A rate-one non-orthogonal space-time coded OFDM system with estimation for frequency selective channels

In this paper, we investigate the impact of applying the channel estimation method in [1] to an OFDM system equipped with rate 1 nonorthogonal space time block code for K transmit and 1 receive antennas. A new training pattern based on the Hadamard construction is designed that enables estimation of the K channels separately and thus reduces the effective noise variance in the estimate. The simulation result shows that using this low rank channel estimation in frequency selective slow fading channels yields very good BER performance comparable to the case when channel is known at the receiver. Moreover, the use of rate 1 non-orthogonal STBC achieves significantly superior performance vis-a-vis Alamouti's orthogonal STBC.