Minimum Mean Partial Interference Criterion for Serial Processing Structure of Equalizer and MLD in Multipath Fading MIMO Channel

This paper proposes a new criterion for equalizer combining weight called the minimum mean partial interference (MMPI) criterion, which is used with a serial processing structure of the equalizer and the maximum likelihood detection (MLD) for single-carrier signals in a multipath fading Multiple-Input Multiple-Output (MIMO) channel. The equalizer with the MMPI weight effectively suppresses multipath interference (MPI) as partial interference when compared with the conventional minimum mean square error (MMSE) equalizer by allowing leaving the inter-antenna interference (IAI) in the MIMO channel, and then the remaining IAIs are effectively suppressed by the MLD. We show that the additional complexity for modifying the MMSE equalizer to be the MMPI equalizer is quite small. Our computer simulation for the combination of the proposed MMPI equalizer and the MLD shows maximum 5.0-dB gain when compared with the conventional MMSE receiver. We also show that the throughput performance of HSDPA is improved by using the MMPI equalizer and MLD.