Blind estimation of multiple co-channel digital signals in vector FIR channels

Abstract

In this paper we examine the problem of detecting multiple co-channel signals arriving at a sensor array in a dispersive, slowly fading environment. This problem of separating and estimating co-channel signals has recently drawn much attention due to its applications in digital mobile radio. First, we propose a spatio-temporal approach for estimating both the channel and the signals in a delay-spread multipath fading environment. In this approach we exploit the discrete-alphabet property of some of the digital modulation schemes in this algorithm. This algorithm is applicable to an unknown array geometry and propagation environment, and hence it is especially attractive to digital mobile communication applications. Next we examine the matched filter bound for this channel environment. We obtain closed form expressions for the matched filter bound for the single user vector channel. Finally we present some preliminary simulation results to examine the performance of this algorithm and compare it to the single user matched filter bound.