US 6,647,057 B1Granted

Link adapter interface for upgrading existing satellite communication system for enhanced modulation and coding

AssigneeInternational Communications Products, Inc.

InventorsHenry Scott Caldwell, Charles Raymond Burr, Jr.

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Abstract

The standard BPSK modulation and encoding mechanisms employed by the head end of a satellite-linked DATS communication system are replaced with digital video broadcast standard QPSK modulation and Viterbi/Reed-Solomon error correction encoding that are effective to provide significantly improved link performance. Each downlinked receiver site is retrofitted with a front end link adapter interface that is operative to demodulate the link-efficient, replacement modulation and coding to baseband, and then convert the demodulated and MPEG-based packetized baseband signals into an original TDM aggregate baseband signal which is then remodulated and encoded into the communication protocol used by the existing non-upgraded receiver, so that the in-place receiver may demodulate the signal.

Claims25

Dependent claims

For use with a communication system, having a transmit site at which a baseband information signal has been modulated with a first type of digital phase modulation, to produce a first modulated signal for transmission over a communication link to a receiver site, said receiver site containing a receiver that is operative to demodulate and process said first modulated signal to derive said baseband information signal, a method of improving the utilization of said communication link comprising the steps of:

(a) at said transmit site,
(a1) substituting said first type of digital phase modulation with a prescribed error correction encode mechanism and second type of digital phase modulation to produce a second modulated and encoded signal, said second type of digital phase modulation being effective to increase bandwidth efficiency and/or reduce power usage for the transport of said second modulated and encoded signal over said communication link relative to said first type of digital phase modulation, and
(a2) processing said baseband information signal in accordance with said prescribed error correction encode mechanism and said second type of digital phase modulation to produce said second modulated and encoded signal that is transmitted over said communication link to said receiver site;
and
(b) at said receiver site,
(b1) demodulating said second modulated and encoded signal in accordance with said second type of digital phase modulation and processing the demodulated signal in accordance with a prescribed error correction decode mechanism to derive an intermediate baseband signal representative of said baseband information signal,
(b2) processing said intermediate baseband information signal in accordance with said first type of digital phase modulation to reproduce said first modulated signal, and
(c) coupling said reproduced first modulated signal to said receiver, wherein said reproduced first modulated signal is demodulated in accordance with said first type of digital phase modulation and processed to derive said baseband information signal.

5 more elements

For use with a communication system, having a receiver that is operative to process a first modulated and encoded signal transmitted over a communication link in accordance with a first type of digital phase demodulation and error correction decode mechanism, to derive a baseband information signal, a method of processing signals applied to said receiver comprising the steps of:

(a) processing a received signal that has been transported over said communication link in accordance with a second error correction encode mechanism and second type of digital phase modulation that is effective to increase bandwidth efficiency and/or reduce power usage over said communication link relative to said first type of digital phase modulation, in accordance with a second error correction decode mechanism to derive an intermediate baseband signal representative of said baseband information signal;
(b) processing said intermediate baseband information signal in accordance with a first error correction encode mechanism and said first type of digital phase, modulation to reproduce said first modulated and encoded signal;
and
(c) coupling said reproduced first modulated and encoded signal to said receiver, wherein said reproduced first modulated and encoded signal is demodulated in accordance with said first type of digital phase modulation and processed in accordance with said first error correction decode mechanism to derive said baseband information signal.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 09/185,353Filed 3 Nov 1998 · us provisional application
Priority: 3 Nov 1997
Granted: 11 Nov 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04N 21/4382
Interfacing the downstream path of the transmission network originating from a server, e.g. retrieving encoded video stream packets from an IP…
H04B 7/18523
Space-based or airborne stations; Stations for satellite systems: satellite systems for providing broadcast service to terrestrial stations, i.e.…
H04L 1/0003
By adapting the transmission rate: by switching between different modulation schemes
H04N 21/2383
Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth;…: channel…