The Algorithms Of The Spectrum Sharing For Cognitive Radio Based On Game Theory

With rapid development of information society, wireless communication is becoming increasingly important in today. However, the spectrum resource is the bottleneck restricting the development of wireless communications. A number of research survey shows that the fundamental reason for the scarcity of spectrum resources is a serious defect of the fixed spectrum allocation system, resulting in the spectrum resources are not fully utilized, the spectrum utilization is extremely low. Cognitive radio (CR) technology can make full use of the spectrum resources, which improve effectively the spectrum utilization. The spectrum sharing technology is the key in the cognitive radio technology; it has been a hot topic of research at home and abroad.This article mainly studies cognitive radio spectrum sharing technology based on game theory. First, we elaborate the basic principles of game theory in detail, and state the possibility to analyze cognitive radio spectrum sharing by using game theory, given the spectrum sharing model based on game theory. Then we studied a spectrum sharing model that can make full use of idle spectrum of the primary user. To establish the user system's revenue function in terms of the spectrum demand size of the secondary users and idle spectrum of the primary user, we determine the appropriate spectrum prices considering not waste spectrum resources and maximize the profit to ensure that the free spectrum of the primary user system can be fully utilized. Simulation and data analysis show that idle spectrum of the main user system is fully utilized, greatly improving the spectral efficiency.Finally, a new spectrum auction algorithm is studied between the multiple primary user systems. The primary user systems maximize their own profits by using the equilibrium price scheme under the conditions of the quality of service (QoS) constraints. Cognitive users obtain the spectrum demand function through the use of the utility function. With Bertrand game model, we analyze the impact of system parameters (such as channel quality, the spectrum substitutability factor, etc.) on the Nash equilibrium, and static and dynamic spectrum sharing algorithms and stable region. Simulation and numerical analysis shows that total profit of all primary user systems is maximal, the free spectrum is used fully and spectrum utilization is improved.