Xiang Qin Chen

US Patent:

6859466, Feb 22, 2005

Filed:

Nov 7, 2000

Appl. No.:

09/707362

Inventors:

Xiang Chen - Gaithersburg MD, US
Anthony Noerpel - Lovettsville VA, US
Enrique Laborde - Gaitherburg MD, US
David Roos - Boyds MD, US

Assignee:

Hughes Electronics Corporation - El Segundo CA

International Classification:

H04J003/06

US Classification:

370509, 370350, 370315

Abstract:

An approach for is provided for adapting to a variety of link propagation conditions is disclosed. A source terminal generates a packet data burst that includes a header and an optional payload. The header is modulated using a default modulation scheme and is coded using a default coding scheme. A switch is configured to receive and to forward the packet data burst. A destination terminal is configured to demodulate the header using the default modulation scheme and the default coding scheme, and to examine the header to determine a particular coding scheme and a particular modulation scheme associated with the payload. The protocol can be applied to any radio communication system, particularly, to a satellite communication system with multiple satellite terminals.

US Patent:

20030129943, Jul 10, 2003

Filed:

Dec 18, 2001

Appl. No.:

10/023777

Inventors:

Yunsang Park - Rockville MD, US
Doug Wasson - Olney MD, US
Xiang Chen - Gaithersburg MD, US

International Classification:

H04B007/185

US Classification:

455/013400, 455/522000

Abstract:

A system and method is provided for adapting communications links in a satellite system. A quality parameter of a communications link is continuously monitored, wherein the link provides satellite-based packet data service to a user terminal. The method further provides for reducing a short-term sensitivity of the quality parameter such that a modified quality parameter results. An operating parameter of the link is adapted based on the modified quality parameter. By adapting the operating parameter, transmission throughput can be optimized according to the unique channel environment of each user without sacrificing reliability.

US Patent:

20040203393, Oct 14, 2004

Filed:

Mar 13, 2002

Appl. No.:

10/096600

Inventors:

Xiang Chen - Gaithersburg MD, US

International Classification:

H04B015/00

US Classification:

455/063100, 455/454000, 455/012100

Abstract:

A system and method for operating two components of a communication system within the same spectrum is provided. A first component is associated with a first set of channels and a second component is associated with a second set of channels. The center frequencies of the first set of channels are offset from the center frequencies of the second set of channels and rolloff filtering is employed in order to minimize interference between channels in the first component and overlapping channels in the second component.