Deep space optical communications (DSOC) downlink simulation with varying PPM order

Abstract

During the course of a typical deep space mission like the Mars Earth mission, there exist a wide range of operating points, due to the different changes in geometry that consequently cause different link budgets in terms of received signal and noise power. These changes include distance range, Sun-Earth-Probe angle, zenith angle and atmospheric conditions. The different operating points, with different losses (background noise, pointing losses and atmospheric losses), lead to different capacities and data rates over the course of a typical deep space mission. Consequently, different engineering parameters are adjusted and optimized to combat some of these varying losses in order to get acceptable data rates and bit error probabilities. This is a useful reason to analyze and simulate various operating conditions that occur with the varying spatial orbital time periods of the resulting received signal power level, noise power level, capacity, data rates and bit error probabilities. This paper details results of simulations of typical deep space optical communication link operation.