[1] North Univ China, Sch Informat & Commun Engn, Taiyuan 030051, Shanxi, Peoples R China
[2] North Univ China, Engn Technol Res Ctr Shanxi Prov Optoelect Inform, Taiyuan 030051, Shanxi, Peoples R China
[3] North Univ China, Sch Sci, Taiyuan 030051, Shanxi, Peoples R China