Performance of a space-time block coded OFDM system

Combined with antenna diversity, space-time coding is an attractive candidate for high-rate transmission systems such as orthogonal frequency division multiplexing (OFDM) systems. We propose space-time block coded OFDM systems that use training symbols coded by STBC. We use two training symbols at the beginning of each of two OFDM frames that are simultaneously transmitted from two corresponding transmit antennas. Based on the orthogonality of space-time block codes, we perform channel estimation by using training symbols, and compare to EM-based channel estimation methods. From the simulation results, we observe that our space-time block coding technique offers a good approach to channel estimation and better signal quality than the EM-based method.