Towards 250-m gigabits-per-second underwater wireless optical communication using a low-complexity ANN equalizer

Optics Express, Год журнала: 2025, Номер 33(2), С. 2321 - 2321

Опубликована: Янв. 2, 2025

The breakthroughs in communication distance and data rate have been eagerly anticipated by scientists the area of underwater wireless optical (UWOC), which is seriously limited obvious aquatic attenuation channels. high-power laser source ultra-sensitive photodetector are straightforward extending UWOC distance. However, nonlinear impairments caused bandwidth-limited transmitters sensitive receivers severely degrade long-distance UWOC. In this paper, we develop a system using transmitter beam combining 8-channel cascaded diodes (LD) receiver silicon photomultiplier (SiPM). combined linear equalizer low-complexity artificial neural network (ANN) used to robustly achieve 1-Gbps transmission over 250-m system. To best our knowledge, first Gbps-level experimental demonstration >250-meter that has ever reported. lower complexity ANN equalizer, applied order prune input size equalizer. optimal identified as 9. architecture consists two hidden layers, with 10 neurons layer single neuron second layer. performance proposed ANN-based compared systems employing Volterra equalizers. bit error (BER) at 1 Gbps reduced 3.4 × −3 below hard-decision forward correction (HD-FEC) limit. contrast, equalizer-based rates 500 Mbps 750 Mbps, respectively.

Язык: Английский

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Tutorial on laser-based visible light communications [Invited]

Chinese Optics Letters, Год журнала: 2024, Номер 22(9), С. 092502 - 092502

Опубликована: Янв. 1, 2024

Язык: Английский

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

Photonics, Год журнала: 2023, Номер 10(7), С. 811 - 811

Опубликована: Июль 12, 2023

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

Язык: Английский

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Underwater visible light communication: recent advancements and channel modeling

Optical and Quantum Electronics, Год журнала: 2024, Номер 56(10)

Опубликована: Сен. 23, 2024

Язык: Английский

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An Optical Differential Method for Underwater Wireless Communication in Turbid Environments

Photonics, Год журнала: 2025, Номер 12(2), С. 112 - 112

Опубликована: Янв. 27, 2025

Underwater optical communication has emerged as an essential tool for exploring oceanography and marine resources underwater vehicles or robots in recent years. Current techniques mostly rely on the paradigm of intensity modulation direct detection, resorting to more powerful light sources transmitting side sensitive detectors receiving side, thus causing excess energy consumption system costs. Here, a novel approach, namely, differential communications method (ODCM), is proposed extend distance wireless turbid water. The underlying physical reason explained theory demonstrated experiments. It found that stable propagation ODCM could be further extended without relying intensive sources, contrast conventional methods, showing potential longer ranges. Tests are conducted, results show can significantly reduce bit error rate (BER) at same BER level signals. As such, this study provides avenue long-distance environments.

Язык: Английский

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水下轨道角动量光通信

Acta Optica Sinica, Год журнала: 2024, Номер 44(4), С. 0400001 - 0400001

Опубликована: Янв. 1, 2024

回顾了水下轨道角动量(OAM)模式光通信的研究进展,简要介绍了OAM模式的原理和产生、测量方法,全面综述了水下OAM模式的多种光通信方式(编码、复用、广播)以及涉及空水界面的光通信和快速自动对准辅助的光通信,同时介绍了水下其他结构光通信和基于OAM模式的复杂介质光通信。讨论了该领域的未来发展趋势。作为一种空间结构光场,将OAM模式引入水下光通信可开发空间新维度资源,为光通信可持续扩容提供新途径,提高无线光通信在水下短距互连的优势;OAM模式与水下传统通信方式及水下感知技术相结合,有望更好地满足未来高速海洋环境通信和高效海洋资源开发的发展需求。

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Half-spectrum OFDM to quadruple the spectral efficiency of underwater wireless optical communication with digital power division multiplexing

Applied Optics, Год журнала: 2024, Номер 63(9), С. 2352 - 2352

Опубликована: Март 1, 2024

Improving the spectrum efficiency (SE) is an effective method to further enhance data rate of bandwidth-limited underwater wireless optical communication (UWOC) systems. Non-orthogonal frequency-division multiplexing (NOFDM) with a compression factor 0.5 can save half bandwidth without introducing any inter-carrier-interference (ICI) only if total number subcarriers large enough, and we termed it as half-spectrum OFDM (HS-OFDM). To best our knowledge, this first reported work on closed-form HS-OFDM signal in discrete domain from perspective correlation matrix. Due special mathematical property, no extra complex decoding algorithm required at receiver, making simple conventional receiver. Compared traditional OFDM, realize same rate, but larger signal-to-noise ratio (SNR) margin. fully use SNR resource system, propose digital power division multiplexed (DPDM-HS-OFDM) scheme quadruple SE for bandwidth-starved UWOCs. The experimental results show that improve receiver sensitivity by around 4 dB opposed 4QAM-OFDM SE. With help DPDM-HS-OFDM scheme, multi-user UWOC reach up 4.5 Gbps under hard-decision forward error correction (HD-FEC) limit bit (BER) 3.8×10

Язык: Английский

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Underwater Wireless Optical Communications: From the Lab Tank to the Real Sea

Optical Fiber Communication Conference (OFC) 2022, Год журнала: 2024, Номер unknown, С. W4B.7 - W4B.7

Опубликована: Янв. 1, 2024

This paper introduces the recent progress of underwater wireless optical communications (UWOC). Studies in channel dynamics and link alignment issues contribute to mature applications UWOC real sea environments.

Язык: Английский

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Relay aided UWOC-SMF-FSO based hybrid link for underwater wireless optical sensor network

Optical Fiber Technology, Год журнала: 2024, Номер 89, С. 104045 - 104045

Опубликована: Ноя. 21, 2024

Язык: Английский

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Underwater Wireless Optical Communication Utilizing a Semi-Supervised Twin Neural Network-Based Post-Equalizer with Interleaved Consistency Regularization

Journal of Lightwave Technology, Год журнала: 2024, Номер 42(14), С. 4763 - 4773

Опубликована: Март 19, 2024

In this work, a novel semi-supervised twin neural network (semiTNN)-based post-equalizer (PE) is proposed and developed for high-speed 4-level pulse amplitude modulation (PAM4) underwater wireless optical communication (UWOC). Furthermore, semiTNN enabled by dual-drop strategy interleaved consistency regularization (ICR), thereby only requiring small amount of labeled PAM4 symbols as references to be well-trained. The experimental results over 14-m/4-Gbps link reveal that the PE paired with ICR, 5% data, can achieve nearly same bit error rate (BER) performance one trained fully-supervised learning process, resulting in 0.8-dB 4.9-dB sensitivity improvements comparing traditional Volterra nonlinear equalizer (VNE) linear feedforward (FFE) at specific BER 1×10 ^-3 , respectively. When transmission distance further extended 56 m, 10% data reach up 4.26 Gbps under hard-decision forward correction (HD-FEC) threshold, which 90 Mbps 150 larger than VNE FFE, Moreover, even facing bias-current fluctuations, turbulence, bubbles, UWOC systems supported still maintain satisfying some extent. This first time utilize combined an ICR-based loss function UWOC, it highly beneficial practical deployment NN-based PEs future.

Язык: Английский

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