Research On Resource Allocation In Heterogeneous Network Based On Game Theory And Convex Optimization

The research of resource allocation in Heterogeneous network is an indispensable and important problem along with the development of radio communication. Because more than 50% of voice services and more than 70% of the data services are conducted in indoor, so the research of resource allocation in Heterogrnous network made up with small base stations has already become a popular research direction. However, not all base stations can use orthogonal frequency for the limited spectrum resources. Thus, which needs to be addressed in the study of heterogeneous network are the Intra-Tier Interference(ITI), Cross-Tier Interference(CTI) and the problem of power control. the goal of this paperb is to maximize the downlink link data transfer rate of femtocell base station users, at the same time optimizating transmission power of the user and allocation of spectrum.Firstly, the paper introduces the basic concept of heterogeneous network, macrocell, femtocell, the classification of interference, and Wi-Fi packet transmission mechanism. Meanwhile, the paper analyzes the current research of resource allocation in heterogeneous network mainly focuses on two aspects: one is the limitation of authorized spectrum resources; another is the serious interference problem. Based on the above two problems, the research of the paper is carried out mainly from two aspects: first of all, introducing Wi-Fi access point for the limited spectrum resources, in which the users of Femtocell base station not only can share the spectrum resources with the users of Macrocell Base station, but also can share the unlicensed spectrum resources of the Wi-Fi according to the mechanism of LBT. Then, study from the optimization both in power allocation and spectrum allocation to maximize data rates of the Femtocell base station.Secondly, the paper firstly assumes that the case of the spectrum allocation has been completed. Establish the cooperation game model with introduction of cost function, take the transmission power of users of Femtocell base station as game object, and maximize the total throughput of the Femtocell base station. Prove the existence and uniqueness of Nash equilibrium in non-cooperative game model. The simulation shows that the convergence of the proved algorithm is in the number of iterations for 5 to 10 times. Besides, the users not only reduce the interference to the Macrocell base station, but also improve the fairness after the introduction of Wi-Fi into the system model. And then, based on the former system model, the optimization problem is extended to maximize the downlink data rates of users of Femtocell base station, considering ITI and CTI. At the same time, using theory of convex optimization to optimize the user transmission power and spectrum allocation. And simulate the results to verify the rationality of the new model and the feasibility of the optimization method from the iterative convergence, number of users, Qo S and interference threshold.