Frequency-domain space-time precoders for severe time-dispersive channel employing single-carrier modulations

Single carrier (SC) modulations employing frequency domain equalization (FDE) have been shown to be appropriate for severe time-dispersive channels, having similar or better performances than OFDM modulations, while offering the same complexity and lower peak-to-average power ratio. In this paper we introduce a class of low complexity linear frequency domain precoders (multiple-beamformers) for spatially correlated frequency selective multiple-input-multiple-output MIMO systems employing SC modulations. The specific designs targets minimization of a lower bound on the mean-square-error (MSE) under the assumption that only second order statistics of channel (covariance matrix of channel and noise) is available at the transmitter. These precoders are designed for different wideband receivers such as BLAST, MIMO-DFE, linear FDE. The proposed designs are assessed and compared for relatively large correlations and severely frequency selective channels.