Cooperative Spectrum Sharing Based on Minimum Energy Consumption Criterion

In cognitive radio networks (CRNs), unlicensed users, i.e., secondary users (SUs), can utilize the spectrum hole of licensed users, i.e., primary users (PUs), through opportunistic spectrum access. With cooperative relay technology, cognitive radio (CR) can improve spectral efficiency (SE). For green communication, this paper investigates joint power and spectrum allocation between a primary and a secondary link. Then, we propose a scheme according to the minimum energy consumption criterion. The graphic and Newton's methods obtain the optimal solution through a small amount of iteration. Through simulation, we demonstrate that the performance of this scheme is consistent with the one based on maximizing energy efficiency (EE). However, we can implement the former with very low computational complexity.