Improved signal constellations for differential unitary space-time modulations with more than two transmit antennas

In this paper, we propose new and improved unitary signal constellations for differential unitary space-time modulations utilizing more than two transmit antennas. The proposed unitary designs are constructed from fundamental building blocks which comprise the generator matrices of diagonal cyclic codes, and the 2/spl times/2 and 3/spl times/3 rotational matrices. The performances of the proposed codes are superior to those of previously proposed codes.