Technical note
Résumé
In the letter to the editor [1], an improvement over the separation criterion of [2] was proposed for the extraction of a cyclostationary source. The present technical note aims first at demonstrating that the proposed criterion can be simplified down to an eigenvalue problem equivalent to a particular case of the method described in [3]. Secondly, it re-explains why the convolutive model is more appropriate for linear mechanical systems than the instantaneous model considered in [1], [2], and it shows how the same criterion can be extended to extract the contributions of the cyclostationary source in that context. Thirdly, a real-world application confirms these statements, and demonstrates that still better results are obtained using a novel signal extraction method to be presented in a forthcoming paper [4].