Hard decision combining-based cooperative spectrum sensing in cognitive radio systems

In this paper, we propose a cooperative spectrum sensing scheme to maximize the detection probability in cognitive radio systems. We first analytically derive a closed-form expression for the detection and false alarm probability in terms of the number of cooperating users, and then determine the number of cooperating users that maximizes the detection probability for a given false alarm probability. It is shown that the detection probability of cooperative sensing is maximized when the cooperation is performed among users with high signal-to-noise power ratio and interference-to noise-power ratio. Finally, the analytic results are verified by computer simulation.