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).
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Patent number: 6963548Abstract: 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: GrantFiled: April 17, 2000Date of Patent: November 8, 2005Assignee: 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
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Patent number: 6807397Abstract: 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: GrantFiled: October 3, 2002Date of Patent: October 19, 2004Assignee: Hughes Electronics CorporationInventors: 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
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Patent number: 6785553Abstract: 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: GrantFiled: April 24, 2001Date of Patent: August 31, 2004Assignee: The Directv Group, Inc.Inventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Ming U. Chang, Frank A. Hagen
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Patent number: 6766987Abstract: 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: GrantFiled: August 28, 2002Date of Patent: July 27, 2004Assignee: Hughes Electronics CorporationInventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang
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Publication number: 20040056148Abstract: 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: ApplicationFiled: September 5, 2003Publication date: March 25, 2004Applicant: Hughes Electronics CorporationInventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
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Publication number: 20030208317Abstract: 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: ApplicationFiled: April 24, 2001Publication date: November 6, 2003Applicant: HUGHES ELECTRONICS CORPORATIONInventors: Donald C.D. Chang, Kar W. Yung, David C, Cheng, Ming U. Chang, Frank A. Hagen
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Patent number: 6643268Abstract: 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: GrantFiled: August 23, 1999Date of Patent: November 4, 2003Assignee: Hughes Electronics CorporationInventors: Kar W. Yung, David C. Cheng, Thu-Tam Trinh-Perches, Kenneth N. Gibson
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Patent number: 6606307Abstract: 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: GrantFiled: November 2, 1999Date of Patent: August 12, 2003Assignee: Hughes Electronics CorporationInventors: 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
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Publication number: 20030129942Abstract: 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: ApplicationFiled: October 3, 2002Publication date: July 10, 2003Applicant: Hughes Electronics CorporationInventors: Donald C. D. Chang, Kar W. Yung, David C. Cheng, Urban A. Von Der Embse, John I. Novak, Frank A. Taormina, Ming U. Chang
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Publication number: 20030022623Abstract: 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: ApplicationFiled: November 2, 1999Publication date: January 30, 2003Inventors: 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
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Publication number: 20030001048Abstract: 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: ApplicationFiled: August 28, 2002Publication date: January 2, 2003Applicant: Hughes Electronics CorporationInventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
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Patent number: 6501941Abstract: 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: GrantFiled: November 2, 1999Date of Patent: December 31, 2002Assignee: Hughes Electronics CorporationInventors: 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
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Patent number: 6460808Abstract: 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: GrantFiled: October 23, 2001Date of Patent: October 8, 2002Assignee: Hughes Electronics CorporationInventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang
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Publication number: 20020053627Abstract: 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: ApplicationFiled: October 23, 2001Publication date: May 9, 2002Applicant: Hughes Electronics CorporationInventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
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Publication number: 20020003192Abstract: 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: ApplicationFiled: February 13, 2001Publication date: January 10, 2002Applicant: Hughes Electronics CorporationInventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, Arthur W. Wang
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Patent number: 6336612Abstract: 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: GrantFiled: February 13, 2001Date of Patent: January 8, 2002Assignee: Hughes Electronics CorporationInventors: Frank Taormina, Donald C.D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang
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Patent number: 6327872Abstract: 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: GrantFiled: June 27, 2000Date of Patent: December 11, 2001Assignee: The BOC Group, Inc.Inventors: Robert Walter Boyd, Jessi Lynn Pike, David C. Cheng, Kelly Leitch
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Patent number: 6313790Abstract: 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: GrantFiled: February 9, 2001Date of Patent: November 6, 2001Assignee: Hughes Electronics CorporationInventors: Donald C. D. Chang, Kar W. Yung, William J. Nunan, David C. Cheng, Bruce E. Shuman
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Publication number: 20010009405Abstract: 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: ApplicationFiled: February 9, 2001Publication date: July 26, 2001Applicant: Hughes Electronics CorporationInventors: Donald C.D. Chang, Kar W. Yung, William J. Nunan, David C. Cheng, Bruce E. Shuman
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Patent number: 6257526Abstract: 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: GrantFiled: November 9, 1998Date of Patent: July 10, 2001Assignee: Hughes Electronics CorporationInventors: Frank Taormina, Donald C. D. Chang, Kar W. Yung, David C. Cheng, William W. Mayfield, John Novak, III, Arthur W. Wang