Rain attenuation can drastically impact the service availability of satellite communication, especially in the higher frequency bands above 20 GHz, such as the Ka-band. Several countermeasures, including site and time diversity, have been proposed to maintain satellite link service. In this paper, we evaluate the performance of a power boost beam method, which is an adaptive satellite power control technology based on using rain radar data obtained throughout Japan to forecast the power margin. Boost beam analysis is considered for different beam sizes (50, 100, 150, and 200km) and beam numbers (1-4 beams) for a total of 16 cases. Moreover, we used a constant boost power corresponding to the rainfall rate of 20mm/h. The obtained results show that in comparison to the case with no boost, the effective rain intensity in each boost case was reduced.

The advanced satellite broadcasting system in the 21 GHz band or higher frequency bands is expected to be suitable for use in high quality multimedia services in the future. To establish this system, rain attenuation mitigation is very important and the time diversity system has been proposed as an appropriate technology for this purpose. This paper shows principle of time diversity as an attenuation mitigation technology and also shows the effect of time diversity. We also propose a method for predicting time diversity gain as a function of the rain attenuation, cumulative time percentage, and time delay of two data contents or broadcasts.

By using measured attenuation time-series data over 2 years at 19.5GHz with an integration time of 1 sec, effects of the integration time on attenuation statistics are presented. It is observed that the effect on cumulative distribution of attenuation and the relation between annual and the worst-month cumulative time percentages are not significant for the practical prediction purposes. The effect is significant in attenuation duration statistics.