Abstract:
The coal mine underground environment is complex, and there are many factors affecting the electromagnetic wave propagation.This paper uses the ray tracing method to study the wireless channel model of coal mine underground.Firstly, assuming that the underground transmission environment is an empty straight roadway, the electromagnetic wave mode theory is analyzed and the mine wireless channel model is established by using the image method.Secondly, the loss caused by the scene factor is expressed by a formula, and the loss caused by another non-quantizable factor is expressed by the difference between the simulated field strength value and the measured field strength value.The channel modeling in the coal mine is completed by the ray tracing method of the empty straight roadway combined with the losses caused by various factors, and the simulation curve is fitted by the least square method to obtain the mathematical expression of the downhole channel model.The experimental simulation and experimental results show that the theoretical research and analysis of the paper are reliable, and the established model can match the measured data well, which lays a foundation for underground wireless communication in coal mines.