Power efficiency maximization based on cognitive relay transmission.

Cognitive radio is a promising technology. The spectrum scarcity problem can be overcome by enabling unlicensed users to access the licensed spectrum bands. In this paper, we focus on power efficiency maximization of cognitive system by jointly considering the parameters of spectrum sensing time and transmit power. In addition, we propose to investigate power efficiency of cognitive relay transmission scheme based on that of non-relay transmission. Finally, we provide the simulation results to show that the throughput and power efficiency of the proposed approach can be significantly improved compared to that of the non-relay transmission scheme in cognitive radio networks. Furthermore, numerical results demonstrate that there exist the optimal parameters to maximize power efficiency. [ABSTRACT FROM PUBLISHER]