TANG Hongzhong1,2, ZHANG Xiaogang1, CHEN Hua3, LI Xiao2, WANG Xiang2
(1.College of Electrical and Information Engineering, Hunan University, Changsha410082, China; 2. College of Information Engineering, Xiangtan University, Xiangtan411105, China; 3. College of Information Science and Engineering, Hunan University, Changsha410082,China)