Signal fading in land-mobile satellite communication systems: Statistical characteristics of data measured in Japan using EIS-VI

The space-earth links in land-mobile satellite communications are frequentl y cut off as a result of the shadowing and blockage, due to roadside trees, buildings, utility poles, and other artificial obstacles. Knowledge about the fade statistics is therefore important in designing cost-effective land -mobile satellite communication systems. Using a 15.5dBi-gain satellite-tra cking antenna, an S-band (2.1GHz) unmodulated continuous-wave signal transm itted from the elliptically orbiting ETS-VI satellite was measured, while t he vehicle the antenna was mounted on was driven around a city in Okinawa. The investigation reports on fade statistics and fade and nonfade-duration (interfade-duration) statistics for elevation angles ranging from 57.9 degr ees to 66.5 degrees and for several thresholds of fade state (fade margins from 3 to 15dB).