[Qin, Hua; Cao, Buwen; Deng, Shuguang] Hunan City Univ, Coll Informat & Elect Engn, Yiyang 413000, Peoples R China.
[Cao, Buwen; Li, Guanghui; Ding, Pingjian] Hunan Univ, Coll Comp Sci & Elect Engn, Changsha 410082, Hunan, Peoples R China.
[Chen, Shaopeng] Hunan Normal Univ, Coll Math & Comp Sci, Changsha 410081, Hunan, Peoples R China.
[Li, Guanghui] East China Jiaotong Univ, Sch Informat Engn, Nanchang 330013, Jiangxi, Peoples R China.