1. Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina, USA
2. Dipartimento di Ingegneria dell’Informazione, Università di Pisa, Pisa, Italy
3. Electrical and Computer Engineering, North Carolina Agricultural and Technical State University, Greensboro, North Carolina, USA
4. Institute of Telecommunications and Multimedia Applications, Universitat Politècnica de València, Valencia, Spain