Iterative equalization for severe time dispersive MIMO channels

In this work, a minimum mean-squared error (MMSE) iterative equalization method for a severe time dispersive MIMO channel is proposed. To mitigate the severe time dispersiveness of the channel single carrier with cyclic prefix (SCCP) is employed and the equalization is performed in the frequency domain. The use of cyclic prefix (CP) and equalization in the frequency domain simplifies the challenging problem of equalization in MIMO channels due to both the inter-symbol-interference (ISI) and co-antenna interference (CAI). The proposed iterative algorithm works in two stages. The first stage estimates the transmitted frequency domain symbols using a low complexity MMSE equalizer. The second stage finds the a posteriori probabilities of the estimated symbols to find their means and variances to use in the MMSE equalizer in the following iteration. Simulation results show the superior performance of the iterative algorithm when compared with the conventional MMSE equalizer.