Power Control for Cognitive Radio Base on Game Theory

A new technology to achieve the spectrum efficiency usage is cognitive radio. This paper we study the power control of the transmitter in basic cognitive cycle. And game theory is applied for modeling. Non-cooperative power control game which is created by D. Goodman is used; however, we introduce a new sigmoid efficiency function only related with user's SIR. Its advantage is obvious that regardless of the modulation of users' RAT, which is very suitable for cognitive radio system. Specifically, we also modify the traditional pricing function with an addition of path gain. It is proved that the new utility function will bring an obvious improvement comparing to NPG and NPGP used in traditional CDMA systems.