Measurement and challenges for practical spectrum sensing in cognitive radio systems

Spectrum sensing is a an integral part of cognitive radio systems. The majority of the studies in the literature addresses the theoretical aspects and limits of spectrum sensing. Furthermore, the studies that investigate the practical and implementation aspects of spectrum sensing is rather limited and their focus are to quantify spectrum usage. Hence, in this paper, we report spectrogram results and bandwidth utilization statistics obtained from a practical spectrum sensor network testbed. In addition, the practical considerations such as the effects of threshold and interference on spectrum utilization are presented. The results show that threshold level and interference have significant effects on the spectrum utilization. Hence, optimization of threshold for given location and frequency and mitigation of interference are crucial for accurate spectrum sensing.