Game-Theory-Based Interference Management Method In LTE-U System Of Multiple Operators

In recent years,due to the explosive growth of mobile traffic and the high rate of information transmission,the current mobile communication network is under tremendous pressure.Today,Mobile traffic demand is growing crazy,the lack of spectrum resources in the licensed band has become increasingly apparent.In contrast to the 5GHz unlicensed band,with nearly 500 MHz of spectrum resources,currently only Wi-Fi is using.In response to the challenge of increasing traffic day by day,people turned their attention to the unlicensed band,the communications industry advocates proposed the concept of LTE-U(LTE Advanced in Unlicensed Spectrum).At present,most research mainly focused on a single operator deploying LTE in unlicensed band.However,when multiple operators deploy LTE-U system in the unlicensed band,if different operators choose the same channel service users at the same time,not only will cause interference to Wi-Fi,and will cause huge interference with the same frequency between users.Therefore,how to design a reasonable and effective interference management method to maximize the total utility of operators and users respectively in LTE-U system is essential.This paper first builds a Stackelberg game model to analyze the interactive process of multiple operators servicing multiple users.In the phase of game model establishing,Wi-Fi access points are introduced.The operators can predict the users' possible actions to set the optimal interference penalty prices to maximize the benefits they receive from the users.The operators control the transmission power of the users by setting the interference penalty price,and the users adjust the transmission power through the interference penalty price issued by all the operators,thus avoiding intolerable interference to the Wi-Fi service.Then,using the backward induction method to analyze the Stackelberg game from the user side,in the condition of LTE-U key technologyFDMA,based on the Gale-Shapley allocation game theory,a channel matching algorithm is designed for users and sub-band channels,which makes multiple operators service multiple users to avoid interference with the same frequency.Finally,we consider all operators' cooperative and non-cooperative pricing strategies in the operator side,making the Stackelberg game to achieve Stackelberg Equilibrium.The simulation results show that the operators pricing with cooperation strategy is beneficial to enhance the total utility of all operators and all users respectively in the control of Wi-Fi interference and avoid interference with the same frequency.