@conference {ICC2010_AnalogBeam, title = {A general {Pre-FFT} criterion for {MIMO-OFDM} beamforming}, booktitle = {IEEE International Conference on Communications (ICC 2010)}, year = {2010}, month = {May}, address = {Cape Town, South Africa}, author = {V{\'\i}a, Javier and Santamar{\'\i}a, Ignacio and Elvira, Victor and Eickhoff, R.} }