Patents by Inventor David C. Cheng

David C. Cheng 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: 6963548
    Abstract: A novel method and apparatus is described for reducing the number of CDMA codes for a constellation of multiple trasponder platforms serving a number of subscribers in the same service area. A coherent processing technique synchronizes the phase of CDMA signals arriving at a subscriber from multiple trasponder platforms to increase the code capacity and thus the number of possible subscribers for most of the multiple transponder platform systems in current use.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: November 8, 2005
    Assignee: The DIRECTV Group, Inc.
    Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Frank A. Hagen, Ming U. Chang, John I. Novak, III
  • Patent number: 6807397
    Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: October 19, 2004
    Assignee: Hughes Electronics Corporation
    Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Urban A. Von Der Embse, John I. Novak, III, Frank A. Taormina, Ming U. Chang
  • Patent number: 6785553
    Abstract: A method and system for using two-way ranging navigation to accurately determine the location of a transponder platform above-Earth or a fixed or mobile target on the ground or on water. The two-way ranging navigation measurements are used as calibration references, thereby improving the positioning accuracy of GPS. The system includes GPS and a two-way ranging navigation system for taking position measurements of a target. A correction factor is determined as a function of the measurements and the GPS position is adjusted by the correction factor. The method for calibrating GPS using two-way ranging navigation involves taking a two-way ranging navigation measurement and a GPS measurement of a target, determining a correction factor as a function of the measurements, and correcting the GPS position by taking a second GPS measurement and adjusting it by the correction factor.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: August 31, 2004
    Assignee: The Directv Group, Inc.
    Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Ming U. Chang, Frank A. Hagen
  • Patent number: 6766987
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: July 27, 2004
    Assignee: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang
  • Publication number: 20040056148
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is, spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Application
    Filed: September 5, 2003
    Publication date: March 25, 2004
    Applicant: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
  • Publication number: 20030208317
    Abstract: A method and system for using two-way ranging navigation to accurately determine the location of a transponder platform above-Earth or a fixed or mobile target on the ground or on water. The two-way ranging navigation measurements are used as calibration references, thereby improving the positioning accuracy of GPS. The system includes GPS and a two-way ranging navigation system for taking position measurements of a target. A correction factor is determined as a function of the measurements and the GPS position is adjusted by the correction factor. The method for calibrating GPS using two-way ranging navigation involves taking a two-way ranging navigation measurement and a GPS measurement of a target, determining a correction factor as a function of the measurements, and correcting the GPS position by taking a second GPS measurement and adjusting it by the correction factor.
    Type: Application
    Filed: April 24, 2001
    Publication date: November 6, 2003
    Applicant: HUGHES ELECTRONICS CORPORATION
    Inventors: Donald C.D. Chang, Kar W. Yung, David C, Cheng, Ming U. Chang, Frank A. Hagen
  • Patent number: 6643268
    Abstract: A method (100) for identifying re-routing path solutions for signals within a switch network (10). The path solutions are subject to special constraints that provide the most desired solution for a user. The method applies an algorithm that works by transforming a global problem (110) into many individual sub-problems (112). The algorithm then solves the individual sub-problems (112) systematically according to desired constraints until the global solution is met (120). The method finds a unique state for each switch such that the overall requirements of the system are met.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: November 4, 2003
    Assignee: Hughes Electronics Corporation
    Inventors: Kar W. Yung, David C. Cheng, Thu-Tam Trinh-Perches, Kenneth N. Gibson
  • Patent number: 6606307
    Abstract: Methods for operating a satellite constellation are disclosed that utilize spatial diversity and directional gain antennas at ground terminal locations to provide multiple data rate services on a single frequency channel. One method comprises receiving a signal at a first and second satellite in the satellite constellation from a first communications device. A communications channel at a first frequency from the first satellite is used to communicate with the first communications device. A signal from a second communications device is received only at the second satellite at the first frequency, and the second satellite is used to communicate with the second communications device at the first frequency without substantially interfering with the communications with the first communications device.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: August 12, 2003
    Assignee: Hughes Electronics Corporation
    Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Urban A. Von Der Embse, John I. Novak, III, Frank A. Taormina, Ming U. Chang
  • Publication number: 20030129942
    Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.
    Type: Application
    Filed: October 3, 2002
    Publication date: July 10, 2003
    Applicant: Hughes Electronics Corporation
    Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Urban A. Von Der Embse, John I. Novak, Frank A. Taormina, Ming U. Chang
  • Publication number: 20030022623
    Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.
    Type: Application
    Filed: November 2, 1999
    Publication date: January 30, 2003
    Inventors: DONALD C. D. CHANG, KAR W. YUNG, DAVID C. CHENG, URBAN A. VON DER EMBSE, JOHN I. NOVAK III, FRANK A. TAORMINA, MING U. CHANG
  • Publication number: 20030001048
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Application
    Filed: August 28, 2002
    Publication date: January 2, 2003
    Applicant: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
  • Patent number: 6501941
    Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.
    Type: Grant
    Filed: November 2, 1999
    Date of Patent: December 31, 2002
    Assignee: Hughes Electronics Corporation
    Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Urban A. Von Der Embse, John I. Novak, III, Frank A. Taormina, Ming U. Chang
  • Patent number: 6460808
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Grant
    Filed: October 23, 2001
    Date of Patent: October 8, 2002
    Assignee: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang
  • Publication number: 20020053627
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Application
    Filed: October 23, 2001
    Publication date: May 9, 2002
    Applicant: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
  • Publication number: 20020003192
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Application
    Filed: February 13, 2001
    Publication date: January 10, 2002
    Applicant: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
  • Patent number: 6336612
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Grant
    Filed: February 13, 2001
    Date of Patent: January 8, 2002
    Assignee: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang
  • Patent number: 6327872
    Abstract: The present invention provides a method and apparatus for producing a pressurized high purity liquid carbon dioxide stream in which a feed stream composed of carbon dioxide vapor is purified within a purifying filter and then condensed within a condenser. The result liquid is then alternately introduced and dispensed from two first and second pressure accumulation chambers. The first and second pressure accumulation chambers are heated by electrical heaters to pressurize the liquid to the required or desired delivery pressure of the pressurized liquid carbon dioxide stream. Such stream is alternately extracted from the first and second pressure accumulation chambers on a continuous basis in which one of the first and second pressure accumulation chambers acts in a dispensing role while the other is being filled. The pressurized liquid carbon dioxide stream can be further filtered within a particulate filter.
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: December 11, 2001
    Assignee: The BOC Group, Inc.
    Inventors: Robert Walter Boyd, Jessi Lynn Pike, David C. Cheng, Kelly Leitch
  • Patent number: 6313790
    Abstract: A method and system for determining a position of an orbiting transceiver in a communications network includes at least a first and second transceiver at a first and second known location, respectively, on Earth. The first and second transceivers are adapted to transmit and receive communications signals to and from the orbiting transceiver. A processor coupled to one of the first and second transceivers determines a first and second range measurement between each of the first and second transceivers and the orbiting transceiver, respectively, as well as corresponding first and second range rates representative of a time rate of change of the first and second range measurements.
    Type: Grant
    Filed: February 9, 2001
    Date of Patent: November 6, 2001
    Assignee: Hughes Electronics Corporation
    Inventors: Donald C. D. Chang, Kar W. Yung, William J. Nunan, David C. Cheng, Bruce E. Shuman
  • Publication number: 20010009405
    Abstract: A method and system for determining a position of an orbiting transceiver in a communications network includes at least a first and second transceiver at a first and second known location, respectively, on Earth. The first and second transceivers are adapted to transmit and receive communications signals to and from the orbiting transceiver. A processor coupled to one of the first and second transceivers determines a first and second range measurement between each of the first and second transceivers and the orbiting transceiver, respectively, as well as corresponding first and second range rates representative of a time rate of change of the first and second range measurements.
    Type: Application
    Filed: February 9, 2001
    Publication date: July 26, 2001
    Applicant: Hughes Electronics Corporation
    Inventors: Donald C.D. Chang, Kar W. Yung, William J. Nunan, David C. Cheng, Bruce E. Shuman
  • Patent number: 6257526
    Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.
    Type: Grant
    Filed: November 9, 1998
    Date of Patent: July 10, 2001
    Assignee: Hughes Electronics Corporation
    Inventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang