Research On Interference Management In Marcocell-femtocell Network In LTE-A System

With the popularity of intelligent terminal,the demand for data services is increasingly growing,almost 2/3 telephone business of the cellular network and more than 90%of the data business are in the interior,but the survey found that 45%of the company's home and 30%companies have a very poor indoor coverage so that high quality user experience is an great challenge for 4G era.In order to meet the requirement,low power nodes such as femtocell and LTE-A are gradually becoming the research hotspot in the network.However,in the original macro cell,femtocell has changed the original network structure.The new complex network architecture is not only the technical problem of network deployment,but also the problem of spectrum resource allocation,the interference problem of complex scene and the problem caused by different network layer handover.This paper describes and analyzes the traditional methods of interference management.Based on this,a scheme of femtocell and macro cell interference coordination based on interference coordination and spectrum resource allocation is described.The simulation and analysis of the interference coordination scheme is carried out.The results show that the interference coordination scheme has a better performance on Macrocell-Femtocell LTE-A network.In addition,an interference coordination algorithm based on interference graph is proposed.The simulation proved the algorithm has a prominent advantage compared to the common channel frequency configuration.Because the limited Physical Cell Identity(PCI)is not enough to meet a large number of femtocell configuration,and the consequent cross layer interference problem cannot be ignored.In view of the problem of PCI conflict in cross layer handover,a new method based on Hidden Markov Model(HMM)is proposed.PCI is divided into dedicated PCI and reused PCI,and cells which switch more frequently are configured with dedicated PCI,on the contrary,cells which little switch are configured with reused PCI,which can reduce the possibilities of PCI femtocell confusion.As an important parameters which the cell must be configured with in LTE/LTE-A,it aims to distinguish special cell between different cells by the terminal.The simulations show that the hidden Markov model has higher prediction accuracy and effectively reduce the switching of PCI conflict and confusion probabilities.