Recent years have witnessed fast and tremendous
growth in the wireless communication industry.
Future wireless communication systems are expected
to provide a wide variety of new services, from high-
quality voice to high-definition video and wireless
multimedia for anyone, anywhere at anytime. This
results in ever increasing demands for high data
rate through harsh wireless channels over scarce
frequency spectrum and is the key challenge in
wireless system design. In this work, new and novel
downlink multi-user MIMO systems are described and
investigated. The ultimate goal of this work is to
1) investigate the impact of various realistic
considerations, e.g. spatial fading correlation,
imperfect CSI, on system performance and develop
adaptive algorithms to improve system performance
under these considerations, 2) investigate methods
to further improve the spectrum efficiency by
exploiting the synergy between the PHY layer and the
MAC layer. The investigation and analysis of this
work may be helpful in defining MU-MIMO systems for
different scenarios and should be especially useful
to professionals in the wireless communications area.