1. e-TESC Laboratory, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
2. Department of Electrical Engineering, Polytechnic Institute of Coimbra, Coimbra Institute of Engineering, 3030-199 Coimbra, Portugal
3. Department of Electrical and Computer Engineering, INESC Coimbra, University of Coimbra, Polo II, 3030-290 Coimbra, Portugal