[1] Univ Basque Country UPV EHU, Syst Engn & Automat Dept, Donostia San Sebastian 20008, Spain
[2] Univ Las Palmas Gran Canaria, IDeTIC, Inst Desarrollo Tecnol & Innovac Comunicac IDeTIC, Las Palmas Gran Canaria, Spain
[3] Univ Vic Cent Univ Catalonia, Data & Signal Proc Res Grp, Vic, Spain
[4] Escola Univ Politecn Mataro UPC, Barcelona, Spain
[5] Univ Basque Country UPV EHU, Dept Math, Leioa, Spain