A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Cognitive Radio (CR) is a technique used to solve the problem of scarcity of the wireless spectrum. It improves the spectrum efficiency by using spectrum holes by other users called secondary users or unlicensed users without interfering with the primary users or licensed users (PU). The CR is achieved by energy detector, matched filter and cyclostationary detection to sense the spectrum idle or not. Noise plays a negative role in improving Cognitive Radio Networks (CRNS) performance. Cooperative spectrum using fixed sensing time does not provide efficient throughput performance for all values of Signal to Noise Ratio (SNR). This paper presents two proposed approaches to performance enhancement of the efficiency of energy detector in the wireless spectrum .The first approach is based on hybrid Additive Wavelet Transform using Homomorphic(AWTH) with energy detector. The second approach is based on mixing of Haar Discrete Wavelet Transform using Homomorphic method (HDWTH) .The quality metrics that used are the Probability of Detection (Pd) and Probability of the False Alarm (Pf).The two proposed approaches are used to improve the energy detector performance. The quality metrics show that the first approach enhances the Pd point view in the wireless spectrum. On the other hand the second approach achieves maximization for the throughput point view.
