Abstract:

To eliminate the intersymbol interference and fast time varying deep fading of ionosphere channel in high data rate high frequency (HF) transmission systems, a novel iterative combiningequalization algorithm based on minimum mean square error criterion is proposed. The proposed algorithm exchanges log likelihood ratio values through iterative process between soft input soft output (SISO) decoder and SISO combiningequalizer, which realizes the joint optimization of spatial diversity combining and Turbo equalization, and makes full use of both time and frequency domain information. In addition, considering the huge computational burden brought by iterative process, a simplified method with low performance loss is given. Simulation results show that the proposed algorithm can reduce the receiver bit error rate effectively and the lowcomplexity algorithm can achieve an excellent tradeoff between complexity and performance.