Performance analysis of a cognitive radio energy detector over frequency-selective channels

Previous work on an energy detector (ED) has only analytically examined its performance over a flat-fading channel. But for the real environment, the channel should be assumed frequency-selective due to the high date rates. So in this paper we evaluate the performance of an ED over a frequency-selective fading channel. We show that the performance of the ED might improve because of the multipath environment. The average detection probability for the ED over a frequency-selective channel is evaluated analytically and validated through simulation. Further, the outage probability is derived theoretically and supported by computer simulations. The results confirm that there is a significant improvement in the performance of the ED over the frequency-selective fading channel compared with the flat-fading channel. Finally, we show that the detection probability rapidly improves with initial increases in the number of multipaths but later flattens out.