Application of cognitive radio techniques to satellite communication

Applicability of cognitive radio (CR) techniques to satellite communications is investigated and classification for the possible applications is foreseen in this paper. The proposed application scenarios include a) secondary use of satellite spectrum by a terrestrial system, b) secondary use of terrestrial spectrum by a satellite system, and c) a hybrid scenario where terrestrial network coverage is expanded by the use of satellite spots. Key challenges and enabling technologies for each scenario are discussed. Link budget analyses and system simulations are used to define operational limits for interference management in the mentioned scenarios regarding spectrum sensing, transmission power control, and directional antennas. The results show that CR techniques should be applied with caution in satellite bands. However, obvious potential to improve the spectrum efficiency can be seen in each scenario.