QoS Guaranteed Energy Minimization Over Two-Way Relaying Networks

TL;DR

This paper proposes an energy-efficient scheme for two-way relaying networks that dynamically switches between physical-layer network coding and superposition coding based on channel conditions, optimizing power use while maintaining data rate requirements.

Contribution

It introduces a novel switching strategy between PNC and SPC-DNC for energy minimization in TWRNs, with an iterative optimization algorithm for power allocation.

Findings

Switching scheme outperforms single-strategy schemes in energy efficiency

The proposed method reduces overall energy consumption in TWRNs

The scheme is validated through theoretical analysis and simulations

Abstract

In this work, we consider a typical three-node, two-way relaying network (TWRN) over fading channels. The aim is to minimize the entire system energy usage for a TWRN in the long run, while satisfying the required average symmetric exchange rate between the two source nodes. To this end, the energy usage of the physical-layer network coding (PNC) or the superposition coding based digital network coding (SPC-DNC) is analyzed. The rule on selection of both strategies is then derived by comparison. Based on the observed rule, we then design a scheme by switching between PNC and SPC-DNC for each channel realization. The associated optimization problem, through PNC/DNC switching,as well as power allocation on the uplink and the downlink for each channel realization is formulated and solved via an iterative algorithm. It is demonstrated that this switching scheme outperforms the schemes solely employing PNC or SPC-DNC through both theoretical analysis and simulations.