Study On The Indoor Propagation Characteristics At 28GHz Millimeter Wave Based On The SBR And FDTD Hybrid Method

With the continuous improvement on the fourth generation mobile communication system,the fifth generation mobile communication system proposes a higher demand on the transmission rate and bandwidth.The millimeter wave has become a research hotspot,because it has a wider band which can solve the problem on the high-speed broadband wireless interference in the five generation communication system.Based on the hybrid of SBR and FDTD,the indoor propagation characteristics are studied at 28 GHz millimeter wave.The propagation characteristics at 28 GHz band are measured and simulated.The theoretical basis is provided by these results for the planning and design on millimeter-wave indoor communication network.In the thesis,the research hot band,the research status and the basic features on the indoor millimeter wave propagation characteristic are introduced.The basic theory on the hybrid of SBR and FDTD is also introduced.Then,the remcom simulation software and 28 GHz millimeter wave measurement system are briefly described.The simulation results are compared with the experimental results of millimeter-wave propagation in the known literatures.At the same time,the measurement and simulation on 28 GHz millimeter wave propagation is also carried out in indoor environment such as corridor,office and so on.And then,the experimental results and simulation are compared to prove the feasibility of the research on the millimeter-wave propagation characteristics by the SBR and FDTD.Then,the propagation characteristics at 28 GHz millimeter wave are simulated in a large-scale shopping mall environment.The calculation depth of the simulation is discussed,and the effects of reflection,diffraction and transmission are analyzed.The propagation characteristics at 28 GHz millimeter wave band and 2.4GHz communication band were compared,and the impact of different materials on the 28 GHz millimeter wave propagation characteristics is analyzed.It is shown that the efficiency and accuracy of simulation can be taken into account when the four times reflection,the twice transmission and the once diffraction are considered.Compared with the 2.4GHz communication band,the 28 GHz millimeter wave has a larger path loss and a smaller delay.Especially,the 28 GHz millimeter wave is suitable for short-range line-of-sight communication.If the material with a lower relative dielectric constant is used as the wall in the market environment,it can reduce the delay spread to be more conducive to indoor communication.Finally,in the home environment,the delay spread at 28 GHz millimeter-wave is analyzed.The results show that under the line-of-sight environment,the circularly polarized wave can reduce the delay spread more effectively than the linearly polarized wave and the anti-jamming ability of the communication system is improved by using the circularly polarized wave;The influence of wall surface roughness on delay spread at millimeter wave is obvious,but the influence is not obvious in non-line-of-sight environment.