Long-distance Signal Transmission Research Articles

Investigation of electromagnetic wave propagation characteristics across various frequencies in porous media of goaf.

The reliable long-distance transmission of electromagnetic wave signals within goaf is fundamental for the implementation of wireless monitoring and early warning systems for goaf-related disasters. This paper establishes an experimental platform for electromagnetic wave signal transmission within goaf and develops a propagation model for electromagnetic waves in the porous media of goaf. The transmission characteristics of electromagnetic waves at various frequencies within the porous media environment of goaf are investigated through experimental and numerical simulation approaches. The results indicate that the received signal intensity of electromagnetic waves across different frequency bands diminishes with increasing propagation distance in the lossy environment of the goaf. Initially, the decay follows a logarithmic pattern, whereas, at later stages, the attenuation exhibits a gradual and smooth decrease. As the frequency increases, the initial attenuation amplitude of electromagnetic wave intensity rises; however, subsequent attenuation is largely unaffected by frequency, with the later attenuation rate being proportional to porosity. Electromagnetic waves at a frequency of 700 MHz exhibit a low attenuation coefficient under both experimental and simulated conditions, demonstrating superior stability and reliability. This frequency significantly enhances the overall performance of the communication system and is suitable for use as the operational frequency band in wireless sensor networks.

Utilizing the mutant library to investigate the functional characterization of GhGLR3.4 regulating jasmonic acid to defense pest infestation.

The glutamate receptor (GLR) serves as a ligand-gated ion channel that plays a vital role in plant growth, development, and stress response. Nevertheless, research on GLRs in cotton is still very limited. The present study conducted a comprehensive analysis of GLRs gene family in cotton. In total, 41 members of the GLR family were identified in cotton unveiling distinct subgroups in comparison to Arabidopsis. Among these members, the third subgroup highlights its pivotal role in cotton's defense against insect infestation. Furthermore, the CRISPR/Cas9 system was utilized to create a mutant library of GLR members, which consisted of a total of 135 independent mutant lines, resulting in the production of novel cotton materials with valuable breeding potential for pest control. Further, this study elucidates the influence of GhGLR3.4 on jasmonic acid (JA) pathway signal transduction and demonstrated its participation in the influx of intracellular Ca2+, which regulates "calcium transients" following stimulation, thereby influencing multiple intracellular reactions. The study also found that GhGLR3.4 influences the synthesis of the JA pathway and actively partakes in long-distance signal transmission among plants, facilitating the transfer of defense signals to neighbor leaves and thereby triggering systemic defense. Consequently, this research advances our knowledge of plants' comprehensive defense mechanism against insect pest infestation.

Real-time monitoring of aero-engine vibration signals by wireless communication technology

Abstract The conventional way to monitor the vibration signals of aircraft engines is to use wired communication sensors to transmit and collect the signals on a fixed platform on the ground. The signal acquisition equipment of wired communication technology has various drawbacks, resulting in the inability to collect vibration signals when the object under test is in real operating conditions. Based on previous studies, this research team uses a 2.4G wireless transmission scheme to realize short-distance wireless transmission of aero-engine vibration signals, and a 4G cellular communication scheme to realize long-distance wireless transmission of aero-engine vibration signals. The acquired signals are displayed and monitored using the tool developed in LabVIEW2022. The designed tool is successfully applied in the engineering practice of engine maintenance, realizing the remote real-time monitoring of the engine operation status, shortening the monitoring cycle of the equipment from hourly to real-time level, and greatly facilitating the technical support work of engineers and technicians.

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.

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.

Photonic architecture for remote multi-parameter measurement and transmission of microwave signals

A photonic architecture for remote multi-parameter measurement and transmission of microwave signals is proposed and demonstrated, which utilizes a dual-parallel dual-drive Mach-Zehnder modulator (DP-DDMZM) in the antenna unit and a dual-drive Mach-Zehnder modulator (DDMZM) in the processing unit. Doppler frequency shift (DFS) and angle of arrival (AOA) can be determined by analyzing the down-converted intermediate frequency signals. Introducing a reference signal in the processing unit ensures DFS measurement without directional ambiguity. The proposed architecture can also be applied for instantaneous frequency measurement based on down-conversion. Due to the use of optical single sideband modulation, long-distance transmission of radio frequency (RF) signals without dispersion-induced power fading can be achieved. Experiments for accurate and stable DFS and AOA measurement as well as long-distance RF signal transmission with dispersion-induced power fading are presented. The approach avoids the use of optical filters and polarization-related devices, facilitating wideband and stable operation, which is highly desirable. The proposed architecture is a potential solution for microwave photonic antenna remoting, offering support for both remote transmission and multi-parameter measurement.

5G NB-IoT System Integrated with High-Performance Fiber Sensor Inspired by Cirrus and Spider Structures.

Real-time telemedicine detection can solve the problem of the shortage of public medical resources caused by the coming aging society. However, the development of such an integrated monitoring system is hampered by the need for high-performance sensors and the strict-requirement of long-distance signal transmission and reproduction. Here, a bionic crack-spring fiber sensor (CSFS) inspired by spider leg and cirrus whiskers for stretchable and weavable electronics is reported. Trans-scale conductive percolation networks of multilayer graphene around the surface of outer spring-like Polyethylene terephthalate (PET) fibers and printing Ag enable a high sensitivity of 28475.6 and broad sensing range over 250%. The electromechanical changes in different stretching stages are simulated by Comsol to explain the response mechanism. The CSFS is incorporated into the fabric and realized the human-machine interactions (HMIs) for robot control. Furthermore, the 5G Narrowband Internet of Things (NB-IoT) system is developed for human healthcare data collection, transmission, and reproduction together with the integration of the CSFS, illustrating the huge potential of the approach in human-machine communication interfaces and intelligent telemedicine rehabilitation and diagnosis monitoring.

Ca2+/calmodulin-mediated desensitization of glutamate receptors shapes plant systemic wound signalling and anti-herbivore defence.

Plants rely on systemic signalling mechanisms to establish whole-body defence in response to insect and nematode attacks. GLUTAMATE RECEPTOR-LIKE (GLR) genes have been implicated in long-distance transmission of wound signals to initiate the accumulation of the defence hormone jasmonate (JA) at undamaged distal sites. The systemic signalling entails the activation of Ca2+-permeable GLR channels by wound-released glutamate, triggering membrane depolarization and cytosolic Ca2+ influx throughout the whole plant. The systemic electrical and calcium signals rapidly dissipate to restore the resting state, partially due to desensitization of the GLR channels. Here we report the discovery of calmodulin-mediated, Ca2+-dependent desensitization of GLR channels, revealing a negative feedback loop in the orchestration of plant systemic wound responses. A CRISPR-engineered GLR3.3 allele with impaired desensitization showed prolonged systemic electrical signalling and Ca2+ waves, leading to enhanced plant defence against herbivores. Moreover, this Ca2+/calmodulin-mediated desensitization of GLR channels is a highly conserved mechanism in plants, providing a potential target for engineering anti-herbivore defence in crops.

NTIMP1—A Fast Pulse Readout Chip With 1.2 V Power Supply Applied to the Diamond Detector in HIAF

A very fast pulse readout ASIC, NTIMP1, with 1.2 V power supply is presented in this work. It is going to be used as front-end electronics (FEE) for reading out the diamond detector signals in the TOF (Time of Flight) wall of RIBLL2 experiment of the High Intensity Heavy Ion Accelerator Facility (HIAF), China. So that an 8-channel fast front-edge readout chip named as NTIMP1 is proposed in this work. Each channel of NTIMP1 has a high-bandwidth preamplifier (with adjustable thresholds) dealing with differential current input, a fast hysteresis discriminator, and a LVDS (Low-Voltage Differential Signaling) module ensuring long-distance signal transmission. Fabricated with 0.13 μm standard CMOS Technology, NTIMP1 can get an input ranging from 2 fC to 2000 fC and the input impedance of the preamplifier can be adjusted externally with an off-chip resistor, so as to match with the electrode impedance of diamond detector. The bandwidth of the preamplifier is 495.5 MHz, which allows a very short signal peaking time of no more than 1 ns. The jitter of the leading edge is lower than 15 ps with 100 fC input charge suggesting that NTIMP1 is suitable for high-resolution TOF measurement as well as time-slewing correction.

5G Communication: High Gain Array Antenna Operating at 3.5GHz

—5G technology is leverages advanced antenna technology and wider bandwidth to improve the potential of wireless communication that enables a significant increase in the amount of information that can be transmitted through the wireless system. With its ability to deliver higher data rates and lower latency, 5G promises to support a wide range of applications, from immersive virtual reality to autonomous vehicles.However, 5G communication systems are characterized by poor radiation features, which limit their usefulness in wider operational ranges. To overcome these issues, this project will focus on designing a high-gain array antenna operating at 3.5GHz specifically for 5G communication. A directional patch antenna will be designed for a specific base station to provide high radiation network connectivity and superior communication quality. Moreover, the high-gain array antenna at 3.5GHz will be optimized for long-distance point-to-point connections. In this project, a 4x4 patch antenna will be designed and fabricated using FR4 epoxy material to achieve high gain for long-distance signal transmission.

Construction and Application of On-Line Roof Separation Monitoring System Based on High-Precision FBG Indicator

Aiming at the existing problems of low efficiency, lagging monitoring results, and poor reliability and accuracy in the present roadway roof separation monitoring system, a high-precision Fiber Bragg Grating (FBG) separation indicator is designed through theoretical analysis, numerical simulation, and laboratory tests—according to the fiber grating sensing principle. Based on the Microsoft. Net platform, C# programming language, and VS2010 integrated development tools, the corresponding on-line monitoring software is developed. On this basis, a real-time on-line roof separation monitoring system is proposed. The high-precision FBG separator was calibrated and tested in the laboratory and results suggested that both the left and right arm demonstrate good sensitivity and linearity with linear fitting coefficient values of 0.9981 and 0.9979, respectively. The monitoring system was successfully applied to roof separation monitoring of the #14301 rail roadway in the Shaqu coal mine. The monitoring results showed that the on-line roof separation monitoring system based on the high-precision FBG separation indicator has the advantages of high precision, good stability, and long-distance signal transmission, which can achieve real-time dynamic monitoring and provides an effective method for long-term on-line monitoring of roadway roof separation.

Full-Distance A-RoF Transmission Experiment Utilizing Frequency-Optimized FM Conversion

Advances in the long-distance transmission of wideband A-RoF signals are critical. The world’s longest-class transmission using a practical A-RoF system is currently just over 300 km. In this system, CATV/BS/CS video signals are frequency-multiplexed with a bandwidth of 2.1 GHz and transmitted from broadcaster buildings to houses scattered throughout the country. In recent years, there is a demand to extend this bandwidth to 3.2 GHz in order to multiplex 8K/4K ultra-high-definition video. However, A-RoF transmission over 300 km in the 3.2-GHz bandwidth is difficult and no one has been achieved. Our solution is a new transmitter that improves transmission characteristics by changing the FM center frequency and suppressing harmonics. Our experiments clarified the existence of an optimum FM center frequency that is less affected by self-phase modulation, chromatic dispersion, and residual FM signal degradation. The proposed transmitter achieved the target distance and bandwidth for the first time in the world.

Precision Design and Fabrication of Noise-free High-Frequency Amplifier Board for Enhanced Signal Processing

An optical signal processing system is widely used for long-distance signal transmission with high speed and low attenuation. It plays a fundamental role in optical communication systems that involves transmitting, receiving, amplifying, and manipulating optical signals which are high-frequency signals. This paper portrays the design of a high-frequency amplifier to amplify the low-amplitude high-frequency, electrical signal procured from the optical signal. A four-stage high frequency amplifier has been designed using an AD8009 high-frequency Op-amp for the highest frequency of 1GHz, and for the fastest rise time of 0.35 nanoseconds. This amplifier board incorporates the high-frequency PCB design rules related to the characteristic impedance, impedance matching, signal crosstalk, the propagation delay of the transmission lines, transmission techniques for the ground plane, and termination of transmission lines for the effective use of high-frequency signals. It has also counted on the issues of electromagnetic interference, power supply decoupling, noise, and high-speed operational amplifier. The proposed system resulted in suitable amplification of low amplitude high-frequency electrical signal, having no signal cross-talks, electromagnetic interference, signal ringing, signal reflections, and posed larger bandwidth. The improved quality of high frequency processed signals with good signal integrity and moderate circuit oscillations achieved by this system will benefit the optical communication system.

Elements of a Fiber Optic Communication System

Fiber optic connection is the best option for data transmission at gigabit and above rates. Voice, video, telemetry, and data are all transmitted using this method of communication over great distances and over computer networks or local area networks. By converting electronic signals into light, a fibre optic communication system uses light-wave technology to transfer data via fiber. Large bandwidth, smaller diameter, lightweight, long-distance signal transmission, low attenuation, transmission security, and other outstanding characteristics of this type of communication system make it a key component of any telecommunications infrastructure. The characteristic traits, fundamental components, and other aspects of fibre optic communication systems are highlighted in the information that follows.

Male gopher tortoise (Gopherus polyphemus) concentration-dependent social responses to diluted mental gland pheromones

In complex terrestrial environments, chemical signals can be the most important sensory modality for locating conspecifics for potential mating opportunities, especially in spatially segregated populations or habitats. Organisms must evolve chemical signals to maximize the efficacy of conveying information, particularly in creating trails or mate-choice cues. Long-distance transmission of chemical signals may be an increasingly important management concern for small and fractured populations or potentially threatened species, such as gopher tortoises in the southeastern U.S. Mental gland secretions have been shown to have pheromonal function in gopher tortoises, suggesting a potential role as trail or marking pheromones, allowing males to track females or other males to find females. In this study, male gopher tortoises were given paired presentations of a negative control (distilled water) with serial dilutions (1:4, 1:20, 1:100, and 1:500) of male mental gland secretions. Male tortoises were able to discern treatment differences up to 1:20 diluted secretions, responding with an array of social behaviors (e.g. for the 1:20 dilution trial, carapace alignment and head bobbing occurred more frequently for the mental gland secretion relative to the control; p < 0.01). Multivariate principal components analysis yielded PC1 (including, approach, carapace alignment, head bobbing, tasting air, sniffing, and doubleback) that differed by treatment (p = 0.0007) and also was higher for the 1:20 diluted presentation relative to the 1:500 diluted presentation (p = 0.04). This study provides insight into gopher tortoise ecology, mate-choice, and the utility of environmentally diluted mental gland secretions in the external environment when seeking mating opportunities.

Photonics-Aided Terahertz-Wave Wireless Communication

To meet the upcoming 6G communications challenges, terahertz-wave (THz-wave) wireless data transmission over 100 Gb/s is urgently needed in the short term. However, advanced digital signal processing (DSP) technologies suitable for millimeter-wave (mm-wave) bands cannot satisfy the requirements; increasing the carrier frequencies for more spectra is essential. Photonics-aided THz-wave generation (PTG) technology has become a valid way to solve the bandwidth bottleneck. New progress has been made in PTG by using optical frequency combs and optical modulators. The application of DSP technology for heterodyne detection can not only overcome the nonlinear effect in photoelectric devices but also enhance the receiver sensitivity and spectral efficiency. Multidimensional multiplexing technology can reduce the baud rate of each subchannel to realize the long-distance transmission of THz-wave signals. In this tutorial, we introduce the key technologies and principles of ultrahigh speed and large capacity THz-wave signal transmission. These technologies can effectively improve the transmission capacity and distance and reduce the bandwidth required by optical and electronic equipment.

A Split-Type FMICW-Based Guided Wave Radar With Multisegmental Probe for Liquid Level Measurement

In this paper, a specially designed guided wave radar device for measuring the liquid level in the nuclear industry is proposed. A split-type design is introduced to adapt to a strong radiation environment. An L-band frequency modulated interrupted continuous wave (FMICW) radar is designed to ensure the signal-to-noise ratio of echo signal after long-distance signal transmission, which provides the isolation between transmitter and receiver of more than 60 dB using the gating technology. To overcome the shortcomings of limited installation and maintenance space, a novel coaxial waveguide probe with a multi-segmental structure is proposed and simulated. An adaptive signal processing algorithm is developed to remove false echoes and eliminate measurement fluctuations. A prototype of the proposed measurement system is fabricated and evaluated. Static and dynamic liquid level experiments are performed in an outdoor environment to assess performance and verify the effectiveness of the proposed radar. The results show that the standard deviation measurement error of the proposed radar is within 0.4 cm. The proposed system is expected to have a high potential for applications in liquid level measurement under complex conditions.

Low-cross-talk and multi-channel heterogeneous 13-core four-LP mode fiber with a high refractive index ring and a trench

We propose a heterogeneous 13-core few-mode fiber, which is characterized by the combination of a high refractive index ring and a trench. All cores of the optical fiber can stably transmit L P 01 , L P 11 , L P 21 , and L P 02 modes in the C + L band through structural optimization and numerical analysis. The effective refractive index difference of the L P 21 and L P 02 modes reaches 2 × 10 − 3 , which is conducive to the independent transmission of modes. The trench can effectively suppress the inter-core cross talk below − 50 d B / k m at 1550 nm. The proposed few-mode multi-core fiber is conducive to solving the long-distance signal transmission problem of large capacity and low cross talk in future optical communication systems.

An Innovative Infrastructure Based on Shape-Adaptive RIS for Smart Industrial IoTs

Industrial Internet of Things (IoTs) applications will have higher demands in terms of system capacity and wireless transmission performance in the future. Reconfigurable intelligent surfaces (RIS) for the wireless transmission environment reconstruction is currently a research hotspot in the field of wireless communication. In this paper, RIS is applied to industrial IoTs scenarios, and an innovative infrastructure based on shape-adaptive RIS suitable for smart industrial IoTs is proposed. Based on the many advantages of RIS, the proposed infrastructure can meet the significant demands of industrial IoTs in terms of network coverage, system capacity, transmission rate, and communication security. Further, in order to achieve flexible RIS phase adjustment in wider ranges, in this paper, a shape-adaptive RIS mechanism is proposed to regulate RIS-reflected waves in the shape domain, which can be achieved by scalable RIS unit sizes and macroscopically changeable physical shapes. This mechanism can reduce the requirements for RIS-controller and artificial-unit design and expand the spatial distribution of reflected beams, whereas this is difficult to achieve by conventional regulations in the spatial, time, and frequency domains. The simulation results show that, in terms of system-coverage probability, the system performance of RIS is better than that of general communication systems, and the performance of the deformable RIS-based system is the best. In terms of channel gain, the performance of the deformable RIS is related to its surface size. Moreover, the path loss caused by the long-distance transmission of wireless signals can be compensated for by increasing the RIS surface area.

Ultra-low-latency 8K-video-transmission System Utilizing Whitebox Transponder with Disaggregation Configuration

The demand for low-latency transmission of large-capacity video, such as 4K and 8K, is increasing for various applications such as live-broadcast program production, sports viewing, and medical care. In the broadcast industry, low-latency video transmission is required in remote production, an emerging workflow for outside broadcasting. For ideal remote production, long-distance transmission of uncompressed 8K60p video signals, ultra-low latency less than 16.7 ms, and PTP synchronization through network are required; however, no existing video-transmission system fully satisfy these requirements. We focused on optical transport technologies capable of long-distance and large-capacity communication, which were previously used only in telecommunication-carrier networks. To fully utilize optical transport technologies, we propose the first-ever video-transmission system architecture capable of sending and receiving uncompressed 8K video directly through large-capacity optical paths. A transmission timing control in seamless protection switching is also proposed to improve the tolerance to network impairment. As a means of implementation, we focused on whitebox transponder, an emerging type of optical transponder with a disaggregation configuration. The disaggregation configuration enables flexible configuration changes, additional implementations, and cost reduction by separating various functions of optical transponders and controlling them with a standardized interface. We implemented the ultra-low-latency video-transmission system utilizing whitebox transponder Galileo. We developed a hardware plug-in unit for video transmission (VideoPIU), and software to control the VideoPIU. In the video-transmission experiments with 120-km optical fiber, we confirmed that it was capable of transmitting uncompressed 8K60p video stably in 1.3 ms latency and highly accurate PTP synchronization through the optical network, which was required in the ideal remote production. In addition, the application to immersive sports viewing is also presented. Consequently, excellent potential to support the unprecedented applications is demonstrated.