Research On Radio Wave Coverage In Nested Confined Space

The confined space inside the train and the confined space outside the train in the tunnel form a nested confined space.The stable radio wave coverage in the nested confined space is an important guarantee for the safe operation of the train control system and the stability and reliability of the public wireless communication system.The central and western regions of my country have complex terrain and multiple tunnels.In order to improve the performance of wireless communication systems in this type of environment,it is particularly critical to achieve high-efficiency electromagnetic wave coverage in nested confined spaces.However,in the nested confined space,the electromagnetic environment is complex and the physical structure is diverse.To perform accurate radio wave coverage estimation,it is necessary to accurately simulate the nested confined space structure.This paper uses the FDTD method to calculate and analyze the radio wave coverage characteristics of the train control wireless communication system and the public mobile communication system in the nested confined space,and conducts experimental research on the basis of theoretical analysis to obtain the basic data of radio wave coverage in the confined space.The work of this paper has guiding significance for the radio wave coverage estimation and efficient design of the nested confined space along the railway in the central and western regions.The main research contents and innovations of this article are as follows:1)A nested confined space calculation model is established,and the parallel FDTD technology and the equivalent principle are used to simulate the electric field distribution in the tunnel and the car body when the train exists,and the train car body is studied.The influence of material parameters,transmitting antenna position parameters,space diversity,repeater and other factors on the radio wave coverage characteristics of the train control wireless communication system provides a basis for the efficient radio wave coverage design of the train control wireless communication system in the nested confined space.2)The human body and seats are introduced into the train model to construct a more realistic complex environment inside the car body.The shielding loss caused by the train body is studied,and the influence of factors such as the material parameters of the train body,the internal human body loss and the passenger rate,the position and diversity of the transmitting antenna,and the repeater antenna on the coverage of the public wireless communication are analyzed.The radio wave coverage design of the public wireless communication system in the type confined space provides basic data.3)The experimental research environment of the nested confined space is built,and the radio wave coverage in the nested confined space under different transmitting antenna parameters and receiving antenna parameters is measured,and the simulation results are compared to verify the theoretical method.Correctness.According to the test results,the influence of different transmitting antenna parameters and receiving antenna parameters on the radio wave coverage characteristics in the nested confined space is analyzed,and a scheme to achieve efficient radio wave coverage in the nested confined space is proposed.