Research results imply that the performance of space-time trellis codes achieving the maximum diversity mainly depends on minimum determinant among all possible differential signal matrix
as well as the appearance probability of this value.An optimization algorithm of STTC(Space-Time Trellis Cods) is proposed in this paper
and some better performance codes are introduced.As the simulation results show
0.3-1dB is improved on those proposed by exhaustive search.