A Block-by-Block Blind Post-FFT Multistage Beamforming Algorithm for Multiuser OFDM Systems Based on Subcarrier Averaging. - Chong-Yung Chi; Chun-Hsien Peng; Kuan-Chang Huang; Teng-Han Tsai; Wing-Kin Ma (IEEE Trans. Wirel. Commun., 2008)