| In order to meet the urgent demand of the rapid development of wireless communication network, the necessity of researching the more effective anti- interference technology is undeniable and apparent. In terms of the LTE cell of origin, although the interference against mobile customers inside the cell has been largely controlled, the mobile terminal on the edge of the cell is vulnerable to the interference from its neighboring cells and some nearby terminals. Therefore, this project associated with the research center of a telecommunication enterprise abroad mainly aims at tackling the interference for customers on the edge of cells.This thesis, mainly expounds and analyzes the following aspects: the first part focus on the PDCCH channel and the relationship between the interference control and LTE channel. Then according to measured values of the base station power, after synthesizing the persistent state characteristics, transfer characteristics and fluctuation characteristics of the base station power, a model of base station power is set up, in view of the interference of users on LTE cell edge is serious, thus the algorithm based on power sequence is put forward, including 1/2 of frequency reuse power sequence algorithm and the power sequence algorithm of adapting to changes in load. When the power sequence algorithm of adapting to changes in load is used, the weighting factor of the anti- jamming algorithm of LTE will change in time. Meanwhile, PDCCH channel is analyzed in this part and the conclusion drawn shows that there exists a strong correlation between the relevancy degree of PDCCH C hannel Interference Code and Signal-to-Interference Ratio. Therefore, the researcher puts forward the improved algorithm which utilizes power sequence to control the relativity of PDCCH Channel Interference Code.The next part focuses on the analysis of the LTE downlink and the data packet. And a LTE downlink simulation platform is established with the reference of the MATLAB simulation platform. Through the experience in this platform, it is proved that the algorithm based on power sequence can improve Signal-to-Interference Ratio especially in the case of a cell under high load. If the scrambler selected is 2400 bits, SINR can be improved about 2 d B; if it is 2400 bits, SINR can be improved only about 0.8 dB. Then a comparison between the improved algorithm based on power sequence and the traditional frequency reuse algorithm ha s been made, and it is apparent that the former is superior to traditional anti-jamming algorithms. Through a large number of simulation experiments, it is concluded that this algorithm excels the traditional algorithms in many aspects. It is also summarized that when a cell is under relatively low load, the algorithm which combines power sequence with frequency reuse is slightly superior to the algorithm in which PDCCH channel is controlled by power sequence; but when a cell is under a high load, the former is inferior to the latter. This algorithm is eventually implemented by C ++ language.In conclusion, the design of this new algorithm has been accomplished and the simulation results show that this algorithm has improved the SINR to some extent for users on the edge of cells. |
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