School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Department of Physics, University of Aveiro, Campus de Santiago 3810-193 Aveiro, Portugal;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Department of Physics, University of Aveiro, Campus de Santiago 3810-193 Aveiro, Portugal;
School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Siemens SA, R. Irm(a)os Siemens no 1, Alfragide, 2720-093 Amadora, Portugal;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Department of Electronic Telecommunications, University of Aveiro, Campus de Santiago 3810-193 Aveiro, Portugal;
Institute of Telecommunications, Campus de Santiago 3810-193 Aveiro, Portugal;
Department of Physics, University of Aveiro, Campus de Santiago 3810-193 Aveiro, Portugal;