Convergence analysis for linear turbo equalization

In this paper, we propose a method for the analysis of linear turbo equalization that makes use of extrinsic information transfer (EXIT) charts. Given the channel knowledge and a time-invariant set of linear equalizer coefficients, the evolution of soft information in the soft-input soft-output (SISO) equalizer can be estimated via analytically measuring the mutual information between the transmitted symbols and their estimated a priori values at the two end points of an EXIT chart. Using this estimated equalizer EXIT chart and an empirically generated decoder EXIT chart, convergence analysis can be undertaken. In comparison with existing EXIT chart based methods, the proposed approach can significantly reduce the reliance on extensive computer simulation.