1. School of Electrical and Computer Engineering; Georgia Institute of Technology; Atlanta Georgia 30332 USA
2. Georgia Tech-CNRS; UMI 2958; 57070 Metz France
3. CEA-LETI; Minatec Campus; F-38054 Grenoble France
4. LMOPS; University of Lorraine, EA4423; 57070 Metz France