Hard Decision Fusion Based Cooperative Spectrum Sensing over Nakagami-m Fading Channels

In this paper, the performance of energy detection-based spectrum sensing is investigated and the closed-form expression for the probability of detection over Nakagami-m fading channels is derived. Moreover, we further study the cooperative spectrum sensing schemes based on hard decision fusion rules such as the AND, OR and Majority rules. The performance is presented with complementary receiver operating characteristic curves, detection probability vs. average SNR curves and detection probability vs. number of SUs curves. From the numerical results we obtain some conclusions on the above-mentioned fusion rules. On one hand, under the same channel parameters and secondary user number, the detection performance of the AND rule is more strictly constrained by average SNR than the OR and Majority rules. On the other hand, the OR and Majority rules outperform the AND rule, especially when more secondary users are involved in cooperative sensing, more performance improvement is obtained.