Optimum space-time processors with dispersive interference: Unified analysis and required filter span

In this paper, we consider optimum space-time equalizers with unknown dispe rsive interference, consisting of a linear equalizer that both spatially an d temporally whitens the interference and noise, followed by a decision-fee dback equalizer or maximum-likelihood sequence estimator, We first present a unified analysis of the optimum space-time equalizer, and then show that, for typical fading channels with a given signal-to-noise ratio (SNR), near -optimum performance can be achieved with a finite-length equalizer. Expres sions are given for the required filter span as a function of the dispersio n length, number of cochannel interferers, number of antennas, and SNR, whi ch are useful in the design of practical near-optimum space-time equalizers .