EXIT chart analysis of bayesian MMSE turbo receiver for coded MIMO systems

Abstract

The Bayesian minimum mean squared error (MMSE) turbo receiver was proposed in (1) for coded multiple input multiple output (MIMO) systems to exploit both the soft- input soft-output (SISO) decoder's extrinsic information and the detector decision statistic in calculating the Bayesian MMSE estimate of the interference, and simulation results showed about 1.5 dB improvement over the conventional turbo receivers at bit error rate (BER) of 10 �5 (1). In this paper, we present the extrinsic information transfer (EXIT) chart analysis of Bayesian MMSE turbo receiver and show that it has much higher output mutual information than the conventional turbo receivers. The EXIT chart also shows that significantly less number of iterations are required to achieve convergence when compared with the conventional receiver. I. INTRODUCTION Multiple-input multiple-output (MIMO) wireless communi- cation systems have attracted a lot of interest in both research community and industry due to its potentials in delivering high spectral efficiency and robust performance against fading. In order to fully exploit the capacity and diversity advantages of MIMO channels, advanced signal processing techniques have to be applied at the transmitter and receiver. In particular, a turbo receiver which exchanges soft information between the