Tropospheric scintillation for Ku-band satellite communication link in Equatorial Malaysia

Abstract

Tropospheric scintillation is a rapid fluctuation of the amplitude of received signal causes propagation impairments that affect satellite communication systems operating above 10 GHz. This work concentrates on those aspects in equatorial Johor Bahru, Malaysia, based on a two-year Ku-band propagation measurement campaign, utilizing the equipment of Direct Broadcast Receiver (DBR) and Automatic Weather Station (AWS). The study is divided into two parts. First, the investigation of clear sky scintillation through classification and analysis of a time-series satellite broadcasting signals, followed by comparison of the statistical results with existing scintillation prediction models. A new processing method is proposed to enhance the estimation of dry scintillation, specifically for the diurnal behavior of scintillation variance. Second, this study focuses to investigate the relationship between wet scintillation and rain attenuation using experimental measurement, and concentrate on the probability density function (PDF) of different scintillation parameters. From the results, it is concluded that wet scintillation intensity increases with rain attenuation. Thus, the relationship can be phrased by linear equations or power-law. The PDFs of wet scintillation intensity, adapted to a given rain attenuation level, are found lognormally distributed, leading to selection of method for determining the relation between conditional PDFs and rain attenuation. Finally, seasonal and diurnal variations of wet scintillation are also investigated. It is found that wet scintillation fade is likely to occur in the afternoon from 3 pm to 6 pm. Meanwhile, wet scintillation intensity of the inter-monsoon shows a relatively higher rate of change of attenuation. The results can provide system operators and radio communication engineers with critical information on the fluctuations of tropospheric scintillation variance of the satellite signal during a typical day, taking into the account of local meteorological peculiarities.