Research On The Electromagnetic Wave Propagation In The Mine Laneway

The establishment of a reliable mine communication system is an important guarantee for thesafety of coal mine production and disaster relief. Meanwhile, the research on the propagation ofelectromagnetic waves in the mine tunnel is of practical significance to the designing and planningof a mine wireless communication system. This thesis aims to analyze the characteristics ofelectromagnetic wave propagation, and also throw light on the wave mode theory in the mine tunnel.What’s more, it constructs the mine deterministic wireless channel model of the mine tunnel by theray tracing method, which helps understand the influence of rock mass parameters on theelectromagnetic wave and fading characteristics of the transmission of electromagnetic waves in thespecial-shaped cross-section mine tunnel. The main content of this thesis is listed as follows:(1) By using Marcatili approximate analytical methods, this thesis is to analyze the idealrectangular mine tunnel, draw mathematical expressions of horizontal polarization mode andvertical polarization mode field, and finally, deduce the transmission mode attenuation and cutofffrequency of each mode. The branch loss, rough loss and antenna insertion loss which may be metduring the transmission of electromagnetic waves are taken into consideration, together with theaffected factors.(2) By employing the mirror method combined with electromagnetic theory, this thesis is toestablish a multi-path channel prediction model, and propose the calculation method ofthree-dimensional ray path and from the angle of reflection. Under the guidance of Matlab, thethesis is to discuss the influence of the distance, transmission frequency and roadway dimensions onpredicting the intensity distribution. And, through the comparison between the literature andsimulation results, the correctness of the mirror method can be proved.(3) This thesis is to describe the impact of the complex environmental factors in the mine tunnel onthe transmission of electromagnetic waves, and make an analysis of the effects of the electricalparameters on the fading characteristics of radio wave propagation in the mine tunnel. Last but notthe least, it is to make a detailed research on the fading characteristics of the transmission ofelectromagnetic waves in the circular arched roadway.