Performance analysis of cooperative spectrum sensing in rayleigh channel

In cognitive radio networks, cooperative spectrum sensing is employed to detect the presence of primary user quickly. In this paper, we study the sensing performance of a cognitive user U₁ by allowing another cognitive radio user U₂ to act as its relay (cooperation). We take the average power rather than the instantaneous power as the decision statistic, so, we can use multiple signal samples in each observation to make the decision on if the primary user is present. We derive formulas of false alarm and detection probability in Rayleigh channel for the case when U₂ acts as U₁´s relay and for the case when each cognitive user detects the presence of primary user independently. We then analyze the improvement of sensing performance by using cooperation, and discuss the impact of number of sampling points.