On the Performance of Eigenvalue-Based Spectrum Sensing for Cognitive Radio

In this paper, the distribution of the ratio of extreme eigenvalues of complex Wishart matrix is studied in order to calculate the exact decision threshold as a function of the desired probability of false alarm for maximum-minimum eigenvalue (MME) detection method for multiple receiver collaborative spectrum sensing. Furthermore, the proposed exact formulation is simplified for the case of two receiver based collaborative spectrum sensing and with finite number of samples. In addition, an approximate closed form formula of the exact threshold is derived in terms of a desired probability of false alarm for a special case having equal number of receive antennas and signal samples. Finally, using Monte-Carlo simulations, we verify the estimated values of exact decision threshold and their approximated closed-form values. The probability of detection performance has been verified using the proposed exact decision thresholds achieving significant performance gains compared to the performance of the asymptotic decision threshold.