Daniel Fraley

US Patent:

57815402, Jul 14, 1998

Filed:

Jun 30, 1995

Appl. No.:

8/497582

Inventors:

James Eryx Malcolm - Bethesda MD
Daniel Fraley - Germantown MD
Adrian Morris - Gaithersburg MD
David Roos - Boyds MD
Kumar Swaminathan - North Potomac MD
Seok Ho Kim - North Potomac MD
Robert Carroll Marquart - Germantown MD

Assignee:

Hughes Electronics - Los Angeles CA

International Classification:

H04B 7212

US Classification:

370321

Abstract:

The present invention relates to a device and a method for communicating in a mobile communication system. The method provides a carrier signal having a plurality of frames. Each frame has a plurality of time slots, and each time slot comprises a plurality of transmission bits. A group of time slots are assigned to a communication channel. A traffic burst signal having a plurality of traffic symbols is transmitted over the communication channel by transmitting a first preamble over one of the assigned time slots, and transmitting a second preamble and at least one of the traffic symbols over at least one of the other assigned time slots. The second preamble occupies fewer transmission bits than the first preamble. The apparatus for transmitting a telephony signal over an RF channel includes a modem receiving a digitized PCM telephony signal and producing a traffic burst signal, and a transmitting unit in communication with the modem for transmitting a FDMA/TDMA signal carrying a plurality of traffic burst signals. At least one of the traffic burst signals carries a limited preamble message including a header field and a unique word field and at least one digitized voice message associated with a telephone call.

US Patent:

49724401, Nov 20, 1990

Filed:

Sep 23, 1988

Appl. No.:

7/248446

Inventors:

Gregory J. Ernst - Gaithersburg MD
Daniel M. Fraley - Germantown MD

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

H04L 2503

US Classification:

375 60

Abstract:

Transmitter for transmitting communication traffic via phase modulated carrier signals. The device provides for an efficient amplification of a phase modulated carrier signal using Class C amplifier technology. An envelope function is applied to the carrier signal by modulating the Class C amplifier with a related spectrum-suppressing amplitude envelope signal. Phase distortion accompanying the amplitude modulation of the Class C amplifier is compensated by generating a phase offset for the carrier signal. As each envelope function for suppressing the spectrum is generated, a corresponding phase offset may be applied to the carrier signal, avoiding the consequences of phase shift resulting from amplitude modulating the carrier signal in the Class C amplifier.