The Anti-interference Research Of Cell In LTE System

With the wireless communication technology rapidly development, mobile communication has passed 3 generations to Quasi-4rd-generation appears. New wireless communication business demand flexible, wideband and multimedia. Aim to this,3rd Generation Partnership Project (3GPP) provides a series of important new standards, including Long Term Evolution (LTE) and Core Net Work (CN). Both of them become research hotspot recently. Nonetheless, Reuse Factor of OFDM is designed approximate 1, which makes inter-cell interference remarkable and the improvement of throughput is limited. Therefore, this study explores technologies about suppression of Inter-cell interference, fractional frequency reuse and power control became very inportant.In this paper, research can be mainly divided in 3 parts, power control, Fractional Frequency Reuse(FFR) and method which increasing efficiency of Packed Transport Network(PTN).(1) Research on LTE power control. Theory analysis on LTE system models, mainly including E-UTRAN structure and OFDM communication model in LTE's Physics layer, are discussed on this paper. Based on these analyses, reason and solution for Inter-cell interference are given. Current solutions mainly include Interference random, Interference elimination and Interference coordination. Comparing these solutions, we can conclude that interference coordination performs better than Interference random and Interference elimination. Therefore, our research mostly focuses on Interference coordination and analysis on its disadvantage is utilized. Based on analyzing some other Interference coordination approaches'drawback, a new Interference coordination method has been proposed. And this work has been applied for patent. Power control plays an important role in suppression of interference. Schemes about open-loop power control, closed-loop power control and Overload instructions control are researched on this work, a solution for upstream power control is proposed.(2) Research on Fractional Frequency Reuse(FFR). Based on the analysis of LTE system model, frame structure, wireless transmission model, cell distribution model, interference model and system capacity, for a half static state interference coordination solution, an interference model for 19 cells are build and simulation process and functional test data are discussed. Simulations are implemented and a new resource management method is proposed. By simulation, we can conclude that the system model function effectively. New method's property, including SNR probability distribution, cumulative function, throughput and spectral efficiency, are analyzed in our research. Building Interference model performs very important role in the research of interference in LTE system as it can save remarkable resource in practical test and provide possible actions. It is evidenced that LTE anti-interference research has remarkable meaning in improving throughput and spectral.(3)Research on Packed Transport Network(PTN). A new method which grid's utilization ratio can be increased, especially in the case of network congestion and signal instability, this method can set conditional intermittent open administrative port. This kind of working mechanism increases utilization ratio of network without damaging network's protection by the administrative port.