Trellis-coded modulation and transmit diversity: design criteria and performance evaluation

Abstract

This paper presents the selection criteria for trellis codes used with the simple transmit diversity scheme proposed in Alamouti (1998) and reviewed in this paper. The optimum metrics for soft decision Viterbi decoding are derived and the asymptotic coding gains are calculated. The design method achieves both coding gain and a diversity order of 2 using 2 transmit antennas and 1 receive antenna. It is also demonstrated that trellis codes optimized for AWGN are also optimal for use in conjunction with the transmit diversity scheme in Rayleigh fading.