Propagation Model Calibration And Coverage Performance Of NB-IoT At Tianshui

With the rapid development and maturity of the 4G network technology,the NB-IoT technology stand out,it's promoting the communication and intelligence of all device in future.The main scenario of NB-IoT technology is the IoT application which with low throughout and low bandwidth.NB-IoT network focus on high capacity,wide coverage and low latency.so it's important to research the Propagation Model and Network Tuning.The main content and point of view are as follows:Firstly,based on NB-IoT technology,the paper mainly introduces the research progress and development of NB-IoT.By comparing the advantages of NB-IoT technology and other IoT access technology,it highlights the importance of NB-IoT technology research.Secondly,the key technologies of NB-IoT network and three deployment modes of NB-IoT are analyzed,and the static simulation of downlink coexistence and link budget based on 3GPP standard is studied,especially the network coverage theory.Thirdly,the loss of electromagnetic wave is analyzed.The Okumura-Hata model,COST-231 Hata model and standard propagation model are introduced.A new propagation model is proposed,and the simulation and coverage performance analysis are carried out with example.On the basis of standard propagation model,a new propagation model is obtained by multivariate linear regression method.With new propagation model,the propagation distance is obtained by reverse calculation of link budget,and the quatity of covered station in Tianshui City is obtained by microcellular theory.Taking NB-IoT system of Tianshui urban area as a typical area representing most of the urban landforms in Western China,this paper proposes a new linear iteration algorithm based on outdoor standard propagation model with analysis and research existing model calibration algorithm,and carries out three types of typical areas,such as dense urban areas,suburban areas and rural areas of Tianshui.Based on the propagation model calibration of the new model,the model calibration results of three different area are obtained,and the predicted values before and after the model calibration,and compared with the measured data.From the error analysis and experimental simulation results,it can be seen that in small and suburban area with relatively simple geomorphological features,the advantages of model calibration can be fully embodied by using the method proposed in this paper.In addition,this paper uses the calibration model to carry out the wireless network planning and coverage performance analysis of the urban area,and verifies the accuracy of the model through field tests.Through the planning analysis,the design results of the number of base stations in three different areas of the city are obtained,which provides a reference for the future NB-IoT wireless network planning of the city.