Research On Green Spectrum Sharing In Cognitive Radio Network

Dynamic spectrum sharing in cognitive radio networks(CRNs) is a key technology to efficiently solve the problem of low spectrum utilities. Moreover, green communication stresses the concept of energy saving and environmental protection and pusues greater throughput with less energy consumption. As a result, green spectrum sharing based on energy efficiency has attracted extensive attention of researchers.Spectrum sharing technology based on relay cooperation is a win-win strategy. On one hand, it can enhance the transmission reliability and stability of the PUs. On the other hand, it allows secondary users(SUs) to access the licensed spectrum opportunistically. In this paper, spectrum sharing technology based on relay cooperation is investigated to pursue energy efficiency. Giving consideration to both throughput and energy consumption, a new algorithm called green spectrum sharing(GSS) algorithm for power and spectrum sharing time allocation is proposed to maximize the weighted sum energy efficiency of the cognitive system. Compared with the traditional parametric programming algorithm, the proposed GSS algorithm can allocate cooperative spectrum sharing(CSS) time effectively when allocating power for the cooperative relays. More specifically, a best relay selection strategy based on the weighted sum energy efficiency of the cognitive system is designed to select the best cooperative relays. By the relay selection strategy, the cooperative relay set can earn higher energy efficiency under the quality-of-service(Qo S) constraint of primary user(PU) than any other relay sets. Numerical results demonstrate the validity of the proposed GSS algorithm.