Research On Interference Management Between Dual-Layer Network Of Marcocell And Femtocell In LTE-A System

As one of the candidate technologies in4G, LTE-A system have clearly mentioned that it will further enhance the technologies based the LTE standard in MIMO, CoMP, carrier aggregation, and relay. The LTE-A system which based on OFDM can provide faster data rate, better quality of service, and more effective way to use resource. However, when pursuing larger coverage, more than46%indoor equipments are still bearing poor experience. What is more,"dead zone" of service is much more common than before. Therefore, the recent development, which is called Femtocells, has been given a warm welcome and continuous research since it is proposed. It expends the wireless communication application scenes and effectively improves the whole cell performance while the interference scenes in the dual-layer network of Marcocell and Femtocell become much more complex after the introduced Femtocell. There is significant meaning for wireless communication industry of taking serious consideration on how to analyze the entire interference to achieve a better resource allocation and relevant planning and more efficient resource usage.Besides, except for the analysis on the dual-layer interference scenes, the traditional interference management schemes cannot be used without any improvement since the technologies and schemes are proposed based on single layer in original Macrocell network. Therefore, how to propose a new method to effectively control the dual-layer interference and improve the whole throughput have been a very important research subject in the dual-layer network of Macrocell and Femtocell at present.Based on the previous consideration, this thesis mainly focuses on the interference study and interference management scheme in dual-layer network after the introduced Femtocell. Firstly it takes technological analysis on Femtocell and the corresponding challenges. Secondly the uplink and downlink interference scenes have been separately discussed and methodized in dual-layer network. Based on the previous research, new effective interference management and resource allocation schemes are proposed both in the LTE-A uplink and downlink in the end.In the study on interference management, the thesis builds dual-layer modeling and then takes mathematical analysis and formula derivation for transmission rate, final the mathematical expression of system optimization goal can be obtained. In the study of uplink interference, the user equipments expect higher transmission rate and there is larger space in application scene. To maximize the entire throughput is the optimize subject in uplink. While in the downlink, with the increasing user equipments density and transmission path complexity, the optimize subject is how to reduce the average power in the base station. The difference between the new interference management and traditional process is taking the interference technology in frequency assignment joint with power allocation to achieve the optimize subject.Finally for the simulation, Monte Carlo simulation is used to take system level simulation in dual-layer network. The system modeling and parameter design is firstly taken. Then based on the system simulation platform, two Femtocell deployment models including dense dual stripe model and suburban model are introduced. The proposed uplink and downlink interference managements are realized in the suburban model. Compared to reference algorithms, numerous results are analyzed synthetically to show that the proposed algorithm can achieve significant performance gains over the traditional methods, especially in view of the guarantee of UE’s quality of service.