Performance enhancement of space time block coded MIMO systems using training design

This paper considers the performance enhancement of orthogonal space time block coded (OSTBC) multiple-input multiple-output system based on an optimal training strategy. Pairwise error probability (PEP) based performance analysis provides us the training design tools as well as a generic expression for the performance improvement due to optimal training compared to the conventional case for OSTBC system equipped with any number of transmit and receive antennas and any modulation schemes, e.g., M-array PSK, MSK and QAM. It is observed that the linear processing in the receiver, the most attractive feature of OSTBC, although destroys the orthogonality in the presence of channel estimation error (CEE), does not reduce diversity, but, causes performance penalty as a loss of SNR due to training. This loss of performance is quantified analytically and minimized by optimal allocation of power between training and data symbols.