@conference {RamirezValcarceICASSP10, title = {Multiantenna spectrum sensing: detection of spatial correlation among time-series with unknown spectra}, booktitle = {IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)}, year = {2010}, address = {Dallas, TX}, keywords = {cognitive radio, coherence spectrum, generalized likelihood ratio test, Hadamard ratio, multiple-channel signal detection}, author = {David Ram{\'\i}rez and Javier V{\'\i}a and Ignacio Santamar{\'\i}a and R. L{\'o}pez-Valcarce and L. L. Scharf} }