Research On Spectrum Optimization Allocation Based On Potential Game Theory

With the rapid growth of wireless network demand and the number of users,the wireless communication technology is developing rapidly,but the limited wireless spectrum resource cannot satisfy the needs of actual communication development.Such circumstances promote the cognitive radio technologies which can perceive the service condition of spectrum dynamically.Under the premise of ensuring communication quality of authorized users,cognitive users can share the communication spectrum in due time to improve the efficiency of wireless spectrum,alleviating the lack of spectrum resources.The spectrum allocation algorithm determines the spectrum usage of wireless devices,which plays a decisive role in the performance of cognitive radio networks.The problem of spectrum allocation in cognitive wireless networks has been studied.Most of existing research has focused on solving the single-objective optimization problem of spectrum allocation in cognitive radio networks.That is,the amount of interference between cognitive users or the throughput of cognitive system is selected as the optimization target.This kind of research is usually unable to achieve optimal performance,and cannot meet fully the diverse needs in cognitive wireless networks.Therefore,this dissertation is based on the spectrum allocation model of cognitive wireless network to improve the current single-objective optimization spectrum allocation algorithm,and selects the amount of interference between cognitive users,the amount of interference between cognitive users and authorized users,the throughput of cognitive system as the optimization goal,achieving the spectrum optimization allocation of cognitive network diversity target requirements.The main research contents include:1.The problem of spectrum allocation in cognitive radio networks based on potential game theory are studied.The existence and uniqueness of Nash equilibrium under joint objective optimization are proved,which provides a theoretical basis for designing spectrum optimization algorithm based on game theory.2.Aiming at the problem of ignoring authorized users in spectrum allocation algorithm,which has limitations.This dissertation proposes an improved interference coordination non-cooperative spectrum sharing algorithm.Firstly,the spectrum allocation problem is converted to joint optimization problem,and a newutility function and potential function are constructed.Then,the spectrum optimal allocation scheme is realized by using the potential game algorithm.The cognitive user selects the channel which minimizes the system interference and maximizes the throughput to complete the communication,so as to realize the optimal allocation of the spectrum.Finally,the effectiveness and superiority of the proposed algorithm is verified by spectrum allocation simulation.The results show that the proposed algorithm can converge to Nash equilibrium in a short time.Under the condition that the normal communication of authorized users is not influenced,and the throughput and fairness of the cognitive system can be improved obviously while minimizing the amount of the interference among all users.Finally,the efficient utilization of the spectrum is realized.3.Aiming at the problems of more game times and slow processing speed of the existing spectrum allocation algorithm based on the potential game,the adjustment rule is introduced to improve the speed of spectrum allocation.In each game,each cognitive user acquires dynamically the opportunity of channel adjustment according to the rules,reducing the probability that the same user repeats game selection channels.The simulation results show that the game allocation algorithm based on the constraint of the rules not only improves the efficiency of cognitive users to select favorable channels,but also meets the joint optimization requirements of cognitive wireless networks.