Signal Transmission System Research Articles

The Design of a Long-Distance Signal Transmission System in a Bistatic RCS Testing System

In wireless communication and radar systems, long-distance signal transmission poses significant challenges that affect overall system performance. In this paper, we propose an innovative bistatic radar cross section (RCS) testing system designed to address these challenges, with a particular focus on its long-distance signal transmission capabilities. This system is capable of accurately measuring the RCS of a target and improving multipath channel modeling accuracy by using precise RCS values. The integrated upper computer software extracts amplitude and phase information from received echo signals, processes these data, and provides detailed outputs including the target’s RCS, one-dimensional image, and two-dimensional image. The experimental results obtained prove that this system can not only achieve effective long-distance signal transmission but also substantially enhance the accuracy of RCS measurements, offering reliable support for multipath channel modeling. However, the conclusions drawn are preliminary and require further experimental validation to fully substantiate this system’s performance. Future work will focus on improving system accuracy, minimizing the impact of environmental noise, and optimizing data-processing methods to enhance the efficiency of wireless communication and radar applications.

A microfluidic patch for wireless wearable electrochemical detection of sweat metabolites

Wearable sweat sensors provide an innovative detection method for analyzing human physiological and biochemical parameters and play an important role in detecting the potential risks of chronic diseases. Existing commercial wearable sensors (Apple iWatch, HUAWEI smart band) have problems such as single detection index (heart rate or blood pressure), and mainly focus on the physical information. This work studied an integrated microfluidic patch to simultaneously detect several biomarkers (pH, sodium ions, and uric acid) in sweat. We achieved the detection of pH level, sodium, and uric acid in linear ranges of 4–8, 0–160 mM, and 5–160 μM, respectively, covering well the clinically relevant ranges in the healthy human sweat. Laser engraving was chosen to prepare a microfluidic layer, and the sweat collection function was realized by combining hydrophilic and hydrophobic microfluidic synergy. It could efficiently collect the required sweat sample volume (80 μL) within 30 s while avoiding the contamination caused by directly contact with the skin. In addition, a wireless signal acquisition and transmission system was designed with the signal reading, processing, and wireless transmission functions, which can display the testing results in real time on Android phone-specific application software. We combined the wireless system with a microfluidic patch for on-body testing to verify the good wearability of the sweat sensor. This research realized the wireless data processing and transmission while improving sweat collection efficiency. In addition, it could detect various sweat physiological components in real-time, and provides a multiparameter, real-time, and portable sensing platform.

The coupled-motion enhanced wireless signal transmission with long distance based on Maxwell’s displacement current

Wireless signal transmission plays an increasingly imperative role in numerous aspects of modern society, but it still remains challenging to achieve it with low-cost and efficient way. Herein, we demonstrate a long-distance wireless signal transmission system, which mainly includes an electrodeless triboelectric nanogenerator coupled with linear motion and rotational motion (LR-TENG) as a transmitter and a receiver located at a distance. Based on the varying electric field originated from Maxwell's displacement current, the maximum transmission distance of LR-TENG can reach 86 cm under the external excitation of 1 Hz, creating the highest record among the relevant researches. In addition, the influence of obstacle type, thickness, size and position on signal transmission has been systematically investigated for the first time, and the distribution of time-varying electric field in space is also analyzed qualitatively. Furthermore, a Labview interface is developed for accurate positioning in complex scenes relying on the received signals from multiple receivers at different positions. This work illustrates a simple and feasible design method for extending the distance of wireless signal transmission based on TENG, and promotes its application in the field of wireless communication.

MAINTENANCE ACTION ON COURSE POWER AMPLIFIER TRANSMITTER GLIDESLOPE SELEX 2110

The Instrument Landing System (ILS) equipment is one of the aviation navigation tools that provides aircraft with a 3° landing angle. The problem identified that the glideslope signal was out of tolerance. Pilots using the glideslope facility reported this out-of-tolerance signal. This study aimed to identify issues in signal transmission systems and give a solution. The research method was a descriptive analysis to determine the cause of the out-of-tolerance glideslope signal. The result found that the issue was that one of the power amplifiers of the glideslope transmitter was unable to process signals properly, resulting in suboptimal signal transmission power. The power amplifier was replaced to address this issue. This replacement was followed by adjusting the transmission parameters of the glideslope equipment. With the replacement of the power amplifier and the adjustments made to the transmission parameters, the glideslope signal returned to normal, as confirmed by the reports from pilots using the glideslope facility.

Low insertion loss interposer approach for RF applications based on commercial LTCC tape, alkaline-free glass and printed metallization

Materials with high RF performance are in increasing demand due to the needs of modern telecommunications. Glass and low-temperature co-fired ceramics (LTCCs) are both interesting candidates for the design of complex signal transmission systems. Glass can be processed in large panels, and has suitable structure dimensions for silicon processing, but its multilayer capability is limited. LTCC is a mature technology for complex multilayer assemblies, but the structure dimensions and conductor line resolution are restricted by the need to use screen printing technology. The approach presented here combines the advantages of both technological domains: a thin glass sheet is bonded with no additional material to a LTCC multilayer ceramic and sintered to form a tight joint. Metallization of the glass is created using printable pastes and electroplating. Two fabrication routes are compared: etching of printed thick film metal layers, and semi-additive structuring. The results of RF measurements show a low attenuation per unit length for both types of metallization, indicating that our approach is a promising one for the integration of heterogeneous systems of RF transmission modules.

Cyber-physical System for Monitoring and Analyzing Human Biomedical Data

The measurement of arterial hemoglobin oxygen saturation, pulse, and blood pressure was presented. A review of methods for measuring arterial hemoglobin oxygen saturation based on photoplethysmography was provided. The architecture of the hardware and software platform of a cyber-physical system for the primary processing and transmission of information signals, based on a microcontroller with hardware encryption and a Bluetooth module for transmitting encrypted data to a mobile device and a remote server, was considered. Algorithms for measuring blood oxygen saturation and blood pressure were developed. An application for the Android operating system was designed for measuring human biomedical data in real time and analyzing their parameters over a specified period. The developed cyber-physical system is intended for use in medical institutions.

Design and Analysis of a Through-Body Signal Transmission System Based on Human Oxygen Saturation Detection

Design and Analysis of a Through-Body Signal Transmission System Based on Human Oxygen Saturation Detection

FPGA-based CCD signal acquisition and transmission system design

In order to facilitate the analysis and processing of optical signals, an FPGA-based CCD signal acquisition and data transmission system is designed in this work. The system uses an FPGA as the main control device, the TCD1304DG/AP chip as the optical signal detector, and the CYUSB3KIT-003 development board product by Cypress for data transmission. Verilog and Python languages are employed for modular design and on-board verification. Through the coordination of each module, the system successfully achieves CCD signal data acquisition and transmission.

Yoga and Lifestyle Changes: A Path to Improved Fertility - A Narrative Review.

Infertility, a widespread medical condition affecting numerous couples globally, persists as a challenge despite advances in assisted reproductive technologies (ARTs), often burdened by financial, physical, and emotional strains. Complementary and alternative approaches, notably yoga, have garnered attention for potentially enhancing fertility outcomes. Studies reveal yoga's influence on factors contributing to infertility, including reduced oxidative stress (OS) and oxidative DNA damage (ODD). OS, linked to mutagenic base formation, higher malondialdehyde levels, abnormal methylation, and altered gene expression, can impair sperm genome integrity. Yoga's efficacy is evident in lowering OS, positively affecting signal transmission, gene expression, and physiological systems. Furthermore, yoga has a positive impact on addressing the dysregulation of apoptosis, resulting in improved processes such as spermatogenesis, sperm maturation, and motility, while also reducing DNA fragmentation. OS correlates with genome-wide hypomethylation, telomere shortening, and mitochondrial dysfunction, contributing to genome instability. Yoga and meditation significantly reduce OS and ODD, ensuring proper reactive oxygen levels and preserving physiological systems. The review explores potential mechanisms underlying yoga's positive impact on infertility, including enhanced blood flow, reduced inflammation, relaxation response, and modulation of the hypothalamic-pituitary-adrenal axis. Furthermore, a comprehensive review of the literature reveals substantial evidence supporting the positive effects of yoga on infertility factors. These include oxidative stress (OS), oxidative DNA damage (ODD), epigenetic changes, hormonal balance, ovarian function, menstrual irregularities, and stress reduction. In summary, yoga emerges as a promising adjunctive therapy for infertility, demonstrating the potential to mitigate key factors influencing reproductive success. Although preliminary evidence indicates the positive effects of yoga on infertility, further clinical research is imperative to define specific benefits, molecular mechanisms associated, optimal protocols, and long-term effects in infertility treatment plans.

Wide dynamic range photodiodes for microwave photonics and comunication systems

The influence of the design of high-speed photodiodes for microwave photonics and signal transmission systems on the diode dark current is studied experimentally. It is shown that Schottky barrier photodiodes demonstrate the lowest dark currents, excelling photodiodes of the pin design. Photodiodes of 25 micron mesa diameter with the dark current average value as low as 0.4 mA have been manufactured. It is shown the dark current value is controlled by the mesa side wall leakage.

Application of artificial neural networks for predicting lateral and uplift capacity of buried rectangular box carrying pipelines

Urban and offshore subterranean comprehensive pipelines are currently utilized frequently as infrastructure for fitting different engineering pipelines used for electricity, signal transmission, natural gas, petroleum, heating, water supply, and drainage systems. This study utilizes the finite element limit analysis (FELA) and artificial neural network (ANN) to evaluate the pull-out capacity factor of the buried rectangular box carrying the pipelines with internal inclined force in cohesive soil. In FELA, rigorous upper bound and lower bound solutions are performed to achieve the exact result. In this study, a dimensionless parametric analysis is carried out by considering the effect of five parameters viz. buried depth ratio, width-depth ratio, overburden factor, internal inclination angles, and interface factor on the pull-out capacity factor of a buried rectangular box, which can be called as a rectangular pipeline. Two significant samples of the investigated parameters are selected to evaluate the soil failure pattern (failure envelope) using the shear dissipation of soil failure for the buried rectangular pipeline subjected to inclined loading. Using the FELA results, the predictive equations are proposed using ANN, and then sensitivity analysis is performed to examine the sensitivity of each investigated essential parameter on the stability of the underground rectangular pipeline. The predictive ANN model for the buried rectangular pipe subjected to inclined loading is presented as design charts for practice and further investigation.

Design and Application of Downhole Drilling Mud Pulse Signal Transmission System

Time-efficient measurement of undisturbed formation through measurement while drilling technology is an effective means to improve drilling efficiency in deep formations and increase the drilling-encounter ratio of reservoirs. Based on the application and development trend of existing downhole signal transmission technology, a pulse signal transmission system of downhole mud while drilling is designed. The system pulse generation device adopts the structure of a positive pulse generator, which is through the internal driving circuit and hydraulic circuit of the device to drive the valve head to move to generate a mud pulse signal while using the design of a limit switch to optimize the expansion spacing of the valve head so that the generated pulse signal amplitude is close. The system uses combined encoding as the encoding method, while the ground part of the system is designed to monitor and process the collected signals. Finally, the transmission capability and accuracy of the system are tested through field experiments, and the field results show that the system can work smoothly in the downhole environment to transmit downhole data to the wellhead with small errors, which meets the design requirements and field requirements. The field applications are carried out in several wells, such as the Shixi 105 well. The results show that the system has good downhole pulse signal transmission functions such as borehole inclination measurement, which helps to promote the development of existing drilling measurement technology.

EMG signal transmission system under RF schemes

With the rise in pathological conditions during the post-pandemic era, particularly concerning the management of biomedical signals, a significant surge has been observed. This research endeavors to develop a self-adaptive algorithm for the discretization and data encapsulation of electromyographic (EMG) signals. The synthetic signal used for analysis is acquired from the PhysioNet database, specifically focusing on the implementation of the tibialis anterior muscle. A transmission chain is established utilizing the AD9361 transceiver, while a power amplifier is employed for base radio applications, operating at a carrier frequency of 2.45 GHz. The spectral validation of this system reveals that the 16-QAM modulation, which is subjected to testing, yields an accuracy of -15.5 dB NMSE. As a further work, an EMG signal acquisition stage is proposed, based on a high-resolution analog-to-digital converter (ADC) card, alongside the exploration of higher order n-QAM schemes to enhance accuracy in the receiver stage.

Thermal insulating textile based triboelectric nanogenerator for outdoor wearable sensing and interaction

People have shown increasing interests in outdoor activities in recent years. However, the development of smart outdoor clothing for sophisticated health monitoring and multifunctional interaction remains challenging. Here, we develop a thermal-insulating textile (TI-textile) based TENG (TI-TENG) composed of multiple functional layers, including the crucial triboelectrification layer, Ag-coated Nylon electrodes, windproof outer textile, and inner textile lining. The triboelectric output properties of the TI-TENG can be enhanced by material modification and structural optimization. The prepared TI-TENG is demonstrated with multifunctionality (e.g., thermal insulation and antibacterial properties) and intelligences (e.g., sensing and energy harvesting function). In addition, an intelligent human motion monitoring as well as an outdoor wireless signal transmission system are developed by employing the TI-TENGs as self-powered wearable sensors and human-machine interactive interfaces, which are ready for one-button call for emergency rescue during the outdoor activities. The available large-scale production of TI-textile also promise TENG with great commercial potentials, offering a new research direction for multifunctional wearable devices toward self-powered sensing, energy harvesting, and human-machine interaction.

Supporting Informed Public Reactions to Shipping Incidents with Oil Spill Potential: An Innovative Electronic Platform

The analysis of the 2002 Prestige tanker accident showed how public misinformation can worsen marine pollution incidents, rendering their management suboptimal as these evolve, thus raising the issue of appropriately informing and educating coastal and island populations who are at risk. Two decades later, developments in electronic platforms, including Geographic Information Systems (GIS), the Automatic Identification System (AIS) for ship signal transmission, and social media, provide a set of means for public monitoring of such incidents, creating the possibility to antagonise effectively erroneous or malevolent information, which can hinder efficient actions for containing marine pollution risks even without active training of the populations concerned. The authors, in the framework of the development of the Marine Coastal Observatory and Risk Management project “AEGIS+”, have developed E-S.A.V.E., an online innovative platform that (a) meets the needs of different users as revealed by a survey run across groups of them, (b) uses a suitable Geographic Information System (GIS) environment, (c) cooperates with public authorities, for the reliable update of automated systems, and (d) employs an artificial intelligence (AI)-supported tool for social media monitoring; the platform also provides educational resources and information on national and international resources on marine environmental protection and sustainable maritime logistics.

Robust packet loss compensation in the cloud‐based TT&C receiver using a predictive tracking loop with RBF network identification

AbstractIn recent years, ground‐based aerospace tracking, telemetry and control (TT&C) systems have been shifting towards an IP‐based cloud TT&C network architecture to improve signal transmission efficiency and system flexibility. However, this new architecture presents new challenges for the performance of tracking loops in the cloud‐based TT&C receiver. The authors present a predictive compensation tracking loop that addresses the problem of packet loss. The loop utilises radial basis function (RBF) online network identification for robust carrier and code frequency offset tracking. To account for packet loss, the phenomenon is modelled as a Bernoulli random process, and the predictive compensation loop uses the trained RBF network to maintain the system's tracking state. When normal data are received again, the loop can track the received information well and align the frequency offset locking state. The authors compare the performance of the proposed predictive compensation tracking loop with traditional loop tracking performance using data hold strategies under different packet loss rates. The results demonstrate the effectiveness of the proposed approach in maintaining stable tracking and solving in the discontinuous reception of the loop under packet loss environments. The proposed predictive compensation tracking loop offers a practical solution for addressing packet loss, which is a common issue in real‐world applications.

Wide-spectrum optical soliton solutions to the time-fractional cubic-quintic resonant nonlinear Schrödinger equation with parabolic law

The time-fractional cubic-quintic resonant nonlinear Schrödinger equation with parabolic law and its soliton solutions have significant implications to examine the dynamics of optical solitons, self-phase modulation, optical beam propagation in nonlinear media, pulse propagation in optical fibers, nonlinear waveguides, and signal transmission systems. This study focuses on the investigation of different soliton solutions related to various aspects of optical solitons, including their formation, propagation traits, and stability analysis of the mentioned equation. Soliton solutions are able to carry out long-distance transmission without frequent amplification and regeneration. We exploit an advanced mathematical technique, the (G′/G,1/G)-expansion method to descend and analyze the soliton solutions. As a result, a significant number of definitive and efficient solitons, such as compacton, bell-shaped, anti-peakon, breather, periodic, and singular solitons have resulted. The uniqueness of the obtained solutions is established by comparing them with previous results. Also, we discuss in detail the implications of fractional derivative and the application of the obtained solutions to optical fiber communication and other relevant fields. The findings of the present study provide valuable insights into the fundamental nature of optical solitons. These insights will contribute to the design and optimization of future optical networks, enabling the development of faster, more reliable, and higher-capacity communication systems.

Experimental investigation on transmission system of dual-polarization mode-division-multiplexing signals with few-mode erbium-doped fiber amplifiers

The transmission capacity of optical fiber communication can be effectively improved by the combination of dual-polarization (DP) high-order modulation format with mode division multiplexing (MDM) technology. We build up an experimental system for amplification and transmission of DP-MDM signals with orthogonal mode combination (OMC) and identical mode combination (IMC). The MDM transceiver units are composed of mode-selective photonic lanterns (MSPLs) and few-mode polarization controllers (FMPCs). The few-mode erbium-doped fiber amplifier (FM-EDFA) used here is constructed by homemade isolation and wavelength division multiplexers (IWDMs). The amplification and transmission experiments for 100 Gb/s dual-polarization quadrature phase shift keying (DP-QPSK) MDM signals are carried out by the commercial optical transport network (OTN) platform. An effective method of optimally receiving DP-MDM signals are presented by appropriately controlling the FMPC in the MDM receiver unit. The experimental results show that, (1) OMC DP-MDM signals have a better performance than IMC cases in differential modal gain (DMG), which provides a new means to reduce the DMG; and (2) under the optimization conditions, OMC and IMC DP-MDM systems possess a close receiver sensitivity, but the former has a larger optical power margin than the latter by 2.2 dB.

Simplified independent triple-sideband signal generation and transmission scheme based on one I/Q modulator at 0.3-THz.

To meet the ultra-bandwidth high-capacity communication, improve spectral efficiency and reduce the complexity of system structure, we have proposed the independent triple-sideband signal transmission system based on photonics-aided terahertz-wave (THz-wave). In this paper, we demonstrate up to 16-Gbaud independent triple-sideband 16-ary quadrature amplitude modulation (16QAM) signal transmission over 20 km standard single mode fiber (SSMF) at 0.3 THz. At the transmitter, independent triple-sideband 16QAM signals are modulated by an in-phase/quadrature (I/Q) modulator. Carrying independent triple-sideband signals optical carrier coupled with another laser to generate independent triple-sideband terahertz optical signals with a carrier frequency interval of 0.3THz. While at the receiver side, enabled by a photodetector (PD) conversion, we successfully obtain independent triple-sideband terahertz signals with a frequency of 0.3THz. Then we employ a local oscillator (LO) to drive mixer to generate intermediate frequency (IF) signal, and only one ADC is used to sample independent triple-sideband signals, digital signal processing (DSP) is finally performed to obtain independent triple-sideband signals. In this scheme, independent triple-sideband 16QAM signals is delivered over 20 km SSMF under the bit error ratio (BER) of 7% hard-decision forward-error-correction (HD-FEC) threshold of 3.8 × 10-3. Our simulation results show that the independent triple-sideband signal can further improve THz system transmission capacity and spectral efficiency. Our simplified independent triple-sideband THz system has a simple structure, high spectral efficiency, and reduced bandwidth requirements for DAC and ADC, which is a promising solution for future high-speed optical communications.

Virtual-carrier-assisted 12 Gb/s 64QAM millimeter-wave signal transmission at 30 GHz using a 4-bit digital-to-analog converter.

We propose and experimentally demonstrate a radio-frequency digital resolution enhancer (RF-DRE) to mitigate the quantization noise of the RF signal induced by the low-resolution digital-to-analog converter (DAC) in the virtual-carrier-assisted millimeter-wave (mm-wave) signal transmission system. By introducing a bandpass filter (BPF) as the reference for the RF-DRE algorithm, we can design the quantization noise and shape its spectrum inversely to the bandpass filter. By these means, the quantization noise in the target RF frequency range can be effectively mitigated. In the simulation, the bit error rate (BER) of a 4-bit DAC-quantized 16 Gb/s 256QAM signal at 30 GHz is improved from 3.36e-2 to 7.43e-3 by using the RF-DRE. In our experiment, 30 GHz virtual-carrier-assisted mm-wave transmission of 12 Gb/s 64QAM signals over 25 km of standard signal mode fiber (SSMF) is realized. By using the RF-DRE, the BER of a 4-bit DAC-quantized signal can be improved from 6.88e-3 to 1.49e-3, and a 5-bit DAC exhibits a similar performance to an 8-bit DAC without the RF-DRE. Therefore, low-resolution and low-cost DACs can be used for mm-wave signal generation with the help of the proposed RF-DRE.