Performance analysis of cascaded energy and matched filter detector with malicious users in cognitive radio networks

The inefficient use of valuable and scarce spectrum resources can be exploited by cognitive radio (CR) technology. For CR technology, an energy efficient detection techniques with reliable detection performance can guarantee the protection of primary users (PU) from secondary users (SU) and prolong the lifetime of the networks. Also, such CR networks are prone to different kinds of attacks which put down the effective operation of the network. In this paper, we consider the performance analysis of cascaded energy and matched filter (CEM) detector in the presence of malicious users (MU). The observable sensing operation of CEM detector i.e., probability of detection is analyzed with the incorrect sensing information of the MUs. To bring down the consequence of MUs on the spectrum sensing efficiency, we suggest the use of authentication code which will be validated by the fusion center (FC) for overall decision making process. We also showed that there lies a optimum authentication code required for the detection efficiency as the number of MU increases in the network. The equations for for cooperative CEM detector´s false alarm and miss detection probabilities is formulated in the presence of MUs. Simulation results shows the validity of suggested authentication code scheme for cooperative CEM detectors with MUs.