Research On Efficient Turbo Frequency Domain Equalization In STBC-MIMO System

An efficient Turbo Frequency Domain Equalization (FDE) based on symbol-wise minimum mean-square error (MMSE) filtering is proposed for a novel space-time block code (STBC) MIMO system. The transmitter sends a separate data block via STBC using two antennas per group to get diversity gain. The receiver can effectively utilize inter-antenna interference (IAI) and inter-symbol interference (ISI) followed by frequency domain equalization to process soft interference cancellation (SIC). After frequency domain filtering, the symbol Log-likelihood ratio (LLRS) calculated from the outputs of equalizer is as the inputs of the soft-in soft-out (SISO) decoder. Simulation results show that our proposed scheme provides a further substantial gain while not increasing complexity at the receiver.