[1] Sichuan Univ, Coll Elect Engn, Chengdu, Peoples R China
[2] Univ Elect Sci & Technol China, Sch Informat & Commun Engn, Chengdu, Peoples R China
[3] Univ Kentucky, Dept Elect & Comp Engn, Lexington, KY USA
[4] Sichuan Univ, Sch Mech Engn, Chengdu, Peoples R China