Biblio

With the improvement in technology and with the increase in the use of wireless devices there is deficiency of radio spectrum. Cognitive radio is considered as the solution for this problem. Cognitive radio is capable to detect which communication channels are in use and which are free, and immediately move into free channels while avoiding the used ones. This increases the usage of radio frequency spectrum. Any wireless system is prone to attack. Likewise, the main two attacks in the physical layer of cognitive radio are Primary User Emulation Attack (PUEA) and replay attack. This paper focusses on mitigating these two attacks with the aid of authentication tag and distance calculation. Mitigation of these attacks results in error free transmission which in turn fallouts in efficient dynamic spectrum access.