Blind source extraction in a multiuser context

In this paper, we consider the problem of blind detection of DS-CDMA signals in a multipath, asynchronous context (up-link transmission). We show that blind source extraction techniques provide a general framework but must be constrained to ensure the detection of the source signal corresponding to a given spreading sequence. First, we provide an original analysis of the constrained methods derived from the work of Tsatsanis (1997), unifying all these approaches and showing their limitations in multipath propagation. Second, we also propose a complete multiuser detection system based on the constant modulus algorithm, in the case of large channel dispersion (more than one symbol period).