S. D'Oro, P. Mertikopoulos, A. L. Moustakas, and S. Palazzo. In EUCNC '15: Proceedings of the 2015 European Conference on Networks and Communications, 2015.
Cognitive radio (CR) systems allow opportunistic, secondary users (SUs) to access portions of the spectrum that are unused by the network’s licensed primary users (PUs), provided that the induced interference does not compromise the PUs’ performance guarantees. To account for interference constraints of this type, we consider a flexible spectrum access pricing scheme that charges SUs based on the interference that they cause to the system’s PUs (individually, globally, or both), and we examine how SUs can maximize their achievable transmission rate in this setting. We show that the resulting non-cooperative game admits a unique Nash equilibrium under very mild assumptions on the pricing mechanism employed by the network operator. In addition, we derive a dynamic power allocation policy that converges to equilibrium within a few iterations (even for large numbers of users), and which relies only on local signal-to-interference- plus-noise ratio (SINR) measurements. Our theoretical analysis is complemented by extensive numerical simulations which illustrate the performance and scalability properties of the proposed pricing scheme under realistic network conditions.