Spectrum sensing is a major task in Cognitive Radio Networks which determines the presence or absence of Primary User (PU) such that the Secondary User (SU) or opportunistic user can use the unoccupied spectrum. Energy based Primary user Detection is the mostly employed strategy for spectrum sensing while it suffers from ambiguous results due to single threshold based decision making strategy. Hence, this paper proposes a new thresholding mechanism called as Dual Thresholding and applied on the Generalized Energy Detection (GED) to identify whether the Primary user is present or not. In addition, we also introduce a new fusion concept in cooperative spectrum sensing where the decision of Secondary User not only depends on his/her own decision but also on the decisions of other secondary users. Simulation experiments reveal the efficiency of proposed approach in terms of bit error rate, probability of false alarm, probability of detection.

Cognitive Radio Networks, cooperative spectrum sensing, Single Thresholding, Dual thresholding, Fusion, Probability of false alarm, Probability of detection.