1. College of Information Science and Engineering, Hunan Normal University , Changsha 410081 , China
2. Key Laboratory of Computing and Stochastic Mathematics (Ministry of Education), Hunan Normal University , Changsha 410081 , China
3. School of Computer and Communication Engineering, Changsha University of Science and Technology , Changsha 410114 , China
4. Department of Electrical and Computer Engineering, Communication Systems and Networks Research Group, Faculty of Engineering, King Abdulaziz University , Jeddah , Saudi Arabia