A physical layer authentication scheme for countering primary user emulation attack

This paper develops a physical layer user authentication scheme for wireless systems. The approach can be used as an effective counter measure against the primary user emulation attack in cognitive radios. The developed scheme applies to general digital constellations and we establish its optimality in terms of error probability for user authentication. Trade-off analysis is provided that balances the performance of the user authentication for the secondary user and symbol detection for the primary user. In particular, we show that arbitrarily reliable user authentication can be achieved at the price of an almost negligible performance degradation for the primary user under realistic system settings.