Data Communication Applications Research Articles

Analysis and application research on key issues of channel coding

Channel coding plays a crucial role in enhancing the reliability and efficiency of communication systems, particularly when transmission channels are disrupted by noise and interference. This paper presents an in-depth review of various channel coding techniques, their applications, and future research directions. Key topics discussed include prevalent channel coding methods, such as repetition codes, convolutional codes, LDPC codes, turbo codes, and polar codes. The paper also delves into the selection of suitable channel coding parameters and their applications in digital TV, mobile and satellite communications, unmanned aerial vehicle data links, speech communication, and underwater acoustic channels. Moreover, the paper explores the performance analysis and comparison of different channel coding techniques, shedding light on their strengths and weaknesses. Lastly, the paper identifies emerging trends and challenges in channel coding research, providing valuable insights for researchers and practitioners in the field of communication systems. By examining these techniques and future directions, this comprehensive overview aims to contribute to the development of more robust and efficient channel coding schemes for a wide range of communication applications.

From Volumetric to Planar Multiplexing: Phase-Coded Metasurface Without Bragg Effect.

Metasurfaces consisting of planar subwavelength structures with minimal thickness are appealing to emerging technologies such as integrated optics and photonic chips for their small footprint and compatibility with sophisticated planar nanofabrication techniques. However, reduced dimensionality due to the two-dimensional nature of a metasurface poses challenges to the adaptation of a few useful methods that have found great success with conventional optics in three-dimensional space. For instance, Bragg diffraction is the foundation of the well-established technique of phase-coded multiplexing in volume holography. It relies on interference among the scattered waves from multiple layers across the thickness of a sample. In this work, despite losing the dimension in thickness, a metasurface is devised to experimentally demonstrate phase-coded multiplexing by replacing free-space light with a surface wave in its output. The in-plane interference along the propagation of the surface wave resembles the Bragg diffraction, thus enabling phase-coded multiplexing in the two-dimensional design. An example of code-based all optical routing is also achieved by using a multiplexed metasurface, which could find applications in photonic data processing and communications. This article is protected by copyright. All rights reserved.

Factors influencing the successful implementation of a novel digital health application to streamline multidisciplinary communication across multiple organisations for emergency care.

Delivering optimal patient health care requires interdisciplinary clinician communication. A single communication tool across multiple pre-hospital and hospital settings, and between hospital departments is a novel solution to current systems. Fit-for-purpose, secure smartphone applications allow clinical information to be shared quickly between health providers. Little is known as to what underpins their successful implementation in an emergency care context. To identify (a) whether implementing a single, digital health communication application across multiple health care organisations and hospital departments is feasible; (b) the barriers and facilitators to implementation; and (c) which factors are associated with clinicians' intentions to use the technology. We used a multimethod design, evaluating the implementation of a secure, digital communication application (Pulsara™). The technology was trialled in two Australian regional hospitals and 25 Ambulance Victoria branches (AV). Post-training, clinicians involved in treating patients with suspected stroke or cardiac events were administered surveys measuring perceived organisational readiness (Organisational Readiness for Implementing Change), clinicians' intentions (Unified Theory of Acceptance and Use of Technology) and internal motivations (Self-Determination Theory) to use Pulsara™, and the perceived benefits and barriers of use. Quantitative data were descriptively summarised with multivariable associations between factors and intentions to use Pulsara™ examined with linear regression. Qualitative data responses were subjected to directed content analysis (two coders). Participants were paramedics (n = 82, median 44 years) or hospital-based clinicians (n = 90, median 37 years), with organisations perceived to be similarly ready. Regression results (F(11, 136) = 21.28, p = <0.001, Adj R2 = 0.60) indicated Habit, Effort Expectancy, Perceived Organisational Readiness, Performance Expectancy and Organisation membership (AV) as predictors of intending to use Pulsara™. Themes relating to benefits (95% coder agreement) included improved communication, procedural efficiencies and faster patient care. Barriers (92% coder agreement) included network accessibility and remembering passwords. PulsaraTM was initiated 562 times. Implementing multiorganisational, digital health communication applications is feasible, and facilitated when organisations are change-ready for an easy-to-use, effective solution. Developing habitual use is key, supported through implementation strategies (e.g., hands-on training). Benefits should be emphasised (e.g., during education sessions), including streamlining communication and patient flow, and barriers addressed (e.g., identify champions and local technical support) at project commencement.

Efficient Optimization of High‐Quality Epitaxial Lithium Niobate Thin Films by Chemical Beam Vapor Deposition: Impact of Cationic Stoichiometry

AbstractLithium niobate is a material of special interest for its challenging functional properties, which can suit various applications. However, high quality 200‐mm LixNb1‐xO3 thin film grown on sapphire substrate have never been reported so far which limits these potential applications. This paper reports the efficient optimization of high quality LiNbO3 thin film deposition on sapphire (001) substrate through chemical beam vapor deposition in a combinatorial configuration. With this technique, flow ratio of Li/Nb can be tuned from ≈0.25 to ≈2.45 on a single wafer. Various complementary characterizations (by means of diffraction, microscopy and spectroscopy techniques) have been performed at different areas of the film (different cationic ratios) in order to investigate the impact of the cationic stoichiometry deviation on the film properties. Close to cationic stoichiometry (LiNbO3), the epitaxial films are of high quality (single phase in spite of two in‐plane domains, low mosaicity of 0.04°, low surface roughness, refractive index and band gap close to bulk values). Deviating from the stoichiometry conditions, secondary phases are detected (LiNb3O8 for Nb‐rich flow ratios, and Li3NbO4 with partial amorphization for Li‐rich flow ratios). LiNbO3 films are of high interest for various key applications in data communications among others.

A Low Jitter, Wideband Clock Generator for Multi-Protocol Data Communications Applications

This paper presents a charge-pump phase-locked loop (PLL) frequency-synthesizer-based low-jitter wideband clock generator for multi-protocol data communications applications. Automatic frequency calibration (AFC) using linear variable time window technology and modified multi-modulus dividers (MMD) based on sub-multi-modulus dividers (SMMD) are developed for faster locking, lower jitter, and implementation of multi-protocol data communications applications. The clock generator is fabricated in 0.18 μm CMOS technology. The measured division ratio of the multi-modulus divider ranges from 1.875 to 25, and the output frequency is 46.875~625 MHz. The lock time does not exceed 30 μs, while jitter is less than 500 fs.

An RGB Color Image Steganography Scheme by Binary Lower Triangular Matrix

Steganography is an area where researchers focus on how to develop novel hiding techniques that are aided by the mathematical or computational model. In order to conceal the secret bits in a cover image, the imperceptible property and embedding payload capacity must be maintained. In most of the developed methods, some selective least significant bits (LSBs) of each pixel of the cover image is modified to hide the data which may lead to substantial distortion in the stego-image especially when the payload size is large. Therefore, to attain the trade-off between payload capacity and image quality, the authors have devised a binary lower triangular matrix-based secret message embedding process in which data can be hidden in the color pixel. In this secret message embedding process, the secret data is embedded aided by the binary lower triangular matrix. The formulated mathematical model for the secret message embedding process has ensured a secure embedding technique with reduced aberration on the stego-image. The proposed steganography scheme is preserving significant visual quality while emphasizing the security aspect by adopting an indirect data-hiding mechanism in contrast to the conventional mechanism. Furthermore, for the betterment of the visual properties of the stego-image, we have generically extended the formulation and tested it to check the visual quality. The empirical results of the proposed steganography scheme depict outcomes satisfactorily for the RGB color images. Researchers can explore and apply this novel data-hiding scheme in different data communication applications.

Direct photoluminescence manipulation in Er-doped AgNbO3 lead-free antiferroelectrics via reversible electric-field-induced symmetry modulations

The electric field-modulated photoluminescent (E-PL) effect has received much attention because of its potential applications in optical data storage and communication. Based on the E-induced antiferroelectric-ferroelectric (AFE-FE) phase transition, a large and reversible modulation of the PL intensity was previously realized in lanthanum-doped Pb(Zr0.9Ti0.1)O3 (PLZT) ceramics. However, such systems contain abundant leads and are thus toxic to humans and the environment. In this work, Er-doped AgNbO3 (ANO) lead-free ceramics were prepared, and their E-PL effect was investigated. From the perspective of the crystallographic symmetry, the reversibly E-induced orthorhombic Pbcm to orthorhombic Pmc21 transition results in a negative PL intensity change of 25%, which is different from the positive 30% PL modulation in the PLZT system triggered by the AFE-FE orthorhombic-rhombohedral phase transition. This symmetry-dependent negative PL modulation in ANO ceramics enriches the understanding of the E-PL effect in AFEs and provides an environmentally friendly alternative for multifunctional optoelectronics.

Directions of application of artificial intelligence in digital marketing communications

The digital transformation of modern economic life has found its reflection in the field of marketing communications, having formed a virtually new form of communication between market entities-digital. A distinctive feature of this form is the personalization of the message, the high selectivity of the consumer’s choice, as well as the possibility of a permanent communication process in which the consumer has the opportunity to independently create content about the company and its product, as well as actively distribute it for their own purposes, sometimes different from the goals of the company. The use of digital marketing communications in the activities of companies provides a number of advantages, such as the infinity and global coverage of the market, the versatility of market impact effects, personalization of communications, etc., which cannot be realized without artificial intelligence technologies. The scope of artificial intelligence in modern companies is extensive. Today, many innovative solutions for the automation of production and other business processes of companies are unthinkable without artificial intelligence. Artificial intelligence is «busy» in routine marketing processes, for example, accompanying the process of purchasing and delivering goods to the consumer, etc. The subject of research in this article is the possibility of creating content, implementing the targeting process and other areas of application in digital marketing communications of artificial intelligence. The object of the study is modern developments in the field of digital marketing communications, which contribute to the formation of effective interactions with the consumer by «fixing» them in behavioral models.

Effect of three-dimensional target and reference data alignment method in an open digital dental communication application on the external surface trueness of CAD-CAM provisional crowns

Effect of three-dimensional target and reference data alignment method in an open digital dental communication application on the external surface trueness of CAD-CAM provisional crowns

Algorithmic Obfuscation for LDPC Decoders

In order to protect intellectual property against untrusted foundry, many logic-locking schemes have been developed. The main idea of logic locking is to insert a key-controlled block into a circuit to make the circuit function incorrectly without right keys. However, in the case that the algorithm implemented by the circuit is naturally fault-tolerant or self-correcting, existing logic-locking schemes do not affect the system performance much even if wrong keys are used. One example is low-density parity-check (LDPC) error-correcting decoder, which has broad applications in digital communications and storage. This paper proposes two algorithmic-level obfuscation methods for LDPC decoders. By modifying the decoding process and locking the stopping criterion, our new designs substantially degrade the decoder throughput and/or error-correcting performance when the wrong key is used. Besides, our designs are also resistant to the SAT, AppSAT and removal attacks. For an example LDPC decoder, our proposed methods reduce the throughput to less than 1/3 and/or increase the decoder error rate by at least two orders of magnitude with only 0.33% area overhead.

Terahertz Wave Propagation Characteristics in Graded Teflon Based Solid-Core Photonic Crystal Fibre

In the past few years, photonic crystal fibre (PCF) in the Terahertz spectrum is drawing significant attention because of its multifaceted applications in high-speed data communication, spectroscopy, sensing, etc. The proposed PCF structure is based on a Teflon solid core surrounded by porous cladding. Teflon has been used as a background material because of its high flexibility and the possibility of making longer PCFs, which is capable of guiding waves in the THz region. The porous cladding consists of circular air-holes positioned hexagonally whose diameters increase with each subsequent layer keeping the pitch constant thus providing a graded-index profile. The diameters of air holes in each hexagonal layer are 1 mm, 1.2 mm and 1.5 mm respectively, maintaining a constant pitch of 2mm and a perfectly matched layer (PML) thickness of 3mm. We have examined the transmission characteristics of the proposed profile in the frequency range of 0.8 THz to 2.5 THz. The modal solution of the profile is solved using the Finite Element Method based on COMSOL Multiphysics version 5.5. Using the graded-index profile, we have obtained a large effective modal area of around 5.6 mm2 at 1 THz and a low confinement loss of 2.25 × 10−4 dB/km at the same frequency. Due to this large effective modal area, we get higher damage threshold and weaker non-linear effects, making it suitable for high power applications.

High-speed uni-traveling-carrier photodiodes on silicon nitride

Integrated photonics is an emerging technology for many existing and future telecommunication and data communication applications. One platform of particular interest is silicon nitride (SiN), thanks to—among others—its very low-loss waveguides. However, it lacks active devices, such as lasers, amplifiers, and photodiodes. For this, hybrid or heterogeneous integration is needed. Here, we bring high-speed uni-traveling-carrier photodiodes to a low-loss SiN-platform by means of micro-transfer-printing. This versatile technology for heterogeneous integration not only allows very dense and material-efficient III–V integration but also eases the fabrication, yielding high-performance detectors. The waveguide-coupled photodiodes feature a responsivity of 0.3 A/W at 1550 nm, a dark current of 10 nA, and a bandwidth of 155 GHz at a low bias. At zero bias, a record bandwidth of 135 GHz is achieved. We further demonstrate that this integrated detector can be used for direct photomixing at terahertz frequencies. A back-to-back communication link with a carrier frequency of around 300 GHz is set up, and data rates up to 160 Gbit/s with a low error vector magnitude are shown, showcasing a near-identical performance at zero bias.

Enhancement of the CAST Block Algorithm Based on Novel S-Box for Image Encryption.

due to the rapid growth of data communication and multimedia system applications, security becomes a critical issue in the communication and storage of images. This study aims to improve encryption and decryption for various types of images by decreasing time consumption and strengthening security. An algorithm is proposed for encrypting images based on the Carlisle Adams and Stafford Tavares CAST block cipher algorithm with 3D and 2D logistic maps. A chaotic function that increases the randomness in the encrypted data and images, thereby breaking the relation sequence through the encryption procedure, is introduced. The time is decreased by using three secure and private S-Boxes rather than using six S-Boxes, as in the traditional method. Moreover, the CAST encryption algorithm was modified to be used on the private keys and substitution stage (S-Boxes), with the keys and S-Boxes of the encryption algorithm being generated according to the 2D and 3D chaotic map functions. The proposed system passed all evaluation criteria, including (MSE, PSNR, EQ, MD, SC, NC, AD, SNR, SIM, MAE, Time, CC, Entropy, and histograms). Moreover, the results also illustrate that the created S-Boxes passed all evaluation criteria; compared with the results of the traditional method that was used in creating S-Box, the proposed method achieved better results than other methods used in the other works. The proposed solution improves the entropy which is between (7.991-7.999), reduces the processing time which is between (0.5-11 s/Images), and improves NCPR, which is between (0.991-1). The proposed solution focuses on reducing the total processing time for encryption and decryption and improving transmission security. Finally, this solution provides a fast security system for surgical telepresence with secure real-time communication. The complexity of this work needs to know the S-Box creation method used, the chaotic method, the values of the chaotic parameters, and which of these methods was used in the encryption process.

A Fast and Sensitive Schottky Photodiode With Surface Plasmon Enhanced Photocurrent and Extremely Low Dark Current for High-Frequency Applications in Near-Infrared

High-speed, high-photoresponse, low-dark current photodetectors with monolithic integration compatibility on a single silicon chip have a vital role in fast optical communication. Schottky barrier junctions provide ultrahigh frequency bandwidth, which makes them suitable for a high-speed data rate optical transition system. In this article, we proposed the novel design of a fast silicon Schottky photodiode (SPD) with reduced dark current and enhanced photocurrent to produce an acceptable photo-to-dark current ratio. A differential Schottky diode is used in series with the designed SPD to reduce the final dark current delivered to the next signal conditioner electronics. A periodic plasmonic array is applied on the metallic Schottky contact layer to localize the illuminated light in the depletion region of Schottky contact and increase light absorption, which results in enhanced photocurrent. The simulation of the device shows a photo-to-dark current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${2.7} \times {10}^{{4}}$ </tex-math></inline-formula> at room temperature and 1-V biasing voltage, which is much greater than the reported data. Moreover, the design results in a complementary metal–oxide–semiconductor (CMOS)-compatible photodiode (PD) with 28-time reduced dark current and 3.3-time photocurrent enhancement with an ultrafast impulse response of 3 ps and a response time of about 18 ps that are attractive for ultra-fast data communication applications in 850-nm region.

Impact of Diffusion Profile on the Modulation Response of Single-Mode Disorder-Defined VCSELs

The impact of diffusion profile shaping through the use of tensilely and compressively strained diffusion masks on the modulation response of single-mode vertical-cavity surface-emitting lasers (VCSELs) using disorder-defined apertures is investigated. VCSELs designed for high-power single-fundamental-mode emission through the use apertures defined via impurity-induced disordering (IID) in conjunction with a standard oxide-confinement process are characterized to extract high-frequency optical cavity parameters across oxide aperture and diffusion mask strain variations. The 3-dB small-signal bandwidth is maintained for a 7.68 mW single-mode 850 nm VCSEL with an oxide aperture of 13 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> using a tensilely strained diffusion mask relative to a non-disordered multimode device of the same oxide aperture. A large K-factor reduction is also observed, from 0.248 ns to 0.045 ns, indicating that damping and photon lifetimes within the cavity of VCSELs employing disorder-defined apertures are substantially reduced. Performance implications to data communication applications are discussed.

Monolithic Photonic Integrated Circuit Based on Silicon Nitride and Lithium Niobate on Insulator Hybrid Platform

Monolithic Photonic Integrated Circuits In article number 2200121, Yonghui Tian, Guanghui Ren and co-workers experimentally demonstrate a monolithic photonic integrated circuit (PIC) for high-speed data communication application on the thin-film lithium niobate on insulator (LNOI) platform. The proposed PIC shows high data modulation rate of 70 Gbps for single channel and the total data throughput reaches up to 280 Gbps, which opens up new avenues for achieving large-scale monolithic integration on the LNOI platform in future.

Factors influencing schizotypal personality trait-dependent immersion and digital media usage: Adaptation and maladaptation

Immersion in the digital environment has been widely researched; however, the effects of adaptive and maladaptive schizotypal personality traits on immersion have received relatively little attention up till now. This study investigates the factors of personal immersion while using entertainment and digital communication applications and other variables such as problematic internet usage, and Facebook addiction. The Immersive Tendency Questionnaire was applied to measure participants' tendency to experience artistic and life-like scenarios in traditional settings (reading a book and watching a movie) and digital environments (playing computer games and using the internet). The study was conducted with 717 college students and graduate persons including, 186 males (mean age: 28.49) and 531 females (mean age: 28.4). The results show that lowered focusing abilities are directly linked with deficiencies in self-coherence, and maladaptive behavior that manifests in problematic internet and Facebook usage. Furthermore, the attention/focusing ability during immersion is accompanied by coherent self-structure and psychological well-being. Therefore, for people who have adequate focusing skills and coherent self-structure, the usage of social media and computer gaming can be considered adequate digital tools for developing their cognitive and social skills.

Low Power, Compact Integrated Photonic Sampler Based on a Silicon Ring Modulator

Sampling is the primary functional step of an analogue to digital conversion, required for sensing, measurement, signal processing, metrology, and various data communication applications. Here we present, for the first time, to the best of our knowledge, the optical sampling of different microwave signals with sinc-pulse sequences with a very compact integrated silicon photonics ring modulator. By a simple time interleaving with three branches, the employed ring modulator enables ultra-compact photonic integrated analog to digital converters with a sampling rate of three times the RF bandwidth of itself and of the used photodetector and electronic devices. Therefore, its analogue bandwidth is 50% higher than the RF bandwidth of the incorporated electronics and photonics. Thus, the method might enable high-bandwidth analogue to digital converters with ultra-compact footprint and lower power consumption for future communication systems, sensors, and measurement devices.

QUANTITATIVE ANALYSIS OF THE ACADEMIC DEVELOPMENT EVOLUTION KNOWLEDGE GRAPH OF MUSEUM DISPLAY DESIGN ORIENTED TO AUDIENCE'S PSYCHOLOGICAL EXPERIENCE

QUANTITATIVE ANALYSIS OF THE ACADEMIC DEVELOPMENT EVOLUTION KNOWLEDGE GRAPH OF MUSEUM DISPLAY DESIGN ORIENTED TO AUDIENCE'S PSYCHOLOGICAL EXPERIENCE

Monolithic Photonic Integrated Circuit Based on Silicon Nitride and Lithium Niobate on Insulator Hybrid Platform

Lithium niobate on insulator (LNOI) has been demonstrated as a promising platform for photonic integrated circuits (PICs), thanks to its excellent properties such as strong electro‐optic effect, low material loss, and wide transparency window. Herein, a monolithic PIC for high‐speed data communication application on a lithium‐niobate‐etchless platform with silicon nitride (Si3N4) as a loading material is proposed and demonstrated. The fabricated PIC consists of four racetrack resonator modulators and a pair of four‐channel mode (de)multiplexers, which shows high data modulation rate of 70 Gbps for single channel and the total data throughput reaches up to 280 Gbps. To the best of knowledge, this is the first demonstration of PIC consisting of high‐speed electro‐optical modulators and (de)multiplexers with such high data capacity on Si3N4‐LNOI hybrid platform, which opens up new avenues for achieving large‐scale monolithic integration on LNOI platform in future.