Research On Interference Suppression Of Two-tier Femtocell Heterogeneous Networks

In recent years, the rate of communication network is required to improve. The heterogeneous network has received the attention of experts and scholars at home and abroad, and the appearance of Femtocell has brought the hope to the solution of the problem of indoor coverage. Femtocell is a micro base station of small coverage and low transmission power. Also it is deployed and managed by users, and plug and play, so it is very convenient. Its own technical characteristics make it have advantages in improving the system capacity, expanding coverage, and enhancing the quality of service compared to other technologies. But there are both advantages and disadvantages. The introduction of Femtocell has also brought a series of problems, of which the interference is one of the main problems.Under this kind of background, the problem of interference suppression in heterogeneous networks is studied in this paper using the two-tier heterogeneous networks composed of Femtocell and Macrocell as the research object.First, the LTE/LTE-A system and the technical features and advantages of Femtocell are described briefly in this paper. Then under the typical interference scenarios, the simulation shows the influence after the introduction of the Femtocell. The interference suppression algorithm is studied next from two aspects of power control and frequency distribution. In the aspect of power control, this thesis uses game theory to analyse the system, and based on the proof of the Nash equilibrium in Stackelberg Game through the analysis of function under the non cooperative game model, a link protection method is combined to optimize Femtocell performance further. In terms of frequency distribution, two methods of fractional frequency reuse and soft frequency reuse based on frequency reuse are introduced briefly, then three improved schemes of fractional frequency reuse are compared, finally the conclusion is draw through the simulation results in the simulation environment of the specific parameters.