Malicious user suppression for cooperative spectrum sensing in cognitive radio networks using Dixon´s outlier detection method

Cooperation among multiple secondary users improves the cognitive radio sensing system performance, but the presence of malicious secondary users may severely degrade the same. In this paper, we study the detection and elimination of such malicious users in a cooperative sensing system using Dixon´s outlier test and compare its performance with Grubb´s test and boxplot test. We have shown using receiver operating characteristics curves that Dixon´s test outperforms Grubb´s test and boxplot test for the case of a single malicious user. We also illustrate the limitations of Dixon´s test for several malicious users using an example of two malicious users in a cooperative spectrum sensing setting for cognitive radio.