Global MMSE design for SDMA in downlink of multi-user MIMO systems
Suili Feng · Journal of Guilin University of Electronic Technology · 2007
Using the Spatial Division Multiple Access(SDMA) in the downlink can improve the capacity of a multi-user MIMO system.The BD(Block Diagonalization) algorithm can diagonalize a multi-user MIMO channel and decouple it into several parallel independent point-to-point MIMO channels,which can suppress the Multi User Interference(MUI) between the users completely.This paper proposes on the basis of the BD algorithm a design method for SDMA that can minimize the MSE of the system.With a constraint of the total transmission power of the downlink,the algorithm transmission allocates the power of each user dynamically according the noise power of each user and jointly optimizes both the encoding filter of base station and the decoding filter of each user.