Patent ID: 6532251
Filing Date: 2003-03-11
Classification: G01S,H04B

Abstract:
A method for data message bit synchronization of a spread spectrum signal having a repeating sequence of pseudorandom code bits modulated with data message bits having a data bit time that is an integer number of a repeat time of the pseudorandom code bits, comprising:receiving a first spread spectrum signal; determining a code phase delay; performing a plurality of coherent correlations at the determined code phase delay between the first spread spectrum signal and a first replica signal for a time interval corresponding to the data bit time; the plurality of coherent correlations corresponding in number to the integer number of the repeat time of the pseudorandom code bits; offsetting each of the coherent correlations relative to a previous correlation by the repeat time of the pseudorandom code bits; determining a magnitude of each of the plurality of coherent correlations; generating a plurality of non-coherent sums of magnitudes for each of the plurality of coherent correlations over at least two data bit times, the plurality of non-coherent sums of magnitudes corresponding in number to the integer number of the repeat time of the pseudorandom code bits.