On space-time coding for quasi-static multiple-antenna channels

We propose a new space-time coding scheme for the quasi-static multiple-antenna channel with perfect channel state information at the receiver and no channel state information at the transmitter. The new scheme includes both trellis space-time codes and layered space-time codes as special cases. When the number of transmit antennas is not larger than the number of receive antennas our scheme can be efficiently decoded by minimum mean-square error (MMSE) decision-feedback interference cancellation coupled with Viterbi decoding through the use of per-survivor processing (PSP). We discuss the code design for the new scheme, and show that finding codes with optimal diversity is much easier than for conventional trellis space-time codes. We provide an upper bound to the word-error rate of our scheme which is both accurate and easy to evaluate. Then, we find upper and lower bounds to the information outage probability with discrete i.i.d. inputs (as opposed to Gaussian inputs, as in most previous works) and we show that the MMSE front-end yields a large advantage over the whitened matched filter front-end when coupled with the decision-feedback PSP-based decoder. Our scheme yields a large performance gain with respect to coded V-BLAST of similar complexity, and it can be easily coupled with the recently proposed linear-dispersion precoding to handle the case of a number of receive antennas smaller than the number of transmit antennas.