Exploiting Multichannel Diversity in Cognitive Radio Networks

Abstract

Abstract-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.

Error Rate Analysis of Cognitive Radio Transmissions with Imperfect Channel Sensing

“…The work in [6] mainly focused on the power allocation scheme minimizing the upper bound on the symbol error probability of phase shift keying (PSK) in multiple antenna transmissions of secondary users. The authors in [7] proposed a channel switching algorithm for secondary users by exploiting the multichannel diversity to maximize the received SNR at the secondary receiver and evaluated the transmission performance in terms of average symbol error probability. The optimal antenna selection that minimizes the symbol error probability in underlay cognitive radio systems was investigated in [8].…”