Sliding-window based soft decision equalization for frequency selective MIMO channels

In this paper, we develop a novel sliding windowing soft-decision equalization (SW-SDE) technique for frequency selective MIMO channels in the quest for low-complexity equalizers with BER performance competitive to that of ML sequence detection. The proposed SW-SDE algorithm takes advantage of the Toeplitz channel matrix structure embodied in an equalization problem. It processes the data samples through a series of overlapping sliding windows to reduce complexity, and at the same time performs implicit noise tracking to maintain near-optimum performance. With its low complexity, simple implementation and near-optimum performance offered by iterative soft-decision processing, the proposed SW-SDE method is an attractive candidate to deliver efficient reception solution to practical high-capacity MIMO systems. Simulation comparisons of SW-SDE with MMSE-based MIMO DFE and sphere decoded quasi-ML detection are presented.