Lattice-Reduction-Aided Detection with Successive Interference Cancelation for Multiuser Space-Time Block Coded Systems

Abstract

Effective detectors with low-complexity are considered for the Alamoutis multiuser space-time block coded (STBC)systems. Viewing the noiseless received signals from Q users as a lattice with basis vectors being the columns of the totalchannel matrix H, we apply lattice reduction to transform the original basis into a nearly orthogonal one which improvesthe decision regions against noise. Then, linear detection using zero-forcing (ZF) and minimum-mean-square-error (MMSE)methods is performed on the transformed basis to detect transmitted signals from the Q users. These lattice-reduction-aided(LRA) linear detectors significantly improve BER of the linear detectors and, more importantly, allow us to achieve fulldiversity at high Eb/N0 regions.