Patents by Inventor Junwen Zhang

Junwen Zhang 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: 9912431
    Abstract: Duo-binary encoding is used for encoding I and Q data prior to performing orthogonal frequency division multiplexing based transmission using discrete Fourier transform spreading (DFT-S). Advantageously, duo-binary encoding improves robustness of the encoded signal to inter symbol interference, making the degradation caused by the subsequent DFT-S stage less susceptible to reduction in bit error rate performance.
    Type: Grant
    Filed: February 12, 2016
    Date of Patent: March 6, 2018
    Assignee: ZTE Corporation
    Inventors: Jianjun Yu, Fan Li, Junwen Zhang, Xiao Xin, Hung-Chang Chien
  • Patent number: 9912500
    Abstract: The filter estimate produced by post-equalization processing of an optical signal at a receiver is used to generate pre-equalizer filter coefficients that are communicated back to the source of the optical signal for performing pre-equalization. In one advantageous aspect, the already existing post-equalization modules of an optical receive equipment can thus be used to produce, in addition, a pre-equalizer filter for use by the source side.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: March 6, 2018
    Assignee: ZTE Corporation
    Inventors: Jianjun Yu, Hung-Chang Chien, Junwen Zhang
  • Publication number: 20170237501
    Abstract: Disclosed systems, methods, and computer program products enable high symbol-rate optical Nyquist signal generation with roll-off factors approaching zero by combining digital and all-optical methods. The combined digital and all-optical methods utilize all-optical sine-shaped pulse generation and orthogonal time-division multiplexing with quadrature amplitude modulation using digital Nyquist signals. Disclosed embodiments exhibit inter-channel-interference penalties that are less than 0.5-dB for both 75-GBaud and 125-GBaud optical Nyquist signals, in contrast to conventional signals generated using rectangular waveform driving signals that exhibit penalties greater than 2.5-dB and 1.5-dB for 75-GBaud and 125-GBaud signals, respectively. The disclosed embodiments, therefore, enable significant improvement over conventional systems by reducing inter-channel-interference penalties caused by excess modulation induced bandwidth.
    Type: Application
    Filed: October 26, 2016
    Publication date: August 17, 2017
    Inventors: Jianjun Yu, Junwen Zhang
  • Patent number: 9698914
    Abstract: Systems, devices and techniques for processing received QPSK modulated optical signals include sampling the received signal at twice the baud rate, thereby producing samples that are then processed as 9-QAM symbols using a decision directed least squares optimization method. A third stage of channel equalization is filtering performs channel equalization to mitigate linear filtering effects along the transmission link. Data bits are then recovered from the resulting symbol estimates. The received optical signal may also include dual polarized signals for increased bandwidth capacity.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: July 4, 2017
    Assignee: ZTE Corporation
    Inventors: Jianjun Yu, Junwen Zhang
  • Publication number: 20160285657
    Abstract: The filter estimate produced by post-equalization processing of an optical signal at a receiver is used to generate pre-equalizer filter coefficients that are communicated back to the source of the optical signal for performing pre-equalization. In one advantageous aspect, the already existing post-equalization modules of an optical receive equipment can thus be used to produce, in addition, a pre-equalizer filter for use by the source side.
    Type: Application
    Filed: October 31, 2014
    Publication date: September 29, 2016
    Inventors: Jianjun YU, Hung-Chang CHIEN, Junwen ZHANG
  • Publication number: 20160248540
    Abstract: Duo-binary encoding is used for encoding I and Q data prior to performing orthogonal frequency division multiplexing based transmission using discrete Fourier transform spreading (DFT-S). Advantageously, duo-binary encoding improves robustness of the encoded signal to inter symbol interference, making the degradation caused by the subsequent DFT-S stage less susceptible to reduction in bit error rate performance.
    Type: Application
    Filed: February 12, 2016
    Publication date: August 25, 2016
    Inventors: Jianjun Yu, Fan Li, Junwen Zhang, Xiao Xin, Hung-Chang Chien
  • Publication number: 20160211939
    Abstract: An optical transmitter multiplexes multiple optical channels for transmission over an optical communication medium. The spectrum of modulated signal in each optical channel is lowpass filtered in the electrical (digital) domain at half the channel baud rate such that super Nyquist signal multiplexing can be achieved in the optical domain without having to perform optical filtering. An optical coupler may be used to multiplex the multiple optical channels.
    Type: Application
    Filed: August 26, 2014
    Publication date: July 21, 2016
    Applicant: ZTE Corporation
    Inventors: Jianjun Yu, Junwen Zhang
  • Publication number: 20160065313
    Abstract: Systems, devices and techniques for processing received QPSK modulated optical signals include sampling the received signal at twice the baud rate, thereby producing samples that are then processed as 9-QAM symbols using a decision directed least squares optimization method. A third stage of channel equalization is filtering performs channel equalization to mitigate linear filtering effects along the transmission link. Data bits are then recovered from the resulting symbol estimates. The received optical signal may also include dual polarized signals for increased bandwidth capacity.
    Type: Application
    Filed: March 28, 2014
    Publication date: March 3, 2016
    Inventors: Jianjun Yu, Junwen Zhang
  • Patent number: 9225455
    Abstract: Systems, devices and techniques for processing an optical signal transmitted from a source over a transmission medium having a length L and performing compensation of non-linear distortions include formulating the compensation as a digital back propagation algorithm by logically dividing the length L into N steps and compensating non-linear distortions for each step as a function of an attenuation adjusting constant parameter that can be selected from a range between 0.3 and 0.7.
    Type: Grant
    Filed: January 14, 2014
    Date of Patent: December 29, 2015
    Assignee: ZTE (USA) Inc.
    Inventors: Jianjun Yu, Junwen Zhang
  • Publication number: 20140199076
    Abstract: Systems, devices and techniques for processing an optical signal transmitted from a source over a transmission medium having a length L and performing compensation of non-linear distortions include formulating the compensation as a digital back propagation algorithm by logically dividing the length L into N steps and compensating non-linear distortions for each step as a function of an attenuation adjusting constant parameter that can be selected from a range between 0.3 and 0.7.
    Type: Application
    Filed: January 14, 2014
    Publication date: July 17, 2014
    Applicant: ZTE (USA) Inc.
    Inventors: Jianjun Yu, Junwen Zhang