Two-Stage Credit Threshold on Cooperative Spectrum Sensing to Exclude Malicious Users in Mobile Cognitive Radio Networks

Abstract

In cognitive radio networks (CRNs), spectrum sensing data falsification (SSDF) is one of the most typical attack which hugely degrades the detection performance of cooperative spectrum sensing (CSS). SSDF and defense strategies have been an active field of research, but countermeasures of existing researches are sensitive to the number of malicious users (MUs). In this paper, we propose a two-stage credit threshold (TSCT) scheme based CSS to counter arbitrary number of MUs who exist in CRNs. We divide the network region into cells according to channel condition, and CSS procedure is conducted into two stages, which are the secondary user (SU) stage and cell stage. Our proposed scheme can effectively remove MUs in the SU stage and weaken the bad effects of remnant MUs in the cell stage. In comparison to existing schemes, simulation results show that the proposed scheme can provide with better detection performance regardless of detection rounds, and can work well when MUs outnumber SUs while previous schemes fail.