Evaluation of Spectrum Opportunity of Cognitive Radio Systems

We evaluate spectrum opportunity, which is achievable if channel availability and successful channel utilization for a secondary user are granted, considering region of interference (ROI) for the secondary user. ROI is mainly dependent upon three ranges: the transmission range of the SU transmitter, the carrier sensing range of the SU transmitter, and the interference range of the SU receiver. Numerical result shows a proper carrier sensing range of a secondary user transmitter might be needed in order to get desired spectrum opportunity for the secondary user.