Comments on adaptive IIR filtering with monic normalization

An equation error algorithm is known to give a significant bias in case the output signal is contaminated by white noise, A simple bias removal scheme was proposed in a recent letter. Here, we provide some complementary analy sis of that algorithm. It is shown how it can be interpreted as an instrume ntal variable method. Further, by analytical examples, it is demonstrated t hat the method does not always lead to convergent estimates, even for arbit rarily small step sizes.