Universally Near Optimal Online Power Control for Energy Harvesting Nodes

TL;DR

This paper introduces a simple online power control policy for energy harvesting nodes that is nearly optimal across all parameters, requiring minimal information about energy arrival distributions.

Contribution

It presents a universally near-optimal online power control policy that depends only on the mean energy arrival, outperforming existing heuristics.

Findings

Achieves near-optimal long-term throughput within constant gaps

Policy depends only on the mean of energy arrivals

Provides a simple formula to approximate throughput

Abstract

We consider online power control for an energy harvesting system with random i.i.d. energy arrivals and a finite size battery. We propose a simple online power control policy for this channel that requires minimal information regarding the distribution of the energy arrivals and prove that it is universally near-optimal for all parameter values. In particular, the policy depends on the distribution of the energy arrival process only through its mean and it achieves the optimal long-term average throughput of the channel within both constant additive and multiplicative gaps. Existing heuristics for online power control fail to achieve such universal performance. This result also allows us to approximate the long-term average throughput of the system with a simple formula, which sheds some light on the qualitative behavior of the throughput, namely how it depends on the distribution of the energy arrivals and the size of the battery.