A Study on the Satellite Diversity and Time Delayed Diversity Techniques in Ku-band Satellite Communications Links

摘要

The effects of satellite and time delayed diversity techniques on Ku-band rain attenuation were investigated in three propagation paths with azimuth angle separations of 30 to 60 deg, using the radio waves continuously received from several kinds of Ku-band satellites at Osaka Electro-Communication University (OECU) during 2003-2008. The improvement of unavailable time percentages of 0.1-0.01% due to rain attenuation is found to be increased by more than one order, as the time delayed diversity of about 60 min is also introduced between the two satellite paths, compared to the original improvement for the satellite diversity being a few tens of the percents. This improvement is shown to be more effective when the time delay is applied to the satellite with its orbital position westward to the other one. Also, the effects are more conspicuous in rainfall events with cold or stationary fronts than typhoon or shower. In Ku band, the improvement of the unavailable time percentages exceeding one order is thus expected for the attenuation of greater than about 4 dB with time delay of 60 min.