comprised in the transmit antenna subset. ### Claim 19 (depends on 18) The apparatus according to claim 18, wherein for each bit in the bitmap: when a value of the bit is 1, it indicates that the corresponding transmit antenna is comprised in the transmit antenna subset; and when a value of the bit is 0, it indicates that the corresponding transmit antenna is not comprised in the transmit antenna subset. ### Claim 20 An apparatus in wireless communications system, the apparatus comprising: a processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, wherein the programming, when executed by the processor, instructing the apparatus to: send a multiple input multiple output (MIMO) spatial configuration frame, wherein the MIMO spatial configuration frame comprises one or more user mask fields; and receive a multiple input multiple output (MIMO) beamforming (BF) feedback frame, wherein the MIMO BF feedback frame comprises information indicating a transmit antenna subset of an initiator and one or more channel state information blocks that represent channel state information between the transmit antenna subset of the initiator and one or more receive antennas of a responder, and wherein the transmit antenna subset of the initiator is determined based on the one or more user mask fields of the MIMO spatial configuration frame.