Pricing-based primary-secondary user power control game for cognitive radio networks

In cognitive radio networks, if the license spectrum that is allocated to the primary users (PUs) is not utilized, the unutilized spectrum can be used by the secondary users (SUs). This unutilized spectrum is called spectrum hole. However, when the SUs access the spectrum hole, they become source of interference to the others primary and secondary users. Interference temperature is the model, which used to manage the amount of interference that the PU can tolerate. Therefore, efficient power control is crucial to control the interference in the cognitive radio system and promote system quality. Previous works on power control are mainly focus on the SUs SIR maximization as the QoS requirements, ignoring the Primary User (PU). In this paper, PU is considered that has a general utility function, and a linear pricing function is used for SUs utility function. Pricing is an effective tool used to reduce the potential harmful effect of the system and guarantee the PU QoS. We formulated the power control game as a non-cooperative game, in which the first player is the PU. The number of SUs in the system is limited by the status of PU and its ability to achieve its QoS rather than used the interference temperature limits. The numerical results show that the proposed power control algorithm with pricing reduce the power consumed by PU and SUs terminals, and improved the utility functions of PU and SUs.