Spread Spectrum Signal Acquisition in the Presence of Fractional Doppler Frequency Offset

In high dynamic environment, the spread spectrum signal acquisition is one of the most challenging step in the process of DS/SS systems Synchronization. A novel twin- frequency-cell detection method using the locally optimum (LO) test statistic is addressed for spread spectrum signal acquisition in the presence of fractional Doppler frequency offset (FDFO) under Doppler frequency searching. In the twin-cell detection, To alleviate the correlation value reduction due to the FDFO, two consecutive correlator outputs under consecutive estimated DFO are combined to form the decision variable. The computer simulation results show that the proposed scheme offers superior acquisition performance over the conventional scheme based on the one cell estimated DFO detection.