1. College of Information and Communication Engineering, Harbin Engineering University, Harbin 150001, China
2. Key Laboratory of Advanced Marine Communication and Information Technology, Ministry of Industry and Information Technology, Harbin 150001, China
3. Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, 15784 Athens, Greece
4. Department of Computer Science, Information Technology University of the Punjab, Lahore 54000, Pakistan