Multichannel spectrum sensing via multivariate power spectrum analysis

Recently several time-domain approaches relying on the generalized likelihood ratio test (GLRT) paradigm have been proposed for multiple antenna spectrum sensing in cognitive radios. These approaches are suitable for flat-fading channels in white noise with equal noise variances across antennas; knowledge of the noise variance is not required, unlike the energy detector. In this paper we investigate a method based on analysis of the multivariate power spectral density (PSD) of the received multiantenna signal. Our proposed approach is also based on GLRT, but exploits the noisy signal PSD which is allowed to be colored with unknown PSD but must be uncorrelated across sensors under the null hypothesis (PU signal absent). An analytical method for calculation of the test threshold is provided and illustrated via simulations.