The Research And Improvement Of Interference Management In Femtocell Heterogeneous Networks Based On Power Control

With the development of mobile communication technology, LTE has been considered as the fourth-generation mobile communication(4G)technology after 3G technology by 3GPP. Due to the high frequency of the wireless signal of the LTE system, the penetration capability of the wireless signal is poor and forming the signal coverage holes easily in the buildings. The study shows that the majority of communication service requests are initiated by the user in the interior. Therefore, based on the purpose to improve indoor signal coverage and improve the user experience, the industry proposed Femtocell.In the LTE system, Femtocell is formed through the deployment of the HeNB(Home eNode B). HeNB with plug-and-play features is purchased by the user, and formed LTE-Femtocell heterogeneous systems with LTE Macrocell after booting. Before deployment HeNB, lacking of network planning and design will lead to inter-cell interference between LTE Macrocell and Femtocell intricately.Therefore, the study of inter-cell interference coordination scheme(ICIC), especially the HeNB power control algorithm is of great significance.This thesis is based on the LTE Femtocell related standardization agreement with the literature, a detailed analysis of the key technologies of LTE and Femtocell, LTE-Femtocell deployment scenarios, interference scenes, uplink and downlink power control mechanism, then making downlink interference as the starting point, and focusing on researching the interference of HeNB’s on the Macrocell downlink(DL), when Femtocell and LTE Macrocell co-channel deployment, and summarizing about five HeNB downlink power control algorithms to reduce the interference. Finally, based on the research of LTE open source system level simulation platform, build the LTE-Femtocell system-level simulation platform for this article, and prior to the proposed power control algorithms for system-level simulation one by one. According to the simulation results, although the performances of the proposed power control algorithms may be different, but there is a clear trade-off between the MUE outage and HUE performance(outage and average throughput)for all the power setting schemes. Therefore,all the proposed schemes may reduce the interference of HeNB’s on the Macrocell downlink(DL)effectively.