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Coal is the main source of energy in our country , for a long time , the safe production of coal enterprises still a key issue . Due to the special nature of the underground environment , radio wave propagation in the roadway encounter great difficulties , coal mine communication is also very complex , plays a very important role in the communication of mine safety production , personnel scheduling , information gathering , to establish underground communication system, it is necessary to consider the transmission of the radio wave propagation characteristics of the different levels of , for different transmission characteristics , in order to achieve downhole flexible, fast and efficient communication . Communication environment based on coal mine roadway waveguide mode theory , analysis to study the propagation of radio waves in downhole limited space , to improve the analysis of the factors affecting the underground radio wave propagation characteristics , and draw some useful conclusions , analysis of research roadway near-field region and the far field propagation model proposed hybrid forecasting model , using the free space radio wave propagation loss model predicts that in the near-field zone ; to establish air straight roadway forecast model in the far-field region . The introduction of the difference between loss model based on predictive modeling , using the method of least squares , and thus the establishment of a mixed loss correction model using Matlab simulation , through the comparison of experimental data and simulation curve , come to the reasonableness of the theoretical method , which provides a theoretical basis for the establishment of underground communication system .
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