A Power Control Method Based On Cooperative Game In Cognitive Radio

Cognitive radio is a new technology to enhance the ratio of spectrum utilization, which uses spectrum sharing technology to make secondary users (SU) utilize authorized band jointly with primary users(PU), but the transmit power from cognitive users will disturb the QoS of PUs. In order to guarantee the QoS of both PUs and SUs, cognitive radio adopts power control technology to realize the allocation of transmit power.This paper first researches on non-cooperative game power control algorithm, namely NPGP algorithm. The simulation analysis shows that NPGP algorithm realize communication with each other by maximizing their utility, which can not guarantee pareto optimality. Then the paper focuses on traditional cooperative game power control algorithm, NBS algorithm. We find that NBS algorithm can reach higher SINR level than non-cooperative game power control algorithm, but its transmit power is much higher, which will inevitably increase interference on the primary users. This paper presents a new power control method based on cooperative game, NBSE algorithm.On the basis of traditional NBS algorithm, the new algorithm brings in the concept of near user and remote user, and adopts an improved function to decrease the transmit power of secondary user, which reduces the interference on the primary users. We can use Newton iterative method to realize the iterative formula of NBSE. Simulation results show that the NBSE algorithm has a lower transmit power than traditional NBS algorithm and the non-cooperative game algorithm. It can reduce the interference upon the primary user and also can guarantee the QoS of cognitive user. Therefore, this algorithm is able to reach a better compromise between transmit power and SINR.