Reliability Of Signal Transmission Research Articles

Scaled Elastic Hydrogel Interfaces for Brain Electrophysiology

AbstractThe advancement in brain–computer interface technology has facilitated real‐time communication between the brain and external devices, rapidly expanding invasive brain–computer interfaces. Nevertheless, little progress has been made in improving the one‐way, noninvasive brain–computer interface technology using conductive methods, necessitating enhancements to the current paste contact electrodes. In this paper, a captivating spherical electrode is fabricated that exhibits noncytotoxic properties, combining alginate hydrogel with indium tin oxide conductor components. The electrode's remarkable and consistent electrical conductivity enables it to generate stable adaptive deformations that conform to diverse scalp topographies. Most impedance values fall below 10 kΩ, indicating heightened hydrophilicity compared to traditional conductive pastes, as evidenced by contact angle measurements. An empirical electroencephalography data collection study confirms its conductivity and signal transmission reliability. The acquired electroencephalography signals are utilized for emotion recognition utilizing band energy ratio analysis and support vector machine (SVM) algorithms. The operation of this system is both straightforward and convenient, requiring minimal preparation before and after the collection of electroencephalography signals. Utilizing an extensive range of raw materials and straightforward preparatory procedures enhances the potential industrial application of hydrogel electrodes, thereby significantly contributing to advancing civilian electroencephalography equipment and investigating depression‐related pathologies.

Enhanced symbol capacity and loss budget employing joint channel coded modulation in DMT-WDM-PON

A joint channel coded modulation scheme based on symbol division multiplexing (SDM) is proposed and experimentally demonstrated in a 100-Gb/s discrete multi-tone wavelength division multiplexing passive optical network (DMT-WDM-PON) with enhanced symbol capacity and system power loss budget. The SDM was performed through low-density parity check (LDPC) coded quadrature amplitude modulation (QAM) following the optimized many-to-one mapping rule. By time domain multiplexing all four 6-bit/symbol 64QAM symbols together onto the same complex constellation point, the produced SDM-16QAM can achieve a 50% symbol capacity gain compared to the typical 16QAM with the same symbol rate. For low-latency intention, the fifth-generation new radio standard LDPC code with ultra-short code length and flexible code rate is structured to provide high signal transmission reliability and a robust mechanism within both intra- and inter-SDM symbols, supporting the iterative SDM de-multiplexing. The SDM significantly reduces the QAM orders and widens the constellation Euclidean distance, which can optimize the signal launch fiber power and reduce the resolution requirements for optoelectronic and electronic components, thus leading to apparent enhancement of the power loss budget to serve more optical network units. The experimental results show that a 4.11-dB power loss budget gain can be achieved including 1.25-dB superior receiver power sensitivity and 2.86-dB improvement of launch fiber power in the proposed DMT-WDM-PON over 20-km fiber transmission.

Multi-Relay Cognitive Network With Anti-Fragile Relay Communication for Intelligent Transportation System Under Aggregated Interference

The rapid development and continuous innovation of wireless services have led to a boom in the number and types of smart terminals. The huge amount of data that deep learning needs to calculate relies on the continuous improvement of hardware devices to solve. Therefore, the realization of intelligent transportation system(ITS) has become the general trend. The increase in the number of Internet of Things devices and the changes in the location of vehicles in the Internet of Vehicles(IOV) system have put forward higher requirements for the reliability and effectiveness of information transmission and the effective use of spectrum resources. Aiming at the influence and elimination of aggregated interference in intelligent transportation system, an anti-fragile communication algorithm is proposed to improve the reliability of signal transmission. At the same time, the outage probability of energy harvesting and cognitive radio technology enhanced with relay cooperative transmission under cognitive wireless network system with the aggregate interference can be deduced in detail. Finally, the correctness of theoretical analysis and the reliability of the proposed anti-fragile communication algorithms are verified by simulation experiments.

System optimization for index modulated OFDM

This paper introduces the system optimization scheme of OFDM-IM, an emerging modulation technology that combines OFDM technology and modulation index technology to improve spectral efficiency and system reliability while ensuring high-speed transmission. However, as a new technology, OFDM still has shortcomings. This paper investigates three system optimization schemes for OFDM-IM: he deep learning-based OFDM-IM optimization scheme, MIMO-OFDM-IM, and LDPC coding-assisted subcarrier index protection scheme. It is found that these three optimization schemes are indeed helpful for optimizing the performance of OFDM-IM through system simulation experiments. The IM-OFDM system optimization based on deep learning is very helpful for IM-OFDM in terms of channel estimation, signal detection, and modulation classification. MIMO-OFDM-IM can increase channel capacity and signal transmission reliability. By protecting the subcarrier index, LDPC codes can effectively reduce the subcarrier error rate and improve the reliability and performance of IM-OFDM systems. Due to their different technical characteristics, the three optimization schemes have different advantages. They also have their application scenarios in which they excel. However, considering these technologies are relatively new, there are still certain drawbacks to these three technologies. Researchers need to continue to study them in-depth and gradually overcome them.

Output-Feedback Control for Fuzzy Singularly Perturbed Systems: A Nonhomogeneous Stochastic Communication Protocol Approach.

In this study, the output-feedback control (OFC) strategy design problem is explored for a type of Takagi-Sugeno fuzzy singular perturbed system. To alleviate the communication load and improve the reliability of signal transmission, a novel stochastic communication protocol (SCP) is proposed. In particular, the SCP is scheduled based on a nonhomogeneous Markov chain, where the time-varying transition probability matrix is characterized by a polytope-structure-based set. Different from the existing homogeneous Markov SCP, a nonhomogeneous Markov SCP depicts the data transmission in a more reasonable manner. To detect the actual network mode, a hidden Markov process observer is addressed. By virtue of the hidden Markov model with partly unidentified detection probabilities, an asynchronous OFC law is formulated. By establishing a novel Lyapunov-Krasovskii functional with a singular perturbation parameter and a nonhomogeneous Markov process, a sufficient condition is exploited to guarantee the stochastic stability of the resulting system, and the solution for the asynchronous controller is portrayed. Eventually, the validity of the attained methodology is expressed through a practical example.

RF Circuit EMI Suppression and EMC Analysis

The radio frequency circuit will generate strong electromagnetic interference in the process of signal transmission, and its own resistance to electromagnetic interference is weak, and the radio frequency circuits operating in the same electromagnetic environment are prone to mutual interference. Therefore, it is necessary to analyze the electromagnetic interference effect of radio frequency circuits, and then find effective suppression measures, build a good public electromagnetic environment, realize electromagnetic compatibility, and ensure the reliability of signal transmission. This research first briefly introduces electromagnetic interference and electromagnetic compatibility and then analyzes the key points of electromagnetic interference suppression in radio frequency circuits. On this basis, the specific application of electromagnetic interference suppression and electromagnetic compatibility technology of radio frequency circuit is discussed. It can serve as a guide for the design of the radio frequency circuit by analyzing the characteristics and suppression mechanism of the electromagnetic interference of the radio frequency circuit. To ensure the suppression impact of electromagnetic interference, various suppression measures are broadly implemented in accordance with the three components of electromagnetic interference. The electromagnetic compatibility-based design of RF circuits can reduce the mutual interference of RF circuits in the system and guarantee the stability and dependability of signal transmission.

Mechanical simulation for the bending process of the AMOLED panel pad

Panel pad bending is a critical process to improve the screen-to-body ratio of an active-matrix organic light-emitting diode (AMOLED) panel. The failure analysis of the metal wirings is the key to ensure the reliability of signal transmission when the pad be bent to the back of the panel. In the present work, the sub-modeling technique combined with the periodic boundary condition was used to simulate the stress distribution of the bending area of the pad. The progressive failure of bent metal wirings was investigated by the extended finite element method. It is proved to be rational to prevent the wirings damage if the interlayer dielectric is replaced by an organic layer. In order to reduce stress of metal wirings, it is a measure to replace the original ultraviolet (UV) curable adhesive with a higher-modulus UV adhesive. The simulated results also show that rectangular perforations can avoid the stress concentration caused by the holes compared with circular perforations. For better stress distribution of metal wirings, it is necessary to increase the lengths of the rectangular holes and decrease the widths of that to a certain extent, which is helpful for restraining crack propagation by means of low-stress zones and holes.

An integrated approach for electromagnetic compatible commercial aircraft engine cable harnessing

Signal transmission reliability of cable harnesses is essential to commercial aircraft engine performance and flight safety as a commercial aircraft operates in growingly complex electromagnetic (EM) environments. Investigating EM responses of aircraft engine cable harnesses under high-intensity radiated field (HIRF) excitations enables optimization of cable harness configurations, and ensures satisfaction of airworthiness requirements of electromagnetic compatibility (EMC). Comprehending EM responses of aircraft engine cable harnesses also significantly improves robustness of the engine control system against EM disturbances. In alignment with industrial information integration engineering (IIIE), this work develops an integrated EM compatible cable harnessing model consisting sub-models accounting for disciplinary concerns of engine system performance, cable materials, cable structures, EM interferences, electric loadings, control robustness, etc. Then, this work verifies and validates the proposed cable harnessing models by conducting numerical experiments on a given cable harness subject to a number of EM wave interferences. The cable harnessing models and the tandem numerical analysis approaches developed in this work appreciably overcomes deficiencies appeared in relevant previous studies, and substantially support developments of a commercial aircraft engine.

Underwater Acoustic Covert Communication Based on Compressed Sensing

Compressed sensing technology is currently a relatively mature channel estimation technology, and the sparsity of the underwater acoustic channel provides a basis for the application of compressed sensing technology to the underwater acoustic channel. Channel estimation is one of the most commonly used signal reconstruction methods. The signal is reconstructed based on compressed sensing technology to improve the reliability of signal transmission. The key to compressed sensing technology is the SL0 algorithm. Based on the SL0 algorithm, a new objective function is proposed to better approximate the L0 norm. In a very short time, the original signal can be reconstructed accurately and the signal transmission is improved. Finally a simulation experiment is used to compare the proposed objective function with the previously proposed objective function, which proves that the performance of the proposed objective function is better.

Design of shock-resistant miniaturized shipborne radar confluence ring

In order to reduce the overall size of the shipborne radar and improve the reliability of signal transmission, a miniaturized design has been carried out on the shipboard radar confluence ring. The miniaturized confluence ring adopted the electric contact form that the brush wires and the conductive ring are matched. The brush wires and the conductive ring coating used high-performance noble metal electrical contact materials, and the contact force was designed to be 0.1N to ensure the reliable and effective electrical contact. In addition, the dynamic design analysis method (DDAM) was used to analyze the shock resistance of the confluence ring. The test results showed that the size of the confluence ring had been reduced, all performance indicators met the requirements, and reliable transmission of various signals could be realized; the calculation results showed that the maximum impact stress of the confluence ring was less than the yield strength of the shell material, which met the requirements of the ship equipment shock resistance design requirements. The design method and analysis results have reference value and guiding significance for the miniaturization design and shock assessment of shipborne radar confluence ring.

10-Gbps real-time wireless link over 1.5 km at 220-GHz band based on Schottky-diode transceiver and 16-QAM modulation

A wireless link working at 220-GHz band is proposed for point-to-point high-speed communication. The system is primarily composed of sub-terahertz transceivers and baseband data processing platforms. Subharmonic mixers based on Schottky diode are developed and measured with a double-sideband (DSB) noise temperature of lower than 1100 K from 205 GHz to 230 GHz. High-selectivity waveguide bandpass filters are designed to reject the image sideband noise from entering the receiver. Two 58-dBi Cassegrain antennas are used to compensate for the large energy losses contributed by free space path and atmospheric absorption. Besides, sub-THz amplifiers based on InP HEMT technology are developed to further increase the transmitting power. To improve spectrum efficiency, 16 quadrature amplitude modulation is adopted. Forward error correction is implemented by using Reed-Solomon codes to reinforce the reliability of signal transmission. An outdoor wireless link is finally established within 1.5 km, and a data rate of 10 Gbps is achieved in real-time mode with an EVM of 9.53% (BER 1.4×10-9). For demonstration, uncompressed ultra-HD videos are successfully transmitted. Note that any auxiliary electronic testing and measurement equipment is not required while communicating. It is believed that this article provides an effective and practical solution for future long-distance high-speed communication.

Placement Design for a Stacked Die Package With Reliable Wireless Connections

In this article, vertical interconnection implemented as capacitive-based chip-to-chip differential signaling offers crosstalk noise reduction in three-dimensional (3-D) die stacking. To investigate the effects of signal transmission reliability on the 3-D stacked die structure, this article aims at providing the parametric models. The signal and noise properties of capacitively coupled channels are studied using a 3-D electromagnetic field solver to extract the mixed-mode scattering parameters of the differential signal pads. Corner differential arrangements are considered, and their abilities to reject noise are investigated through the proposed parametric models. The exponential decay and generalized exponential decay models are formulated and estimated with the simulated data to assess the transmission quality of the signal. It is observed that there is a nonlinear pattern of the signal-to-noise ratio values related to differential frequency responses for the given pad overlap and the pitch size. The performances of the two models are compared through the root-mean-square error and the mean absolute percentage error for sample fitting as well as for extrapolation prediction. The characteristics of the generalized exponential decay models are also presented and illustrated. The proposed design methodology can be applied to expedite the optimized implementation of capacitive coupling interconnection for a specific operating frequency band.

Micro-drilling characteristics of sequential glass fiber-reinforced resin-based/copper foil multi-layer sheets

High frequency printed circuit board (HFPCB), a sequential glass fiber-reinforced resin-based/copper foil multi-layer sheet, is widely used as printed circuit boards in next-generation 5G communication base stations, radar antenna, smart cars, etc. Micro-holes are key components that enable the interconnections of different layers, fixed electronic components, and high-density wiring. However, hole wall debris and micro-drill breakage during the micro-drilling of sequential glass fiber-reinforced resin-based/copper foil multi-layer sheet negatively affect the quality and reliability of signal transmission. Herein, chip removal, chip morphology, drilling temperature, thrust force characteristics, and hole wall morphology of HFPCB micro-drilling are investigated. The effect of chip morphology on chip removal is analyzed. Additionally, the effects of thrust force and micro-drill breakage are analyzed. The formation mechanism of hole wall debris is proposed. Compared with traditional FR4, the fracture mechanism and control method of micro-drill breakage are proposed by analyzing the characteristics and cause of typical thrust force variations. Results show that the drilling temperature and chip removal of HFPCB are primary factors causing hole wall debris. The morphology of HFPCB chips primarily includes the chips of copper foil, agglomerate chips of resin layer, and mixed copper-foil–resin chips. The increase in prepreg, resin content, and number of multi-layers causes a large amount of cutting heat during HFPCB micro-drilling. Meanwhile, the large thickness, large depth ratio, and diameter resulted in poor chip removal. Subsequently, the constant accumulation of heat in the hole resulted in resin melting, followed by adhering to the hole wall, thus generating hole wall debris through a thermo-mechanical coupling extrusion. The long-term fluctuation of thrust force is the main reason for micro-drill breakage during micro-drilling.

Power cognition: Enabling intelligent energy harvesting and resource allocation for solar-powered UAVs

Solar-powered unmanned aerial vehicles (SUAVs) are a promising solution to increase the flight time of unmanned aerial vehicles (UAVs) in the sky, reducing human interventions for battery charging. Exploiting networked SUAVs for providing long-duration wireless communication cannot only improve the signal transmission reliability but realize energy autonomy. To reap these benefits, in this article, we propose an efficient energy and radio resource management framework based on intelligent power cognition at the SUAVs. Thereby, power-cognitive SUAVs can learn the environment including the spatial distributions of solar energy density, the channel state evolution, and the traffic patterns of wireless communication applications in adaption to the environment changes. These SUAVs intelligently adjust the energy harvesting, information transmission, and flight trajectory to improve the utilization of solar energy for two primary goals: staying aloft over a long time period and achieving high communication performance. We adopt reinforcement learning to compute the optimal decisions for maximization of the total system throughput within the lifetime of the SUAV. Simulation results show that the proposed power cognition scheme can simultaneously improve the communication throughput and the harvested energy for SUAVs.

Improving transmission reliability of inductive coupling temperature-salinity-depth mooring cable system

Inductive coupling temperature-salinity-depth mooring cable is an important instrument for measuring deep sea environment. However, the channel characteristics change depending on the load and marine environment, and these characteristics affect the signal transmission reliability. In this paper, an inductive coupling temperature-salinity-depth communication system is developed and channel characteristics are derived theoretically. The amplitude-frequency and phase-frequency characteristics in seawater and freshwater environments are measured using the frequency-sweep method in laboratory. The measured results are compared with the theoretical results. The accuracy of the results is verified by recovering a square-wave using the measured amplitude-frequency and phase-frequency characteristics. Next, amplitude shift keying modulation is used to test the signal transmission reliability and the results show that the error rates are high due to the influence of noise. Finally, to improve the signal transmission reliability, a concatenated code comprising of Reed-Solomon and convolution code is used. The concatenated code can make the error rate less than 1.906% and 6.502% in sea water and fresh water, respectively. The study provides an important experimental evidence for understanding the channel characteristics and improving signal transmission reliability of inductive coupling temperature-salinity-depth mooring cable.

High frequency neurons determine effective connectivity in neuronal networks

The emergence of flexible information channels in brain networks is a fundamental question in neuroscience. Understanding the mechanisms of dynamic routing of information would have far-reaching implications in a number of disciplines ranging from biology and medicine to information technologies and engineering. In this work, we show that the presence of a node firing at a higher frequency in a network with local connections, leads to reliable transmission of signals and establishes a preferential direction of information flow. Thus, by raising the firing rate a low degree node can behave as a functional hub, spreading its activity patterns polysynaptically in the network. Therefore, in an otherwise homogeneous and undirected network, firing rate is a tunable parameter that introduces directionality and enhances the reliability of signal transmission. The intrinsic firing rate across neuronal populations may thus determine preferred routes for signal transmission that can be easily controlled by changing the firing rate in specific nodes. We show that the results are generic and the same mechanism works in the networks with more complex topology.

Reliability of signal transmission in stochastic nerve axon equations

We introduce a method for computing probabilities for spontaneous activity and propagation failure of the action potential in spatially extended, conductance-based neuronal models subject to noise, based on statistical properties of the membrane potential. We compare different estimators with respect to the quality of detection, computational costs and robustness and propose the integral of the membrane potential along the axon as an appropriate estimator to detect both spontaneous activity and propagation failure. Performing a model reduction we achieve a simplified analytical expression based on the linearization at the resting potential (resp. the traveling action potential). This allows to approximate the probabilities for spontaneous activity and propagation failure in terms of (classical) hitting probabilities of one-dimensional linear stochastic differential equations. The quality of the approximation with respect to the noise amplitude is discussed and illustrated with numerical results for the spatially extended Hodgkin-Huxley equations. Python simulation code is supplied on GitHub under the link https://github.com/deristnochda/Hodgkin-Huxley-SPDE.

Exploration of Digital Frequency Band System

Digital modulation techniques is a very important method of realizing modern communication. The showing up of Digital modulation techniques promoted the development of modern communication.. Research on digital communications modulation theory, provide an effective modulation, compressed signal transmission band, increase channel multiplexing efficiency, improve signal transmission reliability, has important significance in practice.

The extracellular matrix molecule brevican is an integral component of the machinery mediating fast synaptic transmission at the calyx of Held.

The proteoglycan brevican is a major component of the extracellular matrix of perineuronal nets and is highly enriched in the perisynaptic space suggesting a role for synaptic transmission. We have introduced the calyx of Held in the auditory brainstem as a model system to study the impact of brevican on dynamics and reliability of synaptic transmission. In vivo extracellular single-unit recordings at the calyx of Held in brevican-deficient mice yielded a significant increase in the action potential (AP) transmission delay and a prolongation of pre- and postsynaptic APs. The changes in dynamics of signal transmission were accompanied by the reduction of presynaptic vGlut1 and ultrastructural changes in the perisynaptic space. These data show that brevican is an important mediator of fast synaptic transmission at the calyx of Held. The extracellular matrix is an integral part of the neural tissue. Its most conspicuous manifestation in the brain are the perineuronal nets (PNs) which surround somata and proximal dendrites of distinct neuron types. The chondroitin sulfate proteoglycan brevican is a major component of PNs. In contrast to other PN-comprising proteoglycans (e.g. aggrecan and neurocan), brevican is mainly expressed in the perisynaptic space closely associated with both the pre- and postsynaptic membrane. This specific localization prompted the hypothesis that brevican might play a role in synaptic transmission. In the present study we specifically investigated the role of brevican in synaptic transmission at a central synapse, the calyx of Held in the medial nucleus of the trapezoid body, by the use of in vivo electrophysiology, immunohistochemistry, biochemistry and electron microscopy. In vivo extracellular single-unit recordings were acquired in brevican-deficient mice and the dynamics and reliability of synaptic transmission were compared to wild-type littermates. In knockout mice, the speed of pre-to-postsynaptic action potential (AP) transmission was reduced and the duration of the respective pre- and postsynaptic APs increased. The reliability of signal transmission, however, was not affected by the lack of brevican. The changes in dynamics of signal transmission were accompanied by the reduction of (i) presynaptic vGlut1 and (ii) the size of subsynaptic cavities. The present results suggest an essential role of brevican for the functionality of high-speed synaptic transmission at the calyx of Held.

Optimal size of stochastic Hodgkin-Huxley neuronal systems for maximal energy efficiency in coding pulse signals.

The generation and conduction of action potentials (APs) represents a fundamental means of communication in the nervous system and is a metabolically expensive process. In this paper, we investigate the energy efficiency of neural systems in transferring pulse signals with APs. By analytically solving a bistable neuron model that mimics the AP generation with a particle crossing the barrier of a double well, we find the optimal number of ion channels that maximizes the energy efficiency of a neuron. We also investigate the energy efficiency of a neuron population in which the input pulse signals are represented with synchronized spikes and read out with a downstream coincidence detector neuron. We find an optimal number of neurons in neuron population, as well as the number of ion channels in each neuron that maximizes the energy efficiency. The energy efficiency also depends on the characters of the input signals, e.g., the pulse strength and the interpulse intervals. These results are confirmed by computer simulation of the stochastic Hodgkin-Huxley model with a detailed description of the ion channel random gating. We argue that the tradeoff between signal transmission reliability and energy cost may influence the size of the neural systems when energy use is constrained.