Searching good space-time trellis codes of high complexity

This paper discusses some issues in designing space-time trellis codes of high complexity, i.e., when the total number of candidate codes is large or the total number of pairwise error events is large. By adding windows in the search domain and combining the equal states in error state trellis, the complexity of search is greatly reduced. And at the same time, we can still find some codes which have very good performance. We present some new codes of high complexity at the end of this paper and show that our codes have better performance than many codes before.