Pulse or digital communications – Repeaters – Testing
Patent
1989-11-30
1991-06-18
Chin, Stephen
Pulse or digital communications
Repeaters
Testing
375 86, 329304, H04L 2718
Patent
active
050254553
ABSTRACT:
A demodulator for OQPSK signals modulated with two unique words resolves eight possible cominbations of phase ambiguity which may product data error by first processing received I.sub.R and Q.sub.R data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the unique words to not only reverse the received I.sub.R and Q.sub.R data channels, but to also invert (complement) the I.sub.R and/or Q.sub.R data, or to at least complement the I.sub.R and Q.sub.R data for systems using nontransparent codes that do not have rotation direction ambiguity.
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Adams Harold W.
Chin Stephen
Jones Thomas H.
Manning John R.
The United States of America as represented by the Administer, N
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