On Covariance Matrix Based Spectrum Sensing Over Frequency-Selective Channels

This paper concerns covariance matrix-based spectrum sensing over frequency-selective channels. The impact of frequency-selective channels on the covariance matrix of received signals is analyzed in frequency domain, and it is shown that the phases of channel spectra degrade the performance of covariance matrix-based detectors. To overcome this problem, we propose a new detector which employs only the magnitude spectra of received signals and therefore achieves considerable performance gain. Theoretical performance, in terms of the false-alarm and detection probabilities of the proposed detector, is analyzed. Simulation results verify our theoretical analyses and demonstrate the superior performance of the proposed detector.