Pulse or digital communications – Spread spectrum – Direct sequence
Reexamination Certificate
2006-11-07
2006-11-07
Bocure, Tesfaldet (Department: 2611)
Pulse or digital communications
Spread spectrum
Direct sequence
C375S149000, C370S335000
Reexamination Certificate
active
07133440
ABSTRACT:
A method and system for open-loop acquisition of a pseudo-noise (PN) encoded QPSK burst signal is provided. The method includes the steps of determining a PN correlation accumulation (PNCA) threshold and a sync threshold. Searching for a burst signal synchronization by searching a burst preamble for a sync word exceeding the sync threshold. In response to detecting the sync word, performing a PNCA of at least 256 bits following the detected sync word and comparing the PNCA of the at least 256 bits with the PNCA threshold. The comparison further includes the step of verifying that the PNCA of the 256 bits following the detected sync word exceeds the PNCA threshold and then verifying sync word detection. Next, using the burst preamble an estimate of carrier signal frequency is determined; and using a subsequent burst preamble carrier signal frequency and carrier signal phase is determined.
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Horne Lyman D.
Jones Delon
Kingston Samuel
Perkins Steven
Bocure Tesfaldet
Harrington & Smith,LLP
L-3 Communications Corporation
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