In the paper

we propose a new design of unitary space-time constellations which is generated based on a combination of permutation method and rotation method.This method can provide better performance for the unitary space-time constellation signal.At the same time

for this joint constellation

a new classification demodulation algorithm is given.This algorithm can recognize the class of transmission signal with very low error probability and reduce the research range under the maximum-likelihood algorithm

so both the error performance and the complexity of constellations can be improved.Theoretical analysis and simulation results all show that the performances of proposed constellations are better than some other constellations which are designed by only one method while the complexity of demodulation is reduced greatly.