1. imec, Kapeldreef 75, Leuven B-3001, BelgiumbKU Leuven, Department of Electrical Engineering (ESAT), Kasteelpark Arenberg 10, Leuven B-3001, Belgium
2. imec, Kapeldreef 75, Leuven B-3001, Belgium
3. Stanford University, Department of Electrical Engineering, 420 Via Palou, Stanford, California 94305, United States
4. University of Athens, Department of Informatics and Telecommunications, Panepistimiopolis, Athens 15784, Greece