Research And Application Of Multi-frequency Field Strength Prediction Of Typical Indoor Scenes Based On FDTD

With the rapid development of mobile communication technology and the popularization of Internet of Things applications,short-range wireless communication networks are widely used in indoor scenarios such as personal users,local offices,and industrial Internet of Things.Users have higher and higher requirements for the use of mobile communication networks indoors,service efficiency and quality.However,due to the influence of indoor architectural design and the different needs of later use,the extremely complex indoor space environment is constructed,which makes the signal of indoor short-distance wireless communication network vulnerable to interference in the process of propagation.How to accurately,real-time and quickly predict and display the signal coverage of indoor short-range mobile communication networks is a major research hotspot.Therefore,adhering to the relevant knowledge of wireless communication networks,it is an important research topic to predict the field strength coverage of indoor microwave 2.4G band and indoor 5G band signals,understand their propagation rules and characteristics,and model and predict the propagation of radio waves.The main work of this paper is to study the propagation characteristics of short-range wireless channels through the improved FDTD algorithm,compare the frequency bands with the measured data,verify the feasibility of the improved FDTD algorithm,establish the FDTD optimized propagation model,and realize the signal field intensity visualization of indoor shortrange wireless channels.Firstly,this paper improves the FDTD algorithm,introduces the development process and improvement points in detail,and expounds on the advantages and feasibility of the algorithm.Through the simulation of indoor scenes,the propagation prediction and RSSI visualization of indoor short-range radio waves are realized.Secondly,for the frequency band below 3.3GHz,the reliability and effectiveness of the improved FDTD algorithm applied to the indoor scene in the low frequency band are verified:(1)The indoor wireless signal field strength coverage prediction research is carried out for the2.45 GHz frequency signal,and the data analysis and RSSI visualization of different scenarios are realized.Based on the CW test method,multiple measured data verifications were performed on different indoor specific scenarios in LOS and NLOS conditions,which confirmed the feasibility of the improved algorithm in the field strength prediction of indoor specific scenarios.The predicted path loss is compared with other classical indoor propagation models,which shows that the proposed algorithm and the improved FDTD propagation loss model have certain applicability in different scenarios.(2)For 5G indoor frequency band signals,this paper selects 3.3GHz frequency for indoor short-range wireless signal field strength coverage prediction research,and evaluates its propagation loss.In the corridor scenario,data analysis is carried out in two cases of LOS and NLOS,which provides a theoretical model and data basis for the study of path loss of indoor 5G channel in specific scenarios.Finally,based on the simulation data of the improved FDTD algorithm,the FDTD propagation model is improved according to the existing indoor propagation model,and the general model of FDTD path loss is established.In the 0.3-3.3GHz band,the correlation coefficient of the basic transmission loss is explored,and the relationship between the basic transmission loss and the frequency and transmission distance,the wall loss and the human body loss are studied.Through the fitting of the experimental data,the relevant parameters of the model are summarized and sorted out,and the channel propagation characteristic parameters of the specific scene are extracted to generate the FDTD basic transmission loss model.The usage scenarios and detailed parameters of the model are summarized to provide data basis for later research work.