Low-Complexity Iterative Block Decision Feedback Equalization for SC-FDE System

The Single Carrier Frequency Domain Equalization (SC-FDE) system can effectively work in frequency selective fading channels. The Iterative Block Decision Feedback Equalization (IBDFE) is efficient nonlinear equalization in SC-FDE systems. However, the computational complexity is high and the complexity is proportional to the number of iterations. In this paper, a low-complexity IB-DFE is proposed. The transmitted symbols go through a linear equalizer based on the minimum-mean-square-error (MMSE) criterion and the estimated symbols is as the output of the conventional feedback equalizer. The feedforward equalizer structure remains the same. Compared with the conventional IBDFE, the iteration is cancelled and the implementation complexity is reduced. Simulation results show that the performance of the proposed simplified design is similar to the traditional iterative IBDFE under frequency selective fading channels, but it imposes a lower complexity than the conventional IBDFE.