Research On Power Control Algorithm Based On Game Theory In Cognitive Radio

Due to the continuous emergence of various new wireless communication technologies,wireless spectrum resources are gradually decreasing,and the shortage of spectrum resources has seriously limited the development of wireless communication technologies.To solve the contradiction between the rapid development of communication technology and the shortage of spectrum resources,researchers have proposed cognitive radio technology,which can adjust transmission parameters according to the characteristics of the surrounding environment,so that primary and secondary users can share a frequency band at different times or under the condition of meeting interference temperature constraints,thus improving spectrum utilization.However,this communication method of coexistence of primary and secondary users will inevitably cause interference,and designing a reasonable power control algorithm is one of the important ways to solve this problem.Power control,as one of the key technologies of cognitive radio,can ensure that the secondary users can meet their communication quality without affecting the normal communication of the primary users in the communication process.This thesis takes the power control problem in cognitive radio as the research object,uses game theory to model,and proposes effective algorithms to study the design specification problem of selecting the best power,maximizing throughput and total benefit.The main work is as follows:1.To address the problems of power consumption and interference in the existing power control algorithms,an more effective power control algorithm is proposed,which is modeled by a non-cooperative game,and the existence and uniqueness of Nash equilibrium are proved.By using the cost function,each secondary user in a non-cooperative game becomes cooperative and the Nash equilibrium can converge to the optimal solution.Compared with the other three algorithms,the simulation results show that the proposed power control algorithm can overcome the near-far effect and reduce the transmission power of secondary users,thereby reducing the inter-user interference and achieving fair spectrum sharing among users while satisfying the Signal to Interference Noise Ratio(SINR)demand of different secondary users.2.This thesis proposes a power control game algorithm for cognitive radio,which improves and optimizes the S-type effective function and cost function to achieve fairness of power control for secondary users.The improved utility function can improve the throughput and total benefit of the system.The existence and uniqueness of Nash equilibrium are proved using knowledge of supermodel game theory.The simulation results show that the algorithm in this thesis has better performance in terms of throughput and total benefit compared with other algorithms,thus proving the better performance of this thesis.3.A distributed power control algorithm based on dynamic target SINR is designed to optimize the system throughput and ensure fairness among secondary users.The algorithm introduces dynamic target SINR to ensure that the SINR values of all secondary users reach the minimum acceptable target SINR while improving the system throughput by increasing the actual SINR obtained by some users.By comparing the proposed algorithm with two classical algorithms in simulation experiments,the effectiveness and feasibility of the algorithm are proved,and the overall performance of the system is effectively improved.