Over 700 MHz –3 dB Bandwidth UOWC System Based on Blue HV-LED With T-Bridge Pre-Equalizer

Zhang, Ziying; Lai, Yuanjia; Lv, Junlong; Liu, Pan; Teng, Dongdong; Wang, Gang; Liu, Lilin

doi:10.1109/jphot.2019.2910090

Cited by 31 publications

(4 citation statements)

References 31 publications

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“…Hence, the LED-based UOWC system is widely used in short-range applications with a large signal coverage area (tens of meters transmission distance [10,41,49,56]). However, the modulation bandwidth is typically limited to tens of MHz [10,57] or hundreds of MHz [58], restricting the transmission data rate [54,58]. Compared with LED, the LD transmitter has the advantage of broad modulation bandwidth over the GHz range [11,27,[59][60][61].…”

Section: Introductionmentioning

confidence: 99%

High-Speed Underwater Optical Wireless Communication with Advanced Signal Processing Methods Survey

Fang

Wang

et al. 2023

Photonics

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Underwater wireless communication (UWC) technology has attracted widespread attention in the past few years. Compared with conventional acoustic underwater wireless communication technology, underwater optical wireless communication (UOWC) technology has promising potential to provide high data rate wireless connections due to the large license-free bandwidth. Building a high-performance and reliable UOWC system has become the target of researchers and various advanced and innovative technologies have been proposed and investigated. Among them, better hardware such as transmitters and receivers, as well as more advanced modulation and signal processing techniques, are key factors in improving UOWC system performance. In this paper, we review the recent development in UOWC systems. In particular, we provide a brief introduction to different types of UOWC systems based on channel configuration, and we focus on various recent studies on advanced signal processing methods in UOWC systems, including both traditional non-machine learning (NML) equalizers and machine learning (ML) schemes based on neural networks. In addition, we also discuss the key challenges in UOWC systems for future applications.

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Section: Introductionmentioning

confidence: 99%

High-Speed Underwater Optical Wireless Communication with Advanced Signal Processing Methods Survey

Fang

Wang

et al. 2023

Photonics

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“…The same year witnessed the utilization of the photomultiplier tube (PMT) in UWOC systems [6]. In 2019, offline high-speed underwater communication experiments exceeding Gbps were successfully completed [7]. In 2020, an FPGA-based UWOC system capable of full-duplex real-time communication was developed [8].…”

Section: Introductionmentioning

confidence: 99%

Real-Time Underwater Wireless Optical Communication System Based on LEDs and Estimation of Maximum Communication Distance

Zhang,

Zhou

2023

Sensors

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This paper presents a real-time underwater wireless optical communication (UWOC) system. The transmitter of our UWOC system is equipped with four blue LEDs, and we have implemented pre-emphasis technology to extend the modulation bandwidth of these LEDs. At the receiver end, a 3 mm diameter APD is utilized. Both the transmitter and receiver are housed in watertight chassis and are submerged in a water pool to conduct real-time underwater experiments. Through these experiments, we have obtained impressive results. The data rate achieved by our system reaches up to 135 Mbps, with a BER of 5.9 × 10−3, at a distance of 10 m. Additionally, we have developed a convenient method for measuring the underwater attenuation coefficient, using which we have found the attenuation coefficient of the water in experiments to be 0.289 dB/m. Furthermore, we propose a technique to estimate the maximum communication distance of an on–off keying UWOC system with intersymbol interference, based on the Q factor. By applying this method, we conclude that under the same water quality conditions, our system can achieve a maximum communication distance of 25.4 m at 80 Mbps. Overall, our research showcases the successful implementation of a real-time UWOC system, along with novel methods for measuring the underwater attenuation coefficient and estimating the maximum communication distance.

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“…A passive analogue pre-equalizer based on simple RLC circuit is reported [15] that extends LED bandwidth by an order of magnitude, from 1 MHz to 11 MHz, but also at the expense of substantial power loss of approximately 12 dB. More sophisticated passive equalizers in the from of T-bridge networks, configured as single stage [16] and cascaded [17], were demonstrated to extend the LED bandwidth by over an order of magnitude also at the expense of substantial loss in signal power. Another form of passive equalisation is reported in [18], which aims to incorporate the LED diffusion capacitance into a pseudo-artificial transmission line, which is a simple technique that can yield significant bandwidth extension, but also incurs substantial loss in signal power.…”

Section: Introductionmentioning

confidence: 99%

Use of Negative Impedance Converters for Bandwidth Extension of Optical Transmitters

Kassem

Darwazeh

2021

IEEE Open J. Circuits Syst.

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The design and advantages of a novel light emitting diode (LED) bandwidth extension technique, based on the adoption of negative impedance converters (NICs), are discussed in the context of visible light communication systems. The design principles of the proposed negative impedance converter are introduced, with analytical derivations of the impedance frequency behaviour and the circuit performance frequency limitations. A two-transistor circuit is designed to generate a negative capacitance over the range −3 to −5 nF and is experimentally demonstrated, using discrete transistors, passive elements and commercially available LED constructed on a PCB, with frequencies up to 50 MHz. NIC design considerations necessary to obtain optimum LED bandwidth extension are discussed and outlined. Measurements demonstrate advantageously the optically lossless nature of the proposed solution and that, unlike traditional passive equalization or pre-distortion based bandwidth extension techniques, substantial improvement in the LED bandwidth, of up to 400 % can be obtained without compromising the output optical power.INDEX TERMS Negative impedance converters, negative capacitance, light emitting diodes, visible light communication.AMANY KASSEM (Graduate Student Member, IEEE) received the B.Sc. degree in electrical and electronic engineering from the Queen Mary University of London, U.K., in 2015, and the M.Sc. degree in optical and wireless communications from University College London, London, U.K., in 2016, where she is currently pursuing the Ph.D. degree in electronic and electrical engineering. Her research interests include the development of high-speed electronic circuits including wideband amplifiers and negative impedance converters to enable higher transmission rates in optical communication systems.IZZAT DARWAZEH (Senior Member, IEEE) received the M.Sc. and Ph.D. degrees in electronic engineering from the

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Over 700 MHz –3 dB Bandwidth UOWC System Based on Blue HV-LED With T-Bridge Pre-Equalizer

Cited by 31 publications

References 31 publications

High-Speed Underwater Optical Wireless Communication with Advanced Signal Processing Methods Survey

High-Speed Underwater Optical Wireless Communication with Advanced Signal Processing Methods Survey

Real-Time Underwater Wireless Optical Communication System Based on LEDs and Estimation of Maximum Communication Distance

Use of Negative Impedance Converters for Bandwidth Extension of Optical Transmitters

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