title: IMPACT OF THE DISTANCE VARIATION AND MODULATION TYPE ON THE DOWNLINK COMMUNICATION CHANNEL OF THE LEO SATELLITES.
abstract: This paper presents a simulation and analysis of a high-speed LEO-to- Ground communication channel operating in the X-band, quantitatively assessing the impact of varying slant distance and modulation schemes on link quality. A dynamic, end-to-end simulation model was developed using Systems Tool Kit (STK) from Ansys, Inc. to analyze the Signal to noise ratio (SNR) of a typical LEO satellite pass. The simulation demonstrates an extreme variation in link quality: at zenith, a robust SNR supports 