Savings on Transmit Power through Designed Horizon Plane for LEO Satellite Ground Stations

Abstract

Low Earth Orbit (LEO) satellites are used for public networking and for scientific purposes. Established satellite ground stations can communicate with LEO satellites only when the satellite is in their visibility region, since LEO satellites move too fast relative to a ground station on the Earth. Each ground station is characterized by its own ideal horizon plane. Because of natural barriers that plane is modified to the designed one, defined by minimal elevation, in order to avoid natural obstacles. Designed horizon plane implementation implies also the power saving from the satellite to be transmitted. The major loss in communication between the LEO satellite and the ground station is the free space loss. Free space loss varies since the distance from the ground station to the satellite varies over time. Free space loss is usually compensated through variable satellite transmit power toward the downlink. In order to obtain the constant downlink margin at the receiver, all over the time, for analytical and simulation purposes, the altitudes from 600km to 1200km are considered. For each altitude it is calculated the power saving by designed horizon plane implementation compared the ideal horizon plane, for different altitudes.

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