Energy Detector Based Spectrum Sensing Performance Analysis over Fading Environment

Abstract

Energy detection approach for sensing of spectrum is an extremely effective method of detection in comparison of other spectrum sensing methods when secondary user lacks adequate knowledge of primary user's channel conditions. Because of multipath propagation and shadowing effects, performance of energy detector employed in a cognitive radio system is severely influenced. In this paper, we have evaluated performance of energy detector over fading environment. Hypothesis testing was utilized for spectrum sensing to find out whether the primary user's signal was available or missing. Performance assessment for spectrum sensing using the energy detector was carried out primarily on the basis of probability of false alarm and probability of detection. We have examined the impact of SNR on probability of detection in order to assess the performance of spectrum sensing using energy detector. Also the receiver operating characteristic curve was plotted for performance analysis of spectrum sensing employing energy detector. In addition, we also examined the impact of threshold value on the probability of the false alarm. We have found that probability of detection improves when we increase the value of signal to noise ratio and use more number of samples. We have also observed that false alarm probability decreases when we increase the threshold value.