Exploiting Multichannel Diversity in Cognitive Radio Networks

Cognitive radios hold tremendous promise for increasing spectral efficiency in wireless systems. In cognitive radio networks, secondary users equipped with frequency-agile cognitive radios communicate with one another via spectrum that is not being used by the primary, licensed users of the spectrum. We consider a multichannel cognitive radio network scenario in which a secondary transmitter can switch to different channels for opportunistic communications. Multichannel diversity can be achieved by dynamically switching to different channels during transmission. Our numerical results show that even a simple randomized channel switching scheme can significantly reduce the average symbol error probability. We also propose a scheduling algorithm based on maximizing signal-to-noise ratio to further improve the performance of cognitive transmission.