Research On Channel Characteristics And Link Performance Between Satellites

Satellite communication is widely used in modern communication because of its advantage of not being affected by the ground environment.With the development of military communication modernization and informatization, satellite communication is not only confined between satellite and satellite, satellite and ground, but also can be used between satellite and aircraft.STK is a software produced by AGI company in the United States. It can be used to simulate the whole process of aircrafts from launch to fly.Since the performance of inter-satellite links is an important indicator for evaluating the performance of satellite communication systems, it is of practical significance to study and analyze the performance of inter-satellite links. As STK does not have a strong mathematical computing power, it cannot independently complete satellite communication performance analysis. Under the background, this paper uses MATLAB and STK to analyze the link performance between two moving satellites. The main content and innovation of this paper are as follows:Firstly, the conversion from a Cartesian Coordinate System to a Satellite Coordinate System for geosynchronous and LEO satellites is described in detail with actual motion of the satellite. The concrete numerical forms of three mathematical descriptions, namely Euler angle,direction cosine matrix and quaternion, are given to realize the conversion of coordinate system. On this basis, the relationship between the three mathematical descriptions is improved and the detailed process of conversion between the three descriptions is studied. The mathematical formulas for the conversion between the three descriptions are given in different angles. According to the actual demand, it can choose the most suitable mathematical description to complete the coordinate system conversion.Secondly, this paper design and build a visual simulation platform.The platform integrates the STK X component in the GUI interface of MATLAB and calls the STK secondary development package to complete the scene setting, the satellite adding, the analysis of visible time period between satellites, and the satellite data extracting.Combining with the coordinate system conversion, the angle between the vector from the transmitter to the receiver and the normal direction of the satellite antenna is calculated and the antenna gain is calculated from the angle to complete the analysis and research on the SNR between satellites link. What's more, it can simulate the actual movement of two satellites to achieve visualization of simulation platform in 2D and 3D views.