1. School of Electronics and Telecommunications, Hanoi University of Science and Technology, 01 Dai Co Viet, Hanoi, Vietnam
2. Department of Military Science, Hellenic Army Academy, Athens, GR-16673, Greece
3. Biomedical Engineering Department, Amirkabir University of Technology, Tehran 15875-4413, Iran
4. School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, P. R. China
5. Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR, P. R. China