Capacity of Gaussian MAC Powered by Energy Harvesters without Storage Buffer

TL;DR

This paper characterizes the capacity region of a Gaussian multiple access channel with energy-harvesting sensor nodes that lack energy buffers, analyzing scenarios with and without energy information at the decoder.

Contribution

It introduces the capacity region for a GMAC with energy harvesters without buffers and compares it to the case with an infinite buffer, including scenarios with unknown energy states.

Findings

Capacity region with no energy buffer derived

Impact of energy harvesting information on achievable rates analyzed

Comparison between bufferless and buffered energy harvesting scenarios

Abstract

We consider a Gaussian multiple access channel (GMAC) where the users are sensor nodes powered by energy harvesters. The energy harvester has no buffer to store the harvested energy and hence the energy need to be expended immediately. We assume that the decoder has perfect knowledge of the energy harvesting process. We characterize the capacity region of such a GMAC. We also provide the capacity region when one of the users has infinite buffer to store the energy harvested. Next we find the achievable rates when the energy harvesting information is not available at the decoder.