  Optimal data detection in multiple-input multiple-output (MIMO) communication
systems with a large number of antennas at both ends of the wireless link
entails prohibitive computational complexity. In order to reduce the
computational complexity, a variety of sub-optimal detection algorithms have
been proposed in the literature. In this paper, we analyze the optimality of a
novel data-detection method for large MIMO systems that relies on approximate
message passing (AMP). We show that our algorithm, referred to as
individually-optimal (IO) large-MIMO AMP (short IO-LAMA), is able to perform IO
data detection given certain conditions on the MIMO system and the
constellation set (e.g., QAM or PSK) are met.
