Joint prefiltering and MLSE equalization of space-time-coded transmissions over frequency-selective channels

The problem of designing a front-end prefilter to improve the performance and/or reduce the complexity of maximum likelihood sequence estimation equalization of space-time-coded signals is addressed in this paper. The front-end prefilter performs channel shortening without excessive noise enhancement and is constrained to be a finite impulse response filter for practical implementation. Transmission scenarios emphasized assume two transmit antennas (with delay diversity or space-time trellis coding) and either one or two receive antennas. Extensions to more antennas are straightforward. Various design parameters (such as number of prefilter taps, number of equalizer states, and decision delay) are optimized using Monte Carlo simulations in a typical urban EDGE environment.