NB-IoT Coverage Research In Qiongzhou Strait Based On Improved SPM Model

In recent years,China has implemented the policy of a maritime power,and is establishing a Hainan Free Trade Zone and a free trade port.The number of large vessels passing through the Qiongzhou Strait will increase year by year,and the ship pollution will be more serious.The current maritime sector Mainly use AIS ship automatic identification system,GPS/Beidou positioning,VHF VHF communication and other methods to supervise the ship,there are problems of small coverage,complicated system,many types of equipment,high communication costs,etc.,Qiongzhou Strait The requirement of ship network supervision is that the network coverage is large,mainly monitoring the ship's position,route,speed,sewage discharge,ballast water,etc.The data transmission volume is small,and the network delay and network speed requirements are very low,which is very suitable for building NB.-IoT network.The NB-IoT network coverage is carried out in the Qiongzhou Strait,and the NB-IoT ship networking network can be effectively established by using its network coverage,low cost,support for large-scale connection,and installing NB-IoT terminals on ships.According to the characteristics of NB-IoT network and the regulatory requirements of Qiongzhou Strait for past ships,this paper based on an improved electromagnetic wave maritime propagation model,carried out the link estimation and coverage simulation coverage of the NB-IoT network coverage of Qiongzhou Strait,which was proved in Qiongzhou Strait.The feasibility of establishing an NB-IoT network.Firstly,according to the characteristics of electromagnetic wave maritime propagation,various classical propagation models are compared.Based on the standard electromagnetic wave propagation model-SPM model,an improved electromagnetic wave propagation model of Qiongzhou Strait is proposed,and the reflection loss model and rain attenuation are added.Model and atmospheric absorption loss model,using MATLAB 2016a software to simulate and analyze the proposed improved model.The CW test experimental environment was set up in Qiongzhou Strait,and the sea surface electromagnetic wave transmission loss test was carried out according to Lee's law on the beautiful sand coast of Haikou and the experimental data was recorded.At the same time,based on an improved WLS algorithm,the K-K7 value of SPM model is corrected by introducing CW results into MATLAB,and a reasonable SPM improved model of Qiongzhou Strait is obtained,which can accurately reflect the transmission loss of Qiongzhou Strait sea surface communication.According to the revised propagation model,the existing base station on the Qiongzhou Strait coast is used to set the accurate maximum transmit power,antenna gain,interference margin and other parameters by using the Stand alone deployment method of NB-IoT technology,and the NB-IoT system of Qiongzhou Strait is obtained.Link the budget results and initially estimate the network size.Perform link-level simulation on NB-IoT system to test the relationship between BLER and SNR.Use ATOLL software to simulate NB-IoT network and Monte Carlo simulation to obtain optimal cell coverage and signal field strength coverage,and simulate test users.Access success rate and throughput of the service.The application of the NB-IoT network to marine coverage is of great significance for strengthening the maritime supervision of the Qiongzhou Strait,traffic and environmental monitoring,search and rescue,and maintaining the stability of the water safety situation.It plays an important role in the intelligent transformation of offshore operations and related industries.