Double Threshold Based Cooperative Spectrum Sensing with Consideration of History of Sensing Nodes in Cognitive Radio Networks

As cognitive radio networks are being used as a method which helps in determining the spectrum vacancy and utilize the spectrum efficiently, spectrum sensing is one of the key technology for this application. Among all the spectrum sensing techniques, energy detection is mostly preferred because of its simplicity and also since it does not require any prior knowledge of the signal. However, major challenges appear due to multipath fading, hidden terminal problem, shadowing and receiver noise uncertainty. To mitigate the impact of these issues cooperative spectrum sensing turns out to be an effective method for improving the performance. In this paper, cooperative spectrum sensing along with double threshold detection method which considers the previous sensing history is used in which two thresholds are considered and compared to a test statistic and accordingly a decision regarding the presence and absence of the primary user is made. Simulation results shows that under cooperative sensing the proposed double threshold method performs better than energy detection method and conventional double threshold detection method under various parameters such as SNR, probability of detection, probability of false alarm and number of samples.