Summary
International Symposium on Antennas and Propagation
2012
Session Number:POS2
Session:
Number:POS2-35
Effects of Azimuthal Difference on Orbital Diversity Using Multiple Satellites
Ayumi Iwasa, Takeshi Manabe, Wataru Chujo, Shin-ichi Yamamoto,
pp.-
Publication Date:2012/10/29
Online ISSN:2188-5079
Summary:
Satellite communication is now one of the popular ways of communication, broadcasting, navigation systems, earth observation systems, and so on. For transmitting vast amount of data quickly, the higher frequencies, for example, the Ku (12/14 GHz) and Ka (20/30 GHz) bands are more suitable than the lower frequencies. However, because there is a problem of using the higher frequencies over 10 GHz on the earth-satellite communication, we need to take measures against the problem. At the higher frequencies over 10 GHz, satellite signal strength is easily weakened by heavy rainfall. Hydrometeor scattering and absorption, occurring when radio waves propagate through the lower atmosphere, result in power loss. There are some diversity methods but this paper presents orbital diversity technique using four satellites through the position of the effect of azimuthal difference. In this paper, we show about two-year-long measurement results of rain attenuation for four geostationary satellites links differing in their azimuthal angles to show the effects of orbital diversity. The orbital diversity gain is found to increase linearly as a function of the angular separation of two satellites for cumulative probabilities less than 0.01 % while the increase of the diversity gain is not appreciable for cumulative probabilities higher than 0.05 %. This indicates that we can achieve the orbital diversity gain higher than 2 dB for heavy rains for which the cumulative probability is lower than 0.01 % when we take the azimuthal separation of two satellites wider than about 50 deg.