[1] North China Univ Water Resources & Elect Power, Sch Math & Informat Sci, Zhengzhou 450011, Peoples R China
[2] Pingdingshan Univ, Sch Elect & Informat Engn, Pingdingshan 467099, Henan, Peoples R China
[3] Huazhong Univ Sci & Technol, Sch Phys, Wuhan 430074, Peoples R China