Bidirectional User Throughput Maximization Based on Feedback Reduction in LiFi Networks

TL;DR

This paper proposes feedback reduction techniques for LiFi networks, leveraging the static optical channel to enhance bidirectional throughput by minimizing feedback without sacrificing performance.

Contribution

It introduces two novel feedback reduction schemes for LiFi networks and derives the optimal update interval to maximize user throughput.

Findings

Proposed schemes outperform one-bit and full-feedback methods in throughput.

Optimal update interval significantly improves bidirectional user throughput.

Feedback reduction maintains high performance with less overhead.

Abstract

Channel adaptive signalling, which is based on feedback, can result in almost any performance metric enhancement. Unlike the radio frequency (RF) channel, the optical wireless communications (OWCs) channel is fairly static. This feature enables a potential improvement of the bidirectional user throughput by reducing the amount of feedback. Light-Fidelity (LiFi) is a subset of OWCs, and it is a bidirectional, high-speed and fully networked wireless communication technology where visible light and infrared are used in downlink and uplink respectively. In this paper, two techniques for reducing the amount of feedback in LiFi cellular networks are proposed, i) Limited-content feedback (LCF) scheme based on reducing the content of feedback information and ii) Limited-frequency feedback (LFF) based on the update interval scheme that lets the receiver to transmit feedback information after some data frames transmission. Furthermore, based on the random waypoint (RWP) mobility model, the optimum update interval which provides maximum bidirectional user equipment (UE) throughput, has been derived. Results show that the proposed schemes can achieve better average overall throughput compared to the benchmark one-bit feedback and full-feedback mechanisms.