Iterative combined decision feedback equalization and decoding for broadband wireless single carrier systems

Single carrier transmission with frequency domain equalization (SC/FDE) exhibits approximately the same performance and signal processing complexity as orthogonal frequency division multiplexing (OFDM) for broadband wireless access (BWA) systems or W-LANs. We propose the extension with low complexity iterative decision feedback equalization and decoding for conventional blockwise SC/FDE transmission. The described turbo-like scheme approximately achieves the efficiency of ideal decision feedback equalization. We also demonstrate that the feedback of softly decided symbols before the first decoding step provides an extra gain. Simulation results show a remarkable performance increase for highly frequency selective multipath channels.