TONG Yao-nan1,3, HE Yi-gang1,2, YIN Bai-qiang1, YU Wen-xin1, LONG Ying2
(1.School of Electrical and Information Engineering, Hunan Univ, Changsha,Hunan410082, China;2. School of Electrical Engineering and Automation, Hefei Univ of Technology, Hefei,Anhui230009, China;3. School of Information and Communication Engineering, Hunan Institute of Science and Technology, Yueyang,Hunan 414006, China)