1. Signals & Systems, Chalmers University of Technology , Göteborg, Sweden
2. Electrical Engineering Department (ESAT-SCD) and the Optimization in Engineering Center (OPTEC), K.U. Leuven , Leuven-Heverlee, Belgium
3. IMT Institute for Advanced Studies Lucca , Lucca, Italy
4. IMTEK, University of Freiburg , Freiburg, Germany