Hughes Electronics Corporation

The Directv Group, Inc.

David C Cheng

Kar W Yung

Donald C D Chang

John I Novak, Iii

Frank A Taormina

Ming U Chang

Arthur W Wang

William W Mayfield

Urban A Von Der Embse

Frank A Hagen

William J Nunan

Bruce E Shuman

Donald Cd Chang

Kenneth N Gibson

Thu-Tam Trinh-Perches

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.

Coherent synchronization of code division multiple access signals

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.

Method for identifying growth limits of handheld services for mobile satellite communications

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.

Position location of multiple transponding platforms and users using two-way ranging as a calibration reference for GPS

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.

Satellite system and method of deploying same

A method ( ) for identifying re-routing path solutions for signals within a switch network ( ). 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 ( ) into many individual sub-problems ( ). The algorithm then solves the individual sub-problems ( ) systematically according to desired constraints until the global solution is met ( ). The method finds a unique state for each switch such that the overall requirements of the system are met.

Method for re-routing signals in a switch network

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.

Techniques for utilization of bandwidth space assets

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. The processor then determines a circle of intersection representative of the set of possible positions for the orbiting transceiver based on the first range measurement and the first range rate wherein the circle of intersection includes a specific orientation in space, a specific radius and a center in a specific, three-dimensional position relative to the known position of the first transceiver. An angular position of the orbiting transceiver is then determined along the circle of intersection based on the known position of the second transceiver and the second range measurement. Finally, the position of the orbiting transceiver is determined based on the circle of intersection and the angular position.

Method and system for determining a position of a transceiver in a communications network

A method and system for using two-way ranging navigation to accurately determine the range along the path from source to destination by measuring the time delay during round-trip communication via satellite. 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.

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Palos Verdes Estates, CA, United States of America

David C Cheng