Pulse or digital communications – Spread spectrum – Direct sequence
Patent
1986-12-31
1989-07-11
Griffin, Robert L.
Pulse or digital communications
Spread spectrum
Direct sequence
375120, 370104, 332 16R, H04L 706, H03D 324
Patent
active
048478768
ABSTRACT:
A timing recovery apparatus for a burst mode communication receiver. The apparatus provides for optimum sampling and digitizing of received data at a plurality of data rates. In particular, a VCO is phase-locked to a local frequency reference prior to data being received. A reference timing preamble transmitted prior to the data is filtered and fed to the VCO causing it to injection lock such that the VCO becomes phase aligned with the preamble. The VCO is then permitted to "free run" during data transmission and continues to operate at substantially the same frequency. A synchronous divider and multiplexer, responsive to the VCO, allows selection of sampling clocks for the plurality of data rates. The divider is forced to a known state during VCO injection locking, to assure that the sampling clocks have maintained the proper phase for optimal sampling at the corresponding data rate. Further, means is provided to monitor the frequency of the VCO. Should the VCO frequency drift more than a predetermined amount an indication of such is produced.
REFERENCES:
patent: 3622913 (1971-11-01), Shipley
patent: 3963996 (1976-06-01), Skerlos
patent: 4017803 (1977-04-01), Baker
patent: 4063193 (1977-12-01), Wilcox
patent: 4169248 (1979-09-01), Hongu et al.
patent: 4286237 (1981-08-01), James
patent: 4321483 (1982-03-01), Dugan
patent: 4561101 (1985-12-01), Pinsard et al.
patent: 4565975 (1986-01-01), Gegner et al.
patent: 4633488 (1986-12-01), Shaw
"Digital Communications by Satellite", J. Spiker, Jr. Prentice-Hall, 1977, pp. 429-437.
Baumbach Randall L.
Berard Richard G.
Curtis Robert G.
Griffin Robert L.
Maginniss Christopher L.
Raytheon Company
Sharkansky Richard M.
Telesz Jr. Andrew J.
LandOfFree
Timing recovery scheme for burst communication systems does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Timing recovery scheme for burst communication systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Timing recovery scheme for burst communication systems will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-443064