Patent ID: 6044105
Filing Date: 2000-03-28
Classification: H04B,H04L

Abstract:
A method for implementing a spread spectrum matched filter with Doppler correction, including the steps of:(a) receiving an input sample of a complex signal to be Doppler shift corrected and correlated to a code signal;(b) complex mixing at least a portion of the input sample with a Doppler shift correction value;(c) computing complex products for the mixed portion of the input sample with a current code phase of the code signal;(d) summing the computed complex products as a current complex integration value;(e) computing the square root value of the sum of the squares of the current complex integration value, each square root value having a magnitude and an associated code phase;(f) shifting the code signal to a next current code phase;(g) repeating steps (c) through (f) for the current code phase of the code signal;(h) outputing the code phase and magnitude of the computed square root value having the largest magnitude as an indication of correlation between the input sample and the code signal, corrected for Doppler shift.