Iterative receive algorithm for SFBC-OFDM systems in time-frequency dispersive fading channels
Liangcai Gan · Chinese Journal of Radio Science · 2009
Based on the generalized M(GM) channel estimation algorithm and the zero forcing principle,an iterative equalized generalized M(EQ-GM) algorithm is proposed and applied to the space frequency block coded orthogonal frequency division multiplexing systems.In the scheme,a frequency domain zero forcing equalizer for the 2×2 SFBC-OFDM system is deduced,in order to eliminate the channel coefficient differences of the adjacent subcarriers introduced by the frequency selective channel.Therefore,the receive algorithm can maintain the orthogonality of the SFBC codes,suppress the error propagation,accelerate the iteration convergence and hence improve the system performance effectively.Simulation results show that when the normalized Doppler is large,the SFBC-OFDM system can converge rapidly by using the EQ-GM algorithm.When the proposed system is compared with the expectation maximization(EM) SFBC-OFDM system and the time domain Kalman SFBC-OFDM system,gains of 8 dB and 14 dB can be obtained respectively.