Blind Estimation of Spreading Sequence Based on Fast Approximated Power Iteration

Direct sequence spread spectrum (DSSS) signals are now widely used for communications, as well as for multiple access. DSSS transmitters use a spreading sequence to modulate the baseband signal before transmission. A receiver which does not know the spreading sequence cannot demodulate the signal. In the paper, we propose a method which can estimate the spreading sequence in a non-cooperative context. The method is based on fast approximated power iteration. The theoretic analysis and computer simulation results show that this algorithm can estimate spreading sequence quickly and accurately at low SNR. The algorithm has much less computation and storage than EVD, and its performance is better than the neural network algorithm and projection approximation subspace tracking algorithm.