1. School of Physics and Electronic Information, Anhui Normal University, Wuhu, China
2. School of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, China
3. Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, USA
4. Department of Automatic Control and Systems Engineering, The University of Sheffield, Sheffield, U.K
5. School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Melbourne, VIC, Australia