Power Allocation Strategies in Energy Harvesting Wireless Cooperative Networks

TL;DR

This paper investigates various energy allocation strategies in a wireless cooperative network with energy harvesting relays, analyzing their impact on system outage performance and proposing methods balancing complexity and efficiency.

Contribution

It introduces two centralized power allocation strategies, including a water-filling method, and an auction-based scheme for improved system performance and complexity tradeoffs.

Findings

Asymptotic outage performance decays as log(SNR)/SNR for non-cooperative strategy.

Centralized strategies achieve faster decay rates, with water-filling being optimal but complex.

Simulation results validate analytical models and compare performance of proposed schemes.

Abstract

In this paper, a wireless cooperative network is considered, in which multiple source-destination pairs communicate with each other via an energy harvesting relay. The focus of this paper is on the relay's strategies to distribute the harvested energy among the multiple users and their impact on the system performance. Specifically, a non-cooperative strategy is to use the energy harvested from the i-th source as the relay transmission power to the i-th destination, to which asymptotic results show that its outage performance decays as logSNR over SNR. A faster decaying rate, 1 over SNR, can be achieved by the two centralized strategies proposed this the paper, where the water filling based one can achieve optimal performance with respect to several criteria, with a price of high complexity. An auction based power allocation scheme is also proposed to achieve a better tradeoff between the system performance and complexity. Simulation results are provided to confirm the accuracy of the developed analytical results and facilitate a better performance comparison.