1. CNIT-RaSS (National Interuniversity Consortium on Telecommunications-Radar and Surveillance Systems National Laboratory), Galleria Gerace No. 18, 56124 Pisa, Italy
2. Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland
3. Signal Theory and Communications Department, Polytechnic School, University of Alcalá, Campus Universitario, s/n, 28805 Alcalá de Henares, Madrid, Spain