SIC-based decoding algorithm for space-frequency coded transmitter diversity

A new decoding algorithm based on successive interference cancellation (SIC) is presented for space-frequency coded transmitter diversity (SFC-TD) in OFDM systems. In the previously proposed SFC-TD technique, the complex channel gain between adjacent subcarriers is assumed to be constant. By using a simple decoder at the receiver, which is similar to matched filter (MF), satisfactory bit error rate (BER) performance can be obtained in small delay spread channels. Whereas, in large delay spread channels, the great variation in complex channel gain between adjacent subcarriers will introduce inter-subcarrier interference in the decoding process and degrade the BER performance. In order to combat the interference introduced by the channel gain variation between adjacent subcarriers, a SIC-based decoder with modest complexity increase is addressed in this paper. Simulation results indicate that the SIC-based SFC-TD technique significantly outperforms the MF-based SFC-TD technique when the delay spread is large in frequency selective fading channels.