Research On Dynamic Time-varying Channel Interference Mechanism And Evaluation Technology For Space Internet Constellation System

The rapid development of spatial information networks and global commercial aerospace,as well as the massive deployment of giant constellation systems,has dramatically increased the demand for spatial frequencies and orbital resources.As a basic element of the development of the space information network,spatial frequency resources have limited and non-renewable attributes,and have become a valuable resource for the major space powers to compete for.The frequency resource shortage situation results in serious co-channel interference,diverse interference factors,complex interference mechanism,interference model and evaluation criteria.Typical problems such as the lack of interference models under spatial dynamic time-varying channels constrain the development of the space Internet constellation systems.In this background,this dissertation studies the channel characteristics of the space Internet constellation system in high dynamic time-varying state,extracts the factors affecting the frequency interference estimation between the space Internet constellation systems,and deeply analyzes the mechanism of interference generation in different communication scenarios.Meanwhile,the interference scene communication model and the orbit model are constructed to establish interference avoidance measures,and the interference evaluation method suitable for large-scale constellation system is proposed.Based on this,a set of interference evaluation simulation model system is established,which verifies the feasibility and reasonableness of the interference model and evaluation method.The research results of this dissertation can provide a basis for the frequency interference assessment and avoidance measures of the space Internet constellation systems in practical applications.The main contents of this dissertation include:1).By studying the propagation theory of electromagnetic waves in random media,the channel characteristics of the space Internet constellation system in high dynamic time-varying communication scenarios are analyzed,the channel model is also established,the channel parameters affecting the transmission performance of the communication link are clarified,which is established for signal interference compatibility evaluation as the basic theoretical framework;2).By analyzing in detail the common technical characteristics of the current space Internet constellation systems,from the aspects of the orbital configuration,multiple access mode,communication protocol,access mode,and interference avoidance of the constellation,the key factors affecting the interference assessment are studied and characteristic factors is extracted,such as the satellite orbit parameters,antenna type,beam characteristics,channel model,and avoidance strategy,etc.Which is used as the basis for the establishment of interference assessment models and parameter determination;3).Through the analysis of the operation law of the space Internet constellation system,the static interference scene between the geosynchronous orbit satellite system(GSO)and the non-synchronous orbit satellite system(NGSO)and the dynamics between the non-synchronous orbit satellite(NGSO)constellation systems are determined.The applicable interference mathematical model is established,which focuses on the interference mechanism of the NGSO constellation system under dynamic time-varying channels.The indicators and evaluation methods for supporting multi-constellation system interference assessment are proposed as the basis for the establishment of the interference assessment systems;4).Based on the research on the influence factors and interference assessment methods of the space Internet constellation system,the techniques simulation models for the spatial dynamic time-varying channel are further studied,including the radio wave propagation model,the orbit prediction and extrapolation model,the multi-beam antenna model,the interference scene model,and the interference avoidance model,etc.For the key problems of interference scene modeling and interference avoidance strategy design,a large-scale constellation interference scene modeling algorithm,an interference avoidance method based on GSO arc segment isolation angle adjustment satellite attitude and based on The interference avoidance algorithm of MCS joint power control is verified by algorithm,which lays a foundation for the realization of the space Internet constellation system interference assessment system.5).In order to systematically verify the interference mechanism,interference mathematical model,interference assessment and interference avoidance method,the interference evaluation simulation system is designed and implemented,and the system architecture and simulation scene are established.Designed various parts and parameter configuration implementation schemes,developed a demonstration verification component,used simulation data comparison and Oneweb constellation system instance verification method,frequency between NGSO and NGSO satellites,NGSO and GSO satellites,and NGSO satellite constellation The interference analysis is carried out to verify the availability and rationality of the proposed interference analysis method,the established interference model and the interference estimation implementation technology.The research work of this paper is carried out in the background of the vigorous development of the global spatial information network,and it is aimed at the practical application requirements of large-scale constellation systems in the acquisition and use of frequency resources,breaking through the key to the analysis and evaluation of the frequency interference analysis of large-scale Internet constellation systems.The interference analysis,evaluation method and simulation implementation technology which are proposed in the dissertation can be used as the theoretical basis and technical support for practical application of engineering.