Patents by Inventor Edem Ibragimov

Edem Ibragimov 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: 20190181962
    Abstract: The technology disclosed in this patent document can be implemented to provide an analog front part of an optical receiver module for coherent optical detection where the optical receiver module receives the optical input from a fiber link, performs optical to electrical conversion and analog processing for carrier frequency compensation, optical phase noise compensation and polarization rotation, and generates an analog electrical output for subsequent signal processing for coherent optical detection. The analog processing for the polarization rotation is placed downstream from the analog processing for carrier frequency compensation, and in some implementations, downstream from the analog processing for optical phase noise compensation.
    Type: Application
    Filed: February 15, 2019
    Publication date: June 13, 2019
    Inventor: Edem IBRAGIMOV
  • Patent number: 8565621
    Abstract: A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: October 22, 2013
    Assignee: Opnext Subsystems, Inc.
    Inventors: Edem Ibragimov, Sunil Kumar Singh Khatana
  • Patent number: 8437632
    Abstract: Systems and techniques for optical communications based on polarization division multiplexing are described.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: May 7, 2013
    Assignee: Opnext Subsystems, Inc.
    Inventors: Edem Ibragimov, Theodore J. Schmidt
  • Patent number: 8428183
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: April 23, 2013
    Assignee: Opnext Subsystems, Inc.
    Inventors: Sunil Kumar Singh Khatana, Edem Ibragimov
  • Publication number: 20120250793
    Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.
    Type: Application
    Filed: April 1, 2011
    Publication date: October 4, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Sunil Kumar Singh Khatana, Edem Ibragimov
  • Publication number: 20120224847
    Abstract: A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.
    Type: Application
    Filed: September 23, 2011
    Publication date: September 6, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Edem Ibragimov, Sunil Kumar Singh Khatana
  • Publication number: 20120020659
    Abstract: Systems and techniques for optical communications based on polarization division multiplexing are described.
    Type: Application
    Filed: October 3, 2011
    Publication date: January 26, 2012
    Applicant: OPNEXT SUBSYSTEMS, INC.
    Inventors: Edem Ibragimov, Theodore J. Schmidt
  • Patent number: 8032025
    Abstract: Systems and techniques for optical communications based on polarization division multiplexing are described.
    Type: Grant
    Filed: October 22, 2008
    Date of Patent: October 4, 2011
    Assignee: Opnext Subsystems, Inc.
    Inventors: Edem Ibragimov, Theodore J. Schmidt
  • Publication number: 20100098420
    Abstract: Systems and techniques for optical communications based on polarization division multiplexing are described.
    Type: Application
    Filed: October 22, 2008
    Publication date: April 22, 2010
    Applicant: STRATALIGHT COMMUNICATIONS, INC.
    Inventors: Edem Ibragimov, Theodore J. Schmidt
  • Patent number: 7627031
    Abstract: An apparatus and method for adaptively introducing a compensating signal latency related to a signal latency of a data symbol decision circuit. Adaptive timing control circuitry, including an interpolating mixer implemented as a tapped delay line with correlated tap coefficients, introduces a latency adaptively and substantially matching the latency of the data decision circuit for use within an adaptive equalizer, thereby minimizing the mean-squared error of such decision circuit. This adaptive latency is used in generating the feedback error signal which, in turn, can be used by the feedforward equalizer for dynamically adjusting its adaptive filter tap coefficients.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: December 1, 2009
    Assignee: Scintera Networks Inc.
    Inventors: Qian Yu, Venugopal Balasubramonian, Jishnu Bhattacharjee, Debanjan Mukherjee, Abhijit Phanse, Abhijit G. Shanbhag, Edem Ibragimov, Fabian Giroud
  • Patent number: 7561617
    Abstract: Systems and methods are disclosed to provide channel monitoring and/or performance monitoring for a communication channel. For example, in accordance with an embodiment of the present invention, an equalizer is disclosed that equalizes for channel distortions and also provides channel and performance monitoring information, such as for example bandwidth estimation, channel identification, signal-to-noise ratio, chromatic dispersion, and/or polarization-mode dispersion.
    Type: Grant
    Filed: September 21, 2007
    Date of Patent: July 14, 2009
    Assignee: INPHI Corporation
    Inventors: Abhijit G. Shanbhag, Abhijit Phanse, Jishnu Bhattacharjee, Debanjan Mukherjee, Prashant Choudhary, Edem Ibragimov, Venugopal Balasubramonian, Qian Yu, Madabusi Govindarajan
  • Patent number: 7505515
    Abstract: A continuous time equalizer for equalizing an input signal using a feedforward equalizer portion and a feedback equalizer portion is provided that includes: a slicer operable to make bit decisions on a combined output from the feedforward and feedback equalizer portions; an adaptive delay circuit operable to delay the combined output to form a delayed output; and a controller operable to control the delay provided by the adaptive delay circuit such that a first group delay through the slicer and a second group delay through the adaptive delay circuit in response to a sinusoidal form of the input signal are substantially equal.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: March 17, 2009
    Assignee: Scintera Networks, Inc.
    Inventors: Prashant Choudhary, Qian Yu, Edem Ibragimov, Venu Balasubramonian, Debanjan Mukherjee, Jishnu Bhattacharjee, Fabian Giroud
  • Patent number: 7421021
    Abstract: An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: September 2, 2008
    Assignee: Inphi Corporation
    Inventors: Venugopal Balasubramonian, Jishnu Bhattacharjee, Edem Ibragimov, Debanjan Mukherjee, Abhijit Phanse, Abhijit Shanbhag, Qian Yu
  • Patent number: 7394849
    Abstract: A decision feedback equalizer with dynamic feedback control for use in an adaptive signal equalizer. Timing within the decision feedback loop is dynamically controlled to optimize recovery of the data signal by the output signal slicer. The dynamic timing is controlled by a signal formed as a combination of feedback and feedforward signals. The feedback signal is an error signal related to a difference between pre-slicer and post-slicer signals. The feedforward signal is formed by differentiating and delaying the incoming data signal.
    Type: Grant
    Filed: October 9, 2006
    Date of Patent: July 1, 2008
    Assignee: Scintera Networks Inc.
    Inventors: Edem Ibragimov, Qian Yu, Prashant Choudhary
  • Patent number: 7379495
    Abstract: An apparatus and method for adaptively introducing a compensating signal latency related to a signal latency of a data symbol decision circuit. Adaptive timing control circuitry, including an interpolating mixer implemented as a tapped delay line with correlated tap coefficients, introduces a latency adaptively and substantially matching the latency of the data decision circuit for use within an adaptive equalizer, thereby minimizing the mean-squared error of such decision circuit. This adaptive latency is used in generating the feedback error signal which, in turn, can be used by the feedforward equalizer for dynamically adjusting its adaptive filter tap coefficients.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: May 27, 2008
    Assignee: Scintera Networks Inc.
    Inventors: Qian Yu, Venugopal Balasubramonian, Jishnu Bhattacharjee, Debanjan Mukherjee, Abhijit Phanse, Abhijit G. Shanbhag, Edem Ibragimov, Fabian Giroud
  • Patent number: 7339988
    Abstract: Systems and methods are disclosed to provide channel monitoring and/or performance monitoring for a communication channel. For example, in accordance with an embodiment of the present invention, an equalizer is disclosed that equalizes for channel distortions and also provides channel and performance monitoring information, such as for example bandwidth estimation, channel identification, signal-to-noise ratio, chromatic dispersion, and/or polarization-mode dispersion.
    Type: Grant
    Filed: July 3, 2003
    Date of Patent: March 4, 2008
    Assignee: Scintera Networks, Inc.
    Inventors: Abhijit G. Shanbhag, Abhijit Phanse, Jishnu Bhattacharjee, Debanjan Mukherjee, Prashant Choudhary, Edem Ibragimov, Venugopal Balasubramonian, Qian Yu, Madabusi Govindarajan
  • Publication number: 20070230557
    Abstract: An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.
    Type: Application
    Filed: June 7, 2007
    Publication date: October 4, 2007
    Applicant: Scintera Networks, Inc.
    Inventors: Venugopal Balasubramonian, Jishnu Bhattacharjee, Edem Ibragimov, Debanjan Mukherjee, Abhijit Phanse, Abhijit Shanbhag, Qian Yu
  • Patent number: 7266145
    Abstract: An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: September 4, 2007
    Assignee: Scintera Networks, Inc.
    Inventors: Venugopal Balasubramonian, Jishnu Bhattacharjee, Edem Ibragimov, Debanjan Mukherjee, Abhijit Phanse, Abhijit G. Shanbhag, Qian Yu
  • Publication number: 20070091995
    Abstract: A decision feedback equalizer with dynamic feedback control for use in an adaptive signal equalizer. Timing within the decision feedback loop is dynamically controlled to optimize recovery of the data signal by the output signal slicer. The dynamic timing is controlled by a signal formed as a combination of feedback and feedforward signals. The feedback signal is an error signal related to a difference between pre-slicer and post-slicer signals. The feedforward signal is formed by differentiating and delaying the incoming data signal.
    Type: Application
    Filed: October 9, 2006
    Publication date: April 26, 2007
    Applicant: SCINTERA NETWORKS, INC.
    Inventors: Edem Ibragimov, Qian Yu, Prashant Choudhary
  • Patent number: 7120193
    Abstract: A decision feedback equalizer with dynamic feedback control for use in an adaptive signal equalizer. Timing within the decision feedback loop is dynamically controlled to optimize recovery of the data signal by the output signal slicer.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: October 10, 2006
    Assignee: Scintera Networks, Inc.
    Inventors: Edem Ibragimov, Qian Yu, Prashant Choudhary