Abstract:
Rain is a dominant source of attenuation at higher frequencies and consequently it
degrades the system performance of microwave satellite and terrestrial links in tropical
and subtropical regions. Bangladesh has a subtropical monsoon climate characterized by
wide seasonal variations in rainfall and most parts of the country receive at least 2000
mm of rainfall per year. The knowledge of rain fade and its performance is essential in
order to optimize system capacity and meet quality and reliability. The rain intensity
data for Bangladesh is not available since it has not been measured so far. In this thesis,
investigations have been carried out to find the rain fade and intensity data and their
effect on the performance of terrestrial and satellite microwave links in Bangladesh. In
this regard, long term rainfall data are collected from 34 meteorological stations of
Bangladesh for thirteen years. The collected data are converted to 1-minute integration
time rain intensity which can be used to design microwave systems in any parts of
Bangladesh. The converted rain intensity data are used to estimate rain fades at C, Ku
and Ka bands for both terrestrial and earth to satellite microwave links. The converted
rain intensity data and ITU-R recommended rain intensity are used to estimate the
deviation of rain fades at C, Ku and Ka-bands for comparison. The deviations are found
to be small at lower frequency bands and are significantly higher at higher frequency
bands. Performance of terrestrial and earth-to-satellite links in terms of Carrier-to-
Noise (CNR) are also evaluated considering the predicted rain fades at different
frequency bands operating in Bangladesh.
