4. Multi-Site-Diversity Modelling in Satellite Communications Using Gaussian Copula

New models of two-site-diversity systems based on a Gaussian copula are described, applying our own measurements as well additional experimental data from available databases. The prediction models fit the experimental data of the combined rain-attenuation CCDF from 53 two-site-diversity experiments to the theoretical expression of the combined CCDFs using Gaussian copulas. In addition to the combined channel-attenuation prediction for the two-site-diversity systems, the models are also extended for multi-site systems. The rain-attenuation CCDFs of the single sites are required as the input parameters to the models. The first model considers the distance between the Earth stations, while the second one, in addition to distance, also considers the baseline and elevation angles as the input parameters. The models are validated in terms of their error performance. The predicted joint-exceedance probability distributions are compared to the experimental distributions for numerous site-diversity experiments. The errors are calculated according to the ITU-R P.311 error criteria and expressed as mean errors, standard deviations, and rms values.