[1] St Francis Xavier Univ, Dept Comp Sci, Antigonish, NS B2G 2W5, Canada
[2] Beihang Univ, Sch Automat Sci & Elect Engn, Beijing 100191, Peoples R China
[3] Univ Elect Sci & Technol China, Sch Informat & Commun Engn, Chengdu 611731, Peoples R China
[4] McMaster Univ, Dept Elect & Comp Engn, Hamilton, ON L8S 4K1, Canada