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Universidad Politécnica de Madrid (UPM) is participating in the Alphasat propagation experiment by measuring the copolar level of the Q-Band beacon at 39.4 GHz since April 2014. In this paper the results of the first two complete years of measurements (until March 2016) are presented with regards to excess and total attenuation. The reference level is calculated on an event-by-event basis in the first...
For the last decades satellite communication systems have been moving towards higher and higher frequencies; rain attenuation along the Earth-satellite path can be an important limiting factor for the system availability, especially in tropical regions where rain events can be particularly intense. One of the possible countermeasures is site diversity. In this paper we evaluate the performance of...
Reliable estimates of satellite channel characteristics are of great importance for satellite communications, especially with use of even higher frequencies as Ka-band and in near future Q- and V-band. At a given rain rate the shape of rain drop size distributions (DSDs) considerably influences the corresponding specific attenuation. In previous work it was shown, that annual DSD statistics give evidence...
The attenuation due to rain is one of the main impairments in satellite communications. It is well known that rain attenuation is dependent on the elevation angle of the link, being more severe at low elevation angles; this has a definite impact on the design of TLC and data download systems based on low earth orbit (LEO) satellites. As measurements at various elevation angles are seldom available,...
The usage of Fade Mitigation Techniques (FMT) is mandatory for satellite communications operating over 10GHz once the atmospheric propagation effects get severe with the increase of the frequency-band. Site Diversity (SD) and Orbital Diversity (OD) are two effective techniques to mitigate rain attenuation. Considering an operation at Q-band (40GHz) both these schemes are preliminary investigated:...
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