1. School of Communication and Information Engineering, Chongqing University of Posts and Telecommunications, Chongqing, China
2. Department of Information Technology, Kennesaw State University, Marietta, GA, USA
3. Department of Electrical Engineering and Computer Science, Howard University, Washington, DC, USA
4. Electrical Engineering Department, University of Brasilia, Brasilia, Brazil
5. Department of Information and Electronic Engineering, International Hellenic University, Thessaloniki, Greece
6. College of Computer and Cyber Security, Fujian Normal University, Fuzhou, China