Patents by Inventor Seiji Okamoto

Seiji Okamoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11003611
    Abstract: A bridge apparatus includes slave circuits connected to each other via a bus. Each of the slave circuits is connected to one of master apparatuses, function as a slave for the master apparatus connected thereto, and performs communication in accordance with a protocol in which the number of masters in a system is restricted. Addresses of memories are respectively set in the slave circuits, and the memories are connected to the master apparatuses to which the slave circuits are respectively connected. When a first master apparatus accesses a memory connected to a second master apparatus by specifying a first address of the memory, the bridge apparatus causes the first master apparatus and the second master apparatus to communicate via a first slave circuit, a second slave circuit in which an address corresponding to the first address is set, and the bus, based on the addresses of the memories.
    Type: Grant
    Filed: September 29, 2020
    Date of Patent: May 11, 2021
    Assignee: SOCIONEXT INC.
    Inventors: Eiichi Nimoda, Seiji Goto, Satoru Okamoto, Shuichi Yamane, Yasuo Nishiguchi
  • Publication number: 20210028857
    Abstract: There is provided an optical transmission system in which a plurality of optical transmission and reception apparatuses perform 1-to-N transmission and reception of optical signals (N is an integer equal to or greater than 1), the optical transmission system being configured to select a communication condition that includes at least a modulation scheme or a baud rate and is a communication condition when each of the optical transmission and reception apparatuses performs transmission and reception in accordance with a transmission line condition that is between any one first optical transmission and reception apparatus and each of second optical transmission and reception apparatuses, which are N grounds, other than the first optical transmission and reception apparatus.
    Type: Application
    Filed: March 1, 2019
    Publication date: January 28, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Fumikazu INUZUKA, Shokei KOBAYASHI, Akira HIRANO, Wataru KAWAKAMI, Tetsuro INUI, Seiki KUWABARA, Kei KITAMURA, Takafumi TANAKA, Takuya ODA, Hideki NISHIZAWA, Seiji OKAMOTO
  • Publication number: 20210013963
    Abstract: A state estimating device includes a pre-processing unit and an estimating unit. The pre-processing unit acquires data representing at one or more of a phase of a signal transmitted from a transmission unit of a transmission device and received at a reception unit of another transmission device via a transmission path, a reception strength, a reception quality, a voltage after conversion into an electric signal, and a signal processing parameter used in reception processing, and processes the acquired data into feature data to be used for state estimation. The estimating unit estimates a state of the transmission path, an abnormal state of the transmission unit, or an abnormal state of the reception unit, on the basis of the feature data.
    Type: Application
    Filed: February 13, 2019
    Publication date: January 14, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Seiki KUWABARA, Wataru KAWAKAMI, Hideki NISHIZAWA, Seiji OKAMOTO, Akira HIRANO, Shokei KOBAYASHI, Tetsuro INUI, Takuya ODA, Fumikazu INUZUKA, Takafumi TANAKA
  • Patent number: 10841006
    Abstract: A signal-to-noise ratio (SNR) estimation method includes an optical signal transmission step of inserting at least one pair of signal sequences into transmission data and transmitting the transmission data into which the at least one pair of signal sequences is inserted, a signal sequence extraction step of extracting the at least one pair of signal sequences from a received signal obtained by receiving the transmitted transmission data, an inner product calculation step of calculating an inner product value of the extracted at least one pair of signal sequences, a reception power calculation step of calculating reception power of the extracted at least one pair of signal sequences, and an SNR calculation step of calculating an SNR of the at least one pair of signal sequences on the basis of the calculated inner product value and the calculated reception power.
    Type: Grant
    Filed: March 26, 2018
    Date of Patent: November 17, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Seiji Okamoto, Yoshiaki Kisaka, Kengo Horikoshi, Mitsuteru Yoshida, Masahiro Suzuki
  • Patent number: 10826620
    Abstract: An optical receiver that demodulates an optical modulation signal into a baseband signal, which is an electrical signal, and decodes a received symbol acquired by converting the baseband signal. The optical receiver includes: an analog-to-digital converter that converts the baseband signal into a digital signal of which the number of samples per received symbol is M/N (samples/symbol), M and N being positive integers, M/N being not an integer, and “M>N” being satisfied; and an adaptive equalization processing unit that executes an equalization operation set in advance to output the received symbol on the basis of the digital signal of which the number of samples per received symbol is M/N (samples/symbol) and a predetermined tap coefficient digital signal equalization tap coefficients used for equalization of a signal, the coefficient being updated in any sampling period.
    Type: Grant
    Filed: October 25, 2017
    Date of Patent: November 3, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Fukutaro Hamaoka, Seiji Okamoto, Masanori Nakamura, Kengo Horikoshi, Yoshiaki Kisaka
  • Publication number: 20200265818
    Abstract: A pressing surface of a hammer and a to-be-pressed surface of a key switch have relatively-concaved shapes in a longitudinal direction of the hammer. When a switch body is pressed by the hammer, an inclination caused by an overall curvature of the switch body that results from the fact that the switch body is pressed by the hammer from an oblique direction is canceled by an inclination of the switch body caused by partial compression and deformation that results from the relatively-concaved shapes, so that movable contacts in the switch body frontally face stationary contacts and come into contact with the stationary contacts, respectively.
    Type: Application
    Filed: February 6, 2020
    Publication date: August 20, 2020
    Inventor: Seiji Okamoto
  • Patent number: 10651944
    Abstract: An optical transmitter of an optical data transmission system transmitting data through an optical fiber transmission path includes a main signal generator that converts first transmission data into a predetermined signal format to generate a first signal, a DCSK modulator that DCSK-modulates second transmission data to generate a second signal, a signal-multiplexer that performs time-division multiplexing of the first signal and the second signal, and an electro-optical converter that converts a multiplexed signal obtained by the time-division multiplexing of the signal-multiplexer from an electric signal into an optical signal, and outputs the optical signal to the optical fiber transmission path.
    Type: Grant
    Filed: July 26, 2017
    Date of Patent: May 12, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kengo Horikoshi, Seiji Okamoto, Asuka Matsushita, Mitsuteru Yoshida, Fukutaro Hamaoka, Yoshiaki Yamada, Yoshiaki Kisaka
  • Publication number: 20200052793
    Abstract: An optical receiver that demodulates an optical modulation signal into a baseband signal, which is an electrical signal, and decodes a received symbol acquired by converting the baseband signal. The optical receiver includes: an analog-to-digital converter that converts the baseband signal into a digital signal of which the number of samples per received symbol is M/N (samples/symbol), M and N being positive integers, M/N being not an integer, and “M >N” being satisfied; and an adaptive equalization processing unit that executes an equalization operation set in advance to output the received symbol on the basis of the digital signal of which the number of samples per received symbol is M/N (samples/symbol) and a predetermined tap coefficient digital signal equalization tap coefficients used for equalization of a signal, the coefficient being updated in any sampling period.
    Type: Application
    Filed: October 25, 2017
    Publication date: February 13, 2020
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Fukutaro HAMAOKA, Seiji OKAMOTO, Masanori NAKAMURA, Kengo HORIKOSHI, Yoshiaki KISAKA
  • Publication number: 20200028586
    Abstract: A signal-to-noise ratio (SNR) estimation method includes an optical signal transmission step of inserting at least one pair of signal sequences into transmission data and transmitting the transmission data into which the at least one pair of signal sequences is inserted, a signal sequence extraction step of extracting the at least one pair of signal sequences from a received signal obtained by receiving the transmitted transmission data, an inner product calculation step of calculating an inner product value of the extracted at least one pair of signal sequences, a reception power calculation step of calculating reception power of the extracted at least one pair of signal sequences, and an SNR calculation step of calculating an SNR of the at least one pair of signal sequences on the basis of the calculated inner product value and the calculated reception power.
    Type: Application
    Filed: March 26, 2018
    Publication date: January 23, 2020
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Seiji OKAMOTO, Yoshiaki KISAKA, Kengo HORIKOSHI, Mitsuteru YOSHIDA, Masahiro SUZUKI
  • Patent number: 10523335
    Abstract: Fourier transform is performed on a reception signal to obtain a first calculation value. Fourier transform is performed on a known signal to obtain a second calculation value. The first calculation value is divided by the second calculation value to obtain a third calculation value. Inverse Fourier transform is performed on the third calculation value to obtain a fourth calculation value. A maximum value of an amplitude of the fourth calculation value and a sample point at which the maximum value is obtained are detected. The position of the known signal in the reception signal is detected from the sample point at which the maximum value is obtained.
    Type: Grant
    Filed: June 21, 2017
    Date of Patent: December 31, 2019
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Yasuharu Onuma, Etsushi Yamazaki, Tomohiro Takamuku, Masahiro Tachibana, Mitsuteru Yoshida, Masahito Tomizawa, Seiji Okamoto
  • Publication number: 20190273560
    Abstract: An optical transmitter of an optical data transmission system transmitting data through an optical fiber transmission path includes a main signal generator that converts first transmission data into a predetermined signal format to generate a first signal, a DCSK modulator that DCSK-modulates second transmission data to generate a second signal, a signal-multiplexer that performs time-division multiplexing of the first signal and the second signal, and an electro-optical converter that converts a multiplexed signal obtained by the time-division multiplexing of the signal-multiplexer from an electric signal into an optical signal, and outputs the optical signal to the optical fiber transmission path.
    Type: Application
    Filed: July 26, 2017
    Publication date: September 5, 2019
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kengo HORIKOSHI, Seiji OKAMOTO, Asuka MATSUSHITA, Mitsuteru YOSHIDA, Fukutaro HAMAOKA, Yoshiaki YAMADA, Yoshiaki KISAKA
  • Patent number: 10389452
    Abstract: A coherent optical reception device includes a local oscillation laser that supplies laser light, a coherent optical reception front-end unit that receives a multi-level modulated optical signal, demodulates the optical signal on the basis of the laser light, and converts a demodulated optical signal into an electrical analog signal, an analog-to-digital converter that converts the analog signal into a digital signal, a compensation unit that compensates for an influence of dispersion due to a wavelength or a polarized wave of the optical signal and recovers a carrier phase of the digital signal, a constellation distortion compensation unit that compensates for constellation distortion of the multi-level modulation included in the digital signal in which an influence of dispersion is compensated for by the compensation unit, and an error correction decoding unit that performs error correction of the digital signal in which the constellation distortion is compensated for.
    Type: Grant
    Filed: October 17, 2016
    Date of Patent: August 20, 2019
    Assignees: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT Electronics Corporation
    Inventors: Kengo Horikoshi, Mitsuteru Yoshida, Seiji Okamoto, Eiichi Hosoya, Etsushi Yamazaki, Yasuharu Onuma, Tomohiro Takamuku, Naoki Miura, Sadayuki Yasuda
  • Patent number: 10381705
    Abstract: A power combiner/power divider has a disk shaped housing cavity and a housing of electrically conductive material, such as metal. A junction pin is positioned centrally in the power combiner/divider. Additional ports are positioned radially along the periphery of the disk shaped portion. Tapered waveguides may extend from the radially positioned ports to the centrally positioned junction pin. A hollow radial cavity provided in the cavity holds a dielectric insert that may have tapering extensions radiating from a central ring. The ring surrounds the centrally positioned port.
    Type: Grant
    Filed: June 16, 2017
    Date of Patent: August 13, 2019
    Assignee: Mercury Systems, Inc.
    Inventor: Douglas Seiji Okamoto
  • Publication number: 20190165868
    Abstract: Fourier transform is performed on a reception signal to obtain a first calculation value. Fourier transform is performed on a known signal to obtain a second calculation value. The first calculation value is divided by the second calculation value to obtain a third calculation value. Inverse Fourier transform is performed on the third calculation value to obtain a fourth calculation value. A maximum value of an amplitude of the fourth calculation value and a sample point at which the maximum value is obtained are detected. The position of the known signal in the reception signal is detected from the sample point at which the maximum value is obtained.
    Type: Application
    Filed: June 21, 2017
    Publication date: May 30, 2019
    Inventors: Yasuharu ONUMA, Etsushi YAMAZAKI, Tomohiro TAKAMUKU, Masahiro TACHIBANA, Mitsuteru YOSHIDA, Masahito TOMIZAWA, Seiji OKAMOTO
  • Patent number: 10230853
    Abstract: A terminal device including a detection unit that detects a sound, and an output unit that outputs information regarding a detection method of detecting the sound by the detection unit.
    Type: Grant
    Filed: August 2, 2016
    Date of Patent: March 12, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Seiji Okamoto, Junichi Hirota, Tsutomu Udaka, Tomoyuki Mitsuhashi
  • Publication number: 20190013876
    Abstract: A coherent optical reception device includes a local oscillation laser that supplies laser light, a coherent optical reception front-end unit that receives a multi-level modulated optical signal, demodulates the optical signal on the basis of the laser light, and converts a demodulated optical signal into an electrical analog signal, an analog-to-digital converter that converts the analog signal into a digital signal, a compensation unit that compensates for an influence of dispersion due to a wavelength or a polarized wave of the optical signal and recovers a carrier phase of the digital signal, a constellation distortion compensation unit that compensates for constellation distortion of the multi-level modulation included in the digital signal in which an influence of dispersion is compensated for by the compensation unit, and an error correction decoding unit that performs error correction of the digital signal in which the constellation distortion is compensated for.
    Type: Application
    Filed: October 17, 2016
    Publication date: January 10, 2019
    Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT Electronics Corporation
    Inventors: Kengo HORIKOSHI, Mitsuteru YOSHIDA, Seiji OKAMOTO, Eiichi HOSOYA, Etsushi YAMAZAKI, Yasuharu ONUMA, Tomohiro TAKAMUKU, Naoki MIURA, Sadayuki YASUDA
  • Patent number: 10171173
    Abstract: An optical signal transmission apparatus includes a modulation unit which modulates a transmission signal, a training signal sequence generation unit which generates a plurality of signal sequences having power concentrated in a plurality of different frequency bands, at least one of an amplitude and a phase of the plurality of signal sequences being modulated, as a training signal sequence, a signal multiplexing unit which appends the training signal sequence to the transmission signal, and an electro-optical conversion unit which converts a signal sequence obtained by appending the training signal sequence to the transmission signal into an optical signal and transmits the optical signal.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: January 1, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Seiji Okamoto, Koichi Ishihara, Etsushi Yamazaki, Mitsuteru Yoshida, Tomoyoshi Kataoka, Kazushige Yonenaga, Yoshiaki Kisaka, Masanori Nakamura, Masahito Tomizawa
  • Publication number: 20180366806
    Abstract: A power combiner/power divider has a disk shaped housing cavity and a housing of electrically conductive material, such as metal. A junction pin is positioned centrally in the power combiner/divider. Additional ports are positioned radially along the periphery of the disk shaped portion. Tapered waveguides may extend from the radially positioned ports to the centrally positioned junction pin. A hollow radial cavity provided in the cavity holds a dielectric insert that may have tapering extensions radiating from a central ring. The ring surrounds the centrally positioned port.
    Type: Application
    Filed: June 16, 2017
    Publication date: December 20, 2018
    Inventor: Douglas Seiji OKAMOTO
  • Patent number: 10038507
    Abstract: An increase in circuit scale is suppressed and a phase variation caused in a transmission path or the like is compensated for.
    Type: Grant
    Filed: February 13, 2014
    Date of Patent: July 31, 2018
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru Yoshida, Etsushi Yamazaki, Seiji Okamoto, Hiroyuki Uzawa, Kengo Horikoshi, Koichi Ishihara, Takayuki Kobayashi, Yoshiaki Kisaka, Masahito Tomizawa, Naoki Fujiwara, Tomoyoshi Kataoka, Kazushige Yonenaga
  • Patent number: 9942652
    Abstract: A terminal device includes a detection unit that detects sound, and an output unit that outputs information regarding a position of the detection unit relative to a target apparatus which is a target to detect the sound by the detection unit.
    Type: Grant
    Filed: August 2, 2016
    Date of Patent: April 10, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Seiji Okamoto, Tsutomu Udaka, Tomoyuki Mitsuhashi, Junichi Hirota