Green-Energy-Powered Cognitive Radio Networks for Both Improved Spectrum Efficiency and Energy Efficiency

In this paper, we give an overview of cognitive radio (CR) based IoT (CIoT) systems powered by green energy. First, we give a general framework of the CIoT platform and explain the need of green energy power for CIoT. Then, we discuss the spectrum sharing schemes and the energy management schemes for CIoT in detail. Furthermore, we propose an advanced scheme with optimal spectrum sharing and energy management for CIoT, which is illustrated by a real-world scenario. Finally, we present several research challenges for green energy powered CIoT.