# US 12,224,779 B2 · Transmitter, receiver, transmission method, reception method, and non-transitory computer readable storage medium for performing beamforming in wireless transmission > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,779 B2 - Document ID: US12224779B2 - Status: Granted - Kind: B2 - Application number: 18/066,210 - Filed: 2022-12-14 - Published: 2023-06-22 - Granted: 2025-02-11 - Earliest claimed: 2021-12-20 - Assignees: Panasonic Holdings Corporation - Applicants: Panasonic Holdings Corporation - Inventors: Mikihiro Ouchi; Tomohiro Kimura; Yusuke Chinda; Kazuhiko Kikuchi - Web page: https://patentgrep.com/patent/US12224779B2 ## CPC - H04B 1/0007: {wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage} - H04B 17/11: for calibration - H04B 17/12: of transmit antennas, e.g. of the amplitude or phase - H04B 17/21: for calibration; for correcting measurements - H04B 17/364: Delay profiles - H04B: TRANSMISSION ## Abstract A transmission method is performed by a transmitter including antenna elements. The transmission method includes: generating a digital calibration signal; performing digital-to-analog conversion on second digital signals to generate first analog signals, the second digital signals being obtained by adding the digital calibration signal to each of a plurality of first digital signals each corresponding to respective one of the antenna elements; performing analog-to-digital conversion on the first analog signals to generate third digital signals each corresponding to respective one of the antenna elements, the first analog signals each passing through respective one of the antenna elements; performing correlation calculation between the digital calibration signal and each of the third digital signals to calculate transmission delay characteristics each corresponding to respective one of the antenna elements; calculating transmission delay correction amounts based on the transmission delay characteristics; and correcting the transmission delay characteristics based on the transmission delay correction amounts. ## Claims ### Claim 1 A transmitter comprising: a plurality of antenna elements; a calibration signal generator which, in operation, generates a digital calibration signal; a transmission processing execution unit which, in operation, performs transmission processing including digital-to-analog conversion on second digital signals to generate first analog signals, the second digital signals being obtained by adding the digital calibration signal to each of a plurality of first digital signals, the first digital signals each corresponding to respective one of the antenna elements; a reception processing execution unit which, in operation, performs reception processing including analog-to-digital conversion on the first analog signals to generate third digital signals each corresponding to respective one of the antenna elements, the first analog signals each passing through respective one of the antenna elements; a transmission characteristics calculator which, in operation, performs correlation calculation between the digital calibration signal and each of the third digital signals to calculate transmission delay characteristics each corresponding to respective one of the antenna elements and which, in operation, calculates transmission delay correction amounts based on the transmission delay characteristics, each of the transmission delay correction amounts corresponding to respective one of the antenna elements; and a transmission characteristics corrector which, in operation, corrects the transmission delay characteristics based on the transmission delay correction amounts. ### Claim 2 (depends on 1) The transmitter according to claim 1, wherein the transmission characteristics calculator calculates the transmission delay characteristics by performing the correlation calculation to obtain early-late (E-L) correlation values. ### Claim 3 (depends on 1) The transmitter according to claim 1, wherein the transmission characteristics calculator calculates the transmission delay characteristics by performing the correlation calculation at a high-speed sampling rate. ### Claim 4 (depends on 1) The transmitter according to claim 1, wherein the transmission characteristics calculator calculates the transmission delay correction amounts to allow antenna elements other than a reference antenna element among the antenna elements to be identical in the transmission delay characteristics to the reference antenna element having a median delay among the antenna elements. ### Claim 5 (depends on 2) The transmitter according to claim 2, wherein the calibration signal generator adjusts an amount of delay of the digital calibration signal to allow a reference antenna element having a median delay among the antenna elements to have an E-L correlation value of 0, and the transmission characteristics calculator calculates the transmission delay correction amounts to allow the antenna elements other than the reference antenna element among the antenna elements to have E-L correlation values of 0. ### Claim 6 (depends on 4) The transmitter according to claim 4, wherein the reference antenna element is specified based on design information. ### Claim 7 (depends on 4) The transmitter according to claim 4, wherein the transmission characteristics calculator specifies the reference antenna element based on the transmission delay characteristics of all the antenna elements. ### Claim 8 A receiver comprising: a plurality of antenna elements; a calibration signal generator which, in operation, generates a digital calibration signal; a transmission processing execution unit which, in operation, performs transmission processing including digital-to-analog conversion on the digital calibration signal to generate a first analog signal; a reception processing execution unit which, in operation, performs reception processing including analog-to-digital conversion on third analog signals to generate first digital signals each corresponding to respective one of the antenna elements, the third analog signals being obtained by adding the first analog signal to each of a plurality of second analog signals, the second analog signals each received via corresponding one of the antenna elements; a reception characteristics calculator which, in operation, performs correlation calculation between the digital calibration signal and each of the first digital signals to calculate reception delay characteristics each corresponding to respective one of the antenna elements and which, in operation, calculates reception delay correction amounts based on the reception delay characteristics, each of the reception delay correction amounts corresponding to respective one of the antenna elements; and a reception characteristics corrector which, in operation, corrects the reception delay characteristics based on the reception delay correction amounts. ### Claim 9 (depends on 8) The receiver according to claim 8, wherein the reception characteristics calculator calculates the reception delay characteristics by performing the correlation calculation to obtain E-L correlation values. ### Claim 10 (depends on 8) The receiver according to claim 8, wherein the reception characteristics calculator calculates the reception delay characteristics by performing the correlation calculation at a high-speed sampling rate. ### Claim 11 (depends on 8) The receiver according to claim 8, wherein the reception characteristics calculator calculates the reception delay correction amounts to allow the antenna elements other than a reference antenna element among the antenna elements to be identical in the reception delay characteristics to the reference antenna element having a median delay among the antenna elements. ### Claim 12 (depends on 9) The receiver according to claim 9, wherein the calibration signal generator adjusts an amount of delay of the digital calibration signal to allow a reference antenna element having a median delay among the antenna elements to have an E-L correlation value of 0, and the reception characteristics calculator calculates the reception delay correction amounts to allow the antenna elements other than the reference antenna element among the antenna elements to have E-L correlation values of 0. ### Claim 13 (depends on 11) The receiver according to claim 11, wherein the reference antenna element is specified based on design information. ### Claim 14 (depends on 11) The receiver according to claim 11, wherein the reception characteristics calculator specifies the reference antenna element based on the reception delay characteristics of all the antenna elements. ### Claim 15 A transmission method performed by a transmitter including a plurality of antenna elements, the transmission method comprising: generating a digital calibration signal; performing transmission processing including digital-to-analog conversion on second digital signals to generate first analog signals, the second digital signals being obtained by adding the digital calibration signal to each of a plurality of first digital signals, the first digital signals each corresponding to respective one of the antenna elements; performing reception processing including analog-to-digital conversion on the first analog signals to generate third digital signals each corresponding to respective one of the antenna elements, the first analog signals each passing through respective one of the antenna elements; performing correlation calculation between the digital calibration signal and each of the third digital signals to calculate transmission delay characteristics each corresponding to respective one of the antenna elements; calculating transmission delay correction amounts based on the transmission delay characteristics, each of the transmission delay correction amounts corresponding to respective one of the antenna elements; and correcting the transmission delay characteristics based on the transmission delay correction amounts. ### Claim 16 A reception method performed by a receiver including a plurality of antenna elements, the reception method comprising: generating a digital calibration signal; performing transmission processing including digital-to-analog conversion on the digital calibration signal to generate a first analog signal; performing reception processing including analog-to-digital conversion on third analog signals to generate first digital signals each corresponding to respective one of the antenna elements, the third analog signals being obtained by adding the first analog signal to each of a plurality of second analog signals, the second analog signals each received via corresponding one of the antenna elements; performing correlation calculation between the digital calibration signal and each of the first digital signals to calculate reception delay characteristics each corresponding to respective one of the antenna elements; calculating reception delay correction amounts based on the reception delay characteristics, each of the reception delay correction amounts corresponding to respective one of the antenna elements; and correcting the reception delay characteristics based on the reception delay correction amounts. ### Claim 17 (depends on 15) A non-transitory computer readable storage medium storing instructions, when executed by a processor, for causing a transmitter to execute the transmission method according to claim 15. ### Claim 18 (depends on 16) A non-transitory computer readable storage medium storing instructions, when executed by a processor, for causing a receiver to execute the reception method according to claim 16.