# US 12,009,868 B2 · Coefficient update amount output device, coefficient update device, coefficient update amount output method, and recording medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,868 B2 - Document ID: US12009868B2 - Status: Granted - Kind: B2 - Application number: 17/766,296 - Filed: 2020-09-11 - Published: 2024-02-15 - Granted: 2024-06-11 - Earliest claimed: 2019-10-21 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Manabu Arikawa - Web page: https://patentgrep.com/patent/US12009868B2 ## CPC - H04B 10/541: {Digital intensity or amplitude modulation} - H04B 10/612: {for optical signals modulated with a format different from binary or higher-order PSK [X-PSK], e.g. QAM, DPSK, FSK, MSK, ASK} - H03H 17/02: Frequency selective networks {(digital computers for complex mathematical operations G06F17/10)} - H03H 17/06: Non-recursive filters - H03H 21/00: Adaptive networks - H04B 10/614: {comprising one or more polarization beam splitters, e.g. polarization multiplexed [PolMux] X-PSK coherent receivers, polarization diversity heterodyne coherent receivers (H04J14/06 takes precedence)} - H04B 10/616: {Details of the electronic signal processing in coherent optical receivers} - H04B 10/6165: {Estimation of the phase of the received optical signal, phase error estimation or phase error correction} - H04L 27/38: Demodulator circuits; Receiver circuits - H04B: TRANSMISSION - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In order to suppress wrong convergence of a filter coefficient without reducing data communication speed, this filter coefficient update amount output device is provided with: a first output unit which outputs a first coefficient update amount derived from a difference between a temporary determination result regarding a processed reception sample value that is the reception sample value on which filter processing by a digital filter has been performed and the processed reception sample value; a second output unit which outputs a second coefficient update amount derived from a gradient with respect to the filter coefficient such that the magnitude of a difference between statistical information on the processed reception sample value during some duration of time, and a set value regarding the statistical information is minimized; and a third output unit which outputs the coefficient update amount derived from the first coefficient update amount and the second coefficient update amount. ## Claims ### Claim 1 A filter coefficient update amount output device configured to output a coefficient update amount being a value for updating a filter coefficient of a digital filter included in an equalization device configured to equalize a received sample value of a received signal received with coherent reception by means of digital data processing, the filter coefficient update amount output device comprising: a first output unit configured to output a first coefficient update amount derived from a difference between a temporary determination result concerning a processed received sample value being the received sample value on which filter processing by the digital filter has been performed, and the processed received sample value; a second output unit configured to output a second coefficient update amount derived from a gradient with respect to the filter coefficient in such a way as to minimize a magnitude of a difference between statistical information on the processed received sample value for a given time width, and a set value for the statistical information; and a third output unit configured to output the coefficient update amount derived from the first coefficient update amount and the second coefficient update amount. ### Claim 2 (depends on 1) The filter coefficient update amount output device according to claim 1, wherein the set value is a desired value being an expected value for the statistical information. ### Claim 3 (depends on 2) The filter coefficient update amount output device according to claim 2, wherein the set value is based on a transmitted Probabilistic Constellation Shaping signal. ### Claim 4 (depends on 2) The filter coefficient update amount output device according to claim 2, wherein the statistical information is average intensity of a received symbol related to the blocked received sample value after processing. ### Claim 5 (depends on 2) The filter coefficient update amount output device according to claim 2, wherein the statistical information is probability density derived from kernel density estimation of a blocked received symbol. ### Claim 6 (depends on 2) The filter coefficient update amount output device according to claim 2, wherein the digital filter performs time-domain filter processing. ### Claim 7 (depends on 1) The filter coefficient update amount output device according to claim 1, wherein the set value is based on a transmitted Probabilistic Constellation Shaping signal. ### Claim 8 (depends on 7) The filter coefficient update amount output device according to claim 7, wherein the statistical information is average intensity of a received symbol related to the blocked received sample value after processing. ### Claim 9 (depends on 7) The filter coefficient update amount output device according to claim 7, wherein the statistical information is probability density derived from kernel density estimation of a blocked received symbol. ### Claim 10 (depends on 7) The filter coefficient update amount output device according to claim 7, wherein the digital filter performs time-domain filter processing. ### Claim 11 (depends on 1) The filter coefficient update amount output device according to claim 1, wherein the statistical information is average intensity of a received symbol related to the blocked received sample value after processing. ### Claim 12 (depends on 1) The filter coefficient update amount output device according to claim 1, wherein the statistical information is probability density derived from kernel density estimation of a blocked received symbol. ### Claim 13 (depends on 1) The filter coefficient update amount output device according to claim 1, wherein the digital filter performs time-domain filter processing. ### Claim 14 (depends on 1) The filter coefficient update amount output device according to claim 1, wherein the digital filter performs frequency-domain filter processing. ### Claim 15 (depends on 1) A filter coefficient update device configured to update the filter coefficient by means of the filter coefficient update amount output device according to claim 1. ### Claim 16 (depends on 15) An equalization device comprising the filter coefficient update device according to claim 15 and the digital filter. ### Claim 17 (depends on 16) A receiving device comprising the equalization device according to claim 16. ### Claim 18 (depends on 17) A communication system comprising the receiving device according to claim 17. ### Claim 19 A filter coefficient update amount output method of outputting a coefficient update amount being a value for updating a filter coefficient of a digital filter included in an equalization device configured to equalize a received sample value of a received signal received with coherent reception by means of digital data processing, the filter coefficient update amount output method comprising: performing first output for outputting a first coefficient update amount derived from a difference between a temporary determination result concerning a processed received sample value being the received sample value on which filter processing by the digital filter has been performed, and the processed received sample value; performing second output for outputting a second coefficient update amount derived from a gradient with respect to the filter coefficient in such a way as to minimize a magnitude of a difference between statistical information on the processed received sample value for a given time width, and a set value for the statistical information; and performing third output for outputting the coefficient update amount derived from the first coefficient update amount and the second coefficient update amount. ### Claim 20 A recording medium recording a filter coefficient update amount output program causing a computer to perform filter coefficient update amount output for outputting a coefficient update amount being a value for updating a filter coefficient of a digital filter included in an equalization device configured to equalize a received sample value of a received signal received with coherent reception by means of digital data processing, the program causing the computer to perform: processing of performing first output for outputting a first coefficient update amount derived from a difference between a temporary determination result concerning a processed received sample value being the received sample value on which filter processing by the digital filter has been performed, and the processed received sample value; processing of performing second output for outputting a second coefficient update amount derived from a gradient with respect to the filter coefficient in such a way as to minimize a magnitude of a difference between statistical information on the processed received sample value for a given time width, and a set value for the statistical information; and processing of performing third output for outputting the coefficient update amount derived from the first coefficient update amount and the second coefficient update amount.