Utility-based power control in hierarchical spectrum sharing networks for cognitive radio

In this paper, we propose utility-based power control algorithm jointing with admission control (UPCAC) for distributed communication in the hierarchical spectrum sharing network (HSSN) for cognitive radio. We formulate a utility function (payoff function minus price function) to reflect the tradeoff policy between the protecting for primary users (PUs) and the supporting to quality of service (QoS) requirements for cognitive radio users (CRUs). We also analyze the geometric characteristics of payoff function and price function, and base the parameter setting of utility function on this analysis. Finally, we design corresponding power control protocol based on UPCAC for HSSN. Simulation results indicate that 1) UPCAC can meet the protection for PUs as well as the QoS requirements of CRUs by flexibly setting parameters; 2) UPCAC guarantees power convergence by jointing power control with admission control; 3) UPCAC achieves desirable admission ratio and spectrum efficiency.