Communication Systems Research Articles

Beam Scanning with Ultra-Low Sidelobes and In-Band Ultra-Low Scattering Characteristics Empowered by Single Space-Time-Coding Radiation-Scattering Metasurface.

The integrated modulation of radiation and scattering provides an unprecedented opportunity to reduce the number of electromagnetic (EM) apertures in the platform while simultaneously enhancing communication and stealth performance. Nevertheless, achieving full-polarization, arbitrary amplitude, and phase modulation of radiation scattering remains a challenge. In this paper, a strategy that realizes space-time coding of radiation scattering within the same frequency band, which enables the simultaneous and independent modulation of amplitude and phase, is proposed. To address the limitations of the high sideband levels (SBLs) of conventional space-time-coding metasurfaces, a strategy comprising nonuniform modulation periods and stochastic coding is proposed. Consequently, beam scanning with ultra-low sidelobe levels (SLLs) and suppressed SBLs is achieved in the radiation mode (RM). In scattering mode (SM), in-band low scattering characteristics are achieved within the same operating frequency band as RM. A prototype of a space-time-coding radiation-scattering metasurface (STCRSM) is fabricated and the aforementioned functionalities are validated by measurements. Furthermore, the proposed strategy does not necessitate the utilization of optimization algorithms and exhibits low SLLs and low SBLs, which will make it flourish in RF stealth applications, such as covert communication systems.

Distributed communication interference resource scheduling using the master-slave parallel scheduling genetic algorithm

With the increasing intelligence and diversification of communication interference in recent years, communication interference resource scheduling has received more attention. However, the existing interference scenario models have been developed mostly for remote high-power interference with a fixed number of jamming devices without considering power constraints. In addition, there have been fewer scenario models for short-range distributed communication interference with a variable number of jamming devices and power constraints. To address these shortcomings, this study designs a distributed communication interference resource scheduling model based distributed communication interference deployment and system operational hours and introduces the stepped logarithmic jamming-to-signal ratio. The proposed model can improve the scheduling ability of the master-slave parallel scheduling genetic algorithm (MSPSGA) in terms of the number of interference devices and the system’s operational time by using four scheduling strategies referring to the searching number, global number, master-slave population power, and fixed-position power. The experimental results show that the MSPSGA can improve the success rate of searching for the minimum number of jamming devices by 40% and prolong the system’s operational time by 128%. In addition, it can reduce the algorithm running time in the scenario with a high-speed countermeasure, the generation time of the jamming scheme, and the average power consumption by 4%, 84%, and 57%, respectively. Further, the proposed resource scheduling model can reduce the search ranges for the number of jamming devices and the system’s operational time by 93% and 79%, respectively.

Ethernet Passive Mutual Authentication Scheme on Quantum Networks

In the context of increasing demand for secure and efficient communication networks, addressing the issue of mutual authentication in ethernet passive optical networks (EPONs) has become both valuable and practically significant. This paper proposes a solution based on ideal lattices. The proposed scheme leverages the security of the ring learning with errors (RLWE) problem to establish a robust public-key cryptosystem. By involving ONUs, OLTs, and an SDN controller in the authentication process, it enables mutual authentication through a series of message exchanges facilitated by the SDN controller. Utilizing approximate smooth projection hash functions for secure key exchange and verification, the scheme ensures robust security performance against various attacks, including man-in-the-middle, impersonation, replay, and known key secrecy attacks. Simulation results demonstrate that the proposed solution introduces minimal delay and maintains a high registration success rate compared to traditional authentication methods. Additionally, this paper explores the convergence of quantum network protocols with EPONs, highlighting their potential to achieve unprecedented levels of communication security. Integrating quantum technology with EPON networks, due to the unique security properties of quantum, can also better prevent man-in-the-middle attacks. Secure interception detection techniques based on fundamental quantum properties provide a fundamental security direction for future communication systems, aligning with the growing interest in quantum-resistant cryptographic protocols.

Framework for Analyzing Spatial Interference in Vehicle-to-Vehicle Communication Networks with Positional Errors

This paper introduces a novel framework for evaluating vehicle-to-vehicle (V2V) communication systems, employing beamforming and null steering techniques. Addressing challenges such as electromagnetic interference from other vehicles within the network as well as diverse road conditions, the framework defines the simulation environment for V2V networks across different traffic scenarios to assess system reliability. The analytical components of the proposed framework are structured as follows: a comprehensive framework is developed, serving as the basis for implementing a simulator that leverages advanced spatial signal processing algorithms to evaluate V2V networks across specific scenarios, accounting for the effects of positional errors. The framework integrates multiple blocks, including road modeling, system modeling, and performance evaluation, providing adaptability for different algorithms or configurations. Positional inaccuracies are examined, highlighting their effects on system performance, particularly in scenarios where null steering accuracy is imperfect, thus underscoring the need for enhanced interference management strategies.

Scalable Terahertz Room Temperature Photoreceivers Based on Large‐Area Hexagonal Boron Nitride and Graphene Heterostructures

AbstractThe development of scalable techniques for large‐area growth of layered materials unlocks technological opportunities for the implementation of devices and components suitable for on‐chip integration on photonic integrated platforms. Here, terahertz (THz) photoreceivers based on large‐area hexagonal boron nitride/single‐layer graphene (SLG)/hexagonal boron nitride heterostructures, prepared by chemical vapor deposition and realized by means of an industrially scalable method, are reported. The photo‐thermoelectric sensors are integrated on‐chip with planar antennas, on‐chip radio frequency circuitry, a low‐pass hammer‐head filter and coplanar strip lines, combining nanosecond response time and large sensitivity. Room temperature responsivities of ≈4 V W−1, with noise equivalent power ≈4 nWHz−1/2 at high (2.86 THz) frequencies are reached, in a fully frequency‐scalable architecture. This paves the way for multiplexed hyperspectral THz cameras and optical communication systems.

A novel fault prediction modeling and simulation method for power communication networks

The power communication network is the key to ensuring the safe operation of the distribution network, and how to quickly and accurately predict faults is a challenging task, especially considering the variable topology of the distribution network. To address this issue, common faults will be modeled and simulated to predict faults in power communication systems. In this study, considering the generalized Laplacian smoothing filters and the long sequence representation capability of the Transformer, an adaptive graph encoder based on historical performance graph embedding is proposed and used for fault prediction in power communication networks. The proposed method consists of two modules: (1) To better alleviate high-frequency noise in node features, a carefully designed Laplacian smoothing filter is first applied. (2) Adopting a transformer-based adaptive encoder to iteratively enhance filtering characteristics for better node embedding. The performance of the proposed method in fault prediction tasks is tested using a dataset collected from a real power communication network. The experimental results show that the proposed method consistently outperforms other fault prediction methods in terms of performance.

Disaster Risk Management and Emergency Response Legislations and Strategies Awareness in Tanzania: A Case of Dar Es Salaam City

This study evaluated major cities’ compliance and awareness to the disaster management and emergency response legislations and strategies in Tanzania with a focus on Dar es salaam city that have experienced persistent undesirable disasters and emergencies that arise from both natural and manmade. The study also focused at actions and programs embarked by the Dar es Salaam City Governments (Ilala, Temeke, Ubungo and Kinondoni) to implement the established disaster and emergency response legislations and strategies in dealing with the challenges identified and their way forward. The outcome of this research was contemplated to significantly assist individuals, community, the local government and other interested parties in dealing with disasters and emergencies, and enhance understanding and compliance and awareness to the disaster management and emergency response legislations and strategies urban and rural dwellers with disaster-resilient. This study deployed descriptive research design and survey to gather information about the research problem under the study. The survey provided quantitative account of views of sampled population and their attitudes, and provided chance to test correlation among population variables of the population samples in which 105 respondents were conveniently selected for this study. The study found that the majority of the population are aware the about the disasters that are likely to occur in their localities and their associated impacts both health and economic impacts, but however they are not satisfied with the strategies implemented by the government to deal with them. The study revealed that, the public officials responsible for emergency response and disaster management in Dar es Salaam are aware about the legislations and plans in dealing with disasters and emergency response but the compliance to them are below average due to various factors like resources constraints, insufficient personnel, low involvement of community, insufficient institutional coordination between emergency responders, insufficient infrastructures that affect response time to emergencies, inadequate urban land use planning and strategies and political influenced decision making. The study proposed that the government have to review and follow up implementation of developed urban land use plans base on disaster risk assessment and management reports, to intensify and provide public awareness campaigns on disaster risk management and emergency response strategies, capacity building to government officials and emergency responders on new urban development technologies and enhance their knowledge and competencies, and to review and establish a coordinated emergency response plans in major cities and establishment of early warning systems with coordinated communication systems among responders.

Design and realization of XOR, OR, and NAND light logic gates using GaAs heterostructure

This study introduces a novel structure based on a GaAs quantum well for implementing XOR, OR, and NAND light logic gates. This structure has unique advantages compared to classical p-n junction-based devices, including polarity-independent operation, radiation emission, and a more straightforward design. The suggested structure consists of two photoconductive devices and a logic gate device. When 850 nm light from the fiber optic cable illuminates the photoconductive device, the photoconductive device and the pulsed signal source are triggered simultaneously and supply the logic gate device, enabling it to perform the desired logic operation (XOR, OR, and NAND). Notably, at room temperature, the primary emission wavelength of these optical logic gate devices is 812 ± 1 nm. This design offers a compact, efficient, and versatile approach to light logic gates, with potential applications in optical computing and communication systems. Furthermore, the data transfer rate of these optical logic gates has been demonstrated to be comparable to that of electrical circuits currently used in technology.

Quantifying degradation in animal acoustic signals with the R package baRulho

Abstract Animal acoustic signals are shaped by selection to convey information based on their tempo, intensity, and frequency. However, sound signals degrade as they transmit over space and across physical obstacles (e.g., vegetation or infrastructure), which affects communication potential. Therefore, propagation experiments are designed to quantify changes in signal structure in a given habitat by broadcasting and re‐recording animal sounds at increasing distances. We introduce ‘baRulho’, an R package designed to simplify the implementation of sound propagation experiments. We highlight the package features with a case study testing the effects of habitat and acoustic structure on signal propagation, two common factors evaluated in such experiments. Synthesized sounds that varied in frequency, duration, and frequency and amplitude modulation were broadcast and re‐recorded at five increasing distances in open and closed understory at the Bosque de Tlalpan, Mexico City. With this data, we showcase baRulho's functions to prepare master sound files, annotate re‐recorded test sounds, as well as to calculate and visualize measures that quantify the degradation of acoustic signals in the time and frequency domain. Degradation measures in baRulho adequately quantified acoustic degradation, following predicted patterns of sound propagation in natural environments. Re‐recorded signals degraded less in open understory compared to closed understory, with higher‐frequency sounds exhibiting more degradation. Furthermore, frequency modulated sounds degraded to a greater extent than pure tones. The increased attenuation and reverberation observed in higher frequency sounds and closed habitats suggest that factors such as absorption and scattering by vegetation play significant roles in propagation patterns. The R package ‘baRulho’ provides an open‐source, user‐friendly suite of tools designed to facilitate the analysis of animal sound degradation. Notably, baRulho offers similar results to other sound analysis software but with significantly reduced processing time. Moreover, the package minimizes the potential for user error through automated test file annotation and verification procedures. We hope that baRulho can help enhance accessibility to propagation experiments within the research community, ultimately contributing to a deeper understanding of the ecological drivers of animal communication systems.

A Study on International Communication Strategies of Chinese Culture Based on the 5W Model

Guided by Harold Lasswell’s 5W model, this study explores the current status quo and bottlenecks of international communication of Chinese culture. A framework is constructed for the international dissemination of Chinese culture based on the 5W model and the following strategies are proposed: 1) Linkage and collaboration of multiple subjects to promote synergy, and highlighting the folk subjects “weak” communication force; 2) Fine-tuning universal values and distinctive cultures, and balancing traditional modernity with local characteristics; 3) Media integration to build a diversified communication system, and cross-border cooperation to broaden the communication channels; 4) Distinguishing the audiences to meet their different demand, and the establishment of audience feedback mechanism re-adjustment; 5) Constructing the evaluation system of communication effects, and launching the quantitative analysis to optimize communication strategies. By investigating these strategies, the study aims to address communication bottlenecks and promote the global dissemination of Chinese culture.

Construction of an Experimental Device for Military Communication Using Binary Amplitude Shift Keying

Aims: To address the core requirement for military communication systems—ensuring "timely, accurate, confidential, and secure" communication—this study aims to overcome the limitations of traditional amplitude modulation (AM) methods by developing a modern experimental device using Binary Amplitude Shift Keying (BASK) modulation. Study Design: Traditional military communication systems rely on AM modulation due to its simplicity and ease of implementation. However, AM is susceptible to noise, suitable only for long-wave transmissions (e.g., AM radio), and struggles to integrate with modern technologies like 4G and 5G. To address these challenges, this study explores the mathematical foundation and system design of BASK modulation and demodulation. Methodology: The research investigates the mathematical principles of BASK, designs the system architecture for BASK modulation and demodulation, and develops an experimental device to validate the performance of the BASK-based communication model. Results: The study successfully developed an experimental device that demonstrates the feasibility of using BASK modulation for military communication. The device provides a platform for practical testing and verification of the BASK model, laying the groundwork for further advancements. Conclusion: This research provides a foundation for modernizing military communication devices. By overcoming the limitations of traditional methods and facilitating the integration of advanced technologies, the proposed device meets the stringent requirements of military environments.

Mechanistic insights into Wnt-β-catenin pathway activation and signal transduction.

In multicellular organisms, Wnt proteins govern stem and progenitor cell renewal and differentiation to regulate embryonic development, adult tissue homeostasis and tissue regeneration. Defects in canonical Wnt signalling, which is transduced intracellularly by β-catenin, have been associated with developmental disorders, degenerative diseases and cancers. Although a simple model describing Wnt-β-catenin signalling is widely used to introduce this pathway and has largely remained unchanged over the past 30 years, in this Review we discuss recent studies that have provided important new insights into the mechanisms of Wnt production, receptor activation and intracellular signalling that advance our understanding of the molecular mechanisms that underlie this important cell-cell communication system. In addition, we review the recent development of molecules capable of activating the Wnt-β-catenin pathway with selectivity in vitro and in vivo that is enabling new lines of study to pave the way for the development of Wnt therapies for the treatment of human diseases.

Frequency-Modulated Antipodal Chaos Shift Keying Chaotic Communication on Field Program Gate Array: Prototype Design and Performance Insights

Using chaos for communication can provide more robust channel security, covert transmission, and inherent support for spread-spectrum modulation. Although numerous studies have explored this technology, its practical deployment remains limited due to substantial hardware demands, complex signal processing, and a lack of efficient modulation methods for chaotic signals. In this study, a novel chaotic digital communication system is proposed and studied. A prototype of a frequency-modulated antipodal chaos shift keying (FM-ACSK) system is implemented on an Intel Cyclone V field-programmable gate array (FPGA) along with a complete mathematical model using Matlab R2022a Simulink software. Using FPGAs to implement chaotic oscillators avoids analog system problems such as component drift and high thermal instability while providing determined system parameters, rapid prototyping, and high throughput. The employment of FM over a chaotic modulation layer provides a passband operation (currently at an intermediate frequency of 10.7 MHz) while adding the benefits of carrier frequency offset robustness and constant signal envelope. Within this study, the robustness of FM-ACSK to white noise in the channel was evaluated using bit error rate, which was tested through hardware experiments and simulations. The results show the feasibility and potential performance limitations of this approach to chaotic communication system design.

Piezoelectric and electromechanical synergic optimization in MnCO3‐modified lead magnesium niobate‐lead zirconate titanate ceramics for high‐power antenna

AbstractLead zirconate titanate (PZT)‐based piezoelectric ceramics are crucial components in high‐power magnetoelectric (ME) antenna devices, contributing to the miniaturization of very low frequency (VLF) communication systems. The piezoelectric coefficient (d33) and mechanical quality factor (Qm) determine the quality of the radiation performance of the antenna device and, therefore, play a pivotal role in antenna preparation and selection. However, achieving high values for both d33 and Qm simultaneously proves challenging, as these properties often tend to compete with each other. Herein, we address this challenge by introducing MnCO3‐modified lead magnesium niobate (PMN)‐PZT piezoelectric ceramics, leveraging elements doping to achieve a well‐balanced performance, where the d33 was optimized to 530 pC/N, while concurrently attaining a Qm of 624, being attributed to the synergistic contributions from the defect dipole and lead vacancies. Notably, the PMN‐PZT‐based antenna device exhibits a significantly enhanced converse ME coefficient αCME = 0.138 Oe·cm/V, which improves the antenna emission performance by about 25% compared to commercial PZT‐4 samples. These findings offer a promising theoretical foundation and a feasible technical pathway for the development and design of ME antennas in the future.

Optical semantic communication through multimode fiber: from symbol transmission to sentiment analysis

We propose and validate a novel optical semantic transmission scheme using multimode fiber (MMF). By leveraging the frequency sensitivity of intermodal dispersion in MMFs, we achieve high-dimensional semantic encoding and decoding in the frequency domain. Our system maps symbols to 128 distinct frequencies spaced at 600 kHz intervals, demonstrating a seven-fold increase in capacity compared to conventional communication encoding. We further enhance spectral efficiency by implementing 4-level pulse amplitude modulation (PAM-4), achieving 9.12 bits/s/Hz without decoding errors. Additionally, we explore the application of this system for sentiment analysis using the IMDb movie review dataset. By encoding semantically similar symbols to adjacent frequencies, the system’s noise tolerance is effectively improved, facilitating accurate sentiment analysis. This work highlights the potential of MMF-based semantic communication to enhance both capacity and robustness in optical communication systems, offering promising applications in bandwidth-constrained and noisy environments.

Periodically poled aluminum scandium nitride bulk acoustic wave resonators and filters for communications in the 6G era

Bulk Acoustic Wave (BAW) filters find applications in radio frequency (RF) communication systems for Wi-Fi, 3G, 4G, and 5G networks. In the beyond-5G (potential 6G) era, high-frequency bands (>8 GHz) are expected to require resonators with high-quality factor (Q) and electromechanical coupling (kt2) to form filters with low insertion loss and high selectivity. However, both the Q and kt2 of resonator devices formed in traditional uniform polarization piezoelectric films of aluminum nitride (AlN) and aluminum scandium nitride (AlScN) decrease when scaled beyond 8 GHz. In this work, we utilized 4-layer AlScN periodically poled piezoelectric films (P3F) to construct high-frequency (~17–18 GHz) resonators and filters. The resonator performance is studied over a range of device geometries, with the best resonator achieving a kt2 of 11.8% and a Qp of 236.6 at the parallel resonance frequency (fp) of 17.9 GHz. These resulting figures-of-merit are (FoM1=kt2Qp and FoM2=fpFoM1×10−9) 27.9 and 500, respectively. These and the kt2 are significantly higher than previously reported AlN/AlScN-based resonators operating at similar frequencies. Fabricated 3-element and 6-element filters formed from these resonators demonstrated low insertion losses (IL) of 1.86 and 3.25 dB, and −3 dB bandwidths (BW) of 680 MHz (fractional BW of 3.9%) and 590 MHz (fractional BW of 3.3%) at a ~17.4 GHz center frequency. The 3-element and 6-element filters achieved excellent linearity with in-band input third-order intercept point (IIP3) values of +36 and +40 dBm, respectively, which are significantly higher than previously reported acoustic filters operating at similar frequencies.

Higher order dispersion-managed solitons for the capacity enhancement of fiber optic communication systems

Higher order dispersion-managed solitons for the capacity enhancement of fiber optic communication systems

Bioinformatics exploration of identified garlic-derived antimicrobial peptides: a food-based approach to quorum sensing inhibition in foodborne pathogens

The growing frequency of antibiotic-resistant microorganisms requires novel antimicrobial methods. Quorum Sensing (QS), a bacterial communication system, is critical for controlling virulence factors and biofilm development, contributing to many foodborne bacteria' pathogenicity. Garlic, a natural substance, is a widely consumed plant with antimicrobial properties and antibacterial capabilities, although its peptide components are poorly unknown. This study evaluated garlic-derived peptides' ability to inhibit QS in foodborne bacteria. Two garlic-derived peptides, including VS-9 and F3-3-c, undergo bioinformatics research to determine their structural features, bioactivity, physicochemical parameters, and potential interactions with target modeled proteins of LasR QS from Pseudomonas aeruginosa, Biofilm-associated surface protein (Baps) from Staphylococcus aureus, and sortase A (SrtA) from Staphylococcus aureus. VS-9 has the most favorable structure properties, which could be essential for its inhibitory activity against LasR, Baps, and SrtA proteins. We have modeled, characterized, and docked garlic-derived peptides to assess their antimicrobial properties. Even though VS-9 showed more anti QS activity than F3-3-c, more research is needed to fully understand their mechanisms of action and maximize their therapeutic potential.

Measurement and Analysis of the Rician K-Factor for Low-Altitude UAV Air-to-Ground Communications at 2.5 GHz

The research and development of unmanned aerial vehicles (UAVs) is progressing rapidly, and they are expected to be used in a wide range of applications. In this paper, we evaluated the propagation characteristics of air-to-ground (A2G) communications used by UAVs. Specifically, we investigated the Rician K-factor, which is one of the indicators representing the impact on communication quality. We carried out radio wave propagation measurements for A2G communications at low altitudes in propagation environments with simple (S environment) and complex (C environment) structures within the measurement area and then performed a detailed evaluation of the effect of the distance from buildings, UAV altitude, and antenna installation on the Rician K-factor and propagation characteristics. The measurement and analytical results reveal that the Rician K-factor in an S environment was observed to be high due to the strong dominance of the direct wave. On the other hand, the Rician K-factor in a C environment decreased because of complex multiple reflected and diffracted waves caused by surrounding buildings. In addition, dummy fading signals generated from the useful path calculated with the ray-tracing method using a simple 3D analytical model showed a high degree of agreement with the experimental results. These outcomes provide key parameters for the optimal design of UAV-based A2G communication systems, contributing to the practical application of UAV operations.

Outcomes of a Post-Surgical Follow-Up ProgramME Using Telemedicine in a General and Digestive Surgery Service

Abstract Introduction The digital revolution has significantly transformed healthcare, particularly in the adoption of telemedicine. This study aims to evaluate the initial postoperative progress, patient experience, and outcomes perceived by individuals who underwent surgery in the General and Digestive Surgery services at our hospital. Methods Our hospital employs a fully integrated electronic health record (EHR) system, which includes the mobile application Patient Portal. This platform allows patients to access their complete medical history, schedule consultations, engage in web-based communication, participate in video calls, and interact with a Chatbot, enabling a robust bidirectional communication system. Following discharge, patients received standardized postoperative follow-up forms through the Patient Portal. These forms, which allowed patients to attach multimedia files, were designed to monitor their recovery and progress. Physicians subsequently reviewed the completed forms to assess each patient’s condition. Results Between January 2020 and April 2024, 19,944 telemedicine-based follow-ups were conducted within the Surgery department. These included initial postoperative reviews, long-term follow-ups, pathology monitoring, and test result discussions. All patients reported being satisfied or very satisfied with the care provided via this system. Conclusion Telemedicine can enhance access to postoperative care, offering a safe and efficient follow-up approach without compromising the quality of care perceived by patients or surgeons.