LED beam steering for Li-Fi communications

Mekhiel, Christopher; Fernando, Xavier

doi:10.1109/camad.2016.7790364

Cited by 7 publications

(2 citation statements)

References 17 publications

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“…In the past, LEDs produced only red light, but new LEDs can also produce red, green, and blue (RGB) light. In recent years, LED technology has been improving so that they can produce white light too [25].…”

Section: Li-fi Ledmentioning

confidence: 99%

Employing light fidelity technology in health monitoring system

Al-Dabbagh

Ali

2022

IJEECS

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Light Fidelity (Li-Fi) is an emerging technology that has been in transferring data packets in Internet of Things (IoT) applications. During the COVID-19 pandemic, healthcare institutes try to manage the rapid increase of patients’ numbers. The healthcare team may not have the ability to monitor patients’ stats around the clock with the conventional techniques. In this paper, a healthcare monitoring framework to exchange health data between biosensors and terminals employing Li-Fi technology is proposed. It exploits Li-Fi to transmit data towards a terminal then to a cloud platform. It is intended for use in highly dense healthcare institutes where the number of patients is high. Exploiting Li-Fi to establish connection to cut high cost of other transmission technologies including Wi-Fi and provides less complexity and shorter latency. We evaluate the framework in a real-life environment using biosensors and Li-Fi communication model (for network infrastructure), these two components are connected to a computing terminal to help health staff monitor patients. The computing terminal is connected to a cloud platform to provide remote monitoring and computing resilience. The framework shows superior performance in real-world scenarios compared to Wi-Fi. A comprehensive analysis has been conducted to show the differences between Li-Fi and Wi-Fi.

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Section: Li-fi Ledmentioning

confidence: 99%

Employing light fidelity technology in health monitoring system

Al-Dabbagh

Ali

2022

IJEECS

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“…It is clear that an LED has a small coherence length (∼ µm) due to its broad spectral range. Hence, it's essential to develop a method for increasing the coherence length of an LED to ensure OBS feasibility [26].…”

Section: Opa With Feedbackmentioning

confidence: 99%

Free-Space Optical Beam Steering for Wireless Communications

Mekhiel¹

2021

Preprint

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The implementation of optical of wireless communications (OWC) requires the use of a light-emitting-diode (LED) or laser diode (LD). Due to significant path loss exhibited by these sources in an outdoor environment, an unobstructed point-to-point link must be maintained in order to increase the signal-to-noise ratio (SNR) at the receiver. This thesis considers a solution to alleviate the fundamental limitations of the OWC channel in an outdoor environment by investigating optical beam steering (OBS) to increase the signal strength in the desired direction. Conventional methods to implement on OBS use a microelectromechanical (MEMS) mirror or a spatial light modulator (SLM) which both suffer from low switching frequency. A high frequency OBS device can be created by using optical phased array (OPA). An electro-optic modulator (EOM) such as LiNbO3 can be used to create an OPA but can not be directly integrated in silicon. For monolithic silicon-on-insulator (SOI) solutions, previous literature uses thermo-optic couplers on SOI to implement the OPA, however this introduces the issue of thermal cross-talk. Therefore, this thesis focuses on the use of silicon as the EOM for use in an OPA to create a high frequency monolithic OBS. Our contributions consist of providing a design method for a OBS SOI device which exhibits minimum internal cross-talk and provides propagation in free-space with high directivity and a wide steering range. Additionally, propose the use of an internal heterodyne optical phase locked loop (PLL) to stabilize the OBS instead of an external signal processor for phase correction. This optical PLL reduces beam jitter, minimizes beam squint, and provides active tracking for the output beam towards the receiver. We have also characterized a shadowing scenario in an OWC channel which OBS has the potential to alleviate. Moreover, we simulated the optical far-field radiation pattern from a SOI waveguide to free-space which has not been demonstrated in previous research. Finally, our simulation results of a SOI OPA demonstrates the coherent combining capability of OBS using MEEPTtm and the Optiwavetm suite.

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