Cooperative spectrum sensing over frequency-selective Nakagami-m fading channels

Cooperative spectrum sensing has not been examined over frequency-selective Nakagami-m fading channels when an energy detector (ED) is employed. We show that cooperative spectrum sensing performance might improve more because of both the multipath environment and the Nakagami fading parameter (m). The average detection probability of cooperative spectrum sensing over a Nakagami-m frequency-selective fading channels is evaluated analytically and validated through simulation. We further derive the outage probability theoretically and confirmed by computer simulations where the results confirm that there is a significant improvement for transmission over the Nakagami-m frequency-selective fading channels compared with the Nakagami-m flat-fading channels. Also, the results show that the improvement of the ED is not only dependent on the number of multipaths (L) but also with the Nakagami fading parameter (m). In addition, we show that the detection probability rapidly improves with initial increases in L and m but later levels out. Moreover, the average probability of detection improves when we initially increase L (fixing m), approximately equals the average probability of detection when we initially increase m (fixing L). Finally, the theoretical result (for a uniform power delay profile) explicitly reveals that cooperative spectrum sensing over Nakagami-m frequency-selective fading channels, can achieve a diversity order of mLV , where V is the number of secondary users. (5 pages)