[1] Univ Putra Malaysia UPM, Fac Engn, WiPNET Res Ctr, Dept Comp & Commun Syst Engn, Serdang 43400, Selangor, Malaysia
[2] Univ Carlos III Madrid, Dept Signal Theory & Commun, Madrid 28903, Spain
[3] Rohde & Schwarz, PAT Sq, Shah Alam 40150, Selangor, Malaysia