Energy Detector with Adaptive Optimal Threshold for Enhancing Spectrum Sensing in Cognitive Radio Network

Abstract: Cognitive radio (CR) is a promising solution to resolve the crisis of spectrum underutilization. Spectrum sensing is an indispensable aspect of CR network (CRN). Energy detection method is being recognized as a simple and reliable step for spectrum sensing. The significant factor of the energy detector (ED) is threshold, whose optimum value depends on signal to noise ratio (SNR). However, in a wireless environment, where the received signal is severely degraded due to the uncertain noise, reliable spectrum sensing is not guaranteed. The key metrics of the CRN are total spectrum sensing error probability, throughput, and energy efficiency. For each SNR value, there exists an optimal threshold that minimizes total spectrum sensing error probability and maximizes throughput as well as energy efficiency. Therefore, the threshold of ED should be adaptive in CRN. This paper presents an optimal adaptive threshold by utilizing spectrum sensing errors for each metric in CRN.