Modeling and analysis of visible light communication channels for underground mining environments in mimo systems

Abstract

Modeling the channel for communication systems that use visible light in situations with important perturbations, such as the obstruction of the signal due to shadowing or the scattering due to particles, is a complex problem. One of the environments that present such perturbations is the underground mining environments, which present characteristics not found in indoor environments. Hence, presenting a proper channel model for the application of visible light communications to such environments is relevant. Additionally, visible light systems are sensible to obstructions and phenomena that could degrade the channel performance. Due to this sensibility, modeling the channel using multiple receptors and multiple transmitters can potentially provide a solution to the systems' reliability.

In this work, a channel model for underground mining environments using visible light communications with multiple inputs and multiple outputs will be presented. Using this channel, different communication schemes that take advantage of the spatial diversity will be analyzed with simulations. After that, an optimization framework that improves the behavior of such schemes will be presented. Finally, using the insight of the solutions of the optimization framework, an analytical closed expression of the outage probability of the system given the system variables will be presented.

Modelar el canal para sistemas de comunicaci´on mediante luz visible en situaciones con perturbaciones importantes, tales como la obstrucci´on de la se˜nal y la refracci´on por part´ıculas, es un problema complejo. Uno de los ambientes que presentan tales perturbaciones son los canales en ambientes mineros, los cuales poseen caracter´ısticas dis´ımiles a los ambientes de oficina. Por ello, presentar un modelo para la aplicaci´on de estos sistemas en minas es crucial. Los sistemas de luz visible son sensibles a las obstrucciones y a fen´omenos que degradan el enlace. En consecuencia, modelar el canal en funci´on a la existencia de m´ultiples receptores y m´ultiples transmisores provee soluciones a problemas de fiabilidad. En este trabajo se presentar´a un modelo de canal por luz visible para canales mineros en sistemas con m´ultiples entradas y m´ultiples salidas, tomando en cuenta los distintos fen´omenos existentes dentro de la mina. Posteriormente, se probar´an mediante simulaciones distintos esquemas de comunicaci´on que toman ventaja de la diversidad espacial. Tras ello, se tratar´a de mejorar el comportamiento del sistema en sus distintos grados de libertad. Finalmente, se obtendr´a una m´etrica cerrada sobre las distintas variables del canal mediante una expresi´on de la probabilidad de apag´on que afecta al sistema.