Date Added: Jun 2011
Opportunistic use of White Spaces (WS) has opened up a whole new paradigm in research on Cognitive Radio (CR). One of the issues addressed by the QoS-MOS project is the design of a flexible and efficient PHYsical layer (PHY) for CR systems. To this aim, different modulation techniques are being investigated and are presented in this paper. They fulfill the low out of band leakage and spectral efficiency requirements of a CR operating in fragmented WS. The design of reconfigurable and flexible Radio-Frequency (RF) front-end is also introduced, since its performance is tightly linked to these parameters and to the implementation feasibility and constraints. Emphasis is put on benchmarking the performance of the proposed schemes over classical approaches.