Game Theoretic Analysis of Power Control for Cognitive Network in Licensed Spectrum

In cognitive network, power control is necessary to not only decrease the interference among the unlicensed users, but also avoid the negative effect to the licensed users. In this paper, a noncooperative power control model is proposed for the unlicensed users in licensed spectrum using game theory. In the power control game, an extra part indicating the effect to the licensed users is added into the pricing function. Through game theoretic deduction, it is obtained that a unique Nash equilibrium solution exists under appropriating parameter value of the payoff function. Under the constraint of permitted maximum negative effect to licensed users, the Nash equilibrium solution of the proposed power control game is Pareto optimality and achieves maximum total throughput.