Measured results of urban satellite-diversity (Sat. D) and space-diversity (SD) characteristics for mobile broadcast geostationary satellite system

This paper deals with the urban satellite-diversity (Sat D) and space-diversity (SD) characteristics measurements for mobile broadcast geostationary satellite orbit (GSO) system using the GPS (Global Positioning System) signal. For designing a digital broadcast system from a geostationary satellite, we must clarify attenuation characteristics by urban buildings, electrical light poles and trees etc. Southern orbital arc GPS satellite signals with elevation angle between 40/spl sim/50 degrees data are used for propagation characteristics measurements, rather than actual geostationary satellites. To overcome urban attenuation, the Sat D system and SD system characteristics are systematically examined by using measured data for low and high elevation angles, ie, 40 and 80 degrees. From processing the Sat D characteristics results, improvements of half fade duration time and twice non-fading duration time can be achieved in urban areas by selecting two diversity satellites with separation angle about 90 degrees. On the contrary, for the SD system, the improvement for urban attenuation can not be obtained sufficiently.