Blind estimation of pseudo-random sequences of spread spectrum signals in multi-paths
Fangni Chen · Journal of Zhejiang University(Engineering Science) · 2007
In order to blind estimation the sequence of asynchronous direct spread signals, this work used independent component analysis(ICA) combining with principle component analysis(PCA) to blindly separate the data bits of different users without the knowledge of the channel.Due to the independence of data bits of different users and the quasi-orthogonal of direct sequences,the direct sequence of signals without multi-path interference could be directly obtained by ICA,and the direct sequence of signals with multi-path interference could be further identified according to the triple correlation function(TCF) of m-sequence.This blind estimation method does not need the synchronization information of direct sequence.The performance analysis under Gaussian noise indicates that this blind estimation arithmetic utilizes the spread gain of CDMA systems and the m-sequences can be obtained in lower SNR signal.