Abstract
Satellite communication is ever more popular nowadyas because the need of transmission between satellites and earth stations through space increases rapidly. Various frequency bands, such as C-band, K-band, Ku-band, etc, have been used for different communication requirements. Due to the rapid growth of band usages in the last years, the higher band, Ka-band (20/30GHz), becomes interesting for satellite communication. Nevertheless for transmission frequecy above 10 GHz, atmospheric attenuation will have more serious effect on the transmission quality and rain attenuation in particular will play the dominant role. To predict the characteristics of the propagation and realize reliable communication via Ka-band, we build a satellite communication simulation system for the LEO ROCSAT-1, the first satellite of our nation, ROC. Unlike elsewhere in the world, there is distinct wearther condition around Tainan, Taiwan, area and unlike GEO satellite communication, experiment planning will be needed in detail for reliable communication. For these purposes, satellite link budget should be estimated for the minimun acceptable performance of transmission, especially at low elevation angles.