MIMO Channel Modeling Of Mine Roadway Based On GBSM

In recent years,mining production safety accidents occurred frequently.Mine tunnel communication has become more and more important as a necessary means of dispatching the whole situation,commanding the frontline,and monitoring the security.For the existing wireless communication system,due to the special environment of the mine roadway,the irregular distribution of objects on the four walls of the roadway and in the mine will cause the frequent reflection,diffraction,scattering and absorption of the signal,which will produce significant multipath effect.At the same time,it will make the signal quickly attenuate and greatly shorten the transmission distance.Due to the special environment of the mines and tunnels,irregularly distributed objects on the walls of the tunnels and the mines will cause frequent reflection,diffraction,scattering,and absorption of the signal.These conditions can result in significant multipath effects,and reduction of transmission distance causing by rapid signal attenuation.Therefore,it is urgent to comprehensively consider various factors that affect wireless communication in the mine tunnel environment,and propose a wireless communication model suitable for the special environment.For this purpose,a wireless communication model suitable for mine tunnels was set up and the simulation analysis was given as well.This model is based on the advantages of Multiple Input Multiple Output(MIMO)technology,which is able to establish multiple parallel propagation channels,and greatly improve the quality and efficiency of wireless communication.This model is also combined with Geometry Based Stochastic Model(GBSM)model.The above work provides theoretical support and functional reference for the practical application.This article has done the following works:Firstly,based on the special environment of mine roadway,the factors that affect the wireless communication are analyzed theoretically.The propagation characteristics of wireless signal,MIMO channel modeling methods and typical 2D and 3D MIMO channel models are studied.The feasibility and advantages of MIMO channel modeling based on GBSM are clarified,It provides a theoretical basis for subsequent modeling and analysis.Secondly,a 2D MIMO channel model of mine roadway based on geometry is proposed.The local scatterers around the receiving end in the roadway are modeled as a single ring model of GBSM.The single ring model is used to model the semi-circular scattering scene,single line scattering scene and single ring composite scene respectively.The channel impulse function and channel correlation are deduced according to the geometric structure and theoretical knowledge.Finally,the semi-circular scattering scene,single line scattering scene and single ring composite scene are analyzed Single line scattering scene and single ring compound scene are simulated and analyzed.The simulation results show that the influence law of rice factor and antenna spacing on channel correlation meets the theoretical requirements,which proves that the 2D model of mine roadway model is reasonable,and the 2D MIMO single ring channel model can well reflect the distribution characteristics of scatterers in the roadway and the complex environment of mine roadway,which can be used as the MIMO channel model of mine roadway.Finally,in order to further improve the accuracy of reflecting the structural characteristics of mine roadway and optimize the model,a 3D MIMO channel model of mine roadway based on geometry is proposed.According to several common roadway shapes,the local scatterers around the receiving end in the roadway are modeled as semi cylindrical model,hemispherical model,composite model and crosscut model respectively.The channel impulse function and channel correlation theory of 3D model are deduced,and finally the simulation analysis is carried out.The relationship between the Rician factor,antenna spacing,angle spread and channel correlation in the semi cylindrical model,hemispherical model,composite model and crosscut model is obtained.By comparing the 2D model with the 3D model,we can see that the correlation of each component of the 3D model is consistent with that of the corresponding component of the 2D model,which proves the correctness of the expansion of the 3D model.In the 3D MIMO channel model,the important variables of the vertical dimension are modeled,so as to more accurately simulate the channel model in the 2D environment.Therefore,3D model can also be used as MIMO channel model of mine roadway.