Patents by Inventor Takahito Tanimura

Takahito Tanimura 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: 10999659
    Abstract: An optical network device receives an optical signal, to which polarization information is added, from a transmitter via a transmission line. The receiver generates electric-field-information signal of the optical signal. The processor acquires, for respective polarization rotation amounts, the electric-field-information signal during a period specified by the polarization information. The processor calculates, for respective polarization rotation amounts and based on the electric-field-information signal, evaluation values corresponding to powers of the optical signal at a plurality of positions on the transmission line. The processor calculates, for respective positions, variations in the evaluation values corresponding to the polarization rotation amounts.
    Type: Grant
    Filed: July 24, 2020
    Date of Patent: May 4, 2021
    Assignee: FUJITSU LIMITED
    Inventors: Kazuyuki Tajima, Takahito Tanimura, Setsuo Yoshida, Takeshi Hoshida
  • Patent number: 10972178
    Abstract: A parameter analysis method executable by a computer, the method includes training a model configured to output an index value relating to a characteristic of an optical signal, and changing the characteristic of the optical signal usable for training the model.
    Type: Grant
    Filed: March 4, 2019
    Date of Patent: April 6, 2021
    Assignee: FUJITSU LIMITED
    Inventor: Takahito Tanimura
  • Publication number: 20210092498
    Abstract: An optical network device receives an optical signal, to which polarization information is added, from a transmitter via a transmission line. The receiver generates electric-field-information signal of the optical signal. The processor acquires, for respective polarization rotation amounts, the electric-field-information signal during a period specified by the polarization information. The processor calculates, for respective polarization rotation amounts and based on the electric-field-information signal, evaluation values corresponding to powers of the optical signal at a plurality of positions on the transmission line. The processor calculates, for respective positions, variations in the evaluation values corresponding to the polarization rotation amounts.
    Type: Application
    Filed: July 24, 2020
    Publication date: March 25, 2021
    Applicant: FUJITSU LIMITED
    Inventors: KAZUYUKI TAJIMA, Takahito Tanimura, Setsuo Yoshida, Takeshi Hoshida
  • Patent number: 10853719
    Abstract: A data collecting device includes a receiver configured to receive an optical signal; an optical-to-electrical converter configured to convert the optical signal received by the receiver into an electrical signal; an analog-to-digital converter configured to convert the electrical signal into a digital signal; a data reducing circuit configured to reduce the digital signal output from the analog-to-digital converter; and a transmitter configured to transmit, to a managing device that manages the data collecting device, a signal obtained by reducing the digital signal by the data reducing circuit.
    Type: Grant
    Filed: December 2, 2016
    Date of Patent: December 1, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida
  • Patent number: 10720992
    Abstract: There is provided a transmission apparatus including a transmitter configured to modulate a signal to a first signal having a first wavelength and a signal to a second signal having a second wavelength, and transmit the first signal and the second signal to a transmission line so that the second signal is varied in accordance with variation in an amount of cross phase modulation of the first signal passing through each position on the transmission line, and a signal processor configured to include at least one of a logic device and a processor, and configured to add an amount of chromatic dispersion at which a remaining amount of chromatic dispersion of the first wavelength at a certain position on the transmission line is equal to zero to the first wavelength in the transmission of the first signal and the second signal.
    Type: Grant
    Filed: June 19, 2018
    Date of Patent: July 21, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida, Shigeki Watanabe, Tomoyuki Kato
  • Publication number: 20200153504
    Abstract: A communication device used in an optical communication system, the communication device includes a mode change over device configured to switch between a learning mode for learning a normal state of an optical transmission path before operation and a monitoring mode for monitoring a state of the optical transmission path during operation, an anomaly detector configured to detect an anomaly of the optical transmission path using a prediction model determined by the learning mode when the monitoring mode is selected, and a data writer configured to extract waveform data including information related to the anomaly to output the extracted waveform data to an outside when the anomaly is detected.
    Type: Application
    Filed: November 11, 2019
    Publication date: May 14, 2020
    Applicant: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida
  • Patent number: 10554325
    Abstract: A transmitter transmitting a polarization multiplexed optical signal, includes: a light source; a generating unit configured to split a light of the light source into first and second polarized lights, optically modulate the first and second polarized lights based on an electric data signal, and multiplex the first polarized light optically-modulated and the second polarized light optically-modulated to generate the polarization multiplexed optical signal; and a coupling unit configured to couple a first reference light having a frequency different from a frequency of the light of the light source with the first polarized light and couple a second reference light having a frequency different from the frequency of the light of the light source with the second polarized light, wherein the first reference light and the second reference light have different frequencies.
    Type: Grant
    Filed: August 30, 2018
    Date of Patent: February 4, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Tomohiro Yamauchi, Takahito Tanimura, Takeshi Hoshida, Rafael Puerta Ramirez
  • Patent number: 10425166
    Abstract: An optical transmitter includes, an optical modulator that multilevel-modulates light outputted from a light source, and a processor that outputs a first drive voltage for driving the optical modulator according to an amplitude component when transmission data is symbol-mapped and a second drive voltage for driving the optical modulator according to a phase component when the transmission data is symbol-mapped. A phase shift of phase modulation by the second drive voltage outputted from the processor is greater than 0 and less than ?/2.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: September 24, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Tomohiro Yamauchi, Tomofumi Oyama, Takahito Tanimura, Guoxiu Huang, Takeshi Hoshida
  • Patent number: 10419117
    Abstract: There is provided a monitor device for monitoring a transmission line including a memory, and a processor coupled to the memory and configured to compensate for a portion of chromatic dispersion on electric signals indicating an electric field component of an optical signal, compensate for deterioration due to a nonlinear optical effect on the electric signals on which the portion of chromatic dispersion is compensated, compensate for a remaining chromatic dispersion except for the portion of chromatic dispersion on the electric signals on which the deterioration due to the nonlinear optical effect is compensated, evaluate quality of the electric signals on which remaining chromatic dispersion except for the portion of chromatic dispersion are compensated, and acquire a first compensation amount of the portion of chromatic dispersion and a second compensation amount of the deterioration due to the nonlinear optical effect, when the evaluated quality satisfies a predetermined condition.
    Type: Grant
    Filed: February 14, 2018
    Date of Patent: September 17, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida
  • Publication number: 20190280766
    Abstract: A parameter analysis method executable by a computer, the method includes training a model configured to output an index value relating to a characteristic of an optical signal, and changing the characteristic of the optical signal usable for training the model.
    Type: Application
    Filed: March 4, 2019
    Publication date: September 12, 2019
    Applicant: FUJITSU LIMITED
    Inventor: Takahito Tanimura
  • Patent number: 10313017
    Abstract: An optical transmitter includes: a light source configured to generate CW light; a drive signal generator configured to generate a drive signal; an optical modulator configured to modulate the CW light with the drive signal so as to generate a first optical signal; a combiner configured to combine the first optical signal and a second optical signal generated by using another light source; and a detector configured to detect a frequency difference between a frequency of the CW light and a center frequency of the second optical signal. The drive signal generator includes: a mapper configured to generate an electric field information signal based on input data; and a frequency controller configured to modify the electric field information signal based on the frequency difference such that the frequency of the CW light matches the center frequency of the second optical signal to generate the drive signal.
    Type: Grant
    Filed: July 10, 2017
    Date of Patent: June 4, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida
  • Patent number: 10277328
    Abstract: A signal processing device processes an electric field information signal indicating a polarization multiplexed optical signal in which different modulation formats are used. A first optical signal transmitted in a first polarization component and a second optical signal transmitted in a second polarization component are multiplexed in the polarization multiplexed optical signal. The signal processing device includes a generator and a compensation circuit. The generator selects the first polarization component or the second polarization component based on modulation formats of the first and second optical signals, and generates a compensation value for compensating for an electric field information signal of a selected polarization component based on the electric field information signal of the selected polarization component. The compensation circuit compensates for electric field information signals of the first and second polarization components using the compensation value generated by the generator.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: April 30, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Tomofumi Oyama, Hisao Nakashima, Yoshitaka Nomura, Takeshi Hoshida, Takahito Tanimura
  • Publication number: 20190089479
    Abstract: A transmitter transmitting a polarization multiplexed optical signal, includes: a light source; a generating unit configured to split a light of the light source into first and second polarized lights, optically modulate the first and second polarized lights based on an electric data signal, and multiplex the first polarized light optically-modulated and the second polarized light optically-modulated to generate the polarization multiplexed optical signal; and a coupling unit configured to couple a first reference light having a frequency different from a frequency of the light of the light source with the first polarized light and couple a second reference light having a frequency different from the frequency of the light of the light source with the second polarized light, wherein the first reference light and the second reference light have different frequencies.
    Type: Application
    Filed: August 30, 2018
    Publication date: March 21, 2019
    Applicant: FUJITSU LIMITED
    Inventors: Tomohiro YAMAUCHI, Takahito Tanimura, Takeshi Hoshida, Rafael Puerta Ramirez
  • Patent number: 10193621
    Abstract: An apparatus includes a light source that causes continuous oscillation light to enter one terminal of an optical transmission line, wherein the continuous oscillation light is to propagate a light variation of a first physical amount generated on the optical transmission line to another terminal of the optical transmission line; a photodetector that detects, on the one terminal, light turned back from a light modulation converter provided on the another terminal, wherein the light modulation converter obtains the turned-back light by converting the light variation of the first physical amount into a light variation of a second physical amount; and a processor that calculates a light-variation location generated on the optical transmission line by comparing time variations in the light variation of the first physical amount and the light variation of the second physical amount in the light detected by the photodetector.
    Type: Grant
    Filed: April 23, 2018
    Date of Patent: January 29, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Tomoyuki Kato, Shigeki Watanabe, Takeshi Hoshida, Takahito Tanimura
  • Publication number: 20190020418
    Abstract: An optical transmitter includes, an optical modulator that multilevel-modulates light outputted from a light source, and a processor that outputs a first drive voltage for driving the optical modulator according to an amplitude component when transmission data is symbol-mapped and a second drive voltage for driving the optical modulator according to a phase component when the transmission data is symbol-mapped. A phase shift of phase modulation by the second drive voltage outputted from the processor is greater than 0 and less than ?/2.
    Type: Application
    Filed: July 9, 2018
    Publication date: January 17, 2019
    Applicant: FUJITSU LIMITED
    Inventors: Tomohiro YAMAUCHI, Tomofumi Oyama, Takahito Tanimura, GUOXIU HUANG, Takeshi Hoshida
  • Publication number: 20180375580
    Abstract: There is provided a transmission apparatus including a transmitter configured to modulate a signal to a first signal having a first wavelength and a signal to a second signal having a second wavelength, and transmit the first signal and the second signal to a transmission line so that the second signal is varied in accordance with variation in an amount of cross phase modulation of the first signal passing through each position on the transmission line, and a signal processor configured to include at least one of a logic device and a processor, and configured to add an amount of chromatic dispersion at which a remaining amount of chromatic dispersion of the first wavelength at a certain position on the transmission line is equal to zero to the first wavelength in the transmission of the first signal and the second signal.
    Type: Application
    Filed: June 19, 2018
    Publication date: December 27, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida, Shigeki Watanabe, Tomoyuki Kato
  • Publication number: 20180316422
    Abstract: An apparatus includes a light source that causes continuous oscillation light to enter one terminal of an optical transmission line, wherein the continuous oscillation light is to propagate a light variation of a first physical amount generated on the optical transmission line to another terminal of the optical transmission line; a photodetector that detects, on the one terminal, light turned back from a light modulation converter provided on the another terminal, wherein the light modulation converter obtains the turned-back light by converting the light variation of the first physical amount into a light variation of a second physical amount; and a processor that calculates a light-variation location generated on the optical transmission line by comparing time variations in the light variation of the first physical amount and the light variation of the second physical amount in the light detected by the photodetector.
    Type: Application
    Filed: April 23, 2018
    Publication date: November 1, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Tomoyuki Kato, Shigeki Watanabe, Takeshi Hoshida, Takahito Tanimura
  • Publication number: 20180234184
    Abstract: There is provided a monitor device for monitoring a transmission line including a memory, and a processor coupled to the memory and configured to compensate for a portion of chromatic dispersion on electric signals indicating an electric field component of an optical signal, compensate for deterioration due to a nonlinear optical effect on the electric signals on which the portion of chromatic dispersion is compensated, compensate for a remaining chromatic dispersion except for the portion of chromatic dispersion on the electric signals on which the deterioration due to the nonlinear optical effect is compensated, evaluate quality of the electric signals on which remaining chromatic dispersion except for the portion of chromatic dispersion are compensated, and acquire a first compensation amount of the portion of chromatic dispersion and a second compensation amount of the deterioration due to the nonlinear optical effect, when the evaluated quality satisfies a predetermined condition.
    Type: Application
    Filed: February 14, 2018
    Publication date: August 16, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida
  • Publication number: 20180034552
    Abstract: A signal processing device processes an electric field information signal indicating a polarization multiplexed optical signal in which different modulation formats are used. A first optical signal transmitted in a first polarization component and a second optical signal transmitted in a second polarization component are multiplexed in the polarization multiplexed optical signal. The signal processing device includes a generator and a compensation circuit. The generator selects the first polarization component or the second polarization component based on modulation formats of the first and second optical signals, and generates a compensation value for compensating for an electric field information signal of a selected polarization component based on the electric field information signal of the selected polarization component. The compensation circuit compensates for electric field information signals of the first and second polarization components using the compensation value generated by the generator.
    Type: Application
    Filed: June 29, 2017
    Publication date: February 1, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Tomofumi Oyama, Hisao Nakashima, Yoshitaka Nomura, Takeshi Hoshida, Takahito Tanimura
  • Publication number: 20180026724
    Abstract: An optical transmitter includes: a light source configured to generate CW light; a drive signal generator configured to generate a drive signal; an optical modulator configured to modulate the CW light with the drive signal so as to generate a first optical signal; a combiner configured to combine the first optical signal and a second optical signal generated by using another light source; and a detector configured to detect a frequency difference between a frequency of the CW light and a center frequency of the second optical signal. The drive signal generator includes: a mapper configured to generate an electric field information signal based on input data; and a frequency controller configured to modify the electric field information signal based on the frequency difference such that the frequency of the CW light matches the center frequency of the second optical signal to generate the drive signal.
    Type: Application
    Filed: July 10, 2017
    Publication date: January 25, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Takahito Tanimura, Takeshi Hoshida