Research On Spectrum Sharing Algorithm For Cognitive Radio Based On Game Theory

With the rapid evolution of the wireless communications in the broadband, seamless, intelligent direction, we have to face one of the bottlenecks which is the lack of spectrum resources. At present, the way of specific communications business fixed allocation for spectrum often bring up uneven distribution of resources, and even a waste of the case.This conflicts with widespread concern of the current shortage of spectrum resources. To solve this problem, the only way is to reuse the spectrum and improve the utility of spectrum resource.Cognitive radio technology as a smart spectrum-sharing technologies will be effective in alleviating these contradictions.Through sensing frequency domain, time domain and space domain, it can automatically search and occupy free licensed spectrum, reuse the non-renewable resources.A new way on how to improve spectrum utilization of the wireless communications under the conditions of limited spectrum resources has been addressed.The dissertation is part of results of tweo projects, which are "Research of Spectrum Detection Based on Time-domain Probability Distribution Curve Estimation of Spectrum Usage" sponsored by Research Fund of National Natural Science Foundation of China (No. 60772110) and "Research of Spectrum Sensing and Dynamic Spectrum Access of Cognitive Radio" sponsored by Science and technology Foundation of Huiwei.This dissertation analyses the spectrum sharing problem in cognitive radio based on game theory. The main issues of this paper are as follows:Chapter 1 introduces the background of study about spectrum sharing in cognitive radio and the structure of this dissertation. Chapter 2 introduces the definition and the function of cognitive radio briefly, summarizes actualities about the research on CR, explaines key technology of spectrum sharing in cognitive radio. Then the target of research is submitted for study about spectrum sharing problem.Chapter 3 system analyses the basic principles of game theory and the definition and solution of Nash equilibrium, discusses how to apply game theory to the cognitive radio, puts forward a cognitive radio game model and analysis general steps.Chapter 4, based on incomplete information dynamic game model, proposes a joint channel allocation and power control spectrum sharing algorithm in distributed network (JCAPCGT). Simulation analysis showed that, JCAPCGT algorithm can significantly reduce the average transmission power and save energy costs of CR network, under the premise of guaranteeing the average SINR and fairness performance of CR system. JCAPCGT algorithm is very suitable for the application of energy-constrained CR network.Chapter 5, for the situation of CR user can not acquire other users accurate decision-making information, based on incomplete information static game model, puts forward a spectrum sharing algorithm.And the convergence and the convergence results of algorithm has been theoretical analysised.Simulation experiments validate the convergence and effectivity of the proposed algorithm.Finally, summarizes the dissertation and points out the directions for further study.