Patents by Inventor Tomoyoshi Kataoka

Tomoyoshi Kataoka 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: 10243664
    Abstract: An optical modulator driver circuit (1) includes an amplifier (50, Q10, Q11, R10-R13), and a current amount adjustment circuit (51) capable of adjusting a current amount of the amplifier (50) in accordance with a desired operation mode. The current amount adjustment circuit (51) includes at least two current sources (IS10) that are individually ON/OFF-controllable in accordance with a binary control signal representing the desired operation mode.
    Type: Grant
    Filed: May 9, 2014
    Date of Patent: March 26, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Munehiko Nagatani, Hideyuki Nosaka, Toshihiro Itoh, Koichi Murata, Hiroyuki Fukuyama, Takashi Saida, Shin Kamei, Hiroshi Yamazaki, Nobuhiro Kikuchi, Hiroshi Koizumi, Masafumi Nogawa, Hiroaki Katsurai, Hiroyuki Uzawa, Tomoyoshi Kataoka, Naoki Fujiwara, Hiroto Kawakami, Kengo Horikoshi, Yves Bouvier, Mikio Yoneyama, Shigeki Aisawa, Masahiro Suzuki
  • 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
  • Patent number: 10122462
    Abstract: A transport apparatus includes: a client signal transceiving unit which transceives a client signal; a line signal transceiving unit which performs electric-optic conversion on a line signal to be transmitted, transmits an optical line signal, performs optic-electric conversion on a received line signal, and outputs an electrical line signal; and a plurality of signal processing units which perform signal processing on the client signal to generate the line signal to be transmitted and perform signal processing on the electrical line signal to generate the client signal.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: November 6, 2018
    Assignee: Nippon Telegraph And Telephone Corporation
    Inventors: Takuya Ohara, Kei Kitamura, Yoshiaki Kisaka, Shigeki Aisawa, Masahiro Suzuki, Etsushi Yamazaki, Tomoyoshi Kataoka, Masahito Tomizawa, Yoshiaki Yamada, Mitsuhiro Teshima, Akira Hirano
  • Patent number: 10090921
    Abstract: A light modulation device detects a power of the modulated optical signal modulated by each of an I-component optical modulator and a Q-component optical modulator, synchronously-detects a component of a frequency fd from the power of the modulated optical signal, outputs a dither signal of a frequency fd/n (where n is a positive integer equal to or larger than 1) applied to a first bias voltage or a second bias voltage when adjusting the first bias voltage or the second bias voltage, outputs two dither signals having a frequency fd/m (where m is a positive integer equal to or larger than 1, where n<m), which are mutually orthogonal to each other, applied to the first and second bias voltages when adjusting a third bias voltage, and adjusting bias voltages by increasing or decreasing bias voltages based on a synchronous detection result.
    Type: Grant
    Filed: April 10, 2015
    Date of Patent: October 2, 2018
    Assignees: Nippon Telegraph And Telephone Corporation, NTT Electronics Corporation
    Inventors: Mikio Yoneyama, Hiroto Kawakami, Takashi Ono, Akihiko Matsuura, Tomoyoshi Kataoka, Katsuya Tanaka, Masahiro Tachibana, Yuya Oyama
  • 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: 9667350
    Abstract: The optical receiving device with phase compensation apparatus uses coherent opto-electric conversion and is designed for receiving phase- or quadrature-amplitude-modulated optical signals. The phase compensation apparatus includes following elements: a carrier-phase estimation unit that estimates carrier phase errors in a received symbol string; a gain adjustment unit that adjusts weighting of each symbols in phase error evaluation performed in the carrier-phase adjustment unit; a phase-cycle-slip reduction unit with a phase-cycle-slip detector using statistical processing performed on the output symbols from the carrier-phase estimation unit; and a phase compensation circuit that compensates carrier phase errors of the received signal using an output from the carrier phase estimation unit.
    Type: Grant
    Filed: January 24, 2014
    Date of Patent: May 30, 2017
    Assignee: Nippon Telegraph And Telephone Corporation
    Inventors: Kengo Horikoshi, Kohki Shibahara, Etsushi Yamazaki, Mitsuteru Yoshida, Koichi Ishihara, Takayuki Kobayashi, Yoshiaki Kisaka, Takuya Ohara, Masahito Tomizawa, Tomoyoshi Kataoka
  • Publication number: 20170117961
    Abstract: A light modulation device detects a power of the modulated optical signal modulated by each of an I-component optical modulator and a Q-component optical modulator, synchronously-detects a component of a frequency fd from the power of the modulated optical signal, outputs a dither signal of a frequency fd/n (where n is a positive integer equal to or larger than 1) applied to a first bias voltage or a second bias voltage when adjusting the first bias voltage or the second bias voltage, outputs two dither signals having a frequency fd/m (where m is a positive integer equal to or larger than 1, where n<m), which are mutually orthogonal to each other, applied to the first and second bias voltages when adjusting a third bias voltage, and adjusting bias voltages by increasing or decreasing bias voltages based on a synchronous detection result.
    Type: Application
    Filed: April 10, 2015
    Publication date: April 27, 2017
    Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT Electronics Corporation
    Inventors: Mikio YONEYAMA, Hiroto KAWAKAMI, Takashi ONO, Akihiko MATSUURA, Tomoyoshi KATAOKA, Katsuya TANAKA, Masahiro TACHIBANA, Yuya OYAMA
  • Publication number: 20170111116
    Abstract: A transport apparatus includes: a client signal transceiving unit which transceives a client signal; a line signal transceiving unit which performs electric-optic conversion on a line signal to be transmitted, transmits an optical line signal, performs optic-electric conversion on a received line signal, and outputs an electrical line signal; and a plurality of signal processing units which perform signal processing on the client signal to generate the line signal to be transmitted and perform signal processing on the electrical line signal to generate the client signal.
    Type: Application
    Filed: November 19, 2014
    Publication date: April 20, 2017
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya OHARA, Kei KITAMURA, Yoshiaki KISAKA, Shigeki AISAWA, Masahiro SUZUKI, Etsushi YAMAZAKI, Tomoyoshi KATAOKA, Masahito TOMIZAWA, Yoshiaki YAMADA, Mitsuhiro TESHIMA, Akira HIRANO
  • Patent number: 9621299
    Abstract: The estimation of an amount of chromatic dispersion using a training signal sequence is possible. A transmission method includes: a training signal sequence generation step of generating, as training signal sequences, a plurality of signal sequences having power concentrated in a plurality of frequency bands, the power concentrated at different frequency bands; a training signal sequence selection step of selecting at least one training signal sequence from among the plurality of training signal sequences generated in the training signal sequence generation step, a signal multiplexing step of generating a signal sequence obtained by time-division multiplexing the training signal sequence selected in the training signal sequence selection step with a transmission data sequence, and an electrical-to-optical conversion step of transmitting the signal sequence generated in the signal multiplexing step as an optical signal.
    Type: Grant
    Filed: January 15, 2014
    Date of Patent: April 11, 2017
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Koichi Ishihara, Masato Mizoguchi, Tomoki Murakami, Tomoyoshi Kataoka, Yoshiaki Kisaka, Tadao Nakagawa, Etsushi Yamazaki, Seiji Okamoto, Kengo Horikoshi, Masahito Tomizawa, Riichi Kudo
  • Publication number: 20170070296
    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: Application
    Filed: March 17, 2015
    Publication date: March 9, 2017
    Applicant: 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: 20160087727
    Abstract: An optical modulator driver circuit (1) includes an amplifier (50, Q10, Q11, R10-R13), and a current amount adjustment circuit (51) capable of adjusting a current amount of the amplifier (50) in accordance with a desired operation mode. The current amount adjustment circuit (51) includes at least two current sources (IS10) that are individually ON/OFF-controllable in accordance with a binary control signal representing the desired operation mode.
    Type: Application
    Filed: May 9, 2014
    Publication date: March 24, 2016
    Inventors: Munehiko Nagatani, Hideyuki Nosaka, Toshihiro Itoh, Koichi Murata, Hiroyuki Fukuyama, Takashi Saida, Shin Kamei, Hiroshi Yamazaki, Nobuhiro Kikuchi, Hiroshi Koizumi, Masafumi Nogawa, Hiroaki Katsurai, Hiroyuki Uzawa, Tomoyoshi Kataoka, Naoki Fujiwara, Hiroto Kawakami, Kengo Horikoshi, Yves Bouvier, Mikio Yoneyama, Shigeki Aisawa, Masahiro Suzuki
  • Patent number: 9294826
    Abstract: A wavelength selection switch system includes a wavelength selection switch including an input port and an output port, a nonvolatile memory in which configuration information for controlling an operation of the wavelength selection switch is stored, a high-speed memory in which reading and writing can be performed at a higher speed than in the nonvolatile memory and that stores a copy of the configuration information stored in the nonvolatile memory, and a control unit that controls an operation of the wavelength selection switch based on the configuration information read from the high-speed memory, wherein the control unit periodically reads the configuration information stored in the nonvolatile memory and writes a copy of the read configuration information to the high-speed memory.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: March 22, 2016
    Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics Corporation
    Inventors: Tomoyoshi Kataoka, Mitsunori Fukutoku, Etsu Hashimoto, Akio Sahara, Norio Sato, Yosuke Takeuchi
  • Patent number: 9247324
    Abstract: A wavelength selection switch system includes a wavelength selection switch including an input port and an output port, a nonvolatile memory in which configuration information for controlling an operation of the wavelength selection switch is stored, a high-speed memory in which reading and writing can be performed at a higher speed than in the nonvolatile memory and that stores a copy of the configuration information stored in the nonvolatile memory, and a control unit that controls an operation of the wavelength selection switch based on the configuration information read from the high-speed memory, wherein the control unit periodically reads the configuration information stored in the nonvolatile memory and writes a copy of the read configuration information to the high-speed memory.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: January 26, 2016
    Assignees: Nippon Telegraph and Telephone Corporation, NTT Electronics Corporation
    Inventors: Tomoyoshi Kataoka, Mitsunori Fukutoku, Etsu Hashimoto, Akio Sahara, Norio Sato, Yosuke Takeuchi
  • Publication number: 20150372766
    Abstract: An increase in circuit scale is suppressed and a phase variation caused in a transmission path or the like is compensated for.
    Type: Application
    Filed: February 13, 2014
    Publication date: December 24, 2015
    Applicant: 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
  • Publication number: 20150341138
    Abstract: The estimation of an amount of chromatic dispersion using a training signal sequence is possible. A transmission method includes: a training signal sequence generation step of generating, as training signal sequences, a plurality of signal sequences having power concentrated in a plurality of frequency bands, the power concentrated at different frequency bands; a training signal sequence selection step of selecting at least one training signal sequence from among the plurality of training signal sequences generated in the training signal sequence generation step, a signal multiplexing step of generating a signal sequence obtained by time-division multiplexing the training signal sequence selected in the training signal sequence selection step with a transmission data sequence, and an electrical-to-optical conversion step of transmitting the signal sequence generated in the signal multiplexing step as an optical signal.
    Type: Application
    Filed: January 15, 2014
    Publication date: November 26, 2015
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Koichi ISHIHARA, Masato MIZOGUCHI, Tomoki MURAKAMI, Tomoyoshi KATAOKA, Yoshiaki KISAKA, Tadao NAKAGAWA, Etsushi YAMAZAKI, Seiji OKAMOTO, Kengo HORIKOSHI, Masahito TOMIZAWA, Riichi KUDO
  • Publication number: 20150333838
    Abstract: An optical receiving device receives an optical signal that has been modulated by means of phase modulation or quadrature amplitude modulation, converts the received optical signal into an electrical signal using coherent detection, and performs phase compensation on the converted received signal, and includes: a carrier phase estimation unit that estimates carrier phase errors in a received symbol string obtained from the received signal; a gain adjustment unit that performs gain adjustment on symbols input into the carrier phase adjustment unit; a phase cycle slip reduction unit that, by performing statistical processing on an output from the carrier phase estimation unit, detects general noise that causes a phase cycle slip, and reduces the phase cycle slip; and a phase compensation circuit that compensates carrier phase errors contained in the received signal using an output from the carrier phase estimation unit.
    Type: Application
    Filed: January 24, 2014
    Publication date: November 19, 2015
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kengo HORIKOSHI, Kohki SHIBAHARA, Etsushi YAMAZAKI, Mitsuteru YOSHIDA, Koichi ISHIHARA, Takayuki KOBAYASHI, Yoshiaki KISAKA, Takuya OHARA, Masahito TOMIZAWA, Tomoyoshi KATAOKA
  • Publication number: 20150030327
    Abstract: A wavelength selection switch system includes a wavelength selection switch including an input port and an output port, a nonvolatile memory in which configuration information for controlling an operation of the wavelength selection switch is stored, a high-speed memory in which reading and writing can be performed at a higher speed than in the nonvolatile memory and that stores a copy of the configuration information stored in the nonvolatile memory, and a control unit that controls an operation of the wavelength selection switch based on the configuration information read from the high-speed memory, wherein the control unit periodically reads the configuration information stored in the nonvolatile memory and writes a copy of the read configuration information to the high-speed memory.
    Type: Application
    Filed: February 5, 2013
    Publication date: January 29, 2015
    Applicants: NIPPON TELEGRAPH AND TELEPHONE CORPORATION, NTT Electronics Corporation
    Inventors: Tomoyoshi Kataoka, Mitsunori Fukutoku, Etsu Hashimoto, Akio Sahara, Norio Sato, Yosuke Takeuchi
  • Patent number: 8005374
    Abstract: An optical transmission system is provided in which the optimum operating point of a Mach-Zehnder interferometer, matched to the optical frequency of the light source on the transmitting side, can be set.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: August 23, 2011
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kazushige Yonenaga, Mikio Yoneyama, Masahito Tomizawa, Akira Hirano, Shoichiro Kuwahara, Tomoyoshi Kataoka, Akihide Sano, Gentaro Funatsu
  • Publication number: 20100172653
    Abstract: An optical transmission system is provided in which the optimum operating point of a Mach-Zehnder interferometer, matched to the optical frequency of the light source on the transmitting side, can be set.
    Type: Application
    Filed: March 12, 2010
    Publication date: July 8, 2010
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kazushige Yonenaga, Mikio Yoneyama, Masahito Tomizawa, Akira Hirano, Shoichiro Kuwahara, Tomoyoshi Kataoka, Akihide Sano, Gentaro Funatsu
  • Patent number: 7734194
    Abstract: An optical transmission system is provided in which the optimum operating point of a Mach-Zehnder interferometer, matched to the optical frequency of the light source on the transmitting side, can be set.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: June 8, 2010
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kazushige Yonenaga, Mikio Yoneyama, Masahito Tomizawa, Akira Hirano, Shoichiro Kuwahara, Tomoyoshi Kataoka, Akihide Sano, Gentaro Funatsu