Protocolo de Cooperación Adaptativo para Sistemas de Comunicaciones Opticas Atmosféricas

En concreto, se ha analizado un sistema de comunicaciones cooperativas formado por 3 enlaces FSO con retransmision DF usando IM/DD sobre canales con turbulencia atmosferica y desalineamiento entre el transmisor y el receptor. Se han evaluado las prestaciones de un protocolo de cooperacion adaptativo basado en la seleccion de camino óptico con mayor valor de irradiancia.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Converging Underwater and FSO Ground Communication Links

We propose a new combined underwater-atmospheric optical communication link for providing a high speed optical connectivity between onshore and sumerge systems. New average BER expressions are derived when assuming amplify-and-forward (AF) relay.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Evaluating pointing errors on ergodic capacity of DF relay-assisted FSO communication systems

Ergodic capacity of decode-and-forward (DF) relay-assisted free-space optical (FSO) communication systems when line of sight is available is analyzed over gamma-gamma fading channels with pointing errors. Novel closed-form approximate ergodic capacity expression is obtained in terms of the H-Fox function for a 3-way FSO communication system when the α-μ distribution to efficiently approximate the probability density function (PDF) of the sum of gamma-gamma with pointing errors variates is considered. Moreover, we present a novel asymptotic expression at high signal-to-noise ratio (SNR) for the ergodic capacity of DF relay-assisted FSO systems. The main contribution in this work lies in an in-depth analysis about the impact of pointing errors on the ergodic capacity for cooperative FSO systems. In order to maintain the same performance in terms of capacity, it is corroborated that the presence of pointing errors requires an increase in SNR, which is related to the fraction of the collected power at the receive aperture, i.e. A 0 . Simulation results are further demonstrated to confirm the accuracy and usefulness of the derived results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors wish to acknowledge the financial support given by Spanish MINECO Project TEC2012-32606

Statistical Channel Impulse Response Modeling for Optical Wireless Communication in Turbid Waters

Underwater optical wireless communication (UOWC) systems support high-speed, reliable and cost-effective implementations that are demanded for extending the telecommunication networks to oceans. UOWC systems suffer from attenuation and scattering processes. Particularly, the scattering process can change the direction of the emitted photons, especially in turbid waters. In this way, quantifying the signal attenuation and the time dispersion produced by absorption and scattering is a crucial work. Hence, we propose a new closed-form solution for modeling the channel impulse response for UOWC systems in turbid water that is validated through Monte Carlo simulations and can be used for system design and optimization purposes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Incremento de la capacidad del canal óptico submarino mediante técnicas MISO en presencia de dispersión y turbulencia oceánica

En este trabajo se presenta un sistema con múltiples transmisores y un único receptor (MISO) con el objetivo de analizar las prestaciones en términos de capacidad ergódica de un canal óptico submarino bajo efecto de desvanecimiento de la potencia óptica recibida inducido por la dispersión del medio y turbulencias oceánicas bajo diferentes tipos de agua, distancias y severidad de turbulencias. Con este fin, se obtienen nuevas expresiones matemáticas en forma cerrada que permiten obtener la capacidad ergódica del sistema. Además, se aportan expresiones asintóticas que facilitan el análisis de las prestaciones en función de los diferentes parámetros físicos del sistema. Los resultados obtenidos confirman la mejora de prestaciones del sistema mediante el uso de un mayor número de transmisores en los diferentes escenarios estudiados. Todos los resultados presentados son validados a través de simulaciones Monte Carlo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Caracterización estadística del desvanecimiento inducido por dispersión en sistemas de comunicación óptica inalámbrica submarina

An accurate underwater channel characterization is necessary for underwater optical wireless communication (UOWC) in order to improve its current limitations. This paper presents a new statistical model to characterize the scattering effect in terms of a fading never considered before by means of a Gamma distribution by using only one degree of freedom in clear ocean and coastal waters. The developed fading model is employed to compute the performance of UOWC systems in terms of bit error rate (BER) along with salinity-induced oceanic turbulence modeled by a Weibull distribution. The results demonstrate that the scattering-induced fading effect produces a strong performance degradation particularly in long link distances and, hence, it cannot be neglected when designing advanced communication systems. The analytical results are verified by Monte Carlo simulations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Modelado estadístico del efecto de burbujas de aire en sistemas de comunicaciones ópticos inalámbricos submarinos.

The studies regarding underwater optical communications require an in-deep characterization of the water itself since its properties of absorption and scattering of light affect the transmission in an optical link. That said, this paper presents the modeling and characterization of the statistical behavior regarding the scattering caused by air bubbles of different sizes in an underwater optical wireless channel. It also provides the best statistical fitting according to each case in which a bimodal statistical form was discovered for a large-size air bubbles matter. Furthermore, it explains how all the assembly and installation are made at the laboratory in order to achieve the results obtained. It also features an audio interface as an easy way to get data variations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Process mineralogy of the tailings from Llallagua: towards a sustainable activity

Peer ReviewedObjectius de Desenvolupament Sostenible::17 - Aliança per a Aconseguir els ObjetiusObjectius de Desenvolupament Sostenible::12 - Producció i Consum ResponsablesObjectius de Desenvolupament Sostenible::4 - Educació de QualitatPostprint (published version