High Data Rate Transmission Research Articles

Optimized planar printed UCA configurations for OAM waves and the associated OAM mode content at the receiver

SummaryUtilization of planar printed uniform circular antenna arrays (UCA) to generate the orbital angular momentum (OAM) carrying waves in the millimeter‐wave (mmWave) frequency band is advantageous from the viewpoints of easy signal modulation and mode reconfiguration, low cost, low profile, and straightforward integration with the existing broadband wireless infrastructure. The OAM mmWave UCA are highly promising as the enablers of very high transmission data rates required by hybrid 5G/6G optical and wireless communication systems by complementing and enhancing other technologies currently in use. Therefore, we here contribute a detailed electromagnetic analysis of important constraints of such antenna arrangements aimed at short‐range multimode OAM wave transmission. We investigate (i) the required antenna array dimensions and optimized UCA arrangements for a particular link range and (ii) the corresponding mode structure of OAM waves in the plane of receiving arrays. Four relatively simple antenna configurations operating in the 60‐GHz band are compared. Theoretical assumptions based on ideal OAM modes are critically assessed and, using state‐of‐the‐art numerical electromagnetic analysis, compared to realistically generated OAM waves. The proposed “cyclic transmission setup” resulted in much lower unwanted field components in the region of receiving arrays. RMS magnitudes of unwanted modes are on average about 64% of the received mode, in comparison with 80% (up to 94%) for sequential transmission. The observed mode impurities and mode mixing effects at the receiver indicate the need to dedicate more attention to the system‐level design, the development of efficient receiving arrays, the MIMO processing, and the stream separation.

Evaluation of the Field-Test Results of Advanced ISDB-T System With Low-Rate LDPC Codes

This article analyses low-density parity-check (LDPC) codes for forward error correction (FEC) in the next generation of digital terrestrial broadcasting systems for transmitting high-volume content services, such as ultra high definition television (UHDTV). We assess the performance of the LDPC codes used by the Advanced ISDB-T system with 2x2 MIMO transmission using experimental data obtained in field measurements in Brazil. Channel power, carrier-to-noise threshold, and receiving threshold were measured for four different low-rates LDPC codes, two modulation types, and three receiving antenna heights at outdoor sites in urban areas. The coverage analysis shows that the channel power presents a similar distribution for horizontal and vertical polarized signals. C/N threshold analysis shows that in sites with high vehicular traffic, the C/N threshold and reception threshold values were much higher than in other sites with less heavy vehicular traffic. Among the five coding-modulation combinations used in the field tests, the transmission configuration with LDPC code rate 2/16 and QPSK modulation was the one that presented the best results partially meeting the requirement of C/N <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\leq $</tex-math> </inline-formula> 0dB. The transmission configuration with LDPC code rate 3/16 and QPSK modulation showed C/N results just above 0dB, but offering 50% higher data transmission rate.

Smart Radio Environments with Intelligent Reflecting Surfaces for 6G Sub-Terahertz-Band Communications

Technology for sixth-generation (6G) mobile communication system is now being widely studied. A sub-Terahertz band is expected to play a great role in 6G to enable extremely high data-rate transmission. This paper has two goals. (1) Introduction of 6G concept and propagation characteristics of sub-Terahertz-band radio waves. (2) Performance evaluation of intelligent reflecting surfaces (IRSs) based on beamforming in a sub-Terahertz band for smart radio environments (SREs). We briefly review research on SREs with reconfigurable intelligent surfaces (RISs), and describe requirements and key features of 6G with a sub-Terahertz band. After that, we explain propagation characteristics of sub-Terahertz band radio waves. Important feature is that the number of multipath components is small in a sub-Terahertz band in indoor office environments. This leads to an IRS control method based on beamforming because the number of radio waves out of the optimum beam is very small and power that is not used for transmission from the IRS to user equipment (UE) is little in the environments. We use beams generated by a Butler matrix or a DFT matrix. In simulations, we compare the received power at a UE with that of the upper bound value. Simulation results show that the proposed method reveals good performance in the sense that the received power is not so lower than the upper bound value.

Fiber Optics: The Fundamentals, Types, Advantages and Applications

Abstract: This study's goal is to shed light on recent advancements and improvements in the use of optical fibre as a data transport. It offers a wealth of knowledge on the architectural design, upkeep, troubleshooting, and benefits of fibre optic transmission over copper or electrical transmission. Broadband networks all across the world depend on fibre optic lines as vital telecommunications infrastructure. Optical fibres are now the preferred transmission medium for long-distance and high data rate transmission in telecommunication networks because they offer large transmission bandwidth with hardly any latency. An overview of fibre optic communication systems is provided in this article, together with information on their architectures, important technologies and innovations, applications, types, testing, and troubleshooting.

An improved pilot pattern design-based channel estimation in wireless communication using distribution ant colony optimization

Multiple-Input Multiple-Output (MIMO) communication System-Orthogonal Frequency Division Multiplexing (OFDM) approach can produce reliable transmission of high data rates over broadband wireless medium. This approach makes use of the available spectrum and proves to be a potential candidate for meeting the high demand for data rate. Therefore, channel estimation is a crucial component in MIMOOFDM systems. There exist several issues in channel estimation like Carrier Frequency Offset (CFO) estimation, power allocation and orthogonal pilot optimization. However, computing an optimal pilot pattern is the complex problem. It severely reduces channel estimation accuracy. To overcome this issue, the proposed work focuses on the best possible design for the pilot pattern to get reliable channel estimation. In this proposed work, two pilot pattern design approaches like Carrier Frequency Offset (CFO) estimation, power allocation and orthogonal pilot optimization are combined to provide orthogonal pilot patterns. Creating orthogonal pilot patterns based on Generalized Shift Invariance Property (GSIP) for a MIMOOFDM has been proposed using two pilot pattern design approaches based on Improved Pilot Design with GSIP (IPDGSIP) and Tradeoff Pilot Design with GSIP (TPDGSIP). In PDGSIP, pilot patterns with high mutual coherence are initially obtained, then updated with the best pilot patterns. Here the optimal pilot patterns are generated by using Distribution-based Ant Colony Optimization (DACO) algorithm. Once a pilot pattern is established, TPDGSIP immediately generates new pilot patterns based on GSIP to utilize the pilot distance of the obtained pilot pattern fully. Results from MATLAB simulation demonstrate that the suggested technique performs better in channel estimation in terms of Bit Error Rate (BER), Normalized Mean Square Error (NMSE) and Symbol Error Rate (SER). The proposed PDGSIP-DACO system reduces the NMSE (6%), BER (8%) and SER (20%) when compared to the PDGSIP method.

Investigations on Filtered OFDM with Selective Mapping Method and Partial Transmit Sequence Technique for Future Generation Mobile Communication Systems

Future generation mobile communication system requires asynchronous transmission of data, reduced out-of-band power emission, low peak-to-average power ratio, low latency, high data transmission rate, better spectrum, energy, and power efficiency, etc. Investigations on suitable waveform candidates for future-generation mobile communication have been reported in this paper. Filtered Orthogonal Frequency Division Multiplexing (F- OFDM), F- OFDM with Selective Mapping Method (SLM), and F- OFDM with Partial Transmit Sequence (PTS) technique, have been investigated. Its performances have been evaluated in terms of peak-to-average power ratio (PAPR), bit error rate (BER), and out-of-band power emissions. F–OFDM is a suitable candidate for future-generation mobile communication systems that can be used with single-rate or multirate filters. It can also be used in combination with other PAPR reduction techniques. F-OFDM with PTS technique requires a smaller number of IFFT operations than F-OFDM with SLM. The result obtained from my present investigations reveals that F-OFDM with the PTS technique has 4.3 dB less PAPR than that of OFDM at the cost of marginal increase in the BER value.

A Deep Echo State Network-Based Novel Signal Processing Approach for Underwater Wireless Optical Communication System with PAM and OFDM Signals

Underwater wireless optical communication (UWOC) plays key role in the underwater wireless sensor networks (UWSNs), which have been widely employed for both scientific and commercial applications. UWOC offers high transmission data rates, high security, and low latency communication between nodes in UWSNs. However, significant absorption and scattering loss in underwater channels, due to ocean water conditions, can introduce highly non-linear distortion in the received signals, which can severely deteriorate communication quality. Consequently, addressing the challenge of processing UWOC signals with low optical signal-to-noise ratios (OSNRs) is critical for UWOC systems. Increasing the transmitting optical power and investigating more advanced signal processing technologies to recover transmitted symbols are two primary approaches to improve system tolerance in noisy UWOC signal channels. In this paper, we propose and demonstrate the application of deep echo state networks (DeepESNs) for channel equalization in high-speed UWOC systems to enhance system performance with both PAM and QPSK-OFDM modulations. Our experimental results demonstrate the effectiveness of DeepESNs in UWOC systems, achieving error-free underwater transmission over 40.5 m with data rates up to 167 Mbps. Moreover, we compare the performance of DeepESNs to conventional echo state networks and provide suggestions on the configuration of a DeepESN for UWOC signals.

Energy efficiency augmentation in UWA‐OFDM transducer by peak to average power ratio alleviation through hybrid companding approach

AbstractOrthogonal frequency division multiplexing (OFDM) is a compelling contender for next‐generation fixed and wireless standards to realize high data transmission rates in underwater acoustic (UWA) systems. A specific challenge before transmission over the transducers of the UWA system within an OFDM signal is the high peak to average power ratio (PAPR), which severely affects the energy efficiency of the UWA system. This work aims to enhance the energy efficiency of the UWA system by alleviating the stumbling block mentioned earlier within the OFDM. Moreover, we recommend and design a methodology that incorporates modified repeated frequency‐domain filtering and clipping (RFC) and companding techniques to restrain the PAPR obstacle. Additionally, the modified RFC utilizes various companding techniques (including linear and nonlinear techniques) to achieve the desired objectives without complexity augmentation of the system. We simulate and test our proposed approach against four major parameters: PAPR, bit error rate, energy efficiency, and system performance gain. Statistical results show that our technique offers .36 high‐power amplifier power efficiency (), which is comparatively better than OFDM with selective mapping, OFDM with partial transmit sequences, and OFDM with other hybrid approaches.

Priority Based Transmission Rate Control with Neural Network Controller in WMSNs

Wireless Multimedia Sensor Networks (WMSNs) are networks of wirelessly interconnected sensor nodes equipped with multimedia devices, such as cameras and microphones. Thus a WMSN will have the capability to transmit multimedia data, such as video and audio streams, still images, and scalar data from the environment. Most applications of WMSNs require the delivery of multimedia information with a certain level of Quality of Service (QoS). This is a challenging task because multimedia applications typically produce huge volumes of data requiring high transmission rates and extensive processing; the high data transmission rate of WMSNs usually leads to congestion, which in turn reduces the Quality of Service (QoS) of multimedia applications. To address this challenge, This paper proposes the Neural Control Exponential Weight of Priority Based Rate Control (NEWPBRC) algorithm for adjusting the node transmission rate and facilitate the problem of congestion occur in WMSNs. The proposed algorithm combines Neural Network Controller (NC) with the Exponential Weight of Priority Based Rate Control (EWPBRC) algorithms. The NC controller can calculate the appropriate weight parameter λ in the Exponential Weight (EW) algorithm for estimating the output transmission rate of the sink node, and then ,on the basis of the priority of each child node , an appropriate transmission rate is assigned . The proposed algorithm can support four different traffic classes namely, Real Time traffic class (RT class); High priority, Non Real-Time traffic class (NRT1 class); Medium priority, Non Real-Time traffic class (NRT2 class); and Low priority, Non Real-Time traffic class (NRT3 class). Simulation result shows that the proposed algorithm can effectively reduce congestion and enhance the transmission rate. Furthermore, the proposed algorithm can enhance Quality of Service (QoS) by achieve better throughput, and reduced the transmission delay and loss probability.

High‐Speed Data Communication for Oil and Natural Gas Drilling Based on Triboelectric Nanogenerator

AbstractTriboelectric nanogenerator‐based environmental energy harvesting technology is not only for the applications of the Internet of Things but also has a revolutionary impact on traditional industrial fields. Advanced oil and natural gas drilling technology, for example, horizontal drilling and hydraulic fracturing, has important environmental concerns about water and atmospheric pollution. High data transmission rates and visual and real‐time monitoring are considered potential solutions to avoid both economic and environmental problems. The current data transmission rate for oil and gas drilling is just 5–40 bits per second, despite commercial fifth generation (5G) and future sixth generation (6G) wireless communication technologies with data rates of 10–1000 gigabits per second. Herein, a self‐powered while‐drilling communications system based on a triboelectric nanogenerator is reported. The data transmission rate is three orders of magnitude higher than the traditional method. The free‐standing layered mode triboelectric nanogenerators (FS‐TENGs) can achieve fast information transfer using the harvested energy from the vibration of the pipe wall.

SCMA-Enabled Multi-Cell Edge Computing Networks: Design and Optimization

Multi-access edge computing (MEC) is regarded as a promising approach for providing resource-constrained mobile devices with computing resources through task offloading. Sparse code multiple access (SCMA) is a code-domain non-orthogonal multiple access (NOMA) scheme that can meet the demands of multi-cell MEC networks for high data transmission rates and massive connections. In this paper, we propose an optimization framework for SCMA-enabled multi-cell MEC networks. The joint resource allocation and computation offloading problem is formulated to minimize the system cost, which is defined as the weighted energy cost and latency. Due to the nonconvexity of the proposed optimization problem induced by the coupled optimization variables, we first propose an algorithm based on the block coordinate descent (BCD) method to iteratively optimize the transmit power and edge computing resources allocation by deriving closed-form solutions, and further develop an improved low-complexity simulated annealing (SA) algorithm to solve the computation offloading and multi-cell SCMA codebook allocation problem. To solve the problem of partial state observation and timely decision-making in long-term optimization environment, we put forward a multiagent deep deterministic policy gradient (MADDPG) algorithm with centralized training and distributed execution. Furthermore, we extend the framework to the partial offloading case and propose an algorithm based on alternating convex search for solving the task offloading ratio. Numerical results show that the proposed multi-cell SCMA-MEC scheme achieves lower energy consumption and system latency in comparison to the orthogonal frequency division multiple access (OFDMA) and power-domain (PD) NOMA techniques.

Ultrasonic Energy and Data Transfer through a Metal—Liquid Multi-Layer Channel Enhanced by Automatic Gain and Carrier Control

Ultrasonic communication and power transfer are attractive solutions when conventional electromagnetic-based or wired connections are unfeasible. Most ultrasonic communication applications concern a single-solid barrier. Nevertheless, some relevant scenarios can be composed of several fluid—solid media, through which communication and power transfer are intended. Due to its multi-layer nature, insertion loss and, consequently, the system efficiency considerably decrease. This paper presents an ultrasonic system capable of simultaneously power transferring and transmitting data through a set of two flat steel plates separated by a fluid layer using a pair of co-axially aligned piezoelectric transducers on opposite sides of the barrier. The system is based on frequency modulation and adopts a novel technique for automatic gain and automatic carrier control. The modems used herein were developed specifically for this application, rendering the system able to transfer data at a rate of 19,200 bps, using the frequency shift keying (FSK) modulation scheme and simultaneously transferring 66 mW of power through two flat steel plates (5 mm) separated by a fluid layer (100 mm), which completely supplied a pressure and temperature sensor. The proposed automatic gain control allowed a higher data transmission rate and the automatic carrier control reduced power consumption. The former reduced the transmission error from 12% to 5%, while the latter reduced the global power consumption from 2.6 W to 1.2 W. The proposed system is promising for monitoring applications such as oil wellbore structural health monitoring systems.

One-step precise machining of terahertz microstructures on chip-scale lithium niobate via laser dispersion engineering

Chip-scale lithium niobate (LN) yields a competitive candidate for terahertz (THz) on-chip communications, which could enable high-rate data transmission, non-invasive biosensing, and cloud-based technologies. However, it remains a key challenge to reach such goals to fabricate functional millimeter-scale crack-free THz microstructures on chip-scale LN, especially for industrial use. Here, we propose a one-step crack-free microstructure fabrication approach using dispersion-engineered femtosecond laser pulses without involving any postprocessing method. By laser dispersion engineering, the fabricated one-dimensional photonic crystal can improve the THz transmittance by about 5.8 times compared to the general case. This achievement is based on a thorough investigation into the influence of femtosecond laser temporal dispersion on the lithium niobite machining process. Our findings may further promote the development and industrial applications of LN-based photonics and optoelectronics, especially for chip-scale THz devices, as well as offer insights into the realization of precision machining of other forms of hard and brittle materials.

Design of Hybrid Beamforming System Based on Practical Circuit Parameter of 6-Bit Millimeter-Wave Phase Shifters

This paper addresses the design of a hybrid beamforming system considering the circuit parameter of six-bit millimeter-wave phase shifters based on the process design kit. The phase shifter design adopts 45 nm CMOS silicon on insulator (SOI) technology at 28-GHz. Various circuit topologies are utilized, and in particular, a design is presented based on switched LC components, connected in a cascode manner. The phase shifter configuration is connected in a cascading manner to get the 6-bit phase controls. Six different phase shifters are obtained, which are 180°, 90°, 45°, 22.5°, 11.25°, and 5.6°, with a minimum number of LC components. The circuit parameters of the designed phase shifters are then incorporated in a simulation model of hybrid beamforming for a multiuser MIMO system. The number of OFDM data symbols used in the simulation is ten for eight users, 16 QAM modulation schemes, −25 dB SNR, 120 simulation runs, and around 170 h runtime. Simulation results are obtained considering four and eight users, assuming accurate technology-based models of RFIC components of the phase shifter as well as ideal phase shifter parameters. The results indicate that the performance of the multiuser MIMO system is affected by the accuracy level of the phase shifter RF component models. The outcomes also reveal the performance tradeoff based on user data streams and the number of BS antennas. By optimizing the amount of parallel data streams per user, higher data transmission rates are achieved, while maintaining acceptable error vector magnitude (EVM) values. In addition, stochastic analysis is conducted to investigate the distribution of the RMS EVM. The outcomes show that the best fitting of RMS EVM distribution of the actual and ideal phase shifters agreed with the log-logistic and logistic distributions, respectively. The obtained (mean, variance) values of the actual phase shifters based on accurate library models are (46.997, 481.36), and for ideal components the values are (36.47, 10.44).

Sub-6 GHz V2X-assisted MmWave optimal scheduling for vehicular networks

Sub-6 GHz assisted millimeter wave (mmWave) technology is a promising solution to address the ever-increasing data exchange demand in Vehicle-to-Everything (V2X) communication. The omni-directional sub-6 GHz channels exchange vehicle and control information in the vehicular network, while the directional mmWave technology is used for high-rate data transmission. Consider the huge amounts of vehicular data, the transmission constraints imposed by mmWave, and the unique vehicular ad hoc network (VANET) data features, a sub-6 GHz assisted-mmWave scheduling algorithm is needed to facilitate V2X data transmission. Existing scheduling algorithms in the literature fall short of addressing realistic V2X data features. Therefore, in this paper, we propose a novel objective to maximize the network utility that succinctly captures realistic V2X data features, including varying data sizes, data importance and their freshness decay with transmission delay. We formulate the scheduling problem into a novel mixed-integer sum-of-ratios optimization problem. To solve the challenging NP-complete problem, we first derive an equivalent parametric mixed-integer linear programming problem with existence and uniqueness proofs. Next, we provide the necessary condition for the optimality of the equivalent problem. A novel Parameterization-based Iterative Algorithm (PIA) is then developed to learn the global optimal solution with convergence analysis. Comparative simulation studies with the brute-force algorithm, the widely used branch and bound (BB) method, the greedy algorithm, and our previously developed maximum weight matching based iterative algorithm (MWMIA) are conducted to verify the correctness and effectiveness of the proposed PIA scheduling algorithm.

Beam Divergence Loss Mitigation in Free Space Optical Communication Channel Using Field of View Technique

A rapid advancement in the electronics and telecommunications industries has been observed. As a result, Communication gadgets are becoming more powerful and are more widely adopted. The demand for high data rate transmission is increasing. This has led to spectrum scarcity in Radio Frequency (RF) systems. Consequently, it is necessary to explore other technical means to meet the increasing demand for higher data rates. Free Space Optical Communication (FSOC) is a promising technology that offers one of such means. However, the major technical challenge in the FSOC systems is that, their performance is limited by atmospheric impairments such as: absorption, scattering and turbulence caused by rain, cloud, snow, wind, dust, aerosol, and fog. This research is aimed to addressed beam divergence challenge due to fog and raindrop in a tropical climate using wider field of view technique (FoV). The result showed that, for the fog measurement using mini solar panel at the receiver, the system achieved higher SNR of 60 dB at corresponding BER of 10-4. While, with the photodiode, the system achieved an SNR of 38 dB at same BER. For the rain measurement the same procedure was adopted and the system achieved higher SNR of 90 dB and 58 dB at same BER utilizing both solar panel and photodiode respectively. The result showed that, the fog impairment attenuates optical signal more than of rain by 34 % averagely

A 40-Gbps fiber-FSO convergent transmission system employing OFCL-based WDM and external modulation technique

We have proposed and demonstrated a 40Gbps fiber-free space optics (FSO) convergent system based on external modulation and wavelength division multiplexing (WDM) technique. In this experiment, 4010×4 Gbps signal is successfully transmitted employing WDM scheme over 50 km single mode fiber plus 2.5 km FSO distance. Optical frequency comb lines (OFCL) are generated using a continuous wave laser diode, a radio frequency signal generator, a dual drive Mach Zehnder modulator, and an electrical attenuator. OFC lines, having a side mode suppression ratio (SMSR) value of ∼40 dB and flatness of ∼0.4 dB, are employed as broadband laser source in the presented convergent system. The performance of the fiber-FSO system is investigated theoretically for different weather conditions. Very low power penalty with low bit error rate (BER), clear eye diagrams, and standard Q-factor are achieved in the proposed system. The power penalty is restricted within 2.5 dB and 5.8 dB at a BER of 10−9 for 50 km SMF plus 2.5 km FSO distance in clear weather and 50-km SMF plus 0.4-km FSO distance in heavy fog condition respectively. Thus, the proposed WDM-convergent system is efficient enough for high data rate transmission along with low BER value of ∼10−9 and high Q-factor for different environmental scenarios.

An efficient artificial rabbits optimization‐based user association problems in ultradense network using deep learning model

SummaryThe ability of high splitting gain of dense small cells contributed to the rapid establishment of ultradense networks (UDNs). Its higher efficiency to deal with high traffic data demand made UDN a most‐promising technology for the future 5G environment. However, the UDN creates concern about user association, which causes more complexities in providing a high data transmission rate and low latency rate. To tackle these complexities, in this paper, the ambient intelligence exploration multi‐delay deep deterministic policy gradient‐based artificial rabbits optimization (AEMDPG‐ARO) algorithm is proposed for resolving data rate and the issues of latency in the small base station (SBS) and macro base station (MBS) of the wireless sensor network. The complexity in attaining lower latency and higher data rate is achieved through a novel technique AEMDPG‐ARO. The ambient intelligence exploration multi‐delay (AIEM) is combined with deep deterministic policy gradient (DDPG) for overcoming the local optimum and diversity issues of DDPG. The data sample for this study is obtained through the WINNER channel model. The proposed AEMDPG‐ARO algorithm's efficiency is compared to varied state of art methods. The performance evaluation is carried out with regard to network lifetime, end‐to‐end delay, packet delivery ratio, sum rate overall energy consumption, latency, and minimum rate and maximum rate of the network. The proposed AEMDPG‐ARO algorithm gives better performance with reduced time complexity and better metrics rate in the result analysis. The minimum latency achieved by the proposed AEMDPG‐ARO algorithm is about 0.1 s.

Recent Advances in Optical Injection Locking for Visible Light Communication Applications

The introduction of visible light communication (VLC) technology could increase the capacity of existing wireless communication systems towards 6G networks. In practice, VLC can make good use of lighting system infrastructures to transmit data using light fidelity (Li-Fi). The use of semiconductor light sources, including light-emitting diodes (LEDs) and laser diodes (LDs) are essential to VLC technology because these devices are energy-efficient and have long lifespans. To achieve high-speed VLC links, various technologies have been utilized, including injection locking. Optical injection locking (OIL) is an optical frequency and phase synchronization technique that has been implemented in semiconductor laser systems for performance enhancement. High-performance optoelectronic devices with narrow linewidth, wide tunable emission, large modulation bandwidth and high data transmission rates are desired for advanced VLC. Thus, the features of OIL could be promising for building high-performance VLC systems. In this paper, we present a comprehensive review of the implementation of the injection-locking technique in optical communication systems. The enhancement of characteristics through OIL is elucidated. The applications of OIL in VLC systems are discussed. The prospects of OIL for future VLC systems are evaluated.

Full-duplex underwater wireless blue light communication.

Owing to its relatively low absorption loss and high data transmission rate, wireless blue light communication is becoming an increasingly attractive technology for underwater applications. Here, we demonstrate an underwater optical wireless communication (UOWC) system that communicates using blue light-emitting diodes (LEDs) with a dominant wavelength of 455 nm. Under the on-off keying modulation scheme, the waterproof UOWC system achieves a bidirectional communication rate of 4 Mbps based on the transmission control protocol (TCP) and exhibits real-time full-duplex video communication with a transmission distance of 12 m in a swimming pool, offering great potential for practical use in real-world scenarios, such as carried around or attached to an autonomous vehicle.