A Comparison of Energy Detectability Models for Spectrum Sensing

Energy detection has been adopted as an alternative spectrum sensing method for cognitive radios due to its low computational complexity and not requiring a priori information of the signal to be detected. In this work, we analyze the accuracy of different energy detector models in approximating the exact solution both in AWGN and Rayleigh channels. Our simulations show that all of these models have almost the same performance in Rayleigh channels. Hence, we conclude that any one of them can be used to represent the energy detector´s performance instead of the complicated exact solution in Rayleigh fading channels. Using Edell´s model, we derive the relationship between the number of samples and the signal-to-noise ratio (SNR) for Rayleigh channels similar to the results obtained for AWGN channels. We also verify our analytical results by simulations.