A Simplified Metric for Soft-Output Detection in the Presence of Impulse Noise

We consider iterative decoding over channels affected by impulse noise. Since the hypothesis of perfect knowledge on the statistics of the impulse noise is often unrealistic, we describe a novel metric which results to be both very simple from a computational viewpoint and very robust in the case of a mismatch. The effectiveness of the proposed solution is proved by means of computer simulations, showing that it outperforms the existing suboptimal alternatives and ensures a very limited performance degradation with respect to the optimal detector even in the case of inaccurate information on the statistics of the impulse noise.