OFDM-MIMO system using Cayley differential unitary space time coding

In this paper we present the OFDM-MIMO system using Cayley differential unitary space-time coding. The main advantage of this coding scheme is the ability to have a high transmission rate and low complexity of the encoder-decoder without the need of channel information. The mapping parameters and the basis matrices play an important role in the formation of the Cayley code. The overall system combines the advantages of the OFDM modulation, MIMO channel and Cayley codes. Different decoding methods could be used. The maximum likelihood (ML) and the sphere decoding are the preferred decoding techniques for a better performance.