Analysis Of Channel Characteristics For Inter-satellite Communication In THz Band With Effective Roughness Scattering Model

Space communication network is considered as an important solution to realize global wireless connection in the future wireless communication system.Under the condition of space resources constraints,terahertz band is the main candidate frequency band for the future ultra-high-speed space communication due to its high speed and high bandwidth characteristics.Due to the high frequency of terahertz,the influence of scattering from rough plane on the channel can not be ignored.Aiming at the scattering problem,the effective roughness scattering model is introduced to model the scattering path,and the channel characteristics of inter-satellite terahertz communication link are deeply studied.Firstly,based on the characteristics of inter-satellite terahertz communication,the large-scale fading,small-scale fading and the main influencing factors of inter-satellite communication channel are analyzed.Secondly,the deterministic channel modeling method of inter-satellite terahertz communication is studied based on ray tracing algorithm.In the modeling process,the influence of rough surface scattering on the channel is mainly considered.The reflection coefficient at terahertz frequency is modified by Rayleigh roughness factor.The scattering of rough surface is calculated according to Lambertian scattering model and directional scattering model.When calculating the directional scattering model,the simulation model of the rough surface is generated by the two-dimensional filtering method.After that,the scattering field of the rough surface is calculated according to the moment method,and the scattering coefficient of the satellite surface material is obtained.Then,the directional scattering model is obtained according to the scattering coefficient results.The two scattering models are introduced into the ray tracing algorithm respectively,and the channel characteristics of the intra-orbit and inter-orbit inter-satellite link scenarios are simulated.The simulation paths include direct,reflection,scattering and diffraction paths,and the influencing factors include free space loss,multipath fading and Doppler shift.Finally,according to the simulation results,the key channel parameters of THz communication frequency are analyzed,including receiving power,Rician K factor,delay spread and angle spread.In conclusion,based on the study of the inter-satellite terahertz communication channel,the influence of rough surface scattering on the channel is considered.The channel characteristics of the inter-satellite terahertz communication link are analyzed,which provides a reference for the design and research of the terahertz inter-satellite communication system in the future.