Discrete wavelet packet transform based cooperative spectrum sensing for cognitive radios

Cognitive Radio (CR) can be viewed as a novel approach to improve the overall Spectrum utilisation. In a CR, the most challenging operation is to detect the presence of any unutilized frequencies (White Spaces) in the spectrum by using the appropriate Spectrum Sensing Technique. The choice of Spectrum Sensing Technique is an important factor which determines the performance of a CR. In this paper, the performance evaluation of various centralized and decentralized Cooperative spectrum sensing techniques with variation in SNR and Noise Uncertainty (NU) is performed. A Discrete Wavelet Packet Transform (DWPT) based Cooperative Spectrum Sensing scheme is introduced which has improved spectrum utilisation than the conventional Energy Detector (ED).