Modern többvivős rendszerek kognitív rádiós alkalmazásokban

Abstract

As a result of the analogue-to-digital change-over of TV broadcast which is upcoming in Hungary as well, certain frequency bands will become available. According to recent plans, these frequencies might be used by opportunistically communicating, intelligent radio systems aiming data transmission applications. As the primary (incumbent) user of these frequencies will still be the broadcast sector, data communication systems operating in these frequencies must incorporate sophisticated intelligence and fast spectrum sensing capabilities to prevent interference. The physical layer of these communication systems (the modulation) must meet some special requirements implied by these special constraints. In this paper we introduce and compare four different multicarrier modulation techniques which might be suitable candidates for cognitive radio-based applications.