A design of space-time trellis code to limit the position of received symbols for MPSK

STTCM employing multiple trellis coded modulation (ST-MTCM) considered by Lin achieve maximum transmit diversity gain with parallel paths, and the overall coding gain can be made larger than that achieved by conventional STTCM with the same throughput and the same number of states. To achieve the system performance, after achieving the full diversity, the intra-distance and the inter-distance shown by Lin can determine the system performance, especially, the intra-distance can finalizes the performance. In this paper, we focus attention on maximizing the intra-distance and the inter-distance in quasi-static flat fading channel. We make one of transmit information bits be uncoded bit and then transmitted from two transmit antennas, thus can increase the distance. between each receive constellation points and the distance between two parallel paths, then achieve the largest intra-distance using binary convolutional code instead of the integer matrix calculation as that of Tarokh and Lin. The proposed code achieves the theoretical maximal diversity gain and improves the coding gain compared to known codes.