Quality Of Information Transmission Research Articles

Studying the influence of correction codes on coherent reception of M-PSK signals in the presence of noise and harmonic interference

Objectives. Signals with multiple phase shift keying (M-PSK) exhibiting good spectral and energy characteristics are successfully used in many information transmission systems. These include satellite communication systems, GPS, GLONASS, DVB/DVB-S2, and a set of IEEE 802.11 wireless communication standards. In radio communication channels, the useful signal is affected by various interferences in addition to noise. One of these is harmonic interference. As a result, high intensity harmonic interference practically destroys the reception of M-PSK signals. One of the important requirements for the quality of data transmission is the system error tolerance. There are different ways of improving the quality of information transmission. One of these is the use of corrective encoding technology. The aim of the paper is to assess the noise immunity of a coherent demodulator of M-PSK signals using Hamming codes (7,4) and (15,11), and convolutional encoding with Viterbi decoding algorithm (7,5) when receiving M-PSK signals under noise and harmonic interference in the communication channel.Methods. The methods of statistical radio engineering, optimal signal reception theory and computer simulation modeling were used.Results. Experimental dependencies of the bit error rate on the signal-to-noise ratio and on the intensity of harmonic interference of coherent reception of M-PSK signals in a channel with noise and harmonic interference were obtained using computer simulation modeling. This was done without using correction codes and with Hamming code (7.4) and (15.11) and convolutional encoding with Viterbi decoding algorithm (7,5).Conclusions. It is shown that the application of the correction codes effectively corrects errors in the presence of noise and harmonic interference with lower intensity. The correction is ineffective in the presence of high intensity interference. These results can provide important guidance in designing the reliable and energy efficient system.

Development of a model of the information and analytical system for making decisions on detecting failures of information transmission channels

The object of the research is the channels of information transmission during the control of the information-analytical decision-making system. The development of high technologies and computing capabilities ensures the evolutionary development of smart technologies and socio-cyber-physical systems on the one hand. On the other hand, it forms the integration of targeted (mixed) attacks with the possibility of integration with social engineering methods. In addition, mobile technologies significantly increase the possibilities of data transmission speed. However, this only provides the authentication service, which does not provide a full range of security services. Under such conditions, an urgent task at the decision-making stage is the use of auxiliary systems that ensure the adequacy of decisions and the promptness of their adoption. The proposed mathematical model of the information and analytical system allows to calculate the main technical characteristics of information transmission channels and identify their possible failures. The use of an information and analytical system simplifies the decision-making process, allows to increase the reliability of such decisions due to an increase in the level of automation. Increasing the level of automation in the decision-making process removes subjective factors and the decision depends on the availability of information. Therefore, the reliability of the information transmission channels of the information and analytical system significantly affects the quality of the decisions made. The developed model allows to ensure the required level of reliability of information transmission channels. The obtained results are explained by determining the dependence between the parameters of the information and analytical system and their influence on the quality of information transmission through channels. The results of the study can be used in practice when considering systems with a limited number of states during operation

Joint Radar Jamming and Communication System Design Based on Universal Filtered Multicarrier Chirp Waveform

In this article, we propose a joint waveform based on universal filtered multicarrier (UFMC) chirp for radar jamming and communication joint systems. Modulation of radar jamming chirp signals and communication signals on different subcarrier groups in the UFMC sub-band is used to achieve the waveform design. The jamming signal in the waveform contains a frequency shift coefficient that depends on the delay time, which can effectively improve the anti-frequency hopping ability and enhance the overall jamming efficiency. Simultaneously jamming signals can provide assistance in channel estimation and equalization of communication, improving the information transmission quality of communication subsystems. We concluded through reasonable trade-off analysis that the combined weight of radar jamming and communication is closely related to the overall performance of the waveform. The simulation results show that the proposed UFMC chirp synthesized waveform has good jamming and communication performance. Software defined radio (SDR) simulation experiments demonstrated the effectiveness of this method in practical environments.

Synchronization for neural networks over event-triggered multi-channel: Relay channels under cyber-attacks

This work addresses synchronization for master–slave neural networks (MSNNs) with remote transmission. To reduce the communication frequency, an event-triggered strategy combined with a dynamically adjusted threshold is employed. For the sake of enhancing the information transmission quality, a relay channels protocol that considers cyber-attacks is established, acknowledging that occurrence rates of cyber-attacks may vary across different channels. Furthermore, regarding the limited capacity of channels, the current research considers a multi-channel transmission mechanism, where the transmission arrangement for each channel relies on the occurrence rates of denial-of-service (DoS) attacks. A sufficient condition is then proposed to guarantee the synchronization of MSNNs. Finally, an example is adopted to substantiate the efficiency of the obtained results.

Uncertainty Detection in Supervisor–Operator Audio Records of Real Electrical Network Operations

The quality of verbal communication, understood as the absence of uncertainty in the message transmitted, is a key factor in mission-critical processes. Several processes are handled by direct voice communication between these endpoints and any miscommunication could have an impact in success of the task. For that reason, the quality control of verbal communication is required to ensure that the instructions issued are effectively understood and adequately executed. In this context, it is expected that instructions from the command center are issued once, and that the acknowledgment from the field are minimal. In the present work, the communication between an electrical company control center and factory workers in the field was chosen for analysis. We developed two complementary approaches by using machine learning and deep learning algorithms to assess, in an automatic way, the quality of information transmission in the voice communications. Preliminary results demonstrate that the automatic uncertainty detection is feasible, despite the small number of samples available at the present time. To support further studies, a repository was created in GitHub with the spectrogram and the tokenized words of all audios.

Tensor‐based mobile channel tracking for IRS‐aided transmission systems

AbstractIn communication and sensing integrations, an intelligent reflective surface (IRS) will provide an auxiliary wireless link to enhance coverage and information transmission quality. For IRS‐aided millimetre wave multi‐input multi‐output systems, the instantaneous cascaded channel is highly dimensional, resulting in the difficulty of acquiring channel state information. This letter proposed a tensor‐based Kalman filtering method. Under a parallel factor decomposition condition, a distributed sub‐filter algorithm is established. This method benefits from low‐dimensional tensor modes and known IRS phase shifts. It can track the channel with a few pilot overheads.

Tkachenko Methodology for building radio relay lines based on the use of geospatial information

When planning and organizing communication using modern military digital radios, a crucial and relevant task is to ensure the maximum possible communication range while providing the necessary speed and quality of information transmission. The main factors determining the possible communication range of modern military digital radios, in addition to their characteristics, are the terrain relief, buildings, and vegetation. Additionally, existing height objects in the area, such as communication operator towers, can be used to organize radio relay communication. An analysis showed that existing methods and specialized software can be used for certain calculations of signal levels, but they do not always take into account all necessary technical parameters of radio equipment and additional geospatial information. Moreover, the existing software is not designed to construct multi-interval radio relay lines while considering additional geospatial data. In constructing radio relay lines, there is often a situation where one interval cannot provide communication with the required quality. This situation calls for planning a radio relay line using relay stations. The choice of the location of relay stations depends on many factors, including the possibility of establishing communication, minimizing the number of relays, geospatial information regarding the terrain relief, and the presence of the necessary infrastructure (buildings, power supply, anchor points, towers, etc.) in the area. The article proposes a methodology for constructing radio relay communication lines based on calculations of signal levels while considering geospatial data. This methodology allows analyzing individual radio relay intervals for constructing multi-interval radio relay lines. The software implementation of the developed methodology allows creating software for calculating radio relay lines with the necessary input data and geospatial information regarding the terrain.

Исследование эффективности помехозащищенности радиоканала авиационной радиосвязи

When performing aviation flights the high-quality and reliable communication with the control room becomes important for ensuring the crew safety. The purpose of the study is to investigate the quality of aviation radio communication in different methods of information transmission for developing the technical solutions of radio communication perfection. The equipment used today is designed for instant selection of preset channels and data exchange at fixed operating frequencies of ground control points with aircraft radio equipment in the meter and decimeter ranges. The most important requirement for the aviation radio communication systems is to ensure a high level 
 of noise immunity including protection against active interference. There is considered the process of frequency changing, or frequency hops, as the most successful at the first stage of the study in order to find the least interference-prone operating frequency. The use of pseudorandom frequency changing of radio communication between the ground control points and aircraft radio equipment is studied as one of the ways of leveling interference effects. To increase the stability of the radio line, it is necessary to use digital methods of information transmission. The use of digital methods of encoding information leads to low-level errors in the processes of discretization, modulation, amplification, demodulation and filtering. Due to this, nonlinear quantization allows for a higher level of signal-to-noise ratio. With a constant power level of the transmitter it is possible to carry out stable communication even at higher values 
 of the signal-to-interference ratio, which generally leads to the increasing radio transmission range. Using highly robust coding methods, the probability of error can also be reduced. There are studied different parameters reflecting the quality of information transmission over the radio channel: speech intelligibility, probability of erroneous reception of symbols. Thus, the digital methods of information transmission have higher noise immunity compared to the analog ones, even without special protection measures. Using special measures (noise-proof coding, pseudorandom frequency changing) can significantly increase the jamming protection of the radio communication system.

Interactive Product Design System Based on Intelligent Space Decomposition Technology and Internet of Things Technology

In order to improve the effect of interactive product design, this paper combines intelligent space decomposition technology and Internet of Things technology to construct an interactive product design system. Moreover, this paper applies the interactive signal transmission technology to the interactive product design to improve the real-time information transmission quality of the interactive product. In addition, this paper selects the appropriate filter as the hardware foundation of the system, proposes the overall concept of digital constant ratio timing, and provides sufficient theoretical support for the analog-digital mixing and digital processing links involved in the system. Finally, this paper constructs a system model and combines the experimental research to verify that the interactive product design system based on the intelligent space decomposition technology and the Internet of Things technology can effectively improve the product design effect.

Low-frequency rTMS treatment alters the topographical organization of functional brain networks in schizophrenia patients with auditory verbal hallucination

Auditory verbal hallucinations (AVH) are an important characteristic of schizophrenia. Repeated transcranial magnetic stimulation (rTMS) has been evidence to be effective in treating AVH. We evaluated the topological properties of resting-state functional brain networks in schizophrenia patients with AVH (n = 32) who received 1-Hz rTMS treatment and matched healthy controls (n = 33). The results showed that the psychotic symptoms and certain neurocognitive performances in patients were improved by rTMS treatment. Furthermore, the pretreatment patients showed abnormal global topological metrics compared with the controls, including lower global efficiency (Eglob, represents the relative quality of information transmission between all nodes in the network) and higher characteristic path length (Lp, characterizes the mean shortest distance between any two nodes in the network). The pretreament patients also showed decreased local topological metrics relative to the controls, including the nodal shortest path (NLp, quantifies the mean distance between the given node and the other nodes in the network) and nodal efficiency (Ne, measures the information interchange among the neighbor nodes when one node is removed), mainly located in the prefrontal cortex, occipital cortex, and subcortical regions. While the abnormal global and local topological patterns were normalized in patients after rTMS treatment. The multiple linear regression analysis indicated that the baseline topological metrics could be associated with the clinical responses after treatment in the patient group. The results suggested that the topological organization of the functional brain network was globally and regionally altered in schizophrenia patients with AVH after rTMS treatment and may be a potential therapeutic effect for AVH in schizophrenia.

Assessment of digital channels of communication with defined reliability characteristics

In the classical theory of telecommunications, an indicator of reliability is the probability of an information bit error. In modern international standards and recommendations, there is a hierarchy of quality indicators of the communication channel based on measurements, which is not related to the classical theory of noise immunity. The procedures for measuring the quality indicators of information transmission are possible only when using an already existing telecommunication system. The use of the classical theory of noise immunity makes it possible to provide for the correspondence of the energy parameters to the necessary quality indicators for the future communication system. The research aims to develop a unified methodology to assess the quality of communication channels and combine the classical theory of telecommunications with international recommendations and standards. To find the relationship between them, we analyzed existing methods of assessing the quality of communications channels, developed an algorithm for assessing the quality parameters and analyzed the characteristics of the channel. The methodology helps to assess the level of compliance of the quality parameters of information transmission through the channels of existing digital telecommunication systems with the requirements of international standards and recommendations. It is possible to research the behavior of quality indicators and optimize the operation of existing and design new digital communication channels according to the criteria of the quality of information transmission in accordance with the requirements of international standards and recommendations.

The Research of STBC in MIMO System

MIMO technology refers to the use of multiple transmitting antennas and multiple receiving antennas to improve the quality of information transmission. MIMO technology includes space-time coding, channel modeling, channel estimation, and other technologies. This paper mainly studies the space-time coding technology and precoding technology in the MIMO system through Matlab. First, the Alamouti coding is extended to the MIMO system with more transmitting and receiving antennas. This way can get a space-time block code. Finally, this paper will introduce the precoding technology and compare it with simulation analysis by simulating and analyzing its bit error performance.

Features of the fiber-optics data system using optical solitons

The analysis of the parameters of a high-speed information data system using dispersion-managed solitons is carried out. It is shown that the quality of information transmission can be increased by choosing the input-output point of the symbol sequence on the dispersion map.

Повышение эффективности передачи данных в беспроводных системах связи с ортогональным частотным мультиплексированием

The active introduction of Orthogonal Frequency Division Multiplexing (OFDM) technology is now beginning to be widely used in wireless transmission systems, television, radio communication, and radio broadcasting. The efficiency of using a dedicated frequency band at a constant high transmission rate allows you to combat interference arising from the transmission of a useful information on the radio channel. A method of improving quality of information transmission in communication systems with orthogonal frequency multiplexing is described. It is shown that with an increase in the number of receiving and transmitting antennas, the noise immunity increases significantly. An experiment was carried out to change the number of receiving-transmitting antennas and the signal-to-noise ratio, and the dependence of the appearance of an error on the number of transmitting antennas was obtained. The work investigated the software model of MIMO OFDM (modulators and demodulators). As a result of the analysis, the dependence of the appearance of the error frequency on the probability of the error was obtained. This showed that the use of OFDM and MIMO places increased demands on channel estimation.

Analyzing the code structures of multidimensional signals for a continuous information transmission channel

One of the directions to improve the efficiency of modern telecommunication systems is the transition to the use of multidimensional signals for continuous channels of information transmission. As a result of studies carried out in recent years, it has been established that it is possible to ensure high quality of information transmission in continuous channels by combining demodulation and decoding operations into a single procedure that involves the construction of a code construct for a multidimensional signal. This paper considers issues related to estimating the possibility to improve the efficiency of continuous information transmission channel by changing the signal distance of the code structure. It has been established that the code structures of such types as a hierarchical code construct of signals, a hierarchical code construct of signals with Euclidean metric, a reversible code construct of signals, a reversible code construct of signals with Euclidean metric have the potential, when used, to increase the speed of information transmission along a continuous channel. With a signal distance reduced by 10 percent or larger, it could increase by two times or faster. The estimation of the effect of reducing a signal distance on the efficiency of certain types of code structures was carried out. It has been established that the hierarchical reversible code construct, compared to the hierarchical code construct, provides a win of up to two or more times in the speed of information transmission with a halved signal distance. Implementing the modulation procedure has no fundamental difficulties, on the condition that for each code of the code construct the encoding procedure is known when using binary codes. The results reported here make it possible to build an acceptably complex demodulation procedure according to the specified types of code structures

Energy-Efficient Power Allocation in Non-Linear Energy Harvesting Multiple Relay Systems

In this paper, to maximize the energy efficiency (EE) in the two-hop multi-relay cooperative decoding and forwarding (DF) system for simultaneous wireless information and power transmission (SWIPT), an optimal power allocation algorithm is proposed, in which the relay energy harvesting (EH) adopts a nonlinear model. Under the constraints, including energy causality, the minimum transmission quality of information and the total transmission power at the relays, an optimization problem is constructed to jointly optimize the transmit power and power-splitting (PS) ratios of multiple relays. Although this problem is a nonlinear fractional programming problem, an iterative algorithm is developed to obtain the optimal power allocation. In particular, the joint power allocation at multiple relays is first decoupled into a single relay power allocation, and then single-relay power allocation is performed by the Dinkelbach iteration algorithm, which can be proven that it is a convex programming problem. Its closed form solutions for different polylines of EH models are obtained by using mathematical methods, such as monotonicity, Lagrange multipliers, the KKT condition and the Cardan formula. The simulation results show the superiority of the power allocation algorithm proposed in this paper in terms of EE.

Methods for experimental evaluation of the real noise immunity of digital linear paths

The most important and urgent problem is an objective assessment of the quality of information transmission over a communication channel. Until now, this problem has been dealt with in practice very limited, and, as a rule, subjective assessment methods have been used. An attempt to substantiate the need to move from subjective methods of quality assessment to objective ones will allow, first of all, to automate the control process, eliminate the element of subjectivity, increase the accuracy of the assessment and significantly reduce economic costs. Methods for estimating the parameters of CLT by the error rate, the main parameters of digital paths to be measured, and the norms for them are considered.

Data-Driven Congestion Control of Micro Smart Sensor Networks for Transparent Substations

Micro smart sensors and sensor networks are the key bases for building a fully visible, perceptible and controllable transparent substation in power grid. However, the massive deployment of micro smart sensors often leads to network congestion and directly affects the quality of information transmission. In practice, control design for micro sensor networks is often disturbed by factors such as nonlinearity, time delay and time-varying parameters, and the mathematical model is inaccurate. To solve these problems, this paper proposes a Koopman operator based data-driven congestion control scheme without using any system model information, based on model predictive control (MPC) and extended state observer (ESO). Firstly, according to the Koopman operator theory, a data-driven linear Koopman model for micro smart sensor networks is derived, only using the input/output data. Then an ESO based MPC scheme is designed to obtain the optimal packet dropping probability in the micro smart sensor node buffer area. Specifically, ESO performs real-time online estimation of the modeling errors, such as time-varying parameters, time delay and the external disturbances. Then the estimated modeling errors are viewed as total disturbances and are compensated in MPC, so that the queue length in the node buffer can quickly stabilize at the set value. Extensive simulations are conducted to verify the accuracy of Koopman model, and the effectiveness of the proposed control system design.

Analysis of Equipment Anti-interference Problem in Electronic Information Communication Engineering

This article analyzes the role of equipment anti-interference in electronic information and communication engineering. This paper studies how to improve equipment operating efficiency, reduce the probability of leakage problems, and improve the quality of information transmission. Combining the principle of equipment anti-interference in electronic information and communication engineering, the author studies the related causes of equipment anti-interference problems, how to deal with transmission interference problems, how to deal with external environment and receiving interference problems. In addition, the author also proposed preventive measures against the above problems and countermeasures for the integration of technical work. The purpose of this article is to improve the operational stability of electronic information and communication engineering equipment and improve the anti-interference ability of the equipment.

DISPERSION COMPENSATION USING ELECTRONIC METHODS BROADCASTING SYSTEM

System distortions due to chromatic dispersion (CD), polarization mode dispersion (PMD), laser phase noise and fiber nonlinearities have a significant impact on the performance of high-speed fiber optic networks. In connection with the need to improve the quality of information transmission in high-speed fiber-optic communication systems, coherent detection with a digital signal processing unit is of particular interest. The main goal of the DSP block is to reduce the impact of linear and nonlinear effects that degrade the quality of information transfer. In this direction, the use of adaptive filters with adaptation algorithms for filter coefficients plays an important role. The Constant Modulus Algorithm (CMA) and the Least Mean Square (LMS) method used to compensate for dispersion distortions are presented. The load on transport networks based on fiber-optic transmission systems is increasing at an accelerating rate. This paper discusses the possibility and limitations of increasing the throughput of fiber-optic transmission systems by reducing the distance between carriers. A comparison is made between fixed and flexible grids in terms of the spectral bandwidth efficiency. It is concluded that the use of flexible mesh technology is promising when switching to channel speeds above 100 Gbit/s.