Capacity of Fading Gaussian Channel with an Energy Harvesting Sensor Node

TL;DR

This paper analyzes the Shannon capacity of an energy-harvesting sensor node transmitting over a fading Gaussian channel, considering various energy usage architectures and storage inefficiencies, to optimize network lifetime.

Contribution

It derives the Shannon capacity and achievable rates for an energy-harvesting sensor node under different energy management scenarios and storage inefficiencies.

Findings

Capacity depends on energy harvesting and storage efficiency.

Achievable rates are characterized with storage inefficiencies.

Optimal energy usage strategies improve network lifetime.

Abstract

Network life time maximization is becoming an important design goal in wireless sensor networks. Energy harvesting has recently become a preferred choice for achieving this goal as it provides near perpetual operation. We study such a sensor node with an energy harvesting source and compare various architectures by which the harvested energy is used. We find its Shannon capacity when it is transmitting its observations over a fading AWGN channel with perfect/no channel state information provided at the transmitter. We obtain an achievable rate when there are inefficiencies in energy storage and the capacity when energy is spent in activities other than transmission.