Clustering based blind estimation of PN sequences in M-ary spread spectrum system

To solve the problem of blind estimation of the pseudo-noise(PN) sequence in M-ary spread spectrum system(MSSS), this paper learned from the idea of unsupervised clustering analysis, then proposed a method of estimating PN sequences in M-ary spread spectrum system based on K-means clustering algorithm. In this method, the MSSS signal was divided into non-overlapped individuals to construct a data set, the blind synchronization of the PN sequence was completed by the detection statistic of the data set´s autocorrelation matrix; then the PN sequences set´s scale was estimated by searching the cost function based on K-means clustering algorithm, the cost function´s graph exhibited a significant inflection point,its position indicated the scale of PN sequences set; Finally the PN sequences was estimated by exploiting the clustering property of the data set. Theoretical analysis and computer simulations show that this method can accurately estimate the time delay and PN sequences in MSSS.