Design And Implementation Of Current Field Through Ground Communication System Based On Chirp Signal

With the development of industry,people increasingly need resources in the groundsuch as coal and metals.People need to work in the ground in many occasions.Except Mining,exploration,subway,tunnel also need people to start activities in the ground.But there is not to ensure safety in the ground.There may be overbreak,explosions or other disasters.A communication method is needed when disasters occurs.The traditional wireless communication isinvalid in the ground.The wired communication may be broken when disasters occurs.So it is such practical meaning to develop an effective through-the-earth communication equipment.In this paper,we modulate with Chirp signal,then use conduction current field theory to communicate through the ground.The basic theory of the system was analyzed and verified.The equipment was designed and tested in a mine.The maincontributions are as following :(1)The theory of conducting current field is introduced.The mathematical model of the conduction current field theory is expounded,and the theoretical analysis are verified bythe simulation results.(2)The channel test in the field is carried out,and the results of theoretical analysis are verified.Communication based on the Chirp signal is proposed by analyzing the channel characteristics and noise composition.(3)The electric dipole antenna model is proposed.The method of improving the radiation performance of the electric dipole antenna is studied.The performance of the electric dipole antenna is optimized.(4)The concept and characteristic of Chirp signal are introduced.The characteristics of Chirp modulation are introduced.The performance of Chirp modulation is analyzed and theoretical analysis are verifiedby simulation results.(5)Based on the theoretical analysis results,a set of current field communication system based on Chirp signal is designed,and the module of the system is introduced.The design idea and realization method of each module are introduced.The working flow of the system software module is introduced.(6)The design of the system is testedin the field.The performance is analyzed,this paper also provides the relevant improvement measures.