Measurement And Study Of Coal Mine Tunnel Channel Characteristics

China is a country rich in coal mine resources, and also a country depends oncoal resources seriously. In recent years, how to reduce coal mine accidents and howto ensure safety of coal mine workers attract more and more attention. Real timecommunication in coal mines is an important way to ensure the safety of coalproduction. Wired sensors are widely used now but suffer the complex installing andpoor reliability. To use wireless sensors is a feasible way to overcome theseshortcomings. In this essay, a coal mine channel measuring system is designed fromexisting communication technologies. Then a communication protocol is designed forwireless communications in coal mine tunnels. The final target is to design a wirelesscommunication system used in coal mine tunnels.In this essay, theoretical analysis, hardware and software design, channelmeasuring and scheme design are practiced. Firstly the coal mine tunnel channelcharacteristics are studied and measured, and then a wireless communication protocolis designed for coal mine tunnel wireless communication.In this essay, firstly the coal mine safety situation is introduced, the characteristicof channels in coal mines is discussed and the importance of upgrading coal minewireless communication system is explained. And then the advantages andshortcomings of wired and wireless communication is discussed. And then existingchannel modeling method is studied. After comparing deterministic modeling andempirical modeling, a simple path loss model is chosen as the reference model.After the study of channel modeling, the channel measuring plan, experimentdevice, software and hardware design is decided. A compact slot antenna for circularpolarization is proposed. Then the simulation and experimental results are studied.After the hardware and software design, the channel measuring system is realized anda measurement is accomplished in the coal mine. The result of the measurement isanalyzed.After the channel measurement, a wireless communication protocol is designed for coal mine tunnel wireless communications. The communication process andframe structure is designed.Through the work mentioned above, circular polarized antenna is studied andused in channel measuring system, the coal mine tunnel wireless channel is measuredand studied, and a wireless communication protocol is designed. Therefore, theresults of this essay can be applied in the design of wireless communication system incoal mines.