Turbo-LORD: A MAP-Approaching Soft-Input Soft-Output Detector for Iterative MIMO Receivers

In this paper a novel Soft-Input Soft-Output detector, namely Turbo-LORD, is proposed for iterative MIMO receivers. This is an improved version, capable of managing a priori information, of the Layered ORthogonal lattice Detector recently presented. The implementation is straight and efficient when there are only two transmitting antennas. However, problems arising with more than two antennas are also discussed, along with possible solutions. It is shown that notwithstanding the suboptimal low-complexity implementation, this iterative receiver misses the performance of the turbo MAP detector by only few tenths of dB in various configurations, with very high spectral efficiency.