Wireless Information and Power Transfer in Relaying Systems

While the era of the fifth‐generation (5G) communication systems and beyond is rapidly approaching, future networks pose new challenges, displaying a group of diverse characteristics. This chapter studies wireless cooperative networks in which the available relays can harvest energy from the received radio frequency (RF) signals. It examines two types of networks, those with a single source and destination, and those with multiple sources or destinations. In both types, one or multiple relays are considered, under the assumption that the power consumption at the relay due to information processing is negligible compared to the power used for signal transmission from the relay to the destination. The chapter also discusses some interesting future research directions. Cognitive energy harvesting (EH) relaying is a quite interesting case, since it enables secondary transmission by using the primary users' resources, i.e. bandwidth and energy.