# US 11,451,285 B2 · Efficient extreme high-throughput sounding feedback supporting JMAP and CMAP transmissions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,285 B2 - Document ID: US11451285B2 - Status: Granted - Kind: B2 - Application number: 17/074,432 - Filed: 2020-10-19 - Published: 2021-04-29 - Granted: 2022-09-20 - Earliest claimed: 2019-10-29 - Assignees: MediaTek Singapore Pte. Ltd. - Applicants: MediaTek Singapore Pte. Ltd. - Inventors: Shuling Feng; Jianhan Liu - Web page: https://patentgrep.com/patent/US11451285B2 ## CPC - H04B 7/066: {Combined feedback for a number of channels, e.g. over several subcarriers like in orthogonal frequency division multiplexing [OFDM]} - H04L 25/0204: {of multiple channels} - H04B 7/024: Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems - 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 7/0689: {using different transmission schemes, at least one of them being a diversity transmission scheme} - H04L 5/0035: {Resource allocation in a cooperative multipoint environment} - H04L 25/0248: {Eigen-space methods} - 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 An apparatus implemented in an access point (AP) participates in joint soundings together with one or more other APs in a joint multi-AP (JMAP) configuration to receive joint feedbacks from a plurality of stations (STAs) responding to the joint soundings. The apparatus then performs transmissions in a coordinated multi-AP (CMAP) configuration with the one or more other APs or in a single-AP configuration with no other AP based on the joint feedbacks received while in the JMAP configuration. ## Claims ### Claim 1 A method implemented in an access point (AP), comprising: participating in joint soundings together with one or more other APs in a joint multi-AP (JMAP) configuration to receive joint feedbacks from a plurality of stations (STAs) responding to the joint soundings; and performing transmissions in a coordinated multi-AP (CMAP) configuration with the one or more other APs or in a single-AP configuration with no other AP based on the joint feedbacks received while in the JMAP configuration, wherein the performing of transmissions in the CMAP configuration or in the single-AP configuration comprises reconfiguring to perform the transmissions in the CMAP configuration or in the single-AP configuration using the joint feedbacks received from the plurality of STAs while in the JMAP configuration with no extra information. ### Claim 2 (depends on 1) The method of claim 1, wherein the joint feedbacks received from the plurality of STAs comprise joint channel state information (CSI) from the plurality of STAs. ### Claim 3 (depends on 1) The method of claim 1, before performing the transmissions in the CMAP configuration or in the single-AP configuration, further comprising: reconstructing a respective channel matrix for each of the plurality of STAs based on singular values and corresponding vectors in the joint feedbacks, wherein a dimension of the reconstructed channel matrix is a number of rows corresponding to a number of receivers at a corresponding STA of the plurality of STAs times a number of columns corresponding to a number of total transmitters at the AP and the one or more other APs. ### Claim 4 (depends on 3) The method of claim 3, further comprising: forming a projected channel matrix from the reconstructed channel matrix by extracting a subset of columns of the reconstructed channel matrix corresponding to the AP, wherein a number of the columns extracted corresponds to a transmitter index of the AP. ### Claim 5 (depends on 4) The method of claim 4, wherein the forming of the projected channel matrix comprises forming the projected channel matrix by applying a unitary matrix to the reconstructed channel matrix in an event that the joint feedbacks are uncompressed. ### Claim 6 (depends on 4) The method of claim 4, wherein the forming of the projected channel matrix comprises forming the projected channel matrix by applying a unitary matrix and a rotation vector to the reconstructed channel matrix in an event that the joint feedbacks are compressed. ### Claim 7 A method implemented in an access point (AP), comprising: participating in sequential or joint soundings together with one or more other APs in a coordinated multi-AP (CMAP) configuration to receive feedbacks from a plurality of stations (STAs) responding to the sequential or joint soundings; and performing transmissions in a joint multi-AP (JMAP) configuration with the one or more other APs or in a single-AP configuration with no other AP based at least in part on the feedbacks received while in the CMAP configuration, wherein the participating comprises participating in sequential soundings, and wherein the performing of transmissions in the JMAP configuration or in the single-AP configuration comprises reconfiguring to perform the transmissions in the JMAP configuration or in the single-AP configuration using joint feedbacks received from the plurality of STAs while in the CMAP configuration with no extra information. ### Claim 8 (depends on 7) The method of claim 7, wherein the performing of transmissions in the JMAP configuration comprises reconfiguring to perform the transmissions in the JMAP configuration using sequential feedbacks with extra information received from the plurality of STAs while in the CMAP configuration. ### Claim 9 (depends on 8) The method of claim 8, wherein each of the sequential feedbacks received from the plurality of STAs comprises channel state information (CSI), and wherein the extra information comprises a unitary matrix from each of the plurality of STAs in an event that the sequential feedbacks are uncompressed. ### Claim 10 (depends on 8) The method of claim 8, wherein each of the sequential feedbacks received from the plurality of STAs comprises channel state information (CSI), and wherein the extra information comprises a unitary matrix and a phasor vector corresponding to a matrix V compression. ### Claim 11 (depends on 10) The method of claim 10, wherein the extra information further comprises multiple phase rotation vectors a number of which being equivalent to a total number of APs in the CMAP configuration. ### Claim 12 (depends on 10) The method of claim 10, wherein the extra information further comprises a phase rotation vector corresponding to one of a plurality of APs comprising the AP and the one or more other APs. ### Claim 13 (depends on 8) The method of claim 8, before performing the transmissions in the JMAP configuration or in the single-AP configuration, further comprising: reconstructing a respective channel matrix for each of the plurality of STAs based on all channel state information (CSI) feedback information including extra information. ### Claim 14 (depends on 13) The method of claim 13, wherein the reconstructing of the respective channel matrix comprises reconstructing the respective channel matrix using a unitary matrix, singular values and corresponding vectors in a V matrix from each of the plurality of STAs in an event that the sequential feedbacks are uncompressed. ### Claim 15 (depends on 13) The method of claim 13, wherein the reconstructing of the respective channel matrix comprises reconstructing the respective channel matrix using a unitary matrix, singular values, corresponding compressed vectors and multiple phase rotation vectors from each of the plurality of STAs in an event that the sequential feedbacks are compressed, and wherein a number of the phase rotation vectors is equivalent to a total number of APs in the CMAP configuration. ### Claim 16 (depends on 13) The method of claim 13, wherein the reconstructing of the respective channel matrix comprises reconstructing the respective channel matrix using a unitary matrix, singular values, corresponding compressed vectors and a phase rotation vectors from each of the plurality of STAs in an event that the sequential feedbacks are compressed, and wherein the phase rotation vector corresponds to one of a plurality of APs comprising the AP and the one or more other APs. ### Claim 17 (depends on 13) The method of claim 13, further comprising: reconstructing, by the processor, a respective JMAP channel matrix for each of the plurality of STAs based on channel matrixes reconstructed by a plurality of APs comprising the AP and the one or more other APs for each of the plurality of STAs. ### Claim 18 A method, comprising: participating, by an apparatus implemented in an access point (AP), in joint soundings together with a first set of APs in a joint multi-AP (JMAP) configuration to receive joint feedbacks from a plurality of stations (STAs) responding to the joint soundings; and performing, by the apparatus, transmissions in a reduced JMAP configuration with a second set of APs based on the joint feedbacks received while in the JMAP configuration with no additional feedback information, wherein the first set of APs has more APs than the second set of APs, and wherein the joint feedbacks received from the plurality of STAs comprise joint channel state information (CSI) from the plurality of STAs.