Power Angle Spectrum of Satellite Commu- Nication Downlink in Rain Environment at Millimeter-wave Bands

The study of this paper focuses on the power angle spectrum (PAS) of the satellite communication downlink in rain environment at millimeter-wave bands. The two-dimension angle distribution expression of the incoherent intensity of the ground receiving antenna in rain is deduced in detail. The coherent intensity is discussed according to the first-order multiple scattering approximation theory. The calculation model of PAS is given based on the coherent intensity and the incoherent intensity angle distribution. Based on the Marshall-Palmer raindrop size distribution, the raininduced attenuation coefficient γ = ρ〈σt〉, as well as the average scattering amplitude function of rain area, is calculated and discussed by Mie method; the two-dimension and the one-dimension PASs are simulated and analyzed at different incident angles for different rain rates, frequencies and polarizations. The PAS model and the simulation results given in this paper are important for the quantitative evaluation of the impacts of rain environment on MMW MIMO channel characteristics.