Collaborative Spectrum Sensing based on Signal Correlation in Cognitive Radio Networks

C. Long, H. Wang, and X. Guan (PR China)


Cognitive radio networks, collaborative spectrum sensing, signal correlation analysis


In cognitive radio networks, cognitive (unlicensed) users need to monitor the spectrum of primary (licensed) users for the presence of primary users. Previous works have suggested that collaborative spectrum sensing can increase the performance of energy-based sensing scheme. How ever, the detection threshold is difficult to determine due to the uncertainty of noise power. In this paper, we introduce a signal correlation analysis method to achieve the collab orative spectrum sensing in cognitive radio networks. The proposed method doesn’t need any priori knowledge of the signal and noise power. Our proposed method is based on the following observation: when the primary user is ac tive, the signals received by cognitive users from primary user are correlated; otherwise the signals received by cog nitive users are uncorrelated. Thus, we can distinguish the presence of primary user through the correlation analysis of signal received by cognitive users. To cope with time varying and unknown environmental noise, we introduce alternative testing method to set the detection threshold dy namically. The simulation results show the effectiveness of the proposed approach.

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