High-performance Transmission Research Articles

A Reordering Buffer Management Method at Edge Gateway in Hybrid IP-ICN Multipath Transmission System

Multipath transmission in ICN provides high transmission efficiency and stability. In an IP-ICN compatible network environment, unmodified IP terminal devices can access ICN through gateways, benefiting from these performance enhancements. This paper proposes a gateway framework for hybrid IP-ICN multipath transmission systems, enabling protocol conversion and quality of service management. A packet reordering module is integrated at the egress gateway to address complex packet disorder issues caused by ICN multipath transmission, thereby enhancing the service quality provided to IP terminals. A Reordering Buffer Management Method (RBMM) is introduced, consisting of two key components. First, RBMM employs an improved dynamic threshold scheme for reserved buffer partitioning, efficiently identifying congestion and optimizing buffer resource utilization. Second, a flow-priority-based replacement strategy is designed to enhance fairness in resource allocation by evicting packets with lower delivery probability during congestion. Experimental results demonstrate that RBMM dynamically adapts to varying traffic conditions, maintaining high transmission performance while reducing buffer resource consumption. In comparison to existing methods, RBMM significantly reduces queuing delay and flow completion time, providing more balanced resource allocation when multiple flows compete for limited buffer capacity.

A multi-objective optimization design method for underwater composite sandwich structures with high acoustic transmission and low vibration performance

ABSTRACT To address the issue of reduced structural integrity and optimality resulting from the conventional serial design of sonar dome structures, this paper establishes a multi-objective optimal design model for composite sandwich structures, utilising the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The model's stability and reliability are subsequently validated. Upon this model, a structural optimization design technique is postulated for composite sandwich structures within the realm of Fluid-Structure Interaction (FSI) multi-physics coupling. This approach aims to optimize the lightweight, high-rigidity composite sandwich structure, enhancing its acoustic transmission and minimizing vibration performance under turbulent pressure pulsations. The suggested method notably enhances the efficiency of structural design while ensuring precision. The proposed method effectively addresses the deficiency of serially designed sonar domes by neglecting the synergistic effects among multiple disciplines. In summary, this approach offers technical support and new research perspectives for the design of sonar domes under the coupling of multiple physical fields.

Dynamic stream partitioning for time-triggered traffic in Time-Sensitive Networking

Time-Sensitive Networking (TSN) is a promising network technology that can ensure bounded latency and jitter for industrial real-time scenarios. It establishes the IEEE 802.1 Qbv standard to precisely control the periodic transmission time of the time-triggered (TT) traffic. However, it is still a challenge to efficiently schedule the TT traffic in large-scale networks with high transmission performance. In this paper, we propose a novel method called dynamic stream partitioning (DSP) to solve this problem. It satisfies the IEEE 802.1 Qbv standard and can significantly reduce the scheduling time by reducing the number of constraints. Based on the DSP method, we analyze the impact of stream partitioning on the transmission performance of the TT traffic, and propose an indicator called Normalized Degradation of Performance (NDOP) to quantify it dynamically. Furthermore, we design a partitioning-aware dynamic routing (PADR) to expand the scheduling space. Integrated with NDOP and PADR, we propose a joint routing and dynamic stream partitioning (JR/DSP) algorithm. Extensive simulation experiments verify that the proposed JR/DSP algorithm has higher scalability, transmission performance, and schedulability compared to the static stream partitioning algorithms.

Effects of air-entraining agents and glass powder on the electromagnetic wave transmission and mechanical performances of sulfoaluminate cement

This study prepared a sulfoaluminate cement with high electromagnetic wave transmission performance by adding air entraining agent and glass powder and revealed the related mechanism. The test results showed the air-entraining agents and glass powder cannot affect the type of hydration products of the sulfoaluminate cement. The addition of the air-entraining agents and glass powder reduced the dielectric constant of the SAC while increasing the magnetic permeability. The air-entraining agents and glass powder increased the transmittance with a maximum value of 60.2 %, illustrating the electromagnetic wave transmission performance of the sulfoaluminate cement could be improved. The electrical resistivity of the sulfoaluminate cement with the air-entraining agents and glass powder did not change significantly because the air-entraining agents increased the electrical resistivity and the effect of the glass powder was the opposite. The strengths of the sulfoaluminate cement with the air-entraining agents and glass powder decreased.

W‐band multimode monopulse horn feed for reflector antenna

AbstractThis letter proposes a W‐band multimode monopulse horn (MMH) feed to improve the total efficiency (TE) of the reflector antenna. The feed consists of a MMH and a single‐layer comparator. The MMH utilizes one pyramidal horn and four rectangular waveguides (RWGs) for feeding. The eight electric modes required in the MMH yield excellent sum and difference patterns. The impact of unwanted modes is suppressed using a 90° phase difference approach. The comparator contains four novel 3 dB couplers and E‐plane RWGs, providing low loss and high multiport transmission performance. The MMH feed has been fabricated, tested, and applied to a Cassegrain antenna. The measured maximal TE for the Cassegrain antenna between 90 and 97 GHz is 54.9%. The realized gain of the sum beam is 40.3 dBi at 93.5 GHz. The null depths of difference beams in the azimuth and elevation planes are about −37.7 and −29.1 dB, respectively.

Analysis of PAPR reduction of optical-OTFS for 256-QAM using companding and clipping–filtering algorithms

Abstract The article presents an investigation into Peak-to-Average Power Ratio (PAPR) reduction techniques in Optical Orthogonal Time Frequency Space (O-OTFS) modulation. Focusing on clipping and filtering as well as companding methods, the study explores their efficacy in mitigating PAPR challenges inherent in O-OTFS waveforms. The research evaluates the impact of these techniques on signal quality, particularly in the context of a Rician channel. Clipping and filtering (C&F) are examined for their ability to control amplitude peaks, while companding is analyzed for its role in optimizing dynamic range. The study conducts a comprehensive analysis of Bit Error Rate (BER) and power spectrum density (PSD) under varying conditions, shedding light on how these methods influence the reliability and robustness of OTFS communication. The investigation considers the interplay of these PAPR reduction methods with the unique characteristics of the Rician and Rayleigh channel, which includes a dominant line-of-sight component. The findings contribute valuable insights into designing efficient OTFS modulation systems for real-world scenarios. Ultimately, this research aims to provide a deeper understanding of PAPR reduction strategies in OTFS, offering guidance for optimizing signal processing techniques in communication systems where mitigating PAPR is crucial for achieving high performance and reliable data transmission. It is noted that the proposed C&F and companding algorithms outperform the conventional methods and achieved a PAPR gain of 1–3 dB and BER gain of 10.6–2 dB.

ANALYSIS OF ALGORITHMS FOR THE FORMATION OF CODE STRUCTURES AFFECTING THE QUALITY OF DATA TRANSMISSION IN INFOCOMMUNICATION SYSTEMS

Achieving the best quality indicators of transmission through the channels of modern communication systems is always of urgent importance for developers and users of information communication systems. At the same time, to ensure high transmission reliability and performance, various coding methods and methods of converting the transmitted data can be used. Accordingly, each of the proposed data processing methods has its advantages and disadvantages, which determines their attractiveness or application limitations for the data being transmitted. In this paper, the analysis of algorithms for forming signal code structures of traditional interference-resistant positional codes, codes with an even number of units, and a nine-element Hamming code is carried out. Classical positional coding is inferior in such important data transmission parameters as information capacity and entropy. However, in some cases, for example, when the results of data transfer quality parameters calculations are significantly influenced by the language of the transmitted textual information or the volume of the analyzed text (the influence is more likely to be noticeable in individual cases, and not in general), then an important value acquires the possibility of applying a certain/adapted type of encoding of the transmitted data. The article conducts theoretical research and calculates the main qualitative parameters of the studied code constructions for various initial conditions. A comparative analysis and assessment of the influence of the studied parameters on the quality of data transmission was carried out. Conducted theoretical studies show that, under certain conditions, positional coding provides a significant gain in the main quality indicators of data processing and can be successfully applied for coding and transmission of digital data through the channels of modern information transmission systems. In order to practically confirm the reliability of the obtained results, relevant studies should be conducted, for example, with simulation on a software model of a virtual transmission system with different coding principles on modern computer systems.

Nested multibar cladding elements in negative curvature fibers for CO laser guidance

A numerical study on the multi-bar nested cladding design of chalcogenide glass-based negative curvature hollow-core fiber was carried out to achieve a low-loss light guidance in the mid-infrared spectrum centered at 5.4 μm. Fiber design parameters were systematically optimized, and the effect of the nested bars on the confinement and total loss performance of a five-tubular cladding structure was investigated. An ultra-low transmission loss of 0.112 dB km−1 at 5.4 μm was achieved with As2Se3 triple-bar negative curvature fiber while maintaining low bending sensitivity. The design is also suitable for high transmission performance with alternative infrared glasses and can be potentially used for low-loss light guidance in a wide mid-infrared spectrum.

Preparation and mechanism analysis of nanocrystalline cellulose-tricalcium silicate paste composite with high electromagnetic transmission performance

The tricalcium silicate (C3S) paste with high electromagnetic transmission performance is prepared by addition of nanocrystalline cellulose (NCC), and the enhancement mechanism of electromagnetic transmission performance is revealed. The water to cement ratio (W/C) and the contents of NCC are 0.5 and 1 wt%-4wt%, respectively. The results show that the electromagnetic transmissivity of the C3S paste improves with an increase in NCC content. At the frequency of 3.94 GHz, when the NCC contents are 3 wt% and 4 wt%, the electromagnetic transmission coefficient increases by 113.85% and 153.6%, respectively. The enhancement mechanisms of electromagnetic transmission performance of NCC-C3S pastes are as follows: (1) the polymerization degree of C–S–H and the Van der Waals force between the globules increase; (2) the total volume proportions of low electromagnetic loss C3S and Ca(OH)2 increase; (3) the conductivity of C3S pore solution and the volume proportions of water decrease; (4) the pore volume proportion of the non-harmful pores for electromagnetic energy loss increases.

High-performance transmission mechanism design of multi-stream carrier aggregation for 5G non-standalone network

High-performance transmission mechanism design of multi-stream carrier aggregation for 5G non-standalone network

A wideband and compact Quasi-Yagi antenna based on spoof surface plasmon polaritons

In this paper, a novel wideband end-fire antenna, based on a spoof surface plasmon polaritons (SSPP) transmission line, is proposed. Periodically modulated corrugated metal strips are used as a transmission line for quasi-TEM conversion in the microstrip line to the state of SSPP and the best impedance matching. Due to the strong confinement of the field in the SSPP waveguide and its high transmission performance, it has been used as a transmission line. The antenna consists of SSPP waveguides for the transmission line, a metal plate on the ground as the reflector of the antenna, a metal strip director, and two half-rings to realize the radiation, reaching a wide bandwidth in the range of 4.1 to 8.1 GHz. The simulation results show that this antenna achieves a gain of 6.5 dBi, a bandwidth of 65%, and an efficiency of 97% across a wide operating frequency band, from 4.1 to 8.1 GHz. The proposed end-fire antenna has been fabricated, and the measured results agree well with the simulated results. The end-fire antenna implemented on a dielectric layer also has the advantages of high efficiency, good directivity, high gain, a wide bandwidth, easy fabrication, and a compact size.

A Passive Metasurface for Gain Enhancement of Wide-Angle Millimeter-Wave Multibeam Array Antenna

In this letter, a passive metasurface for gain enhancement of the wide-angle millimeter-wave (mm-wave) multibeam array antenna (MBA) is proposed, and its core includes the wide-angle huygens' unit cell and the point-to-point phase compensation (PPC) method. The huygens' unit cell can achieve high transmission performance of the TM-wave in the range of ±70°. The PPC is to map all the beams of the MBA onto the phase modulation plane (PMP), and then block the PMP, that is, each beam corresponds to an independent block region, and each block region can adjust the phase of associated beam independently. Based on the proposed metasurface, the application for improving the beam performance of the MBA is implemented. It can realize the gain enhancement in the range of the beam pointing angle from −55° to +57°. The gain difference between the central beam and the edge beam is 2.69 dBi, and the gain enhancement range is 7.53 to 8.04 dBi.

UV-blocking composite films containing hydrophilized spruce kraft lignin and nanocellulose: Fabrication and performance evaluation

The development of biodegradable films with good UV-blocking and mechanical properties is of great significance for the alleviation of plastic pollution and the establishment of a sustainable society. Given that most natural biomass–derived films have poor mechanical and UV aging properties and are therefore of limited applicability, additives capable of mitigating these drawbacks are highly sought after. In particular, industrial alkali lignin, which is a byproduct of the pulp and paper industry, features a benzene ring–dominated structure with abundant active functional groups and is therefore a promising natural anti-UV additive and composite reinforcing agent. However, the commercial applications of alkali lignin are hindered by its structural complexity and polydispersity. Herein, spruce kraft lignin was fractionated and purified using acetone, subjected to structural characterization, and then quaternized based on the obtained structural data to increase water solubility. TEMPO-oxidized cellulose was supplemented with quaternized lignin at different loadings, and the mixtures were homogenized under high pressure to obtain uniform and stable lignin-containing nanocellulose dispersions, which were subsequently converted into films through suction filtration–based dewatering under pressure. The quaternization of lignin improved its compatibility with nanocellulose and endowed the corresponding composite films with excellent mechanical properties as well as high visible light transmission and UV-blocking performance. The film with a quaternized lignin loading of 6 % had UVA and UVB shielding efficiencies of 98.3 and 100 %, respectively, and featured a tensile strength (175.2 MPa) and elongation at break (7.6 %) that were 50.4 % and 72.7 % higher than those of the pure nanocellulose (CNF) film prepared under the same conditions, respectively. Thus, our work provides a cost-effective and viable method of preparing fully biomass–derived UV-blocking composite films.

Perovskite Solar Cells: Emerging Photovoltaic Technology for Achieving Net‐Zero Emission Agrivoltaics Ecosystem

The expected population growth and resulting increase in food and energy demands have become global concerns to be addressed with urgent and targeted actions. Agrivoltaics has recently emerged as the practice of co‐locating photovoltaic (PV) infrastructure and agriculture to alleviate land‐use competition between energy and agriculture production. However, PV and agriculture are highly dependent on the utilization of sunlight. Therefore, the design of a PV system is critical for maximizing electricity generation and plant biomass production. Perovskite solar cells (PSCs), as an emerging PV technology, attract intensive attention owing to low fabrication cost, high performance, and tunable transmission. Accordingly, PSCs show promising application in a net‐zero emission agrivoltaics ecosystem. In this perspective, the advantages of PSC‐integrated agrivoltaics are discussed by comparing with traditional PV technologies. Thereafter, the promising and sustainable way is proposed to employ PSCs for electricity generation, plant growth, and aquatic animal development in an agrivoltaics ecosystem. Lastly, a design principle is provided for tailoring PSCs for a sustainable agrivoltaics ecosystem to simultaneously solve the energy and food crises.

Design Consideration, Numerical and Experimental Analyses of Mode-Division-Multiplexed (MDM) Silicon Photonics Integrated Circuit with Sharp Bends.

Due to the popularity of different high bandwidth applications, it is becoming increasingly difficult to satisfy the huge data capacity requirements, since the traditional electrical interconnects suffer significantly from limited bandwidth and huge power consumption. Silicon photonics (SiPh) is one of the important technologies for increasing interconnect capacity and decreasing power consumption. Mode-division multiplexing (MDM) allows signals to be transmitted simultaneously, at different modes, in a single waveguide. Wavelength-division multiplexing (WDM), non-orthogonal multiple access (NOMA) and orthogonal-frequency-division multiplexing (OFDM) can also be utilized to further increase the optical interconnect capacity. In SiPh integrated circuits, waveguide bends are usually inevitable. However, for an MDM system with a multimode bus waveguide, the modal fields will become asymmetric when the waveguide bend is sharp. This will introduce inter-mode coupling and inter-mode crosstalk. One simple approach to achieve sharp bends in multimode bus waveguide is to use a Euler curve. Although it has been reported in the literature that sharp bends based on a Euler curve allow high performance and low inter-mode crosstalk multimode transmissions, we discover, by simulation and experiment, that the transmission performance between two Euler bends is length dependent, particularly when the bends are sharp. We investigate the length dependency of the straight multimode bus waveguide between two Euler bends. High transmission performance can be achieved by a proper design of the waveguide length, width, and bend radius. By using the optimized MDM bus waveguide length with sharp Euler bends, proof-of-concept NOMA-OFDM experimental transmissions, supporting two MDM modes and two NOMA users, are performed.

Dynamic Modeling and Analysis of Epoxy Gear Considering Material Viscoelasticity

With improvements in lubrication and material strength, the power transmitted by plastic gears has increased significantly. To develop high-performance transmission systems, it is necessary to gain deep insights into the dynamic characteristics of plastic gears. However, because plastics are viscoelastic materials, they do not obey Hooke’s law, which is the basis of traditional gear dynamic models. In this study, a refined dynamic model for an epoxy gear pair considering material viscoelasticity and extended tooth contact is established, and the differences in the dynamic responses between an epoxy and a steel gear pair are compared with respect to the dynamic meshing force and dynamic transmission error. The results show that: (1) the plastic gear can restrain the meshing impact, it has a generally lower dynamic meshing force than steel gear pair; (2) the position accuracy is the weak point of plastic gears, and this is significantly affected by the rotation speed; (3) the way to indirectly evaluate the dynamic meshing force by measuring the dynamic transmission error, which is often used for metal gears and is less effective for plastic gears.

The lamellar preparation of continuous porosity-graded Si3N4 ceramics without obvious interfaces for broadband radome application

Traditional layered broadband radomes are challenging to meet the needs of the high-temperature application, due to thermal mismatch between their layers. In this study, porous Si3N4 ceramics with a novel continuous porosity gradient from 54.7% to 82.4% were achieved by lamellar gel-casting, freeze-drying, and subsequent sintering process. The porosity-graded structure in Si3N4 ceramics shows no failure or cracks after sintering, benefiting from the low shrinkage after sintering at 1900 °C with the rapid sintering rate. The continuous porosity-graded structure without obvious interfaces was architected by ice crystal growth during solidification and the growth of rodlike β-Si3N4 grains across the interfaces during sintering. This approach can be beneficial to designing high wave transmission performance at specific broadband for radome.

Silicon metasurface embedded Fabry-Perot cavity enables the high-quality transmission structural color.

While nanoscale color generations have been studied for years, the high-performance transmission structural color, simultaneously equipped with large gamut, high resolution, and optical multiplexing abilities, still remains as a hanging issue. Here, a silicon metasurface embedded Fabry-Perot cavity is demonstrated to address this problem. By changing the planar geometries of meta-atoms, the cavities provide transmission colors with 194% sRGB gamut coverage and 141,111 DPI resolution, along with more than 300% enhanced angular tolerance. Such high density allows two-dimensional color mixing at the diffraction limit scale. Benefitting from the polarization manipulation capacity of the metasurface, arbitrary color arrangements between cyan and red for two orthogonal linear polarizations are also realized. Our proposed cavities can be used in filters, printings, optical storage, and many other applications in need of high quality and density colors.

Ultra-Wideband Differential Line-to-Balanced Line Transitions for Super-High-Speed Digital Transmission.

A conventional differential line (DL), commonly used on typical digital circuit boards for transmitting high-speed digital data, has fundamental limitations on the maximum signal bandwidth (~10 GHz), mainly due to signal skew, multiple line coupling, and EM interference. Therefore, to support super-high-speed digital data transmission, especially for beyond 5G communications, a practical high-performance transmission structure for digital signals is required. Balanced lines (BLs) can transmit the differential signals with multiple advantages of ultra-wide bandwidth, common-mode rejection, reduced crosstalk, phase recovery, and skew reduction, which enable super-high-speed transmission. In order to utilize the BLs in the DL-based digital circuit, connecting structures between a DL and BLs are required, but the DL-to-BL transition structures dominate the operating bandwidth and signal properties. Therefore, in this paper, properties, and design methods for two ultra-wideband DL-to-BL transitions, i.e., DL-to-CPS (coplanar stripline) and DL-to-PSL (parallel stripline) transitions, are presented. Both implemented DL-to-CPS and DL-to-PSL transitions provide high-quality performance up to 40 GHz or higher, significantly enhancing the frequency bandwidth for the transmission of digital signals while providing compatibility with the DL-based PCBs. The fabricated DL-to-CPS transition performs well from DC to 40 GHz with an insertion loss of less than 0.86 dB and a return loss of more than 10 dB, and the fabricated DL-to-PSL transition also provides good performance from DC to 40 GHz, with an insertion loss of less than 1.34 dB and a return loss of more than 10 dB. Therefore, the proposed DL-to-BL transitions can be applied to achieve super-high-speed digital data transmission with over 40 GHz bandwidth, which is more than four times the bandwidth of the DL, supporting over 200 Gbps of digital data transmission on PCBs for the next generation of advanced communications.

High-performance dual-band frequency-selective rasorber based on cascaded metasurface

Frequency-selective rasorbers (FSRs), which have absorptive and transmissive properties at different frequencies, are crucial in a wide range of applications in communication and radar engineering. However, the FSRs currently available usually exhibit a single high-performance transmission band, which cannot meet the rising demands for modern multiband communication/radar systems. In this article, we propose a dual-band frequency-selective rasorber that utilizes a cascaded metasurface and is designed with an equivalent circuit model and parameter optimization. In addition, a prototype dual-band frequency-selective rasorber is fabricated and characterized. Microwave measurements present two highly transparent peaks located near 11.5 and 17.5 GHz with an insertion loss of around 0.5 dB. Also, there are two absorption bands with absorptivities higher than 80% at 3.9–10.2 GHz and 13–15 GHz. Such low insertion loss for both transparent bands is achieved by optimizing the position of resistors through mode analysis. Our approach facilitates the manufacture of high-performance multi-band frequency-selective rasorbers for use in multi-band communication systems.