[1] Qingdao Univ, Sch Elect Engn, Weihai Innovat Res Inst, Qingdao 266000, Peoples R China
[2] Zhejiang Univ Technol, Sch Informat Engn, Hangzhou, Peoples R China
[3] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan, Peoples R China
[4] Qingdao Univ, Univ Ind Joint Ctr Ocean Observat & Broadband Com, Coll Phys, Qingdao, Peoples R China