Diversity systems comparison of satellite visibility improvement for designing mobile broadcasting satellite system

This paper presents the experimental comparison of two diversity systems, namely, satellite diversity (Sat. D) and time-delayed diversity (TDD), in order to design a digital mobile broadcast satellite system (MBSS) using a geostationary satellite orbit (GSO) satellite. In order to design the digital MBSS using the GSO satellite, the attenuation characteristics due to urban buildings, trees, etc., must be studied. The measurements of the characteristics of diversity systems were carried out using Global Positioning System (GPS) signals with a limited elevation angle. By processing the measured data, the satellite visibility characteristics can be improved for the Sat. D and TDD systems. By using the Sat. D system, about 90% satellite visibility can be achieved in Sapporo and Asahikawa cities. Furthermore, the averaged satellite visibility can be improved by a factor of almost two by using the TDD system for the GSO satellite with a delay time of about 3~6 min. An example of the TDD system application for a quasi-zenith satellite system is also discussed