Qian Li Kwok Hung Li Kah Chan Teh Noncoherent Space-Frequency Codes for Broadband MIMO Systems over Frequency-Selective Fading Channels. 554-558 2008 VTC Spring http://dx.doi.org/10.1109/VETECS.2008.125 conf/vtc/2008s db/conf/vtc/vtc2008s.html#LiLT08