Reflection-Based Relaying Techniques in Visible Light Communications: Will it Work?

Borja Genoves Guzman,Cheng Chen,Harald Haas,Victor P Gil Jimenez,Lajos Hanzo

doi:10.1109/access.2020.2990660

Abstract

Visible light communication (VLC) is capable of satisfying the escalating data rate demand in indoor scenarios. The lighting infrastructure may also be exploited in the downlink of a wireless local area network (WLAN), where light-emitting diodes are used for transmitting information. The backhaul of VLC access points (APs) constitutes a potential bottleneck in WLANs, especially in large rooms where the number of APs is high. Thus, an alternative reflection-based cooperative wireless system concept is proposed, where no wired connections are required for connecting the APs. Then, its data rate analysis is developed based on the signal-to-noise ratio attained. The results show that the performance of the cooperative wireless system advocated closely approximates the performance of the traditional wired backhaul. Finally, we demonstrate by using Jain's index of fairness that the proposed scheme provides fair coverage quality for all users.

Highlights

There is an ever-increasing demand for wireless data services that requires new spectrum beyond the radiofrequency (RF) [1] band
In contrast to the existing studies, this paper proposes a cooperative Visible light communication (VLC) system based on relay-assisted techniques, where the signal-reflections gleaned are beneficially exploited as relaying links
The number of UEs, each of them associated with a person, is modeled by the variable λue, whereas the number of additional people without a UE who constitute blockers is denoted by λb

Summary

INTRODUCTION

There is an ever-increasing demand for wireless data services that requires new spectrum beyond the radiofrequency (RF) [1] band. Some studies of cooperative techniques have already been carried out for overcoming the LoS-link blockage using on-off keying (OOK) and direct current-biased optical OFDM (DCO-OFDM) in [14] and [15], respectively All these techniques rely on a wired backhaul that is often assumed to be ideal [16], i.e. lossless, noiseless as well as instantaneous, which theoretically assumes having unlimited capacity. In contrast to the existing studies, this paper proposes a cooperative VLC system based on relay-assisted techniques, where the signal-reflections gleaned are beneficially exploited as relaying links. This way, the knowledge of the neighboring APs location or network topology is no longer required, which would speed-up the deployment of a LiFi network This relaying-based principle makes our LiFi proposal beneficial in the presence of blocking elements, which is a common indoor scenario, because the system performance remains satisfactory even in case of LoS blockage events. If R is capable of reliably processing the signal gleaned from S, R will forward it and the signal received by D relayed from R will be stronger than in case of no cooperation

IMPLEMENTATION

SYSTEM ANALYSIS

PERFORMANCE RESULTS

CONCLUSION