Research Of Fm Radio Broadcasting Coverage And Prediction In Mountain Area Of Yunnan Province

FM radio broadcast has experienced a brilliant development in the 1990 s,and reached its peak around 2010.According to the number of the radio station and the broadcasting time of public program,China is the biggest radio country in the world.However,traditional media like FM radio broadcast has been shrinking in both spreading and profits,new development direction is badly needed for them in the nearly future.On the one hand,with the increasing demand of individual information,the demand for miniaturization,regionalization and community-based broadcasting is increased daily;on the other hand,the demand for national emergency broadcasting system is increased daily,radio spread with regional and fast-setting is highlighted.In this thesis,we have tested and analyzed the coverage of several FM broadcasting in typical regions in Yunnan and proposed a solution using low-power FM transmission to cover the problem of unsatisfactory coverage and future emergency broadcast construction,and discussed the near-field strength model.The main work of this paper is as follows:(1)Based on the analysis and research to the not ideal FM broadcasting in Yunnan,this paper proposes to solve the shortage by using low-power radio coverage.Discussed the planning method,and tested the FM transmission field in small range(0?2.5km)and low power(30W),mountain terrain,which fills the gap of relevant experimental data.(2)The field strength coverage of the test environment is predicted based on the ITU-R P.1546-5 proposal,the ideal environment field strength model and the simulation model provided by HJ / T 10.2-1996 industry standard,then compared with the measured results,the conclusion that the field strength coverage calculation model of ITU-R p.1546-5 proposal is more applicable to the research environment is obtained.(3)Based on the test results and reference literature research,corrections were made to local characteristics,and correction factors adapted to local conditions were obtained.At last the specific solutions for the future FM broadcast planning are proposed.