Patents by Inventor Shoichiro Oda

Shoichiro Oda 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: 11343009
    Abstract: An optical communication component includes three or more couplers, a pair of waveguides, a phase shifter, a detector, and a controller. Each of the couplers multiplexes two input optical signals and two-branch outputs the multiplexed optical signals. Each of the pair of waveguides connects between the couplers and outputs each of the optical signals two-branch output from one of the couplers to another one of the couplers. The phase shifter, included in each of the waveguides, adjusts a phase amount of each of the optical signals passing through the waveguides. The detector detects an amount of power of the optical signal that has been subjected to phase adjustment and that is two-branch output from a most downstream coupler, from among the couplers, located in the traveling direction of the optical signal. The controller controls, based on the detected amount of power, each of the phase shifters.
    Type: Grant
    Filed: March 10, 2021
    Date of Patent: May 24, 2022
    Assignees: FUJITSU LIMITED, PHOTONICS ELECTRONICS TECHNOLOGY RESEARCH ASSOCIATION
    Inventors: Tomoyuki Akiyama, Shoichiro Oda
  • Publication number: 20220109506
    Abstract: An optical transmitter includes: a modulator, square law detector, and a processor. The modulator generates an optical signal indicating transmission data. The square law detector detects an intensity of the optical signal using a photodetector and output first intensity data indicating the detected intensity. The processor calculates, based on the transmission data, an electric field of the optical signal generated by the modulator by using parameters pertaining to a state of the modulator. The processor calculates second intensity data indicating the intensity of the optical signal based on the calculated electric field. The processor updates the parameters so as to reduce a difference between the first intensity data and the second intensity data. The processor controls the state of the modulator based on the parameters.
    Type: Application
    Filed: July 1, 2021
    Publication date: April 7, 2022
    Applicant: FUJITSU LIMITED
    Inventors: Setsuo Yoshida, Shoichiro Oda, KAZUYUKI TAJIMA, Takeshi Hoshida, Takahito Tanimura
  • Publication number: 20220094525
    Abstract: A communication device includes: a counter, a pseudo-random number generator, a symbol generator, a modulator, and a controller. The counter counts symbols transmitted to a correspondent device. The pseudo-random number generator generates a pseudo-random number corresponding to a count value of the counter. The symbol generator generates a transmission symbol from a transmission signal and the pseudo-random number. The modulator generates a modulated signal from the transmission symbol. When a disruption of a communication with the correspondent device is detected, the controller selects, from among a plurality of restoring times determined in advance, a restoring time for resuming the communication, and gives the counter a count value assigned in advance to the selected restoring time. The counter resumes a counting operation from the count value given from the controller when the communication device resumes a communication with the correspondent device.
    Type: Application
    Filed: December 4, 2021
    Publication date: March 24, 2022
    Applicant: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Setsuo Yoshida
  • Patent number: 11228426
    Abstract: A communication device includes: a counter, a pseudo-random number generator, a symbol generator, a modulator, and a controller. The counter counts symbols transmitted to a correspondent device. The pseudo-random number generator generates a pseudo-random number corresponding to a count value of the counter. The symbol generator generates a transmission symbol from a transmission signal and the pseudo-random number. The modulator generates a modulated signal from the transmission symbol. When a disruption of a communication with the correspondent device is detected, the controller selects, from among a plurality of restoring times determined in advance, a restoring time for resuming the communication, and gives the counter a count value assigned in advance to the selected restoring time. The counter resumes a counting operation from the count value given from the controller when the communication device resumes a communication with the correspondent device.
    Type: Grant
    Filed: July 9, 2019
    Date of Patent: January 18, 2022
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Setsuo Yoshida
  • Patent number: 11165502
    Abstract: An optical transmission device includes: a frontend circuit, a converter, an equalizer, a recovery, spectrum detector a correction information generator, and a transmitter. The frontend circuit converts an optical signal received via an optical network into an electric signal. The converter converts an output signal of the frontend circuit into a digital signal. The equalizer equalizes the digital signal or a second digital signal that is generated based on the digital signal. The recovery recovers a symbol from an output signal of the equalizer. The spectrum detector detects a reception spectrum of the optical signal based on the digital signal or the second digital signal. The correction information generator generates, according to the reception spectrum, correction information for correcting a shape of a transmission spectrum of the optical signal. The transmitter transmits the correction information to the source device.
    Type: Grant
    Filed: July 9, 2019
    Date of Patent: November 2, 2021
    Assignee: FUJITSU LIMITED
    Inventors: Yi Ge, Shoichiro Oda, Yuichi Akiyama, Takeshi Hoshida
  • Publication number: 20210306087
    Abstract: An optical communication component includes three or more couplers, a pair of waveguides, a phase shifter, a detector, and a controller. Each of the couplers multiplexes two input optical signals and two-branch outputs the multiplexed optical signals. Each of the pair of waveguides connects between the couplers and outputs each of the optical signals two-branch output from one of the couplers to another one of the couplers. The phase shifter, included in each of the waveguides, adjusts a phase amount of each of the optical signals passing through the waveguides. The detector detects an amount of power of the optical signal that has been subjected to phase adjustment and that is two-branch output from a most downstream coupler, from among the couplers, located in the traveling direction of the optical signal. The controller controls, based on the detected amount of power, each of the phase shifters.
    Type: Application
    Filed: March 10, 2021
    Publication date: September 30, 2021
    Applicants: FUJITSU LIMITED, Photonics Electronics Technology Research Association
    Inventors: Tomoyuki Akiyama, Shoichiro Oda
  • Patent number: 11057144
    Abstract: An optical transmission apparatus includes the optical transceiver configured to generate a test light for each wavelength assignable to the wavelength multiplex light to transmit the test light to the optical transmission line via the wavelength multiplexer and demultiplexer, detect a reflected light for the test light from the optical transmission line, calculate an arrival distance of the test light for the each wavelength from the reflected light for the each wavelength, and set a wavelength having a longest arrival distance among the arrival distances for the respective wavelengths, as a wavelength to be assigned to the signal light in the optical transceiver.
    Type: Grant
    Filed: November 7, 2019
    Date of Patent: July 6, 2021
    Assignee: FUJITSU LIMITED
    Inventors: Masatake Miyabe, Shoichiro Oda
  • Patent number: 11050484
    Abstract: An optical transmission apparatus, includes, a light source configured to output a plurality of light beams having different wavelengths to an optical fiber, a receiver configured to receive, from the optical fiber, a reflected light beam corresponding to each of the wavelengths of the plurality of light beams, and a signal processing circuit configured to estimate a polarization fluctuation portion based on a polarization state of the received reflected light beam corresponding to each of the plurality of wavelengths.
    Type: Grant
    Filed: February 4, 2020
    Date of Patent: June 29, 2021
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Setsuo Yoshida
  • Publication number: 20200259562
    Abstract: An optical transmission apparatus, includes, a light source configured to output a plurality of light beams having different wavelengths to an optical fiber, a receiver configured to receive, from the optical fiber, a reflected light beam corresponding to each of the wavelengths of the plurality of light beams, and a signal processing circuit configured to estimate a polarization fluctuation portion based on a polarization state of the received reflected light beam corresponding to each of the plurality of wavelengths.
    Type: Application
    Filed: February 4, 2020
    Publication date: August 13, 2020
    Applicant: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Setsuo Yoshida
  • Publication number: 20200195365
    Abstract: An optical transmission apparatus includes the optical transceiver configured to generate a test light for each wavelength assignable to the wavelength multiplex light to transmit the test light to the optical transmission line via the wavelength multiplexer and demultiplexer, detect a reflected light for the test light from the optical transmission line, calculate an arrival distance of the test light for the each wavelength from the reflected light for the each wavelength, and set a wavelength having a longest arrival distance among the arrival distances for the respective wavelengths, as a wavelength to be assigned to the signal light in the optical transceiver.
    Type: Application
    Filed: November 7, 2019
    Publication date: June 18, 2020
    Applicant: FUJITSU LIMITED
    Inventors: MASATAKE MIYABE, Shoichiro Oda
  • Publication number: 20200036446
    Abstract: An optical transmission device includes: a frontend circuit, a converter, an equalizer, a recovery, spectrum detector a correction information generator, and a transmitter. The frontend circuit converts an optical signal received via an optical network into an electric signal. The converter converts an output signal of the frontend circuit into a digital signal. The equalizer equalizes the digital signal or a second digital signal that is generated based on the digital signal. The recovery recovers a symbol from an output signal of the equalizer. The spectrum detector detects a reception spectrum of the optical signal based on the digital signal or the second digital signal. The correction information generator generates, according to the reception spectrum, correction information for correcting a shape of a transmission spectrum of the optical signal. The transmitter transmits the correction information to the source device.
    Type: Application
    Filed: July 9, 2019
    Publication date: January 30, 2020
    Applicant: FUJITSU LIMITED
    Inventors: Yi Ge, Shoichiro Oda, YUICHI AKIYAMA, Takeshi Hoshida
  • Publication number: 20200036518
    Abstract: A communication device includes: a counter, a pseudo-random number generator, a symbol generator, a modulator, and a controller. The counter counts symbols transmitted to a correspondent device. The pseudo-random number generator generates a pseudo-random number corresponding to a count value of the counter. The symbol generator generates a transmission symbol from a transmission signal and the pseudo-random number. The modulator generates a modulated signal from the transmission symbol. When a disruption of a communication with the correspondent device is detected, the controller selects, from among a plurality of restoring times determined in advance, a restoring time for resuming the communication, and gives the counter a count value assigned in advance to the selected restoring time. The counter resumes a counting operation from the count value given from the controller when the communication device resumes a communication with the correspondent device.
    Type: Application
    Filed: July 9, 2019
    Publication date: January 30, 2020
    Applicant: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Setsuo Yoshida
  • Patent number: 10396900
    Abstract: A method of controlling a transmission signal, includes transmitting a training signal including four polarization states having a given relation; and performing rotation control and transmission power level control of a polarization component of a data signal, based on a rotation control matrix for a polarization state and an inverse-operation control matrix for a power level imbalance, which are estimated from Stokes parameters related to input power level present on a Poincare sphere acquired from the training signal and Stokes parameters related to output power level present on the Poincare sphere.
    Type: Grant
    Filed: March 16, 2018
    Date of Patent: August 27, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Guoxiu Huang, Setsuo Yoshida, Takeshi Hoshida, Hisao Nakashima, Shoichiro Oda
  • Patent number: 10389437
    Abstract: An optical signal-to-noise ratio measurement device includes a measurement unit and a determination unit and measures an optical signal-to-noise ratio of an optical signal including a fixed pattern in a specified cycle. The measurement unit measures an optical signal-to-noise ratio of the optical signal respectively in a plurality of time sections in a measurement period so as to generate a plurality of measured values, a length of the measurement period being the same or substantially the same as a length of the specified cycle. The determination unit selects, from the plurality of measured values generated by the measurement unit, at least one measured value other than a worst measured value in the plurality of measured values, and determines an optical signal-to-noise ratio of the optical signal based on the selected at least one measured value.
    Type: Grant
    Filed: May 14, 2018
    Date of Patent: August 20, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Setsuo Yoshida, Shoichiro Oda
  • Patent number: 10374703
    Abstract: A transmission device includes: a receiving unit that receives an optical signal; an acquiring unit that acquires spectrum information from the optical signal, the spectrum information relating to a spectrum of the optical signal; and a narrowing calculating unit that calculates an index value for narrowing of a band of the optical signal by calculating a sampling timing error in accordance with the spectrum information, the sampling timing error being an error when a clock signal is extracted from the optical signal.
    Type: Grant
    Filed: August 23, 2018
    Date of Patent: August 6, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Takeshi Hoshida, Hisao Nakashima, Yi Ge
  • Patent number: 10374701
    Abstract: An optical signal-to-noise ratio (OSNR) measuring device includes a processor, wherein the processor executes a process. The process includes: converting an optical signal to an electrical signal; first acquiring a signal intensity from the electrical signal; second acquiring a noise intensity of a predetermined frequency band from the electrical signal; performing a digital conversion on the noise intensity; and computing an OSNR of the optical signal based on the signal intensity and the converted noise intensity. The predetermined frequency band is a frequency band including a folding noise that occurs when the digital conversion is performed.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: August 6, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Setsuo Yoshida, Keisuke Harada
  • Patent number: 10256903
    Abstract: A network controller includes: a first acquisition unit configured to acquire, based on a signal quality amount of each of wavelength paths set in a network of an optical wavelength-multiplexed transmission system, a signal quality amount of each of spans in each of the wavelength paths; an arithmetic unit configured to calculate a signal quality amount of each of spans in a wavelength path of an estimation target, based on the signal quality amount acquired by the first acquisition unit; and an estimation unit configured to estimate a signal quality amount of the wavelength path of the estimation target, based on the signal quality amount calculated by the arithmetic unit.
    Type: Grant
    Filed: November 22, 2017
    Date of Patent: April 9, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Yasuhiko Aoki, Takeshi Hoshida, Hisao Nakashima, Hiroki Oi
  • Publication number: 20190081701
    Abstract: A transmission device includes: a receiving unit that receives an optical signal; an acquiring unit that acquires spectrum information from the optical signal, the spectrum information relating to a spectrum of the optical signal; and a narrowing calculating unit that calculates an index value for narrowing of a band of the optical signal by calculating a sampling timing error in accordance with the spectrum information, the sampling timing error being an error when a clock signal is extracted from the optical signal.
    Type: Application
    Filed: August 23, 2018
    Publication date: March 14, 2019
    Applicant: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Takeshi Hoshida, Hisao Nakashima, Yi Ge
  • Patent number: 10230462
    Abstract: An optical transmission characteristic measurement method includes starting transmission of an optical signal from a transmitting node to a receiving node; receiving a bit error rate value measured by the receiving node and relates to the optical signal; determining whether the bit error rate value is higher than a given threshold; adjusting input power of the optical signal to lower until it is determined that the bit error rate value is higher than the given threshold when it is determined that the bit error rate value is not higher than the given threshold; estimating an optical signal to noise ratio from the bit error rate value when it is determined that the bit error rate value is higher than the given threshold; and calculating an optical signal to noise ratio based on the estimated optical signal to noise ratio and an amount of lowering of the input power.
    Type: Grant
    Filed: November 9, 2017
    Date of Patent: March 12, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Toru Katagiri, Satoru Okano, Masatake Miyabe, Yasuhiko Aoki
  • Patent number: 10230463
    Abstract: A transmitter generates a frequency-modulated CW light so as to transmit it to a path. A receiver receives the CW light that has passed through passband filters included in the path. The receiver includes a processor. The processor measures an optical power of the received CW light every time a center frequency of the CW light is changed and transmitted by the transmitter. The processor calculates transmission characteristics of the CW light that has passed through the passband filters, on the basis of an average value of the optical power that corresponds to a center frequency of the CW light and on the basis of an amplitude component that indicates an amount of change in the optical power, the average value and the amplitude component being obtained as a result of the measurement.
    Type: Grant
    Filed: August 3, 2016
    Date of Patent: March 12, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Guoxiu Huang, Yasuhiko Aoki, Shoichiro Oda, Zhenning Tao, Setsuo Yoshida, Kyosuke Sone