Research On Broadband Mobile Wireless Channel Modeling At Sea Surface

With the mobile wireless network has covered most of the land on the earth,there are still lack of network coverage in the important channels and ocean operating areas.The broadband mobile communications are still relatively backward at seas.In most marine cases,only expensive satellite communications can be used.Thanks to the progress technology,it is expected to achieve wireless network coverage in remote areas and offshore areas.Modeling of marine broadband wireless channels is the basis of constructing a communication system.At present,there are a large number of radio channel measurement work carried out at seas.The time required for the measurement is long and the cost is huge.The channel measurement is limited by environments,and the changing maritime wireless channel can not be accurately described through the measurement.Through channel modeling simulation,it is possible to quickly simulate various mobile scenes and obtain more accurate channel model,and correct the error of empirical model.Therefore,over-sea surface channel modeling simulation is significant.With UAV,the offshore wireless network coverage can be achieved.In this paper,a communication scene between a UAV and a boat is simulated.Then the marine wireless channel is studied.Firstly,an improved spatial partitioning ray tracing algorithm is proposed to track the propagation path of electromagnetic waves at sea surface.The distribution of AoA and EoA are obtained according tracking results,which is subject to the Gaussian distribution or the Rayleigh distribution.The results are greatly different from the traditional terrestrial wireless channel model.The distribution of AoA and EoA can help establish a wireless channel model quickly.Secondly,a mobile channel is simulated and modeled based on the track results.The Doppler frequency shift spectrum and the reception signal is obtained.The envelope of the received signal is subject to Rice distribution.Then,the time-varying channel is simulated and the time-varying channel response function,time-varying frequency response,channel scattering function and average power-delay profiles(APDP)are obtained.The simulation results are compared with the measurement results comes from relevant references,and the results are broadly similar.By comparison,the reliability of the simulation is further verified.Finally,a loss measurement is carried out in the coastal waters near Xiamen based on the simple wireless channel loss measuring platform,and a loss model is built.Then a simulated path loss model is also taken to compare the measurement results the results indicates that both are close which verifies the reliability of the simulation.In this paper,the research on the modeling of sea broadband mobile wireless channel is used to provide reference and guidance for the construction of maritime broadband communication network.The distribution of the multi-path at sea is related to the law of the sea surface.The influence of the sea surface motion law on the sea broadband time-varying channel can be explored next step and the wireless channel model can be optimized.