Blind estimation of PN code in multipath fading direct sequence spread spectrum systems

A combination method is presented to estimate the unknown pseudo-noise (PN) spreading sequence for direct sequence spreading spectrum (DS-SS) signals in frequency selective fading channel. Performance of traditional blind estimator based on eigenanalysis techniques shows significant performance degradation when directly employed in multipath fading environment. Borrowing blind channel estimation and equalization ideas, we provide two methods to mitigate the effect of channel-induced distortion. Eigenanalysis method is then exploited to estimate the PN code. Some illustrative simulations are presented for the combined method and the experimental results are analyzed.