On maximum-likelihood detection and decoding for space-time coding systems

Space-time coding (STC) schemes for communication systems employing multiple transmit and receive antennas have been attracting increased attention. In this paper, we address two interrelated problems: detection of space-time codes under various interference conditions and information transfer from the STC detector to an error-correcting channel decoder. By taking a systematic maximum-likelihood (ML) approach to the joint detection and decoding problem, we show how to design optimal detectors and how to integrate them with a channel decoder. We also discuss various aspects of channel modeling for STC communication receivers. In particular, while many previous works on space-time coding assume that the channel is a stochastic quantity, we find that a deterministic channel model can have some advantages for the receiver design. Finally, we illustrate our results by numerical examples. Index Terms-Interference suppression, maximum-likelihood estimation, maximum-likelihood sequence detection, MIMO systems, space-time coding, soft information