Power Allocation for Multi‐node Energy Harvesting Channels

This chapter considers the design of wireless communication systems with multiple transmission nodes powered by energy harvesters. Different from the point‐to‐point channel case, it is not optimal anymore for the multi‐node scenarios to separately optimize the transmission of each energy harvesting (EH) communication link with only local energy state information (ESI). The chapter investigates the multiple‐access channels with conferencing links and shared energy harvesters and discusses the transmission cooperation among the transmitters. It considers a three‐node relay channel with energy harvesting (EH) sources, where it is shown that the proposed cooperative transmission scheme can exploit a new form of diversity arising from the independent source and relay energy availability over time, termed "energy diversity," even over time‐invariant channels. The chapter turns to a large relay network, where multiple relays are powered by energy harvesters, and shows that the power allocation for each EH relay should be determined by the overall energy distribution among these relays.