Research And Implementation On Downlink Adaptive Power Control Algorithms Of Femtocell In LTE System

With the development of mobile communication technology，LTE has been considered as thefourth-generation mobile communication (4G) technology after3G technology by3GPP. Due tothe high frequency of the wireless signal of the LTE system, the penetration capability of thewireless signal is poor and forming the signal coverage holes easily in the buildings. The studyshows 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 userexperience, the industry proposed Femtocell.In the LTE system, Femtocell is formed through the deployment of the HeNB(Home eNodeB). HeNB with plug-and-play features is purchased by the user, and formed LTE-Femtocellheterogeneous systems with LTE Macrocell after booting. Before deployment HeNB, lacking ofnetwork planning and design will lead to inter-cell interference between LTE Macrocell andFemtocell 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 deploymentscenarios, interference scenes, uplink and downlink power control mechanism, then makingdownlink interference as the starting point, and focusing on researching the interference ofHeNB’s on the Macrocell downlink(DL), when Femtocell and LTE Macrocell co-channeldeployment, and summarizing about five HeNB downlink power control algorithms to reduce theinterference. Finally, based on the research of LTE open source system level simulation platformand the internal system-level simulation platform of Institute of Computing Technology (ICT),Chinese Academy of Sciences(CAS), build the LTE-Femtocell system-level simulation platformfor this article, and prior to the proposed power control algorithms for system-level simulationone by one. According to the simulation results, although the performances of the proposed powercontrol algorithms may be different, but there is a clear trade-off between the MUE outage andHUE 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.