[Zhou, Jian;Li, Xing-hua;Li, Li-jun] Ctr South Univ Forestry & Technol, Machinery & Elect Engn Coll, Changsha 410004, Hunan, Peoples R China.^[Zhou, Dong-chen] Telecom Corp Changning City Hunan Prov, Changning 421500, Peoples R China.^[Cheng, Ke] Lushan Coll Guangxi Univ Technol, Liuzhou 545616, Peoples R China.