Maximum flatness criterion based on extrinsic information transfer charts for symbol mapping design

In bit-interleaved coded modulation with iterative decoding (BICM-ID), the extrinsic information transfer (EXIT) function of the demapper can be parameterised. Using this parameterisation, in conjunction with the EXIT function of the decoder, a symbol mapping design criterion based on the flatness of the gap between the two EXIT functions (called the maximum flatness criterion) is proposed in this study. Simulation results confirm that a good performance can be achieved in terms of convergence rate for fast fading channels and outage probability for slow fading channels.