On the Diversity-Complexity Tradeoff in MIMO Spatial Multiplexing Systems

In MIMO spatial multiplexing systems, maximum likelihood detection achieves maximum receive diversity at the cost of high computational complexity. In contrast, low cost receivers like zero-forcing equalization result in minimum receive diversity. In this paper, we present a novel detection scheme that allows for a continuous tradeoff between diversity and complexity. The proposed receiver consists of a partial equalization stage and of a mismatched ML detector (implemented via a sphere decoder variant). Simulation results confirm that our scheme allows to trade diversity for complexity.