Energy-efficient non-cooperative cognitive radio networks: micro, meso, and macro views

Cognitive radio technology can significantly improve spectrum utilization efficiency via enabling secondary users to access licensed spectrum dynamically without harmful interference to primary users. Most existing works on cognitive radio networks were focused on enhancing spectrum efficiency using spectrum sensing, spectrum sharing, and network deployment schemes. However, the energy efficiency issue was largely ignored. Thus, the dilemma between high energy consumption by fast-growing wireless communications and fewer global energy resources has motivated research on energy-efficient cognitive radio networks for enhancing spectrum efficiency and energy efficiency simultaneously. In this article, we overview energy-efficient non-cooperative cognitive radio networks from the micro, meso, and macro perspectives, where the micro view means how to design energy-efficient spectrum sensing algorithms for each individual secondary user, the meso view means how to coordinate non-cooperative secondary users to share spectrum efficiently, and the macro view means how to deploy cognitive radio networks in an energy-efficient approach.