A Survey of Range-Based Techniques for Localizing Primary User Emulators in Cognitive Radio Network

Abstract

A problem currently facing the wireless communication industry is spectrum underutilization, wherein licensed Primary Users (PUs) only marginally use their bands in time and space. Consequently, Opportunistic Spectrum Sharing (OSS) has been proposed as a solution to this problem with Cognitive Radio (CR) being the enabling technology. CR describes the capability of a radio to dynamically and opportunistically access licensed spectrum without causing interference to the PU. While CR is being developed, one main security problem it faces is Primary User Emulation (PUE) attack. A PUE attack occurs when mischievous Secondary Users (SU), that is CRs, begin to emulate PU signals either to deny other SUs from gaining access to free bands or to simply acquire bandwidth for selfish purposes. In this regard, localization is considered as a solution, wherein the location of the PUE attacker is determined and compared to the location of the true PU transmitter and any significant deviation in their positions is indicative of a PUE attacker. Thus, this paper is a short note describing the different state-of-the-art localization techniques, elucidating their advantages and disadvantages. The approach adopted included identification of the various localization techniques for PUE identification, with subsequent analysis under the following metrics: accuracy, precision, computational complexity, cost, energy efficiency, and size of hardware. It was concluded that the Angle of Arrival and Received Signal Strength Indicator techniques do not require the cooperation of PUE for its detection, hence making these techniques most suitable for use. It is believed that this mini-review will be beneficial particularly for budding researchers seeking enlightenment in this research area.