1. Univ Rennes, CNRS, IETR - UMR 6164, Rennes, France
2. Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, Athens, Greece
3. School of ECE, Ben-Gurion University of the Negev, Beer-Sheva, Israel
4. School of ECEE, Arizona State University, Tempe, AZ, USA