Space-time diversity using orthogonal and amicable orthogonal designs

We consider the utilization of multiple transmitter and receiver antennas for space-time diversity. The optimal SNR scheme, which also provides the best diversity, is outlined. This scheme however involves a reduction in the data rate. Coding schemes are then presented which not only achieve the optimal SNR but also mitigate the reduction of data rate. The proposed schemes are based on the theory of orthogonal designs and amicable orthogonal designs.