[Sun, Miaoping;Nian, Xiaohong] Cent S Univ, Dept Informat Sci & Engn, Changsha 410000, Hunan, Peoples R China.^[Zhang, Jun] Cent South Univ Forestry & Technol, Changsha 410000, Hunan, Peoples R China.^[Tang, Wenyan] Hunan Univ Technol, Coll Elect & Informat Engn, Zhuzhou 412007, Peoples R China.