Impact of Motion-Induced Antenna Pointing Errors in Mobile Satellite Communication

Earth Stations in Motion (ESIM) is a new satellite communication technology which allows mobile platforms to communicate with the Geostationary Orbit (GSO) in the Ka-band. The ESIM’s benefits of providing high-power multiple spot beam coverage and allowing very high data rates makes it ideal for commercial use. Small aperture antennas with precise tracking antenna systems are desirable in ESIM systems in order to limit radio interference to adjacent satellite systems. Even with precision in tracking, motion-induced antenna pointing errors are unavoidable. This paper proposes a methodology to analyze the significant contribution made by motion-related antenna pointing errors to the overall interference effects from ESIM to the Fixed Service (FS) station in the 28 GHz frequency band. The results from computer simulation show that a reduction of 5.2 dB in the boresight Effective Isotropic Radiated Power (EIRP) Spectral Density (ESD) was obtained for a parabolic dish with circular aperture diameter of 0.3 m when a fixed antenna pointing error of 0.5 ̊ was introduced. The overall transmission data rate can be significantly reduced if the International Telecommunication Union (ITU) recommendations are observed.