High-quality Transmission Research Articles

Uniform all-solid chalcogenide Bragg fiber with wide photonic bandgap via extrusion

As the Bragg fiber can guide light by tuning the structure parameters of claddings, it is possible to improve the ability of laser-power transmission in the mid-infrared with effective omnidirectional reflection, but it usually suffers from the disturbance of the air core and functional bandgap. Here, the structural parameters of three pairs of periodic cladding layers were optimized by the plane wave expansion method, and the thickness of each layer is 3.36 µm, consisting of Ge20As20Se15Te45 and As2S3 glasses with a refractive index contrast of Δn = 0.8. The simulation results showed that a wide bandgap of 1.2 µm can be realized in the fiber after structural optimization. Then, a fiber preform was prepared via an improved stacked extrusion based on seven thickness-compensated glass plates. The experimental results show that the all-solid Bragg fiber has three pairs of uniform periodic cladding and an extra-large core. The superior optical fiber structure can also be well maintained in the whole fiber length, and the average ratio of each cladding thickness to the fiber diameter is kept nearly at 3:100. Finally, the fiber loss at 1.55 µm and 2.94 µm is 12 dB/m and 18 dB/m, respectively. In all, such a well-structured all-solid chalcogenide Bragg fiber would pave a new way to develop high-quality laser transmission or optical sensors in mid-infrared.

Long-distance modal power equalization with hybrid pumped FM-EDFA

In a few-mode fiber-based mode division multiplexing system, the different modes as distinct channels suffer from discrepant mode-dependent loss, leading to an intensive channel power imbalance and large bit error. The few-mode erbium-doped fiber amplifier (FM-EDFA) enables mode power regulation to ensure high-quality long-distance transmission. In this paper, we propose an FM-EDFA for long-haul equalization with a core and cladding hybrid pump structure. The particle swarm optimization is applied to determine the multilayered erbium ions doping profile. Based on the profile, targeted compensation for high-order modes with high loss is realized to mitigate the power difference in long-distance transmission. Compared with the single pump selection, the differential modal gain reduces from 6.553 dB to 1.239 dB in the hybrid pump with a 1000 km multistage amplification and transmission. We provide new ideas for loss compensation and power balance in long-distance transmission. This method has the ability of dynamic power adjustment while keeping the design simple.

An exploratory simulation study and prediction model on human brain behavior and activity using an integration of deep neural network and biosensor Rabi antenna

The plasmonic antenna probe is constructed using a silver rod embedded in a modified Mach-Zehnder interferometer (MZI) ad-drop filter. Rabi antennas are formed when space-time control reaches two levels of system oscillation and can be used as human brain sensor probes. Photonic neural networks are designed using brain-Rabi antenna communication, and transmissions are connected via neurons. Communication signals are carried by electron spin (up and down) and adjustable Rabi frequency. Hidden variables and deep brain signals can be obtained by external detection. A Rabi antenna has been developed by simulation using computer simulation technology (CST) software. Additionally, a communication device has been developed that uses the Optiwave program with Finite-Difference Time-Domain (OptiFDTD). The output signal is plotted using the MATLAB program with the parameters of the OptiFDTD simulation results. The proposed antenna oscillates in the frequency range of 192 THz to 202 THz with a maximum gain of 22.4 dBi. The sensitivity of the sensor is calculated along with the result of electron spin and applied to form a human brain connection. Moreover, intelligent machine learning algorithms are proposed to identify high-quality transmissions and predict the behavior of transmissions in the near future. During the process, a root mean square error (RMSE) of 2.3332(±0.2338) was obtained. Finally, it can be said that our proposed model can efficiently predict human mind, thoughts, behavior as well as action/reaction, which can be greatly helpful in the diagnosis of various neuro-degenerative/psychological diseases (such as Alzheimer's, dementia, etc.) and for security purposes.

High-Quality Secure Wireless Transmission Scheme Using Polar Codes and Radio-Wave Encrypted Modulation

High-Quality Secure Wireless Transmission Scheme Using Polar Codes and Radio-Wave Encrypted Modulation

Semantic segmentation-based semantic communication system for image transmission

With the rapid development of artificial intelligence and the widespread use of the Internet of Things, semantic communication, as an emerging communication paradigm, has been attracting great interest. Taking image transmission as an example, from the semantic communication's view, not all pixels in the images are equally important for certain receivers. The existing semantic communication systems directly perform semantic encoding and decoding on the whole image, in which the region of interest cannot be identified. In this paper, we propose a novel semantic communication system for image transmission that can distinguish between Regions Of Interest (ROI) and Regions Of Non-Interest (RONI) based on semantic segmentation, where a semantic segmentation algorithm is used to classify each pixel of the image and distinguish ROI and RONI. The system also enables high-quality transmission of ROI with lower communication overheads by transmissions through different semantic communication networks with different bandwidth requirements. An improved metric θPSNR is proposed to evaluate the transmission accuracy of the novel semantic transmission network. Experimental results show that our proposed system achieves a significant performance improvement compared with existing approaches, namely, existing semantic communication approaches and the conventional approach without semantics.

Genetic optimization of 5G-NR LDPC codes for lowering the error floor of BICM systems

With the wide range of commercial uses of fifth generation (5G), new radio (NR) communication networks, the wireless transmission becomes more efficient, reliable and faster. At the same time, high-quality signal transmission for 5G networks and beyond has also encountered new opportunities and challenges. Channel coding is a key technology to ensure reliable information transmission and service quality. However, the 5G-NR LDPC coded bit-interleaved coded modulation (BICM) sometimes suffers from relatively high error floors, so it can not always guarantee the high-quality and low-delay wireless transmission. In this paper, we propose a further redesign of the 5G-NR LDPC coded BICM based on genetic algorithm (GenAlg). By adjusting the number of the non-zero elements, the corresponding positions and shifting values in base matrix, we optimize the 5G-NR LDPC codes with GenAlg according to the error performances of coded BICM schemes. Simulation results show that the optimized 5G-NR LDPC codes which still support length and rate compatible coding have lower error floors with a little performance loss int the waterfall region compared to the standard 5G-NR LDPC codes with different modulation orders.

Fluorine-free and ultra-thin films prepared by RF-PECVD method for the anticorrosive applications

The high-reliability requirement of 5 G electronic products poses a higher challenge to its protective films, the high transmission quality of high-frequency signals, excellent heat dissipation and anticorrosive capability, which promotes the ultra-thin protective films with good adhesion and anticorrosion. In this work, a nanometer-scale p-HMDSO film was obtained on the Cu alloy with hexamethyldisiloxane (HMDSO) as the precursor by the low-temperature RF-PECVD method. Compared with Parylene and p-PFDA (1H, 1H, 2H, 2H-Perfluorodecyl acrylate) films, the p-HMDSO film possesses better hydrophobicity, mechanical stability and anticorrosive property. The corrosion inhibition efficiency of the p-HMDSO film reaches 99.95%. Meanwhile, it provides 3 orders of magnitude increment of charge-transfer impedance, a salt spray corrosion resistance for 24 h, and the protection of 10 days in the 3.5 wt% NaCl solution, which develops a better application prospect in the protection of integrated electronics.

A feasibility study of multi-mode intelligent fusion medical data transmission technology of industrial Internet of Things combined with medical Internet of Things

As a branch of the Internet of Things (IoT) dedicated to medical care industry, the Internet of Medical Things (IoMT) includes networking devices and applications for medical and health information technology applications. The IoMT still has many shortcomings, such as unstable information transmission, low accuracy of fault diagnosis and classification, and lack of anomaly detection capability. Therefore, this paper first comprehensively describes some relatively new research and popular background technologies of the Industrial Internet of Things (IIoT) and IoMT, and then, according to the functional requirements analysis of the intelligent data transmission system based on IoMT, we discuss in detail the problems of fault diagnosis and resource allocation faced in the IoMT model. An intelligent data transmission model is proposed to apply the wireless communication transmission technology of the industrial Internet of Things to the Internet of Medical Things scene. This model has the ability of high-quality data transmission, high accuracy accident diagnosis classification and real-time anomaly monitoring, which makes up for the shortcomings of traditional IoMT models. In particular, for the accident diagnosis and classification functions in this model, we innovatively adopt the multi-mode data fusion CNN algorithm. The experimental results show that the classification accuracy of the accident diagnosis results is effectively improved. Compared with other algorithms, this model with multi-mode data fusion CNN algorithm improves the data transmission rate, reduces the average data delay, and improves the real-time anomaly monitoring capability of IoMT without increasing the signal leakage rate, thus further improving the overall stability of IoMT.

Organization of High-Quality and Safe Data Transmission in Communication Systems and Radio Access of Marine Robotic Complexes

To date, the issue of developing marine robotic systems for solving various professional tasks of military and civilian purposes is being updated. However, the key aspect of using these systems is the provision of communication, which includes many features and difficulties. The main purpose of the current article is to analyze the trends and prospects for the development of communication systems at marine robotic complexes. The author attempts to make a comprehensive analysis and systematization of knowledge concerning the technical aspects of the organization of communication on marine robotic complexes. The scientific significance of the work lies in the possibility of using the obtained materials as a theoretical basis for further scientific research aimed at developing more efficient communication systems. As a result of the work, the main aspects and solutions for the formation of high-quality and safe data transmission in communication systems and radio access of marine robotic complexes are considered. The scientific novelty of the work lies in the proposal of a solution for the organization of technical data protection in communication systems of marine robotic complexes. The author examines the schematic diagrams of the organization of radio communications and possible ways of integrating information security systems. The scientific value of the work consists in the possibility of using the presented materials for the subsequent implementation of the presented ideas in practice. The main result of the work is the formation of a scientific and theoretical base in the aspects of the formation of data protection in cellular mobile networks on the example of marine robotic complexes. As a solution, it is proposed to use the channel reservation method based on the use of the AnCom RM/E modem. The paper presents the theoretical and algorithmic aspects of the integration of this solution in mobile cellular networks.

THE INFLUENCE OF MARTIAL LAW ON THE INTERNATIONAL INNOVATION ACTIVITY OF ENERGY ENTERPRISES OF UKRAINE

The article is devoted to topical issues of innovative activity of energy enterprises. Since Ukraine has been integrated into the energy space of the European Union since March 16, 2022, a detailed study of changes in the innovative activity of energy enterprises in the impact of the martial law becomes especially relevant. The study reveals theoretical approaches to the interpretation of innovative activity; the essence of the main types of innovations critically necessary for the effective functioning of energy enterprises is characterized; the content of innovative management of enterprises is disclosed; trends and volumes of investments in the energy sector, including in innovative activities, were analyzed; the main aspects of the international innovative activity of energy enterprises are revealed; as well as the changes that occurred in the energy industry under martial law. It is worth noting that the energy sector suffered significant destruction in connection with the beginning of Russia's war against Ukraine. In the light of these events, Ukrainian energy companies faced a number of important problems: rapid restoration of damaged power grids and high-quality transmission of electrical energy to end users. In this way, the legal regime of martial law significantly affected the activities of enterprises, because the problems faced by the energy industry of Ukraine required the newest and most innovative solutions. It is worth noting that in 2022, energy enterprises of Ukraine actively attracted investments for the renewal and reconstruction of fixed assets, and also developed international cooperation with various European structures in the field of energy. In general, the impact of the legal regime of martial law is assessed as negative, because a number of critical problems have arisen, but on the other hand, it contributes to the introduction of innovations and the expansion of international cooperation.

Optimal Relay Selection Strategy for Energy-Efficient Cooperative Multi-Hop Image Transmission in Wireless Multimedia Sensor Network

For high-quality picture transmission through smart devices in Mobile Multimedia Sensor Networks (MWMSN), high transmission rates, throughput, and a low Bit Error Rate are necessary. At the same time, energy efficiency is always a big problem for battery-powered smart devices like smartphones and tablets. MWMSN makes extensive use of cooperative communication to realize the benefits of the Multiple-Input-Multiple-Output technology. Energy consumption and routing are major challenges for Cooperative Mobile Multimedia Sensor Networks since each node in the network have mobility. The dynamic nature of MWSNs increases with mobility and the consequence is reflected in the control traffic overhead. To address these challenges, a Cluster-based Cooperative Multi-Hop Optimal Relay Selection (CCORS) strategy was proposed by using velocity, distance, and link quality parameters. The proposed technique determines the link quality for every pair of nodes based on values of signal strength and distance parameters. The relay nodes are chosen based on the highest possible Quality of Service (QoS) value, which is calculated to assure route stability, reliability, and durability. Further, we obtained an optimal number of cooperative nodes in every hop with the objective to minimize end-to-end energy consumption. Finally, simulation results demonstrate the effectiveness of the proposed algorithm compared to other state of art algorithms.

Image-based axon model highlights heterogeneity in initiation of damage

Head injury simulations predict the occurrence of traumatic brain injury by placing a threshold on the calculated strains for axon tracts within the brain. However, a current roadblock to accurate injury prediction is the selection of an appropriate axon damage threshold. While several computational studies have used models of the axon cytoskeleton to investigate damage initiation, these models all employ an idealized, homogeneous axonal geometry. This homogeneous geometry with regularly spaced microtubules, evenly distributed throughout the model, overestimates axon strength because, in reality, the axon cytoskeleton is heterogeneous. In the heterogeneous cytoskeleton, the weakest cross section determines the initiation of failure, but these weak spots are not present in a homogeneous model. Addressing one source of heterogeneity in the axon cytoskeleton, we present a new semiautomated image analysis pipeline for using serial-section transmission electron micrographs to reconstruct the microtubule geometry of an axon. The image analysis procedure locates microtubules within the images, traces them throughout the image stack, and reconstructs the microtubule structure as a finite element mesh. We demonstrate the image analysis approach using a C. elegans touch receptor neuron due to the availability of high-quality serial-section transmission electron micrograph data sets. The results of the analysis highlight the heterogeneity of the microtubule structure in the spatial variation of both microtubule number and length. Simulations comparing this image-based geometry with homogeneous geometries show that structural heterogeneity in the image-based model creates significant spatial variation in deformation. The homogeneous geometries, on the other hand, deform more uniformly. Since no single homogeneous model can replicate the mechanical behavior of the image-based model, our results argue that heterogeneity in axon microtubule geometry should be considered in determining accurate axon failure thresholds.

The Preliminary Investigation of Communication Characteristics Using Evaporation Duct across the Taiwan Strait

Affected by the Taiwan Strait Warm Current, the evaporation intensity around the Taiwan Strait is significantly higher than in other southern and eastern coastal areas of China. To explore a new and effective method for maritime communication across the Taiwan Strait, we present a preliminary investigation of wireless microwave transmission in an evaporation duct. From 9 to 14 o’clock, the percentage of the evaporation duct height exceeding 10 m reached over 90% in 2020. With the favorable channel in this period, a “straight-through propagation channel” emerged, with a serviceable ratio of 99.00% at a 300 km transmission range. The high-quality transmission with BPSK modulation occurred 98.90% of the year from 12 to 13 o’clock, with 89.89% of the signal-to-noise ratio (SNR) exceeding 90 dB. Based on the effective use of the evaporation duct, the proposed method can provide favorable support for maritime applications across the Taiwan Strait.

Design and analysis of a channel drop filter and demultiplexer based on a photonic crystal super ellipse-shaped ring resonator

In advanced optical communication systems, a photonic crystal (PC) based channel drop filter (CDF) and dense wavelength division multiplexer (DWDM) demultiplexer are essential components in the design of a complete DWDM system, which offers a high transmission data rate. In the present work, a novel PC, CDF filter and demultiplexer based on a ring resonator with a super ellipse shape is designed and analyzed. To design a high-performance device, the performance parameters of the proposed components, such as transmission efficiency, spectral line width, channel spacing, Q-factor and crosstalk, are investigated. The proposed CDF is designed to drop a resonant wavelength with a high quality factor of 3955, and the ring resonator design is extended to the demultiplexer. The demultiplexer is designed to drop the four resonant wavelengths of 1579.8 nm, 1582 nm, 1583.6 nm and 1574.9 nm, respectively. The observed high quality factor (3955), bandwidth (0.4 nm) and transmission efficiency (90%) of the proposed demultiplexer will support high-performance DWDM systems

Multi-Associated Parameters Aggregation-Based Routing and Resources Allocation in Multi-Core Elastic Optical Networks

Space division multiplexing (SDM), as a potential means of enhancing the capacity of optical transmission systems, has attracted widespread attention. However, the adoption of SDM technology has also additionally increased resource dimensions, introduced complex crosstalk, and made it difficult to integrate multi-dimensional fragments. These factors force the transmission constraints to be more complicated. Especially, some factors have a mutual restraint relationship, and excessive consideration of certain factors will cause the deterioration of other ones. Therefore, how to comprehensively consider the associated factors to achieve trade-offs and improve network performance is a problem worthy of study. This paper exploits the advantages of self-organizing feature mapping (SOFM) model to process multi-dimensional data with relevant features. Firstly, multiple constraints will be input into SOFM as mode vectors from the core level. Then, by judging the similarity between the competition layer neuron and the pattern vector, the position of the winning neuron is located, which determines the transmission level of each core. Finally, a routing, core, and spectrum allocation scheme is proposed by preferentially locating the core with higher transmission quality. Along the selected core, the available slots will be classified twice respectively by the number of adjacent cores and crosstalk direction to quickly find the spectrum blocks with relatively small crosstalk. Results indicate the scheme can reduce blocking probability and the resource fragmentation. Further, it can increase the resource utilization within tested network load.

Biotelemetric Experiment in the Radiotelegraphic Bureau of the Maritime Department (1912). A New Episode from the History of the Development of Russian Science

The minutes of the meeting of the Society of Marine Physicians in St. Petersburg dated October 30, 1912, which describes an experiment on the transmission of biomedical data via telecommunications, are published. The head of the workshop of the Radiotelegraph depot A.K. Nikiforov developed a device for remote transmission of the sound picture of the heart, using his own designs of amplifiers and microphones. The experiment was conducted with the participation of doctor A.G. Makarov. The results indicated insufficient broadcast quality and required technical refinement of the device. Comparison with the effectiveness of similar experiments in other countries shows that in the studied period of time, the general level of technical development did not fundamentally allow solving the problem of high-quality transmission of biomedical data over a distance. The fact of the experiment revealed by the author, which occurred against the background of institutionalization of scientific research in the Radiotelegraph Depot, is extremely important from the point of view of systematization of the history of domestic scientific research in the field of biotelemetry. When studying archival materials, the processes of institutionalization of scientific work in the Radiotelegraph Depot were revealed, including regulatory support, creation of organizational structures, distribution of goals and objectives, financing, and resource provision. The formal structuring of scientific activity formed the context for scaling research into other fields of knowledge, which created the basis for A.K. Nikiforov's scientific and design activities in the field of biomedicine. The scientist-engineer made a contribution to the accumulation of knowledge and the future formation of dynamic biotelemetry as a separate scientific direction.

Complex pattern transmission through multimode fiber under diverse light sources

Multimode fibers with high information capacity and ultra-thin diameter offer new possibilities for non-invasive endoscopy and remote high-speed secure communication. However, due to their sensitivity, special demands are thus raised on the light sources, which act as both lighting and information carrier. We build a single-arm multimode fiber image transmission system. The impact of five different sources on transmission quality is systematically compared and analyzed. High-quality transmission of complex grayscale patterns is achieved with inverse transmission matrix. The measured structural similarity exceeds 0.65. Experimental results indicate that random fiber laser with high time–domain stability is suitable for single-fiber imaging. This work is conducive to further study of fiber imaging and provides guidance for novel fiber communication and flexible endoscopy.

Cell-Free Massive MIMO-OFDM for High-Speed Train Communications

Cell-free (CF) massive multiple-input multiple-output (MIMO) systems show great potentials in low-mobility scenarios, due to cell boundary disappearance and strong macro diversity. However, the great Doppler frequency offset (DFO) leads to serious inter-carrier interference in orthogonal frequency division multiplexing (OFDM) technology, which makes it difficult to provide high-quality transmissions for both high-speed train (HST) operation control systems and passengers. In this paper, we focus on the performance of CF massive MIMO-OFDM systems with both fully centralized and local minimum mean square error (MMSE) combining in HST communications. Considering the local maximum ratio (MR) combining, the large-scale fading decoding (LSFD) cooperation and the practical effect of DFO on system performance, exact closed-form expressions for uplink spectral efficiency (SE) expressions are derived. We observe that cooperative MMSE combining achieves better SE performance than uncooperative MR combining. In addition, HST communications with small cell and cellular massive MIMO-OFDM systems are compared in terms of SE. Numerical results reveal that the CF massive MIMO-OFDM system achieves a larger and more uniform SE than the other systems. Finally, the train antenna centric (TA-centric) CF massive MIMO-OFDM system is designed for practical implementation in HST communications, and three power control schemes are adopted to optimize the propagation of TAs for reducing the impact of the DFO.

Time-Synchronized Control of Chaotic Systems in Secure Communication

High-quality data transmission synchronization process is frequently expected in light of secure communication mechanisms (SCMs), especially for space laser communication among the satellite constellation. To improve security and reliability during the data transmission processes prominently, control problems of chaotic synchronization synchronously <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">at the same time</i> are explored. In this paper, several novel error synchronization control protocols are proposed to solve these problems. First, by introducing a norm-normalized sign function (NNSF), unique (fixed-) time-synchronized stability is manifested, such that all non-zero state elements reach the origin synchronously at the same time. And upper bounds of synchronous resident time calculated by offered protocols are irrelevant/relevant to initial states of the error systems. Second, integrated with the (fixed-) time-synchronized stability theories, the (fixed-) time-synchronized sliding mode controllers with special convergent performance are established for two representative types of chaotic systems. Third, the ratio-persistent performance plays a dominating role for simultaneous convergence of the errors. Further, the innovation of the algorithms is reflected in that the decrypted signal is completely consistent with the transmitted message signal within synchronized settling time. Finally, in the simulation, not only theoretical verifications, but also practical verifications of image encryption and decryption processes verify the effectiveness of the SCMs.

Transmit Antenna Selection in NOMA-Based Integrated Satellite-HAP-Terrestrial Networks With Imperfect CSI and SIC

Integrated satellite-high altitude platform-terrestrial networks (IS-HAP-TNs) and non-orthogonal multiple access (NOMA) scheme are considered to be the key components of next generation networks, which can satisfy the demands of high-quality transmission, wide coverage and large-scale connections. In this letter, we analyze the performance of NOMA-based IS-HAP-TNs with transmit antenna selection (TAS) in the presence of imperfect channel state information (CSI) and successive interference cancellation (SIC). Specifically, considering the requirements of different users for spectrum efficiency, two TAS schemes are proposed to balance the system performance and complexity. In addition, the closed-form expressions for the outage probability of the IS-HAP-TNs in the presence of imperfect CSI and SIC are derived to verify the performance of different schemes. Besides, the asymptotic outage behavior and diversity orders at high signal-to-noise ratios are also presented to get further insights. Finally, Monte Carlo simulations manifest the advantages and disadvantages characters of two schemes and reveal the impacts of key parameters on the system performance.