# On Optimal Online Algorithms for Energy Harvesting Systems with Continuous Energy and Data Arrivals

## TL;DR

This paper analyzes online algorithms for energy harvesting communication systems with continuous data and energy arrivals, establishing bounds on their performance compared to offline algorithms.

## Contribution

It introduces two online algorithms that achieve the optimal performance ratio bound of 2, providing new insights into online energy management.

## Key findings

- Optimal online algorithms have a performance ratio of 2.
- Proposed algorithms achieve the upper bound of 2.
- The ratio of online to offline completion time is tightly bounded.

## Abstract

Energy harvesting (EH) has been developed to extend the lifetimes of energy-limited communication systems. In this letter, we consider a single-user EH communication system, in which both of the arrival data and the harvested energy curves are modeled as general functions. Unlike most of the works in the field, we investigate the online algorithms which only acquire the causal information of the arrival data and the harvested energy processes. We study how well the optimal online algorithm works compared with the optimal offline algorithm, and thus our goal is to find the lower and upper bounds for the ratio of the completion time in the optimal online algorithm to the optimal offline algorithm. We propose two online algorithms which achieve the upper bound of 2 on this ratio. Also, we show that this ratio is 2 for the optimal online algorithm.