[1] Harbin Inst Technol, Shenzhen Grad Sch, Commun Engn Res Ctr, Shenzhen, Peoples R China
[2] MIT, Informat & Decis Syst Lab, Cambridge, MA 02139 USA
[3] Tsinghua Univ, Dept Elect Engn, Beijing, Peoples R China
[4] Univ Southern Calif, Dept Elect Engn, Los Angeles, CA USA