Fast PN code acquisition algorithm with the constraints of low input signal noise ratio and low constant false alarm probability

Pseudo noise (PN) code acquisition with very low false alarm and miss probability in a limited period of time is required for the short frame burst-mode direct-sequence spread-spectrum (DSSS) communication systems. A novel noncoherent approach, based on multi-symbol accumulation-to-PN code acquisition and digital matched filters (DMFs), was proposed to solve the problem. It is an improved mode of the traditional DMF single dwell algorithm. By using the method of multi-symbol accumulation, the proposed algorithm can increase the signal-noise ratio (SNR) of code phase detection statistics, so the mean acquisition time is greatly shortened under the constraints of low input SNR and low false alarm probability. Its performance in QPSK-DSSS systems was analyzed. The simulation results show that the proposed algorithm is able to capture PN code fast under the constraints of low SNR and low false alarm probability.