# Opportunistic Wireless Energy Transfer in Point-to-Point Links

## TL;DR

This paper analyzes optimal energy transmission strategies in a point-to-point wireless energy transfer system with finite channel realizations, revealing a simple threshold-based policy that maximizes expected energy transfer.

## Contribution

It introduces a binary, threshold-based optimal policy for wireless energy transfer with causal channel knowledge, simplifying decision-making in finite-horizon scenarios.

## Key findings

- Optimal policy is binary: transmit all or none based on a threshold.
- Threshold decreases as the deadline approaches.
- Analytical and numerical validation of the policy's effectiveness.

## Abstract

In this paper we consider wireless energy transfer for a point-to-point link. The energy transmitter sees a finite number of independent channel realizations, and, armed with (causal) knowledge of the channels, must decide how much energy to transmit in each time slot. The objective is to maximize the expected energy transferred to the receiver at the end of the time period. We show that the optimal energy allocation policy is binary: the transmitter sends no energy or all energy in a slot with this decision based on a simple threshold on the channel. As intuition demands, this threshold for transmission decreases as we move closer to the last available time slot. The performance of the optimal scheme is studied both analytically and numerically.