Complexity Reduction in Iterative MIMO Receivers Based on EXIT Chart Analysis

The application of the Turbo principle in MIMO receivers allows to achieve near-capacity performance with a number of different MIMO detection algorithms. However, this high performance is paid for by a substantial increase in complexity, as detector and decoder have to be run multiple times. In this paper, we show that an analysis of detector and decoder transfer curves in the EXIT chart can be used to select a suitable detection algorithm and parametrization of the outer channel decoder, such that the overall receiver complexity can be substantially decreased while retaining its original performance. In order to enable a flexible adaptation of the receiver parameters, we also propose a simple “measurement device” for mutual information that can be used to steer the parametrization, based on the quality of the soft information at the output of detector and decoder.