Cognitive Radio with Ultra-Wide Bandwidth Location-capable Nodes

In this paper we introduce the basic concepts underlying Cognitive Radio (CR) as an emerging approach for a more flexible usage of the precious radio spectrum resources. After the definition of a possible scenario, we discuss Ultra-Wide Bandwidth (UWB) technology as one of the transmission techniques suitable for implementing a CR system. We then review some recent results concerning interference and coexistence between narrowband (NB) and UWB communication systems. Finally, we show the great potential of the UWB technology in adapting the transmitted spectrum to counteract NB interference and at the same time to guarantee low spectral emissions over existing NB communications.