Multi-Antenna Blind Spectrum Sensing for Cognitive Radios Using Path Correlations

We consider the problem of spectrum sensing in cognitive radios when the secondary user (SU) radio is equipped with multiple antennas. Using an estimate of the cross-correlation among the signals received at different antenna elements, we propose a blind detection method which assumes no prior knowledge of the primary user´s (PU) signaling scheme, the noise power, or the channel path coefficients. Detection and false alarm probabilities of the proposed algorithms are evaluated using an asymptotic analysis and the results are compared to simulation results. It is shown that the proposed method outperforms several recently-proposed blind sensing techniques for cognitive radios using multiple antennas.