Transponder non-linearities and propagation channel effects in land mobile satellite links

A digital land mobile satellite link is analyzed under the joint effect of satellite transponder amplifier non-linearities and the shadowing and multipath nature of the mobile propagation channel, in addition to both, up- and down-link thermal noise. For this purpose, a simulation package is developed to predict system performance in practically encountered environmental conditions represented by Rician, shadowed and Rayleigh channel types. The dominant impairing effect for different environments can be predicted from the resulting evaluation curves, to serve system design purposes. The developed simulation package can be further modified to test different modulation, coding and error correction techniques applied to improve the received signal quality.