# VLC Systems with CGHs

## TL;DR

This paper explores the use of computer generated holograms (CGHs) in visible light communication (VLC) systems to mitigate multipath effects, enhance data rates, and improve signal quality in indoor environments.

## Contribution

It introduces a novel VLC system design utilizing CGHs to direct light beams, reducing reflections and intersymbol interference, thus enabling higher data rates and better performance.

## Key findings

- CGHs increase the 3dB bandwidth of VLC channels.
- The system improves received optical power.
- Performance is validated in ideal and realistic room settings.

## Abstract

The achievable data rate in indoor wireless systems that employ visible light communication (VLC) can be limited by multipath propagation. Here, we use computer generated holograms (CGHs) in VLC system design to improve the achievable system data rate. The CGHs are utilized to produce a fixed broad beam from the light source, selecting the light source that offers the best performance. The CGHs direct this beam to a specific zone on the room's communication floor where the receiver is located. This reduces the effect of diffuse reflections. Consequently, decreasing the intersymbol interference (ISI) and enabling the VLC indoor channel to support higher data rates. We consider two settings to examine our propose VLC system and consider lighting constraints. We evaluate the performance in idealistic and realistic room setting in a diffuse environment with up to second order reflections and also under mobility. The results show that using the CGHs enhances the 3dB bandwidth of the VLC channel and improves the received optical power.

---
Source: https://tomesphere.com/paper/1812.06938