An improved space-time trellis coded modulation scheme on slow Rayleigh fading channels

It has been established that the appropriate criteria for space-time trellis coded modulation (STTCM) design on slow Rayleigh fading channels are maximization of the minimum rank and the minimum determinant of the distance matrices. We show here that when STTCM is used in systems with a large product of the numbers of the transmit and the receive antennas (>3), the multiple fading subchannels between individual transmit and receive antenna pairs converge to an additive white Gaussian noise (AWGN) channel and the design of codes with maximum coding gain is governed by the minimum trace of the distance matrices, or the minimum Euclidean distance between any two codewords over all transmit antennas. A number of new 4 and 8-PSK codes based on the proposed design criterion were constructed and shown to be superior to other known codes.