Abstract
Cognitive radio (CR) is a potentially promising solution to the spectrum crunch problem that faces both future terrestrial and satellite systems. This paper discusses the applicability of CR in satellite/terrestrial spectrum sharing scenarios by modelling interference relations between these systems. It analyses the relative impact of several design parameters that can be tuned in order to reach a particular interference target. A realistic path loss model is considered and gain patterns of directional antennas are taken into account which are found to be efficient in minimising the interference. A generic model that is not restricted to particular systems is developed, and typical parameters are used to analyse the co-existence feasibility in a realistic sharing scenario. The results show that both satellite and terrestrial systems could potentially operate in the same band without degrading each other’s performance if appropriate considerations are taken into account and an appropriate design of the interfering system is carried out.