Patent ID: 7634033
Filing Date: 2009-12-15
Classification: H04B

Abstract:
1. A system for detecting a spread spectrum encoded message within a received signal wherein the spread spectrum encoded message has been encoded with a predetermined pseudonoise code, the spread spectrum encoded message having an unknown code phase, unknown code frequency offset, and unknown carrier frequency offset, the system comprising: a receiver configured to accept the received signal and output a plurality of received signal streams; a first searcher coupled to the receiver and configured to accept at least one of the plurality of received signal streams and search a plurality of code phase hypotheses for the spread spectrum encoded message; a second searcher coupled to the receiver and configured to accept at least one of the plurality of received signal streams and search a plurality of code frequency offset hypotheses for the spread spectrum encoded message; a third searcher coupled to the receiver and configured to accept at least one of the plurality of received signal streams and search a plurality of carrier frequency offset hypotheses for the spread spectrum encoded message, wherein the first searcher, second searcher, and third searcher are configured to search in parallel the plurality of code phase, code frequency offset, and carrier frequency offset hypotheses to produce a plurality of correlation results, wherein the plurality of code frequency offset hypotheses is independent from the plurality of carrier frequency offset hypotheses; and an estimator, coupled to the first searcher, second searcher, and third searcher, and configured to accept the plurality of correlation results and estimate the unknown code phase, unknown code frequency offset, and unknown carrier frequency offset.