An optimal cooperative spectrum sensing method in cognitive radio network over Rayleigh fading channel

Abstract

In cognitive radios, there exist two kinds of detection errors: missed-detection errors and false-alarm errors. These errors severely degrade sensing performance. In this paper, we aim to minimize the total detection probability by considering it as a target function for the optimization of sensing parameters in a Rayleigh fading environment. With this established target function, we perform a discrete difference operation and derive the closed - form expression of the optimal fusion rule for cooperative spectrum sensing. Furthermore, we derive an algorithm to optimize the energy detection threshold for the cognitive users for any fusion rule. A second algorithm that optimizes both the energy threshold and the fusion rule is also proposed so as to minimize the total error probability. Based on this algorithm, an optimal sensing method for a cooperative cognitive radio network is suggested.