Design criteria for space-time trellis codes based on product distance distribution and trace distribution in fast fading channels

It is proposed to use the minimum product distance as the design criterion for a space-time trellis code (STTC) in a fast fading environment. Reference 1 discusses the minimum product distance for all error event paths. Reference 2, on the other hand, discusses the minimum product distance for the minimal error event path. This paper shows, as the first step, that by itself, the minimum product distance for the minimal error event path is not sufficient to evaluate correctly the frame error rate performance of STTC. Then it is shown that the minimum product distance for the error event paths that affect the error rate under consideration is fairly effective as a design criterion. It is further proposed to use the product distance distribution and the average trace of code word distance matrix for the minimal event path as design criteria for the STTC. A computer simulation demonstrates that the proposed design criterion is more effective than the conventional design criterion. A computer search based on the proposed design criterion shows that an STTC that achieves a better frame error rate performance than the conventional STTC can be discovered.