Simulation of impulse response for indoor visible light communications using 3D CAD models

Silvestre Pérez Rodríguez,Francisco José López Hernández,Alejandro José Ayala Alfonso,Rafael Pérez Jiménez,Beatriz Rodríguez Mendoza

doi:10.1186/1687-1499-2013-7

Abstract

In this article, a tool for simulating the channel impulse response for indoor visible light communications using 3D computer-aided design (CAD) models is presented. The simulation tool is based on a previous Monte Carlo ray-tracing algorithm for indoor infrared channel estimation, but including wavelength response evaluation. The 3D scene, or the simulation environment, can be defined using any CAD software in which the user specifies, in addition to the setting geometry, the reflection characteristics of the surface materials as well as the structures of the emitters and receivers involved in the simulation. Also, in an effort to improve the computational efficiency, two optimizations are proposed. The first one consists of dividing the setting into cubic regions of equal size, which offers a calculation improvement of approximately 50% compared to not dividing the 3D scene into sub-regions. The second one involves the parallelization of the simulation algorithm, which provides a computational speed-up proportional to the number of processors used.

Highlights

There has been a growing interest in visible light communications (VLC) in some indoor application scenarios, video/audio transmission for in-home applications, secure network access, or sensor networking [1,2,3,4,5,6,7,8]
The first one consists of dividing the simulation environment into sub-cubes of equal size, so that when a ray is traced in these sub-regions, only those object faces or surfaces that are in the ray propagation path need to be considered
Results we present several simulation results to show the potentiality of the simulation tool to approximately characterize the impulse response of indoor VLC channels

Summary

Introduction

There has been a growing interest in visible light communications (VLC) in some indoor application scenarios, video/audio transmission for in-home applications, secure network access, or sensor networking [1,2,3,4,5,6,7,8]. While the Barry algorithm is deterministic and based on an iterative method [9], the López–Hernández algorithm (called the Monte Carlo ray-tracing algorithm) is based on ray-tracing techniques and Monte Carlo method [10], which exhibits a lower computational cost than the Barry algorithm, especially when a high temporal resolution, complex geometries, and a large number of reflections are considered For this reason, in this article a tool for simulating the impulse response of indoor VLC channels using 3D computer-aided design (CAD) models is presented. The second element consists of implementing the propagation model This refers to the mathematical models that characterize the effect of each of the elements present in the simulation environment (reflecting surfaces, emitters, and receivers), and to the simulation algorithm that, aided by these models, allows the channel response to be computed.

Error estimate of the simulated impulse responses

Results

Conclusions