Effects Of Walls On Transmission Of EM Wave Based On FDTD

The future wireless technology aims at communication anywhere anytime with anyone. Nowadays, with the spring of skyscrapers, the coverage of wireless network problems especially blind areas are on the rise. In indoor environment, walls are structured and built with concrete or reinforced concrete material, which deteriorate the coverage problem by affecting the Electromagnetic wave (EM wave) transmission. At present the effects of walls configuration on transmission of EM wave are not researched widely in practical sense. Previous studies concentrate mainly on the effects in a certain configuration of walls at different frequencies and the simulation configuration is not likely in accord with that in common use. So, there is significance of practicality in research on how the configuration of walls affects the transmission of EM wave.With a closed study of the walls configuration, this paper describes the effects of walls on coverage of wireless network at 900MHz. The walls are subdivided into small cubes, and then finite-difference time-domain (FDTD) method is introduced to calculate the values of the magnetic and electric field in the vertexes versus time. The relationship between the transmitted coefficient and the thickness of concrete and reinforced concrete wall, the diameter of the rebar, the size of the rebar lattice are considered and concluded. The discussion on how the changes of walls configuration affect the transmission of EM wave is given out in detail following the simulation results. In the end, the study is expanded to the EM wave at 1.8GHz and 2.8GHz and some useful results are given out. This paper provides a theoretical reference for wireless network optimization and layout of wireless network construction in the early stage and the results have a practical value for engineering applications.