1. Department of Electronics and Computer Technology, University of Granada, Campus Universitario Fuentenueva, 18071 Granada, Spain
2. Instituto de Investigación en Tecnología Informática Avanzada (INTIA), Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), B7001BBO Tandil, Argentina
3. Department of Electrical and Computer Engineering, Florida State University (FSU), 2525 Pottsdamer Street, Tallahassee, FL 32310, USA