Iterative channel estimation and detection with computational efficient lattice basis reduction for MIMO systems

In multiple-input multiple-output (MIMO) systems, performance can be enhanced by iterative channel estimation and detection (ICED). Note that due to a large size of the signal alphabet, ICED becomes less practical unless a low complexity detector such as a lattice reduction (LR)-based detector is employed. However, as LR has to be performed for each iteration, the resulting complexity can be still high. In this paper, we propose a computational efficient technique to perform the lattice basis reduction within ICED over both static and slowly time-varying block-fading channels, where orthogonal defect of basis is considered to decide whether or not basis reduction is needed for each iteration.