Faculty of Sciences and Technology, Department of Electrical Engineering and CA3 Group of UNINOVA/CTS, NOVA University of Lisbon, Caparica, Portugal.|Faculty of Sciences and Technology, Department of Electrical Engineering and CA3 Group of UNINOVA/CTS, NOVA University of Lisbon, Caparica, Portugal.|Faculty of Sciences and Technology, Department of Electrical Engineering and CA3 Group of UNINOVA/CTS, NOVA University of Lisbon, Caparica, Portugal.|Faculty of Sciences and Technology, Department of Electrical Engineering and CA3 Group of UNINOVA/CTS, NOVA University of Lisbon, Caparica, Portugal.