Lattice-reduction-aided Wiener filtering for communications over ISI channels

Wiener filter is widely used to equalize the signals over inter-symbol interference (ISI) channels because of its low complexity and optimality in terms of mean square error (MSE). However, Wiener filter is generally not optimal in terms of symbol detection error and thus can exhibit considerable error performance degradation in ISI channels. Recently, to enhance the performance of linear equalizers, lattice reduction (LR) technique is proposed, which shows significant gain for multi-input multi-output systems. In this paper, we propose LR-aided Wiener filter that aims at minimizing the MSE for the symbols in lattice-reduced domain. Simulations show that the LR-aided Wiener filter exhibits significant error performance improvement over the Wiener filter, especially for higher-order modulations.