Cooperative Spectrum Sensing in Cognitive Radio Networks using improved Energy Detector under noise Uncertainty

In Cognitive Radio (CR) networks, Cooperative spectrum sensing is applied to reliably detect Primary User (PU) transmissions by fusing the sensed data of multiple Secondary Users (SUs). Moreover, it is well-known that the detection reliability of an individual SU is relatively associated with channel condition but the existence of noise uncertainty in spectrum sensing will make the detector unreliable due to SNR walls . In this paper, cooperative spectrum sensing with double-threshold energy detection scheme is proposed to improve the detection performance under noise uncertainty. In this scheme, each secondary user will use a two-threshold detector for local detection and after any detection the detection results are fused to give the final decision. Simulation results of the proposed scheme show significant performance improvement in terms of detection probability with the consideration of noise uncertainty and better receiver operating characteristic (ROC) performance is obtained in comparison to conventional schemes.

Keywords:

cognitive radio networks , Cooperative Spectrum Sensing (CSS) , noise uncertainty , two-threshold energy detection