Research and Implementation of the Transmission Efficiency of LEO Remote Sensing Satellite Based on Variable Coding Modulation

Abstract Orbit characteristics of LEO remote sensing satellite determine that its downlink capability is limited by transit visual time, the limited number of transit times a day greatly limits the efficiency of satellite transmission. Because the satellite-ground transmission distance will change with the elevation angle of the ground station and the change of the satellite azimuth and elevation angle when the satellite transits, the traditional satellite can't make full use of the link margin in order to ensure the transmission of the longest distance, too much link allowance at high elevation when using fixed modulation mode. Therefore, based on variable coding modulation, the real-time transmission distance is obtained by using servo controller and intelligent calculation method on satellite, through simulation analysis and threshold analysis setting, this paper proposes a more optimized data transmission system design, which can save a lot of satellite-ground link margin and improve the satellite-ground transmission efficiency by about 30%.