Blind estimation algorithm of parameters in PN sequence for DSSS-BPSK signals

A scheme for blind estimation of parameters in direct sequence spread spectrum BPSK (DSSS-BPSK) signals without any prior information in low signal noise ratio (SNR) is proposed in this paper. Considering the characteristics that the Pseudo-Random noise (PN) sequence modulates the information symbols, firstly, a method based on reprocessing of the power spectrum density (RPSD) is used to estimate the period of PN sequence. Then, the staring symbol of the PN codes is determined by using segmentation processing and average cross-correlation calculation. At last, the method of matrix eigen decomposition (EVD) is used to estimate the PN sequence. To evaluate the performance of the estimation scheme, several experiments were carried out in MATLAB at different SNRs. Simulations results show that the algorithm performs well on signals at low SNR in non-cooperation communication system.