Energy-Efficient NC-OFDM/OQAM-Based Cognitive Radio Networks

With the explosive growth of wireless multimedia applications and the demand for high data rate, improving the spectrum and energy efficiencies have been two most critical challenges for wireless communication networks under the background of limited spectrum and energy resources. Cognitive radio and OFDM/OQAM have emerged as two exciting technologies to solve the spectrum scarcity in future cellular networks; thus, energy-efficient communications have attracted increasing attention in cognitive radio networks. In this article, we consider how to make an energy-efficient physical layer design for non-contiguous (NC) OFDM/OQAM-based cognitive radio networks. Specifically, we propose a criterion on how to reduce the high PAPR of NC-OFDM/OQAM signals to achieve high power efficiency. The key idea of the proposed criterion is to jointly reduce the PAPR and suppress the sidelobe in NC-OFDM/OQAM-based CR systems. Extensive simulation results verify that the proposed criterion can provide both significant PAPR reduction and sidelobe suppression, resulting in prominent improvement of energy efficiency in NC-OFDM/OQAM-based cognitive radio networks.