1. School of Mechanical and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China
2. School of Electronics and Information, Wuzhou University, Wuzhou 543002, China
3. College of Communication and Information Technology, Xi’an University of Science and Technology, Xi’an 710699, China
4. School of Information Engineering, Henan Institute of Science and Technology, Xinxiang 453003, China