[1] Tsinghua Univ, Commun Engn, Beijing, Peoples R China
[2] Tsinghua Univ, Elect & Commun Engn, Beijing, Peoples R China
[3] Tsinghua Univ, Sch Informat Sci & Technol, Beijing, Peoples R China
[4] Zhejiang Univ, Dept Informat Sci & Elect Engn, Hangzhou, Peoples R China
[5] Technol Innovat Inst, Abu Dhabi, U Arab Emirates
[6] Univ Houston, Elect & Comp Engn Dept, Comp Sci Dept, Houston, TX USA