Optimal Power and Rate Allocation in the Degraded Gaussian Relay Channel with Energy Harvesting Nodes

TL;DR

This paper investigates optimal power and rate allocation strategies for energy harvesting nodes in a degraded Gaussian relay channel, enhancing wireless network efficiency and sustainability.

Contribution

It introduces a convex optimization approach for energy harvesting relay channels, addressing a complex min-max problem with known energy arrival profiles.

Findings

Proposed a convex optimization method for EH relay channels

Derived solutions for specific harvesting scenarios

Improved understanding of energy-efficient relay communication

Abstract

Energy Harvesting (EH) is a novel technique to prolong the lifetime of the wireless networks such as wireless sensor networks or Ad-Hoc networks, by providing an unlimited source of energy for their nodes. In this sense, it has emerged as a promising technique for Green Communications, recently. On the other hand, cooperative communication with the help of relay nodes improves the performance of wireless communication networks by increasing the system throughput or the reliability as well as the range and efficient energy utilization. In order to investigate the cooperation in EH nodes, in this paper, we consider the problem of optimal power and rate allocation in the degraded full-duplex Gaussian relay channel in which source and relay can harvest energy from their environments. We consider the general stochastic energy arrivals at the source and the relay with known EH times and amounts at the transmitters before the start of transmission. This problem has a min-max optimization form that along with the constraints is not easy to solve. We propose a method based on a mathematical theorem proposed by Terkelsen [1] to transform it to a solvable convex optimization form. Also, we consider some special cases for the harvesting profile of the source and the relay nodes and find their solutions efficiently.