Posicionamiento estratégico de LEDs para mitigar el Blooming Effect en la comunicación óptica por cámara inducido por Rolling Shutter Effect.
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Date
2024
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Publisher
Universidad de Concepción
Abstract
La creciente demanda de capacidad en redes inalámbricas ha evidenciado las limitaciones de las tecnologías basadas en radiofrecuencia (RF), que pronto enfrentarán restricciones en la transmisión de datos. Ante esta situación, ha surgido la comunicación óptica por cámara (OCC), una alternativa innovadora que utiliza la luz visible para transmitir información. La OCC aprovecha la infraestructura existente, utilizando tanto los diodos emisores de luz (LEDs) de la iluminación interior como los sensores de imágenes (IS) en smartphones, lo que facilita su implementación y la hace versátil en entornos interiores. Sin embargo, la OCC presenta limitaciones significativas: las tasas de transferencia de datos actuales, incluso en condiciones óptimas, son bajas, oscilando entre decenas de Kbps y algunos Mbps, lo que es insuficiente para aplicaciones de alta capacidad en el futuro. Además, la mayoría de los estudios se han centrado en entornos ideales, con transmisores cercanos a los receptores, lo que no refleja la realidad. Esto se debe a que para alcanzar tasas de información “altas” se emplea con precisión el mecanismo de obturación de los sensores de imágenes CMOS, conocido como Rolling Shutter (RS), donde la sincronización entre transmisor y receptor es un desafío clave. Además, ocurren muchos fenómenos ópticos que dificultan la decodificación de la información, uno de ellos el efecto "blooming", este efecto ocurre en la diferencia de intensidad de luz entre el área alrededor de la fuente de luz y el área restante del fotograma.
Este estudio presenta la implementación de un sistema de Comunicación Óptica por Cámara basado en el efecto Rolling Shutter Effect, con un enfoque innovador para mitigar el efecto blooming. A diferencia de los métodos existentes en la literatura, se propone una solución sencilla centrada en el ajuste estratégico del posicionamiento de los LEDs. Mediante experimentos, se identifican mejores configuraciones de disposición de LEDs que, para distintas distancias, minimizan eficazmente el impacto del blooming. Este enfoque no solo establece una nueva estrategia para abordar este fenómeno, sino que también contribuye a desarrollar sistemas más robustos en la decodificación de señales ópticas.
The growing demand for capacity in wireless networks has highlighted the limitations of radiofrequency (RF)-based technologies, which are expected to face significant constraints in data transmission soon. In response, Optical Camera Communication (OCC) has emerged as an innovative alternative that uses visible light to transmit information. OCC leverages exis ting infrastructure, utilizing both light-emitting diodes (LEDs) from indoor lighting and image sensors (IS) in smartphones, making it practical and versatile in indoor environments. However, OCC has significant limitations: current data transfer rates, even under optimal conditions, are low, ranging from tens of Kbps to a few Mbps, which is insufficient for future high-capacity applications. Furthermore, most studies have focused on ideal scenarios, with transmitters posi tioned close to receivers, which do not reflect real-world conditions. Achieving “highs” data rates requires precise utilization of the rolling shutter mechanism in CMOS image sensors, known as the Rolling Shutter Effect (RSE), where synchronization between transmitter and receiver be comes a key challenge. Additionally, several optical phenomena complicate data decoding, one of which is the blooming effect. This phenomenon occurs due to the difference in light intensity between the area surrounding the light source and the rest of the frame. This study presents the implementation of an Optical Camera Communication system based on the Rolling Shutter Effect, with an innovative approach to mitigate the blooming effect. Unlike existing methods in the literature, a straightforward solution is proposed, focusing on the strategic positioning of LEDs. Through experimentation, optimal LED configurations for various distances are identified, effectively minimizing the impact of blooming. This approach not only establishes a new strategy to address this phenomenon but also contributes to the development of more robust systems for optical signal decoding.
The growing demand for capacity in wireless networks has highlighted the limitations of radiofrequency (RF)-based technologies, which are expected to face significant constraints in data transmission soon. In response, Optical Camera Communication (OCC) has emerged as an innovative alternative that uses visible light to transmit information. OCC leverages exis ting infrastructure, utilizing both light-emitting diodes (LEDs) from indoor lighting and image sensors (IS) in smartphones, making it practical and versatile in indoor environments. However, OCC has significant limitations: current data transfer rates, even under optimal conditions, are low, ranging from tens of Kbps to a few Mbps, which is insufficient for future high-capacity applications. Furthermore, most studies have focused on ideal scenarios, with transmitters posi tioned close to receivers, which do not reflect real-world conditions. Achieving “highs” data rates requires precise utilization of the rolling shutter mechanism in CMOS image sensors, known as the Rolling Shutter Effect (RSE), where synchronization between transmitter and receiver be comes a key challenge. Additionally, several optical phenomena complicate data decoding, one of which is the blooming effect. This phenomenon occurs due to the difference in light intensity between the area surrounding the light source and the rest of the frame. This study presents the implementation of an Optical Camera Communication system based on the Rolling Shutter Effect, with an innovative approach to mitigate the blooming effect. Unlike existing methods in the literature, a straightforward solution is proposed, focusing on the strategic positioning of LEDs. Through experimentation, optimal LED configurations for various distances are identified, effectively minimizing the impact of blooming. This approach not only establishes a new strategy to address this phenomenon but also contributes to the development of more robust systems for optical signal decoding.
Description
Tesis presentada para optar al título de Ingeniero/a Civil en Telecomunicaciones.
Keywords
Comunicación óptica, Sistemas de transmisión de datos