Joint power control and spectrum allocation for cognitive radio networks via pricing

The current fixed spectrum allocation approach is inefficient in resource utilization and hinders the freedom to dynamically exchange spectrum ownership and deploy new wireless services. To counter this trend, Cognitive Radio (CR), an innovative radio design approach which allows the realization of dynamic spectrum access and services deployment, is under extensive research. So far, most research in spectrum sharing enabled by CRs has mainly concentrated on mechanisms for acquiring and sharing ‘free’ spectrum, while the ‘paid’ spectrum alternative has largely been delegated to the spectrum regulating bodies. In this work, we consider a holistic approach where spectrum is efficiently and dynamically utilized. Our aim is to develop a mechanism that enables joint spectrum allocation, revenue maximization and power control through spectrum pricing while achieving a desired QoS performance. A nested Network-User hierarchy model consisting of a spectrum manager (SM), service provider (SP) and end user for dynamic spectrum leasing is proposed. The SM maximizes the spectrum usage efficiency through monopolistic based price setting. The SP maximizes its revenue by deploying services over the acquired spectrum bands. The end users autonomously trades-off between their utility and spectrum cost through transmission power control — essentially forming a non-cooperative power control game for which we show the existence and uniqueness of the Nash equilibrium. Numerical results are presented to demonstrate the potential of the proposed framework in the spectrum price setting by the SM, revenue maximization by the SP, and power control strategy adopted by the user in various price thresholds.