Spectrum Utilization of Clustered-OFDM-based Opportunistic-Multichannel-ALOHA Cognitive Radio
Sangho Choe · 2012
We present a clustered-OFDM-based opportunistic-multichannel-ALOHA cognitive radio (COCR) for low-cost low-load ad-hoc-based wireless systems like sensor networks, We implement COCR on the basis of opportunistic channel selection and analyze its spectrum efficiency, analytically as well as numerically, under the perfect or imperfect spectrum sensing. Via simulation, we show that the proposed scheme is superior to conventional opportunistic-multichannel-CSMA CR (OMC-CSMA CR) with random channel selection in terms of spectrum utilization ratio especially at a small offered-load (). The maximum spectrum utilization ratio (=max{}) of COCR is 0.8, about 90% of that of conventional OMC-CSMA CR and about 230% of that of conventional opportunistic-multichannel-ALOHA CR (OMC-ALOHA CR).