| Coal is one of the most important energy sources, coal production related to our people’s livelihood, with coal production automation and information technology improved, the mines want better communications. Wireless communication technology of the mine has not match advantage with wired communication to improve mine efficiency, strengthen management and improve security. And as the integration of coal resources in China, the coal industry entered a rapid development of the fast lane, the strength of coal enterprises more powerful, pay more attention to the wireless communication of the mine.Electromagnetic signal transfer in the mine tunnel will not only have a greater transmission loss, even more important will happen reflection, diffraction and scattering phenomena frequently, the multi-path fading is formatied, control the transmission characteristics of electromagnetic signal under the mine is very important to the development and design of the communication system in the mine.First the wireless communication of the mine is researched and analysised, and combine with test results of the electromagnetic noise in Doerping and Ximing of the Xishan Coal and Electricity Group, the UHF frequency band is the band of the wireless communication of the mine. Basd on the transmission loss of electromagnetic signal of the UHF band is studied in the rectangle straight roadway,curved roadway, and rough loss, tilt loss, the path transmission loss model of electromagnetic signal under the mine is established, and the model is verified rightly, the frequency, bending, cross section, rough, tilt and other factors are analysised on the effects of transmission loss of electromagnetic signal through simulation with MATLAB.When the multi-path propagation of electromagnetic signal under the mine is studied, multipath signal amplitude distribution of the small-scale fast fading of mine wireless communication channel is described with the Nakagami distribution through analysis and comparison, Rician simulation process is established with sine wave method, the parameters of the Rician simulation process is determined with equidistant method, then channel simulation model of Nakagami fading is established with inverse transform method based on the Rician simulation process, and the decline parameters of the channel is analyzed, then the mode is verified rightly, and multipath fading of electromagnetic signals of the tunnel is simulated with MATLAB.Finally, based on transmission characteristics of the electromagnetic signal under the mine and analyze the deficiencies of the existing mine communications network, combine with the actual situation of the mine, network architecture of the wireless communication system of the mine is designed, the calculation method of the cell coverage radius is geted through the link budget analysised, and the cell coverage radius under the different environment is analyzed, the calculation method of overlapping regions length is geted with the relation between interference ratio and the area of overlap, the system capacity and base station set is analyzed. |
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