Design of space-time trellis codes in fast and flat fading channel

Improved design criteria for space-time trellis codes in fast fading channel are introduced and utilized. The criteria are based on union bound analysis and derived from the optimal FER performance. In the high SNR region the performance is governed primarily by symbol Hamming distance and the product criterion achieves an optimal coding gain, while in the low SNR region it is achieved by the trace criterion. We also discussed the performance behavior in the moderate SNR region. Finally, simulation results show that the proposed criteria are effective by comparing the performances of different codes.