Patent ID: 6909738
Filing Date: 2005-06-21
Classification: G01S,H04B,H04L

Abstract:
1. A method for acquiring a receiver into a code modulated spread spectrum signal received by the receiver, in which method at least one replica code is used which corresponds to a code used with the modulation having a pre-determined number of chips, and an examination phase is performed, in which a frequency shift of the signal within a selected frequency area is examined, and a code phase of the code used with the modulation is examined, wherein the frequency shift examination is divided into a first estimation phase and a second estimation phase, wherein in the first estimation phase the selected frequency area is divided into a first set of frequencies, and in the second estimation phase a second set of frequencies is examined nearby each frequency of the first set of frequencies, that a comparison for frequencies of the second set of frequencies is performed using the received signal and the replica code, and that the results of the comparison are used to estimate a correct frequency shift.