[1] Nanjing Univ Posts & Telecommun, Inst Adv Technol, Nanjing 210023, Jiangsu, Peoples R China
[2] Univ Leeds, Sch Elect & Elect Engn, Leeds LS2 9JT, W Yorkshire, England
[3] Nanjing Univ Posts & Telecommun, Coll Automat, Nanjing 210023, Jiangsu, Peoples R China
[4] Univ Pretoria, Dept Comp Engn, ZA-0028 Pretoria, South Africa