A DS-SS signal acquisition algorithm for overcoming the impact of non-coherent data modulation

This paper proposes a kind of acquisition algorithm for Direct Sequence Spread Spectrum (DS-SS) signal, which can overcome the adverse impact of the non-coherent data modulation effectively. In the algorithm, the received signal is multiplied by its delay conjugate result to eliminate the impact of the data transition. Then the Fast Fourier Transform (FFT) is used to calculate the circular correlation to estimate the PN code phase. After that, we use the estimate result of the PN code phase to despread the received signal and get the estimate of the Doppler frequency, which is achieved by frequency spectrum analysis with FFT. Theoretical analysis and simulation results show that, compared with the traditional algorithms, the proposed algorithm is not sensitive with the moment the data transition occurs and it saves the acquisition time significantly. The algorithm proposed in this paper can be applied to capture high-speed non-coherent data modulated signals.