Characteristics of rain attenuation time variation in Ka band satellite communications for the kind of rain types in each season

The satellite communication links using the frequency of higher than 10GHz are subject to atmospheric effects, such as rain attenuation and scintillation. To mitigate the attenuation effects, various attenuation compensation techniques, for example, site diversity and transmit power control are introduced to the satellite communication systems. The prediction of the attenuation characteristics is very important, to utilize these compensation techniques to a great extent. Up to now, very few studies have been performed in Japan for detailed attenuation characteristics such as fade slope or fade duration, compared to those of overseas researchers, e.g.,. This study presents detailed attenuation characteristics of the Ka-band satellite signals observed at 1 sec (partly 0.1 sec) interval, at Osaka Electro-Communication University (OECU) in Neyagawa, Osaka from 1997 to 2006. In these periods, rain types of all rainfall events are classified into four kinds of rain types, such as warm, cold, stationary fronts, and typhoon or shower that caused the rain attenuation. The comparison of the fade slope and fade duration characteristics is emphasized according to the difference in these rain types during four seasons of spring, summer, autumn, and winter.