Patents by Inventor Liang DOU

Liang DOU 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).

  • Publication number: 20250219756
    Abstract: Embodiments of the present disclosure provide a fiber shuffle box, a data processing method and a computer storage medium. The fiber shuffle box includes: a shuffle box main body and a splitter, where the splitter is built in the shuffle box main body, the shuffle box main body is provided with a first fiber connection splice for connecting with a line direction unit and a second fiber connection splice for connecting with a local add-drop unit, the splitter is connected between the first fiber connection splice and the second fiber connection splice, and the number of wire cores of the second fiber connection splice is smaller than the number of wire cores of the first fiber connection splice. The fiber shuffle box has higher compatibility.
    Type: Application
    Filed: March 24, 2023
    Publication date: July 3, 2025
    Inventors: Huan ZHANG, Liang DOU, Sai CHEN, Chongjin XIE
  • Publication number: 20240421933
    Abstract: The present disclosure relates to a spectrum adjustment method for an optical transmission system and a network management system. Taking a goal of providing at least one available idle frequency band for a first wavelength channel desired to be created, a spectrum adjustment scheme is generated based on frequency band information of a wavelength channel currently used by a transmitting-end and receiving-end device corresponding to the first wavelength channel in the optical transmission system, where the spectrum adjustment scheme is used to characterize frequency band adjustment information of the wavelength channel that needs to be adjusted. An adjustment instruction is sent to the transmitting-end and receiving-end device based on the spectrum adjustment scheme. Thus, the optimization of spectrum resources can be realized based on the generated spectrum adjustment scheme, thereby providing support for the creation of the first wavelength channel.
    Type: Application
    Filed: January 29, 2023
    Publication date: December 19, 2024
    Inventors: Liang DOU, Boyuan YAN, Chongjin XIE
  • Publication number: 20240339800
    Abstract: A method and an apparatus for controlling an optical fiber amplifier, a system, a transmission node and a storage medium. WDM transmission systems are deployed between a first communication end and a second communication end. At least one target WDM transmission system includes a first transmission node and a second transmission node. The first transmission node receives a first control signal including an identifier of the second transmission node, and switches on a transmit-end optical fiber amplifier of the first transmission node if determining that the first control signal is a normal control signal and the second transmission node identifier matches a pre-stored first reference node identifier. The second transmission node receives a second control signal including an identifier of the first transmission node, and performs a similar judgment to switch on a transmit-end optical fiber amplifier of the second transmission node.
    Type: Application
    Filed: July 29, 2022
    Publication date: October 10, 2024
    Inventors: Huan ZHANG, Liang DOU, Sai CHEN, Chongjin XIE, Xingbin LI
  • Patent number: 12113572
    Abstract: A method for calculating configuration of an optical transmission network includes: acquiring an initial value of an input power of an optical cable; based on the initial value, obtaining an output power of each channel at an end of a section of the optical cable according to a loss of the optical cable; taking the output power of each channel at the end of the section as a boundary condition to calculate the input power of each channel at the section based on an amount of optical power transferred from a high-frequency channel to a low-frequency channel due to an SRS effect; and calculating a first parameter value of an optical amplifier of the section using the input power of each channel at the section and the output power of each channel at the end of a preceding section of the section.
    Type: Grant
    Filed: December 15, 2022
    Date of Patent: October 8, 2024
    Assignee: Alibaba (China) Co., Ltd.
    Inventors: Liang Dou, Chongjin Xie, Jingchi Cheng, Pak Tao Lau
  • Publication number: 20230198615
    Abstract: A method for calculating configuration of an optical transmission network includes: acquiring an initial value of an input power of an optical cable; based on the initial value, obtaining an output power of each channel at an end of a section of the optical cable according to a loss of the optical cable; taking the output power of each channel at the end of the section as a boundary condition to calculate the input power of each channel at the section based on an amount of optical power transferred from a high-frequency channel to a low-frequency channel due to an SRS effect; and calculating a first parameter value of an optical amplifier of the section using the input power of each channel at the section and the output power of each channel at the end of a preceding section of the section.
    Type: Application
    Filed: December 15, 2022
    Publication date: June 22, 2023
    Inventors: Liang DOU, Chongjin XIE, Jingchi CHENG, Botao LIU
  • Publication number: 20230194779
    Abstract: An optical transmission system is provided. The optical transmission system includes a first board card including a multiplexer/demultiplexer, and an optical amplifier. The multiplexer/demultiplexer is configured to receive a plurality of first split optical signals and combine the received plurality of first split optical signals into a first combined optical signal, and the optical amplifier is configured to amplify power of the first combined optical signal.
    Type: Application
    Filed: December 6, 2022
    Publication date: June 22, 2023
    Inventors: Sai CHEN, Chongjin XIE, Huan ZHANG, Liang DOU, Rui LU
  • Patent number: 10771230
    Abstract: An estimating apparatus for bias drift of a transmitting end modulator, a compensating apparatus, a receiver and a method are disclosed. Estimation and compensation of the bias drift are performed directly at the receiving end according to phase recovered received signals, with no need of providing an extra bias control circuit at the transmitting end. Estimating and compensating for the bias drift includes recovering received signals by removing a frequency difference and a phase difference between a transmitting end laser and a receiving end laser producing phase recovered received signals, estimating the bias drift of the transmitting end modulator according to the phase recovered received signals and compensating the bias drift of the transmitting end modulator in a receiver.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: September 8, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Liang Dou, Zhenning Tao
  • Patent number: 10623128
    Abstract: An apparatus and method for processing a frequency offset of a pilot and a receiver where the includes: calculating a correlation function of a channel by using a receiving or received signal and a correlation length; calculating a phase to which the correlation length corresponds according to the correlation function; and calculating a corresponding slope according to phases to which at least two correlation lengths correspond when the phase to which the correlation length corresponds is greater than 2?, and estimating a frequency offset of a pilot of the channel based on the slope. Hence, estimation of a frequency offset of a pilot may be accurately achieved, thereby accurately judging channel spacing.
    Type: Grant
    Filed: April 21, 2017
    Date of Patent: April 14, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Huihui Li, Ying Zhao, Zhenning Tao, Liang Dou
  • Patent number: 10574350
    Abstract: A method and apparatus estimating direct current bias of an optical modulator and a receiver. The method includes: performing signal processing to obtain a phase noise compensated signal, extracting a receiving signal component based on the phase noise compensated signal, removing the receiving signal component from the phase noise compensated signal, and calculating a received signal power based on the signal with the receiving signal component being removed. The method includes calculating a direct current bias of the optical modulator based on the receiving signal component, the received signal power and a drive signal power of the optical modulator.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: February 25, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Yangyang Fan, Liang Dou
  • Patent number: 10491294
    Abstract: A signal processing apparatus and method for monitoring channel spacing which may be configured in a receiver and includes: a first determining unit to determine a frequency range of a pilot of a center channel and a frequency range of a pilot of a neighboring channel using a receive signal; a second determining unit to determine a center channel frequency offset of the center channel pilot according to the center channel frequency range, and determine a frequency offset of the neighboring channel pilot according to the neighboring channel frequency range; and a third determining unit to determine channel spacing between the center channel and the neighboring channel according to the center channel frequency offset, the neighboring channel frequency offset and a frequency of a pilot signal at a transmitter side.
    Type: Grant
    Filed: April 21, 2017
    Date of Patent: November 26, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Huihui Li, Ying Zhao, Zhenning Tao, Liang Dou
  • Patent number: 10439852
    Abstract: Embodiments of the present disclosure provide a signal processing apparatus, a signal transmitting apparatus and a receiver, which are adapted for a frequency division multiplexing system having a high-order modulation format. A receiver having a high-magnification sampling rate by inserting a pilot signal between neighboring subcarriers at a transmitter side, calculating a laser phase noise according to a phase of the pilot signal at a receiver side, and performing down-sampling and equalization processing after performing carrier phase recovery according to the laser phase noise, so that a laser phase noise having a wide frequency may be accurately compensated, thereby having a relatively powerful carrier phase recovery ability.
    Type: Grant
    Filed: April 22, 2016
    Date of Patent: October 8, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Liang Dou, Zhenning Tao
  • Patent number: 10367635
    Abstract: Embodiments of this disclosure provide a signal transmission apparatus, a carrier phase recovery apparatus and method. By inserting phase modulation signals with variable amplitudes into data modulation signals and performing carrier phase recovery on received signals at a receiving end according to the phase modulation signals, the apparatuses and methods are applicable to communications systems of various modulation formats and are compatible with existing communications systems, and calculation complexity is relatively low. Furthermore, as the amplitudes of the inserted phase modulation signals are variable, the phase modulation signals may be flexibly configured in data modulation signals, to lower redundancy and influence on the system capacity is relatively small.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: July 30, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Xiaofei Su, Liang Dou, Zhenning Tao
  • Publication number: 20190222308
    Abstract: A method and apparatus estimating direct current bias of an optical modulator and a receiver. The method includes: performing signal processing to obtain a phase noise compensated signal, extracting a receiving signal component based on the phase noise compensated signal, removing the receiving signal component from the phase noise compensated signal, and calculating a received signal power based on the signal with the receiving signal component being removed. The method includes calculating a direct current bias of the optical modulator based on the receiving signal component, the received signal power and a drive signal power of the optical modulator.
    Type: Application
    Filed: March 28, 2019
    Publication date: July 18, 2019
    Applicant: Fujitsu Limited
    Inventors: Yangyang FAN, Liang DOU
  • Patent number: 10263698
    Abstract: Embodiments of the present disclosure provide a monitoring apparatus for an optical signal to noise ratio, a signal transmission apparatus and a receiver. White noise power of received signals is calculated according to noise power and power of pilot signals of the received signals in different polarization states, and influence of a nonlinear noise is excluded, thereby accurately estimating an optical signal to noise ratio, for example, with a calculation process being simple and an application range being relatively wide.
    Type: Grant
    Filed: October 12, 2016
    Date of Patent: April 16, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Liang Dou, Zhenning Tao
  • Patent number: 10243725
    Abstract: Embodiments of this disclosure provide an apparatus and method for generating a transmitting sequence, a training sequence synchronization apparatus and method, an apparatus and method for estimating channel spacing and a system. The training sequence synchronization apparatus includes: a delay correlation processing unit configured to parallelly perform autocorrelation operations of different delay amounts on a receiving sequence containing a periodic training sequence to obtain multiple parallel correlation sequences; a superimposition processing unit configured to perform a superimposition operation on the multiple parallel correlation sequences to obtain a synchronization correlation sequence; and a synchronization extracting unit configured to perform a synchronization position extraction on the synchronization correlation sequence to obtain a synchronization position of the training sequence. With the embodiments of this disclosure, anti-noise performance of the training sequence may be enhanced.
    Type: Grant
    Filed: March 9, 2017
    Date of Patent: March 26, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Ying Zhao, Liang Dou, Zhenning Tao
  • Patent number: 10230469
    Abstract: Provided is an apparatus for measuring a filtering characteristic, a pre-equalizer and an optical communication equipment where the apparatus includes: a first processing unit configured to determine a filtering characteristic of a receiving end, or determine a joint response of a filtering characteristic of a transmitting end and the filtering characteristic of the receiving end, in a spectrum of a receiving signal obtained after a first measurement signal and a second measurement signal pass through respective filtering modules, according to a nonoverlapped spectral part of the first measurement signal and the second measurement signal. The filtering modules through which the first measurement signal passes include a transmitting end filtering module and a receiving end filtering module, the filtering module through which the second measurement signal passes include the receiving end filtering module.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: March 12, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Yangyang Fan, Liang Dou, Zhenning Tao
  • Patent number: 10225010
    Abstract: A method and apparatus for measuring a filtering characteristic, pre-equalizer and communication equipment. The apparatus for measuring a filtering characteristic includes: a first processing unit configured to determine a filtering characteristic of a receiving end according to an amplitude of a receiving signal obtained after a measurement signal passes through a transmitting end filtering module and a receiving end filtering module at provided different frequency offsets of a transmitting laser of a transmitting end and a local laser of the receiving end.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: March 5, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Zhenning Tao, Yangyang Fan, Liang Dou
  • Patent number: 10171162
    Abstract: An apparatus and method for measuring frequency response characteristics of an optical transmitter and an optical receiver where the apparatus includes: a generating unit configured to generate a driving signal for driving the modulator of the optical transmitter, which comprises at least two frequencies; and a calculating unit configured to respectively calculate the frequency response characteristics of the optical transmitter and the optical receiver according to output signal components in output signals of the optical receiver corresponding to at least two detection signal components of identical amplitudes and different frequencies in detection signals. The frequency response characteristics of the optical transmitter and the optical receiver may be obtained, the amplitude responses and phase responses in the frequency response characteristics may be respectively obtained, and the measurement results are accurate and reliable.
    Type: Grant
    Filed: March 31, 2017
    Date of Patent: January 1, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Cheng Ju, Liang Dou, Zhenning Tao
  • Patent number: 10116388
    Abstract: A method and apparatus for measuring a filtering characteristic, pre-equalizer and communication equipment. The method includes: obtaining a receiving signal after two measurement signals of different spectral ranges pass through different filtering modules and are received at the same time at a receiving end; and determining a part of a filtering characteristic of a receiving end and a part of a joint response according to a nonoverlapped spectral part of the two signals in the spectrum of the receiving signal.
    Type: Grant
    Filed: December 12, 2016
    Date of Patent: October 30, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Yangyang Fan, Zhenning Tao, Liang Dou
  • Patent number: 9998223
    Abstract: Embodiments of the present disclosure provide a calculating apparatus and method for nonlinear weighting coefficient. The calculating apparatus for nonlinear weighting coefficient includes: an approximation processing unit configured to use a rational function to perform approximation processing on a link loss/gain function in intra-channel nonlinear distortion estimation; and a coefficient calculating unit configured to calculate a nonlinear weighting coefficient in the nonlinear distortion estimation by using the approximated link loss/gain function and a large dispersion approximation, to obtain an analytical closed solution of the nonlinear weighting coefficient. With the embodiments of the present disclosure, a weighting coefficient of high precision may be obtained, thereby performing high-precision estimation on nonlinear distortion in case of loss.
    Type: Grant
    Filed: October 9, 2015
    Date of Patent: June 12, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Ying Zhao, Liang Dou, Zhenning Tao