sensing is critical for secondary u

sensing is critical for secondary users to accurately detectprimary users. However, it is vulnerable to attacks from malicioususers, which intentionally report incorrect sensing results, tomislead other secondary users or the fusion center in decisionmaking. Therefore, detection of malicious users is extremelyimportant for spectrum sensing. This paper proposes a decentralized scheme to detect malicious users in cooperative spectrumsensing. The scheme utilizes spatial correlation of received signalstrengths among secondary users in close proximity and is basedon robust outlier-detection technique. We have also proposed aneighborhood majority voting approach for the secondary usersto decide if a specific user is malicious. Simulation results showthat the proposed scheme can achieve a very good performancein detecting malicious users.