Co-operative Spectrum Sensing for Cognitive Radio Systems over Fading Channels

Spectrum Sensing is the fundamental and essential operation in Cognitive Radio (CR) to find the unused frequency bands. To detect the unused spectrum, different types of detectors are used. Energy detector is one of the popular sensing methods because it doesn't need any information regarding transmitted signal. When Cognitive Radio user undergoes fading effect, detection of primary user is very less. So for detecting primary user (PU) more precisely, the CR users co-operate among each other by sharing their information. So we use Cooperative Spectrum Sensing technique which incorporate more number of users, to increase probability of detection. This paper recapitulates the performance comparison of energy detector over different fading channels like (Nakagami-m, Rayleigh, Rician, Weibull channel) and hard decision fusion techniques for Cognitive users. The performance is assessed by means of Receiver Operating Characteristics (ROC) curves. It is clearly observed that Probability of detection increases with the cooperation of more number of secondary users and Weibull fading channel has better detection performance than any other fading channels and also we investigate the effect of SNR over Probability of detection.