1. College of Science, Nanjing University of Posts and Telecommunications, Nanjing, China
2. College of Communication and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, China
3. College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
4. Faculty of Engineering and Applied Science, Memorial University, St. John’s, NL, Canada
5. Singapore University of Technology and Design, Singapore