Line Search Computation of the Block Factor Model for Blind Multi-User Access in Wireless Communications

In this paper, we present a technique for the blind separation of DS-CDMA signals received on an antenna array, for a multi-path propagation scenario that generates inter-symbol-interference. Our method relies on a new third-order tensor decomposition, which is a generalization of the parallel factor model. We start from the observation that the temporal, spatial and spectral diversities give a third-order tensor structure to the received data. This tensor is then decomposed in a sum of contributions, where each contribution fully characterizes one user. We also present a line search scheme that greatly improves the convergence speed of the alternating least squares algorithm previously used