OFDM-MIMO system using optimized differential Cayley unitary space time coding

In this paper, we optimize the OFDM-MIMO system using Cayley differential unitary space-time coding. The overall system combines the advantages of the OFDM modulation, MIMO channel and Cayley codes. A high transmission rate is one of the main advantages of the Cayley code, in addition to the simplicity of the encoder-decoder design, without the need for channel information. The mapping parameters and the basis matrices are the main components of the Cayley code. The optimization process of the Cayley code, with respect to the mapping parameters, is performed for the MIMO channel model represented by the downlink from a base station (BS) to a given user, with the scatterers arranged in the form of circular rings around the transmitter and the receiver.