Fast Acquisition in Long Pseudo Code DSSS System Based on External Memory

In order to achieve acquisition in large Doppler shift, strong interference and low SNR environment with limited memory resource, a parallel frequency domain acquisition method based on external memory is proposed. The method can be applied to a long pseudo code system with a pseudo code length of 8192, and achieving fast acquisition within time of 64 symbols in large Doppler shift and low SNR environment. Meanwhile, the memory consumption problem in long pseudo code DSSS system is solved by using external memory, which can save more than 75% of on-chip memory. The method is simulated by Matlab and implemented on hardware platform. The result shows that the system can achieve acquisition when Es/N0 is 3dB.