Energy detection for single-user sensing in cognitive radio

Abstract

This report presents the energy detector method for single-user over fading channels. Energy detector is an important technique in Cognitive radio for the detection of the presence of primary user. By fixing the probability of false alarm, probability of detection is the major concern in this report. We start with the non-fading channel AWGN and investigate the system performance by observing the relationship between SNR and probability of detection as well as the receiver operating characteristic (ROC) curves. We then investigate the performances over Rayleigh channel, Rician channel and Nakagami Channel. Rather than using the chi-square distribution table to find the probability of detection, this report presents the exact closed-form expressions for both probability of detection and probability of false alarm. Under the latter three channels, some of the performances are better while some of the others are not ideal. However, the general trend still shows our assumption which is with the increment of SNR, the probability of detection will also increase accordingly. After comparing the channels’ features, a simulation of energy detector for the single-user in Cognitive Radio is implemented in order to present the mechanism of Cognitive Radio and energy detector.