Energy efficiency in the wideband regime

In this paper we discuss globally optimal energy-efficient communications in the wideband regime that is characterized by wide signal bandwidth and low spectral efficiency. An end-to-end multiple-hop system with one sender, one receiver, and multiple relays is considered. We discover the globally optimal link adaptation as well as relay deployment strategies such that the whole system can run with the highest energy efficiency. The technologies proposed can be used in various communication systems, such as the deployment and communication of wired core networks and wireless broadband relay backhauls, to improve their energy efficiency.