title: Signal Processing.
authors.affiliation: Pablo Laguna Lasaosa, Dept. of Electronic Eng. and Communications, Centro Politécnico Superior, University of Zaragoza, María de Luna 3, 50015 Zaragoza, Spain, E-mail: laguna@posta.unizar.es.
authors.forename: P
authors.initials: P
authors.lastname: Laguna