[1] Hunan Univ, Sch Phys & Elect, Changsha 410082, Peoples R China
[2] Univ Alberta, Dept Elect & Comp Engn, 9211 116 St NW, Edmonton, AB T6G 1H9, Canada
[3] Shanghai Jiao Tong Univ, Collaborat Innovat Ctr IFSA CICIFSA, Shanghai 200240, Peoples R China
[4] Inst Appl Phys & Computat Math, Beijing 100094, Peoples R China