Patents by Inventor Stephen E. Ralph

Stephen E. Ralph 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: 20220407595
    Abstract: A method comprising: receiving optical output data of an optical device; supplying the optical output data to a trained neural network configured to transform optical output data to optical performance metrics; and executing the trained neural network to transform the supplied optical output data to optical performance metrics for the optical device.
    Type: Application
    Filed: November 5, 2020
    Publication date: December 22, 2022
    Inventors: Siddharth Jacob Varughese, Stephen E. Ralph
  • Patent number: 11381426
    Abstract: Systems and methods are provided for enabling lower-bandwidth hardware components to support higher data rates. In particular, aspects of the disclosed systems and methods use Raised Cosine pulse shaping in short-reach links to band limit the signal spectra and thereby enable existing, such lower-bandwidth components to support higher data rates.
    Type: Grant
    Filed: March 22, 2021
    Date of Patent: July 5, 2022
    Assignee: Georgia Tech Research Corporation
    Inventors: Siddharth Jacob Varughese, Joseph Justin Lavrencik, Stephen E. Ralph, Varghese Antony Thomas
  • Publication number: 20210211334
    Abstract: Systems and methods are provided for enabling lower-bandwidth hardware components to support higher data rates. In particular, aspects of the disclosed systems and methods use Raised Cosine pulse shaping in short-reach links to band limit the signal spectra and thereby enable existing, such lower-bandwidth components to support higher data rates.
    Type: Application
    Filed: March 22, 2021
    Publication date: July 8, 2021
    Inventors: Siddharth Jacob Varughese, Joseph Justin Lavrencik, Stephen E. Ralph, Varghese Antony Thomas
  • Patent number: 10958486
    Abstract: Systems and methods are provided for enabling lower-bandwidth hardware components to support higher data rates. In particular, aspects of the disclosed systems and methods use Raised Cosine pulse shaping in short-reach links to band limit the signal spectra and thereby enable existing, such lower-bandwidth components to support higher data rates.
    Type: Grant
    Filed: September 10, 2018
    Date of Patent: March 23, 2021
    Assignee: Georgia Tech Research Corporation
    Inventors: Siddharth Jacob Varughese, Joseph Justin Lavrencik, Stephen E. Ralph, Varghese Antony Thomas
  • Patent number: 10666277
    Abstract: A method for simulating and optimizing a digital to analog converter is disclosed. The method may include receiving a plurality of digital words. The method may also include determining an effective number of bits, a respective amplitude and a first amplitude correction amount for each digital word. Further, the first amplitude correction amount may be applied to each respective amplitude to generate respective first corrected amplitudes. A timing uncertainty may be determined which may be used to determine a second amplitude correction for each digital word. The second amplitude correction may be applied to each of the respective first corrected amplitudes to generate respective second corrected amplitudes. Next, a representation of an analog signal may be generated based in part on the second corrected amplitudes. Finally, a filter may be applied to the representation of the analog signal and then the representation of the analog signal is outputted.
    Type: Grant
    Filed: July 23, 2019
    Date of Patent: May 26, 2020
    Assignee: Georgia Tech Research Corporation
    Inventors: Siddharth Jacob Varughese, Jerrod Scott Langston, Stephen E. Ralph, Varghese Antony Thomas
  • Publication number: 20200028517
    Abstract: A method for simulating and optimizing a digital to analog converter is disclosed. The method may include receiving a plurality of digital words. The method may also include determining an effective number of bits, a respective amplitude and a first amplitude correction amount for each digital word. Further, the first amplitude correction amount may be applied to each respective amplitude to generate respective first corrected amplitudes. A timing uncertainty may be determined which may be used to determine a second amplitude correction for each digital word. The second amplitude correction may be applied to each of the respective first corrected amplitudes to generate respective second corrected amplitudes. Next, a representation of an analog signal may be generated based in part on the second corrected amplitudes. Finally, a filter may be applied to the representation of the analog signal and then the representation of the analog signal is outputted.
    Type: Application
    Filed: July 23, 2019
    Publication date: January 23, 2020
    Inventors: Siddharth Jacob Varughese, Jerrod Scott Langston, Stephen E. Ralph, Varghese Antony Thomas
  • Publication number: 20190081826
    Abstract: Systems and methods are provided for enabling lower-bandwidth hardware components to support higher data rates. In particular, aspects of the disclosed systems and methods use Raised Cosine pulse shaping in short-reach links to band limit the signal spectra and thereby enable existing, such lower-bandwidth components to support higher data rates.
    Type: Application
    Filed: September 10, 2018
    Publication date: March 14, 2019
    Inventors: Siddharth Jacob Varughese, Joseph Justin Lavrencik, Stephen E. Ralph, Varghese Antony Thomas
  • Patent number: 9794092
    Abstract: Systems and methods for identification and demodulation of complex signal formats are disclosed. In an example embodiment of the disclosed technology, a method includes identifying the signal's frame (or pattern) length, identifying the various modulation formats that compose the frame, determining the ratio of the various modulation formats in the frame, and determining the actual pattern arrangement in the frame. Further, a method can include comparing the determined arrangement to reference patterns to determine the complex signal format.
    Type: Grant
    Filed: March 21, 2016
    Date of Patent: October 17, 2017
    Assignee: Georgia Tech Research Corporation
    Inventors: Pierre P. Isautier, Stephen E. Ralph
  • Patent number: 9768874
    Abstract: Systems and methods for autonomous signal modulation format identification are disclosed. In an example embodiment of the disclosed technology, a method includes mapping an input signal to Stokes space to generate a representation of the input signal in three-dimensional space. The method may further include determining the dimension of the representation and, based on the dimension, selecting a subset of modulation from a plurality of mutually exclusive subsets of modulation formats. Further, the method may include defining a cost function for identifying the modulation format from the selected subset and evaluating the cost function to identify the modulation format.
    Type: Grant
    Filed: December 31, 2014
    Date of Patent: September 19, 2017
    Assignee: Georgia Tech Research Corporation
    Inventors: Stephen E. Ralph, Pierre Paul Roger Isautier
  • Patent number: 9735991
    Abstract: Systems and methods for autonomous signal modulation format identification are disclosed. In an example embodiment of the disclosed technology, a method includes mapping an input signal to Stokes space to determine whether a considered number of three-dimensional clusters value is above or below a predetermined value. The method may include selecting a modulation format from a first set of modulation formats if the considered number of three-dimensional clusters value is above the predetermined value. The method may further include applying higher-order statistics if the considered number of three-dimensional clusters value is below the predetermined value.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: August 15, 2017
    Assignee: Georgia Tech Research Corporation
    Inventors: Stephen E. Ralph, Pierre Isautier
  • Patent number: 8219893
    Abstract: A method and system using the principle of generalized maximum likelihood estimation to resolve sample timing uncertainties that are associated with the decoding of communication signals. By using generalized maximum likelihood estimation, sample timing uncertainty can be resolved by taking multiple samples of the received signal within a symbol period and determining which sample best corresponds to the optimal sample timing. The sample which best corresponds to the optimal sample timing can be determined from a timing index which can be calculated from ambiguity indicators that are based on the samples of the received signal.
    Type: Grant
    Filed: March 29, 2011
    Date of Patent: July 10, 2012
    Assignee: Quellan, Inc.
    Inventors: Andrew Joo Kim, Stephen E. Ralph, Sanjay Bajekal
  • Publication number: 20110222635
    Abstract: A method and system using the principle of generalized maximum likelihood estimation to resolve sample timing uncertainties that are associated with the decoding of communication signals. By using generalized maximum likelihood estimation, sample timing uncertainty can be resolved by taking multiple samples of the received signal within a symbol period and determining which sample best corresponds to the optimal sample timing. The sample which best corresponds to the optimal sample timing can be determined from a timing index which can be calculated from ambiguity indicators that are based on the samples of the received signal.
    Type: Application
    Filed: March 29, 2011
    Publication date: September 15, 2011
    Inventors: Andrew Joo Kim, Stephen E. Ralph, Sanjay Bajekal
  • Patent number: 7934144
    Abstract: A method and system using the principle of generalized maximum likelihood estimation to resolve sample timing uncertainties that are associated with the decoding of communication signals. By using generalized maximum likelihood estimation, sample timing uncertainty can be resolved by taking multiple samples of the received signal within a symbol period and determining which sample best corresponds to the optimal sample timing. The sample which best corresponds to the optimal sample timing can be determined from a timing index which can be calculated from ambiguity indicators that are based on the samples of the received signal.
    Type: Grant
    Filed: November 12, 2003
    Date of Patent: April 26, 2011
    Assignee: Quellan, Inc.
    Inventors: Andrew Joo Kim, Stephen E. Ralph, Sanjay Bajekal
  • Patent number: 7352824
    Abstract: Decreasing the average transmitted power in an optical fiber communication channel using multilevel amplitude modulation in conjunction with Pulse Position Modulation (PPM). This multilevel PPM method does not entail any tradeoff between decreased power per channel and channel bandwidth, enabling a lower average transmitted power compared to On/Off Keying (OOK) with no reduction in aggregate data rate. Therefore, multilevel PPM can be used in high-speed Dense Wavelength Division Multiplexed (DWDM) systems where the maximum number of channels is traditionally limited by nonlinear effects such as self-phase modulation (SPM), cross-phase modulation (XPM), four-wave mixing (FWM), stimulated Brillouin scattering (SBS), and stimulated Raman scattering (SRS). This modulation technique can enable an increased number of channels in DWDM systems, thereby increasing aggregate data rates within those systems.
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: April 1, 2008
    Assignee: Quellan, Inc.
    Inventors: Michael G. Vrazel, Stephen E. Ralph, Vincent Mark Hietala
  • Patent number: 7307569
    Abstract: Data throughput rates are increased in an optical fiber communication system without requiring replacement of the existing optical fiber in a link. Channel throughput is increased by upgrading the components and circuitry in the head and terminal of an optical fiber communication system link. Aggregate throughput in a fiber optic link is increased beyond the range of conventional Wavelength Division Multiplexed (WDM) upgrades, while precluding the necessity of replacing existing fiber plants. The increase in system throughput is achieved by using advanced modulation techniques to encode greater amounts of data into the transmitted spectrum of a channel, thereby increasing the spectral efficiency of each channel. This novel method of increasing transmission capacity by upgrading the head and terminal of the system to achieve greater spectral efficiency and hence throughput, alleviates the need to replace existing fiber plants.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: December 11, 2007
    Assignee: Quellan, Inc.
    Inventors: Michael G. Vrazel, Stephen E. Ralph, Joy Laskar, Sungyong Jung, Vincent Mark Hietala, Edward Gebara
  • Patent number: 7173551
    Abstract: Data throughput rates are increased in an optical fiber communication system without requiring replacement of the existing optical fiber in a link. Channel throughput is increased by upgrading the components and circuitry in the head and terminal of an optical fiber communication system link. Aggregate throughput in a fiber optic link is increased beyond the range of conventional Wavelength Division Multiplexed (WDM) upgrades, while precluding the necessity of replacing existing fiber plants. The increase in system throughput is achieved by using advanced modulation techniques to encode greater amounts of data into the transmitted spectrum of a channel, thereby increasing the spectral efficiency of each channel. This novel method of increasing transmission capacity by upgrading the head and terminal of the system to achieve greater spectral efficiency and hence throughput, alleviates the need to replace existing fiber plants.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: February 6, 2007
    Assignee: Quellan, Inc.
    Inventors: Michael G. Vrazel, Stephen E. Ralph, Joy Laskar, Sungyong Jung, Vincent Mark Hietala, Edward Gebara
  • Patent number: 7149256
    Abstract: Decreasing the average transmitted power in an optical fiber communication channel using multilevel amplitude modulation in conjunction with Pulse Position Modulation (PPM). This multilevel PPM method does not entail any tradeoff between decreased power per channel and channel bandwidth, enabling a lower average transmitted power compared to On/Off Keying (OOK) with no reduction in aggregate data rate. Therefore, multilevel PPM can be used in high-speed Dense Wavelength Division Multiplexed (DWDM) systems where the maximum number of channels is traditionally limited by nonlinear effects such as self-phase modulation (SPM), cross-phase modulation (XPM), four-wave mixing (FWM), stimulated Brillouin scattering (SBS), and stimulated Raman scattering (SRS). This modulation technique can enable an increased number of channels in DWDM systems, thereby increasing aggregate data rates within those systems.
    Type: Grant
    Filed: March 29, 2002
    Date of Patent: December 12, 2006
    Assignee: Quellan, Inc.
    Inventors: Michael G. Vrazel, Stephen E. Ralph, Vincent Mark Hietala
  • Patent number: 6870152
    Abstract: Systems for detection and compensation of modal dispersion in an optical fiber system including a multisegment photodetector coupled to an end of an optical fiber for detecting optical signals exiting the optical fiber and for converting the optical signals to an electrical output are provided. A representative multisegment photodetector includes a plurality of photodetector regions configured such that each of the plurality of photodetectors detects a portion of the plurality of optical signals exiting the end of the optical fiber and modifies the signal to reduce the affects of modal dispersion. Other systems are also provided.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: March 22, 2005
    Assignee: Georgia Tech Research Corporation
    Inventors: Stephen E. Ralph, Ketan Patel
  • Patent number: 6847760
    Abstract: A system is described that includes a system for correcting modal dispersion and errors in an optical fiber system. The system includes a multisegment photodetector coupled to an end of an optical fiber for detecting optical signals exiting the optical fiber and for converting the optical signals to an electrical output, the multisegment photodetector including a plurality of photodetector regions configured such that one of the plurality of photodetectors regions intercepts a mode in a manner distinct from another of the plurality of photodetectors. The system also includes logic configured to receive a resultant signal output from the photodetector regions and provide forward error correction decoding of the resultant signal.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: January 25, 2005
    Assignee: Georgia Tech Research Corporation
    Inventors: Cenk Argon, Steven William McLaughlin, Ketan Patel, Stephen E. Ralph
  • Publication number: 20040247238
    Abstract: A system is described that includes a system for correcting modal dispersion and errors in an optical fiber system. The system includes a multisegment photodetector coupled to an end of an optical fiber for detecting optical signals exiting the optical fiber and for converting the optical signals to an electrical output, the multisegment photodetector including a plurality of photodetector regions configured such that one of the plurality of photodetectors regions intercepts a mode in a manner distinct from another of the plurality of photodetectors. The system also includes logic configured to receive a resultant signal output from the photodetector regions and provide forward error correction decoding of the resultant signal.
    Type: Application
    Filed: July 24, 2002
    Publication date: December 9, 2004
    Applicant: Georgia Tech Research Corporation
    Inventors: Cenk Argon, Steven William McLaughlin, Ketan Patel, Stephen E. Ralph