Three-Site Diversity Based on Q-Band Alphasat Satellite Propagation Campaign in Central Europe

To satisfy the increasing demand for ultra-high data rates, next-generation satellite communications will leverage the vast bandwidth resources available in the Q-band and higher frequencies. However, the signal propagation at these frequencies is highly susceptible to tropospheric impairments, in particular rain-induced attenuation, which can severely degrade Earth-satellite link availability and compromise service continuity. Site diversity has proven to be an effective technique for mitigating these impairments and guarantees high link reliability. In this letter, we present a three-site diversity configuration involving Alphasat satellite and ground stations located in Ljubljana (Slovenia), Graz (Austria), and Budapest (Hungary). Long-term slant-path rain attenuation time series, acquired from the beacon measurements of satellite at each ground stations, are statistically analyzed to evaluate individual site performance and joint diversity gains. Statistical data are subsequently compared with representative prediction models for three-site diversity scenario.