Bit-interleaved trellis coded unitary space-time modulation with iterative decoding

Unitary space-time modulation (USTM) has recently been proposed as a promising approach to employ multiple antennas when the channel state information is not known either to the transmitter or to the receiver. In particular, optimal codes for USTM signals are being searched to improve the reliability. It is well known that trellis codes provide maximum free Euclidean distance but have a low diversity. In this paper, we propose a scheme of bit-interleaved (BI) trellis coded USTM with iterative decoding (ID). This scheme increases the diversity order while preserving reasonable minimum Euclidean distance. It is shown that with a moderate complexity increase, system performance can be improved significantly when compared with both uncoded USTM and trellis coded USTM with symbol interleaving.