# US 10,320,453 B2 · Quantization of channel state information in multiple antenna systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,453 B2 - Document ID: US10320453B2 - Status: Granted - Kind: B2 - Application number: 14/628,570 - Filed: 2015-02-23 - Published: 2015-08-06 - Granted: 2019-06-11 - Earliest claimed: 2006-05-26 - Assignees: Wi-LAN, Inc. - Applicants: Wi-LAN Inc. - Inventors: Bartosz Mielczarek; Witold A. Krzymien - Web page: https://patentgrep.com/patent/US10320453B2 ## CPC - H04B 7/0452: Multi-user MIMO systems - H04B 7/0434: {using multiple eigenmodes} - H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting - H04B 7/0481: {using subset selection of codebooks} - H04B 7/0617: {for beam forming} - H04B 7/0632: {Channel quality parameters, e.g. channel quality indicator [CQI]} - H04B 7/0658: {Feedback reduction} - H04B 7/066: {Combined feedback for a number of channels, e.g. over several subcarriers like in orthogonal frequency division multiplexing [OFDM]} - H04L 1/0029: {Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling (power control H04W52/04)} - H04L 1/003: {Adaptive formatting arrangements particular to signalling, e.g. variable amount of bits} - H04L 1/0687: {Full feedback} - H04L 1/0693: {Partial feedback, e.g. partial channel state information [CSI]} - H04L 25/0204: {of multiple channels} - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method of transmission over multiple wireless channels in a multiple antenna system includes storing channel modulation matrices at a transmitter; receiving quantized channel state information at the transmitter from plural receivers; selecting a transmission modulation matrix using the quantized channel state information from the stored channel modulation matrices; and transmitting over the multiple channels to the plural receivers using the selected transmission modulation matrix. In another embodiment, the method includes storing, at one or more receivers, indexes of modulation matrices generated by a capacity enhancing algorithm; upon a selected one of the one or more receivers receiving a transmission from the transmitter, the selected receiver selecting a modulation matrix from the stored modulation matrices that optimizes transmission between the transmitter and the selected receiver, the selected receiver sending an index representing the selected modulation matrix; and receiving the index at the transmitter from the selected receiver. ## Claims ### Claim 1 A method for wireless transmission from a multiple-antenna transmitter, the method comprising: storing a codebook including pre-quantized channel vectors each having a length N, wherein N is a number of antennas at the transmitter; and in a multi-user multiple input and multiple output (MIMO) mode: receiving a plurality of indices, only one of the plurality of indices from each of a plurality of user devices, each user device comprising a receiver and at least one of the user devices comprising a plurality of antennas, wherein each index corresponds to one of the pre-quantized channel vectors; determining at least one and no more than N vectors based on at least one and no more than N of the received indices and on pre-quantized channel vectors corresponding to the at least one and no more than N received indices; and transmitting data to at least one and no more than N user devices of the plurality of user devices, using the determined vectors; wherein N is greater than one. ### Claim 2 (depends on 1) The method of claim 1, further comprising: setting a limitation on the plurality of receivers which limits the indices received from the plurality of receivers. ### Claim 3 (depends on 1) The method of claim 1, wherein the plurality of indices are each received as channel state information (CSI). ### Claim 4 (depends on 1) The method of claim 1, wherein the transmitting of data to up to N receivers comprises transmitting orthogonal frequency division multiplexed (OFDM) signals using subcarriers. ### Claim 5 (depends on 1) The method of claim 1, wherein the codebook is used for all transmit powers. ### Claim 6 (depends on 1) The method of claim 1, wherein the codebook further comprises pre-quantized channel matrices, the method further comprising, at the transmitter: in a second MIMO mode: receiving, from a receiver, a second index corresponding to one of the pre-quantized channel matrices; determining a matrix based on at least the second index; and transmitting second data to the receiver using the determined matrix. ### Claim 7 (depends on 6) The method of claim 6, wherein the second index is received as channel state information (CSI). ### Claim 8 (depends on 6) The method of claim 6, wherein the transmitting second data to the receiver comprises transmitting orthogonal frequency division multiplexed (OFDM) signals using subcarriers. ### Claim 9 A multiple-antenna transmitter, comprising: N antennas; a memory which stores a codebook including pre-quantized channel vectors each having a length N; the transmitter being operable to, in a multi-user multiple input and multiple output (MIMO) mode: receive a plurality of indices, only one of the plurality of indices from each of a plurality of user devices, each user device comprising a receiver and at least one of the user devices comprising a plurality of antennas, wherein each index corresponds to one of the pre-quantized channel vectors; determine at least one and no more than N vectors based on at least one and no more than N of the received indices and on pre-quantized channel vectors corresponding to the at least one and no more than N received indices; and transmit data to at least one and no more than N user devices of the plurality of user devices, using the determined vectors; wherein N is greater than one. ### Claim 10 (depends on 9) The transmitter of claim 9, further operable to set a limitation on the plurality of receivers which limits the indices received from the plurality of receivers. ### Claim 11 (depends on 9) The transmitter of claim 9, wherein the plurality of indices are each received as channel state information (CSI). ### Claim 12 (depends on 9) The transmitter of claim 9, wherein the transmitting of data to up to N receivers comprises transmitting orthogonal frequency division multiplexed (OFDM) signals using subcarriers. ### Claim 13 (depends on 9) The transmitter of claim 9, wherein the codebook is used for all transmit powers. ### Claim 14 (depends on 9) The transmitter of claim 9, wherein the codebook further comprises pre-quantized channel matrices, and wherein the transmitter is further operable to: in a second MIMO mode: receive, from a receiver, a second index corresponding to one of the pre-quantized channel matrices; determine a matrix based on at least the second index; and transmit second data to the receiver using the determined matrix. ### Claim 15 (depends on 14) The transmitter of claim 14, wherein the second index is received as channel state information (CSI). ### Claim 16 (depends on 14) The transmitter of claim 14, wherein the transmitting second data to the receiver comprises transmitting orthogonal frequency division multiplexed (OFDM) signals using subcarriers. ### Claim 17 A non-transitory computer-readable medium comprising instructions stored thereon which when executed by a processor of a transmitter configure the transmitter to: store a codebook including pre-quantized channel vectors each having a length N, wherein N is a number of antennas at the transmitter; and in a multi-user multiple-input and multiple-output (MIMO) mode: receive a plurality of indices, only one of the plurality of indices from each of a plurality of user devices, each user device comprising a receiver and at least one of the user devices comprising a plurality of antennas, wherein each index corresponds to one of the pre-quantized channel vectors; determine at least one and no more than N vectors based on at least one and no more than N of the received indices and on pre-quantized channel vectors corresponding to the at least one and no more than N received indices; and transmit data to at least one and no more than N user devices of the plurality of user devices, using the determined vectors; wherein N is greater than one. ### Claim 18 (depends on 17) The computer-readable medium of claim 17, further comprising instructions stored thereon which when executed by a processor of a transmitter configure the transmitter to set a limitation on the plurality of receivers which limits the indices received from the plurality of receivers. ### Claim 19 (depends on 17) The computer-readable medium of claim 17, wherein the plurality of indices are each received as channel state information (CSI). ### Claim 20 (depends on 17) The computer-readable medium of claim 17, wherein the transmitting of data to up to N receivers comprises transmitting orthogonal frequency division multiplexed (OFDM) signals using subcarriers. ### Claim 21 (depends on 17) The computer-readable medium of claim 17, wherein the codebook is used for all transmit powers. ### Claim 22 (depends on 17) The computer-readable medium of claim 17, wherein the codebook further comprises pre-quantized channel matrices, the computer-readable medium further comprising instructions stored thereon which when executed by a processor of a transmitter configure the transmitter to: in a second MIMO mode: receive, from a receiver, a second index corresponding to one of the pre-quantized channel matrices; determine a matrix based on at least the second index; and transmit second data to the receiver using the determined matrix. ### Claim 23 (depends on 22) The computer-readable medium of claim 22, wherein the second index is received as channel state information (CSI). ### Claim 24 (depends on 22) The computer-readable medium of claim 22, wherein the transmitting second data to the receiver comprises transmitting orthogonal frequency division multiplexed (OFDM) signals using subcarriers.