Research And Design Of Mine Through-the-earth Wireless Communication System

With the rapid development of ground communication technology, mine wireless communication technologies are constantly developing. Mine wireless communication system to improve mine the modern management level, and to improve labor productivity, to improve safety, to ensure the safety of the miners lives and the national property has a very important significance. However, due to the communication medium of the mine wireless communication through the earth is underground rock rather than "free space". A mine underground strata are complex and different regions varies geological structure, electromagnetic wave propagation in underground strata can produce the great attenuation, and in more complex situations will be reflected, scattering, etc. Therefore, our domestic research for mine wireless communication through the earth has been slow.This paper, based on the development of coal mines wireless communication technology in China, for coal mine wireless communication needs, presents a mine through-the-earth wireless communication system. The communication system mainly consists of three parts:ground communication circuit, rock channel, underground terminal receiver. This paper mainly studies the transmission properties of rock channel, and uses the circuit to achieve rock channel simulation, its contents are as follows:1. The characteristics of the medium is analyzed and electromagnetic parameters of the earth medium on the effect of the electromagnetic wave propagation is discussed, and obtains the signal band through the earth to communication. The mine rock communication channel interference is also discussed and the prevention measures are given. Through the study of communication antennas through land, it gives the suitable antenna.2. Based on the communication system, it establishes a theory model for electromagnetic wave propagation in uneven medium rock and makes a corresponding simulation. At the same time, it uses electromagnetic simulation software CST on the model to analyze. In a certain error range, the propagation theory is applied to a specific field environment and it gives system design specifications.3. It uses the actual circuit to simulate homogeneous rock channel transmission characteristics, at the same time, constructs an inverse filtering circuit, so that the rock channel simulation circuit and the anti-filter circuit cascade to approximately transmit voice-band signal without distortion. It tests the transmission of voice signal in the cascaded system.The tests results show that the voice signal through rock channel simulation circuit with serious distortion,but through the inverse filtering circuit of the cascaded system the voice signal has been restored,which achieves the effect of the system design.The work done in this paper for the design of the mine wireless communication system provides some theoretical support, has certain practical significance.