Joint power control and pricing for underlay relay-based cognitive radio networks

One of the most important issues in cognitive radio networks is to guarantee quality of service (QoS) constraints for primary users. In this paper, a relay-based cognitive radio network is considered in which secondary users compete in a selfish manner to use a relay to improve their utility function, while maintaining interference at the primary receiver to be lower than a certain threshold level. This problem is modeled as a non-cooperative game and by using a proper pricing function in the definition of the utility function, it is shown that despite the selfish behavior of the users, Nash equilibrium (NE) with sub-optimum property is achieved. A distributed and novel algorithm to update joint power and pricing is also proposed. Furthermore, a set of conditions for convergence of the algorithm is provided. Finally, performance of the proposed algorithm in terms of various system parameters is studied through simulations.