Arthur Dean Garrison

US Patent:

59109459, Jun 8, 1999

Filed:

Apr 30, 1996

Appl. No.:

8/643120

Inventors:

Arthur L. Garrison - Redondo Beach CA
Terrence R. Smigla - Manhattan Beach CA
Scott A. Stephens - Manhattan Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

H04J 306

US Classification:

370324

Abstract:

A method and apparatus are provided, for maintaining synchronous return and forward communications links between user terminals and earth stations communicating via a common satellite in a satellite based telecommunications system. Each user terminal maintains a closed synchronization loop with its associated earth station based on timing and frequency error offset signals received by the user terminals. The user terminals update their internal timing and frequency generators based on the received error offset signals. In an earth station sharing embodiment, one of the earth stations is designated as a master earth station while the remaining stations are designated as slave earth stations with respect to a common satellite. The slave earth stations monitor a return link between at least one user terminal and the master earth station. The slave earth stations update their internal reference timing and frequency signal generators, in order to remain synchronous with the return link between the monitored user terminal and the master earth station.

US Patent:

58445218, Dec 1, 1998

Filed:

Dec 2, 1996

Appl. No.:

8/758871

Inventors:

Scott A. Stephens - Manhattan Beach CA
Carl F. Reisig - Irving TX
Arthur L. Garrison - Redondo Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

G01S 502
H04B 7185

US Classification:

342357

Abstract:

A method is provided for determining the geolocation of a mobile terminal within a telecommunications satellite system. The system supports first and second forward communications links from first and second earth stations through first and second satellites to a common mobile terminal. The method includes receiving, at the mobile terminal, first and second forward link communications signals from the first and second earth stations and, based thereon, obtaining synchronization differential data. The synchronization differential data may include timing and frequency synchronization data necessary to maintain synchronization between the first and second communications at the mobile terminal. The mobile terminal transmits the synchronization differential data to the first earth station over the return link. The first earth station receives communications signals from the mobile terminal and based thereon calculates return link synchronization data.

US Patent:

59240156, Jul 13, 1999

Filed:

Apr 30, 1996

Appl. No.:

8/640198

Inventors:

Arthur L. Garrison - Redondo Beach CA
Terrence R. Smigla - Manhattan Beach CA
Scott A. Stephens - Manhattan Beach CA

International Classification:

H04B 7185

US Classification:

455 134

Abstract:

A power control method and apparatus are provided for a satellite based telecommunications system. The system includes a power control subsystem which is operative with systems operations center for distributing available satellite power between earth stations. Each earth station includes a baseband manager which subdivides the available satellite power between subband beams emitted from the satellite. The earth station further includes beam processors which manage the power allocated to each subband within an associated beam in order to maintain a desired signal quality in a forward link between the satellite and user terminals within the associated subbands. The beam processors communicate with modems, each of which is assigned to a particular user terminal. Each modem controls the satellites transmission power in the forward link to the user terminals to maintain a desired signal-to-noise ratio at the user terminal receiver. The signal-to-noise ratio is determined by the corresponding beam processor.