Precoder Design for MIMO Broadcast Channels

Abstract

This paper considers precoder designs in downlink MIMO broadcast channels. We present a MMSE feedback precoding scheme, which is analogue to the MMSE generalized decision feedback equalizer (GDFE) in the uplink MIMO multiple access channel. The proposed scheme obtains the same level of total mean-square error as the MMSE-GDFE in the dual uplink with perfect decision, and it achieves a sum capacity that is very close to the sum capacity of MIMO BC. It can also offer a significant gain over the linear precoding techniques in term of average error probability.