Complex signal transmission using real orthogonal space-time block codes with feedback

In this paper, it is shown that orthogonal space-time block code (OSTBC) matrices designed for real signal transmission can be used for the transmission of complex signals when limited feedback bits are available from receiver to transmitter. This approach simplifies the maximum likelihood (ML) decoding at the receiver while making full rate, full-diversity transmission of complex signals possible using 4 and 8 transmit antennas. Computer simulation results show that when sufficient feedback bits are used, the proposed scheme provides comparable performance to those of the complex OSTBCs with higher decoding complexities.