Blind multiuser vector channel estimation for space-time diffused signals

A near-far resistant channel estimation technique is proposed for DS-CDMA signals transmitted over a multiuser frequency-selective fading channel. The spatially and temporally diffuse rays for a particular user are considered to arrive in clusters, separated in time and/or space. The proposed technique estimates the DOA mean and variance, and the time delay offset and decay factor for each cluster. The technique is shown to effectively resolve sources even where they are closely located in time and space. Furthermore, unlike many DS-CDMA channel estimators, the technique also performs well in the presence of co-code interferers