The increasing demand for long-distance and high-speed communication between devices and people results the reduction of free frequency ranges and also requires a continuos raising of the upper frequency limits.
However we have to face different environmental difficulties in each frequency range.
In case of open-air wave propagation the weather generates a constantly changing fading which depends on time and location.
Above 10GHz the wavelength is comparable with the size of rain drops, therefore the rain-attenuation bacomes more and more significant. This can lead to connection loss even in everyday circumstances.
The system can be optimized by adaptation to the changes of the propagation medium which is undoubtedly beneficial for the environment and economy. This is exceptionally critical in case of satellites because of the limited resources and the required continous and reliable operation at the same time.
In my thesis I am going to introduce the ESA’s (European Space Agency) Alphasat satellite and the experiment based on the deck-installed communication modul.
Based on ITU (International Telecommunication Union) recommendations and 40-50GHz measurements of the HVT department of BUTE, in accordance with the rain intensity data of the department’s weather station I can state, that the positive effects of adaptive modulation technique on the quality and reliability of the connection are confirmed.