Research And Practice On Interference Caused By Passive Components In GSM Indoor Distribution System

With the refined development in constructing of the mobile communication network, the scale of indoor micro-cellular is gradually increasing, and the complexity of indoor distributed systems is also increasing. There are a lot of sites which have interference associated with changes of traffic in mobile network. These sites greatly affect the network performance and lead to a serious decline in the user call perception. Based on previous experience in the investigation of interference, interference with traffic changes are usually associated with passive components. In this thesis, Study, analysis and testing of passive components are conducted, on the basis of the test, analysis of failure phenomena is conducted and got the conclusion that the distribution system interference is due to passive device failure due to relevant indicators.This thesis introduces the background and significance of network optimization,then has a description of the type of interference in the GSM network, and the concept of use and indicators in common indoor distribution components; by statistic methods, the thesis analyzed the correlation of interference and traffic in micro-cellular network, then demonstrated the correlation of interference with traffic changes and downlink transmission of main equipment in micro-cellular system by the test of power controling; briefly described the single-station test in one site, then analyzed that a class of interference in the existing network comes from passive components of indoor distribution system; Through experiments, demonstrated the power tolerance inconsistency of some components in a multi-carrier condition or under single-carrier condition. Then figured the key indicators’passing rate of the submitted components; proved theoretically that the components failure of intermodulation indicator leads to the interference with changes in traffic directly; In the end, the achievements have been applied in practice, and has brought actual economic benefits for company.The study results hava played an active role in improving the efficiency of people on locating the fault points, and saving manpower and material costs, and the research can provide a reliable basis and guidance on the work of being optimization and maintenance of indoor distribution system in the future.