Proposed Communication System Research Articles

Resource Allocation for UAV-RIS-Assisted NOMA-Based URLLC Systems

This work focuses on maximizing the sum rate of ultra-reliable low-latency communication (URLLC) systems by leveraging unmanned aerial vehicle-mounted reconfigurable intelligent surface (UAV-RIS) to provide short packet services for users based on the non-orthogonal multiple access (NOMA) protocol. To optimize the sum rate of system, a joint optimization is performed with respect to the power allocation, UAV position, decoding order, and RIS phase shifts. As the original problem is a non-convex integer optimization problem, it is challenging to obtain the optimal solution. Therefore, approximate solutions are derived using successive convex approximation (SCA), slack variables, and penalty-based methods. The simulation results demonstrate the superiority of the proposed resource allocation algorithm compared with the benchmark algorithm with orthogonal multiple access (OMA) scheme. In addition, this work emphasizes the performance gap between the proposed communication system and the traditional Shannon communication system in terms of throughput and the performance capacity sacrificed to achieve lower latency.

Performance of STAR-RIS-aided cooperative NOMA networks under Nakagami-[formula omitted] fading

In this work, we investigate the performance of the cooperative non-orthogonal multiple access (CNOMA) downlink wireless communication system assisted by the newly emerged technology of simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RISs) over Nakagami-m fading channels. Specifically, outage probability (OP), spectral efficiency (SE), and energy efficiency (EE) are used as the performance metrics. The near user’s mathematically intractable probability density and cumulative distribution functions were approximated through the Gamma moment-matching technique. This was followed by the derivation of the users’ closed-form OP and ergodic rates expressions, where the latter was used to determine the SE and EE of the system. Further, extensive Monte-Carlo simulations confirmed the correctness of the obtained analytical findings. In addition, to inspect the usefulness of CNOMA in the proposed communication system, the comparison with its NOMA counterpart was incorporated into the numerical results. Finally, it was found that the cooperative link can further enhance the SE and EE of the STAR-RIS-based NOMA network.

UAV-assisted FSO communication system with amplify-and-forward protocol under AOA fluctuations: A performance analysis

Free space optical (FSO) communication has recently aroused great interest in academia due to its unique features, such as large transmission band, high data rates, and strong anti-electromagnetic interference. With the aim of evaluating the performance of an FSO communication system and extending the line-of-sight transmission distance, we propose an unmanned aerial vehicle (UAV)-assisted dual-hop FSO communication system equipped with amplify-and-forward protocol at the relay node. Specifically, we consider impairments of atmospheric absorption, pointing errors, atmospheric turbulence, and link interruptions due to angle-of-arrival fluctuations in the relay system. The Gamma-Gamma and Malaga distributions are used to model the influence of atmospheric turbulence on the source-to-UAV and UAV-to-destination links, respectively. We derive closed-form expressions of the probability density function (PDF) and cumulative distribution function (CDF) for the proposed communication system, in terms of the Meijer-G function. Based on the precise PDF and CDF, analytical expressions for the outage probability, average bit error rate, and ergodic capacity are proposed with the aid of the extended generalized bivariate Fox's H function. Finally, we show that there is a match between the analytical results and numerical results, and we analyze the influence of the system and channel parameters on the performance.

Short-Block-Length Low-Density Parity-Check Codes-Based Underwater Acoustic Spread-Spectrum Communication System

Low-density parity-check (LDPC) codes are commonly used in communication systems to improve the system performance, but LDPC codes takes too long for decoding, making communication inefficient and unsuitable for short-frame data transmission methods. In underwater acoustic channels, spread-spectrum communication becomes an effective way to realize long-distance communication. This paper combines short-block LDPC codes with a direct sequence spread spectrum and soft spread spectrum in underwater acoustic communication, addressing the problem of the inapplicability of conventional LDPC codes. The applicability of the proposed method in this paper is verified through simulation tests and pool experiments. The results indicate that the proposed communication system achieves lower bit error rates compared to the classical coding methods used in underwater acoustic spread-spectrum communication systems under the same channel conditions.

A mutually decoupled coil system to improve sensitivity of inductively coupled communication

AbstractThis paper proposes a mutually decoupled transmission and receiver coil (MDC) system to improve the sensitivity of inductively coupled communication. The proposed communication system is intended to be mounted on the frame of a spectacle and used to transfer a detectable voltage signal through weak inductive coupling with an implant measuring intraocular pressure (IOP). The implant consists of a coil that resonates with a capacitor. The capacitance of this capacitor is designed to change with the IOP, thus leading to a change in the self‐resonant frequency of the implant. The transmission coils excite the implant, while the decoupled receiver coils continuously monitor the self‐resonant frequency of the implant. The induced voltage across the receiver coil is used to determine the IOP. Simulation results show that a 1.43% change in the sensor capacitance leads to a 1 mV change in the voltage induced across the receiver coils. The experimental results reveal that raising the self‐inductance of the MDC on the transmission side results in a 0.5%/mV increase in sensitivity.

On secure communication scheme-based mixed discrete-time hyperchaotic systems

The proposed secure communication system is based on mixed discrete-time chaotic systems in this study. To increase signal transmission security over the public channel, this system is composed of two chaotic systems on the transmitter and receiver sides. Borne and Gentina criterion associated with the Benrejeb arrow form matrix is used for stability study and system description to ensure the synchronization between these chaotic systems. The case of electrocardiogram encryption and decryption is considered an application to illustrate the effectiveness of the proposed chaotic encryption approach. The performance analyses of the proposed secure communication under the Additive White Gaussian Noise (AWGN) channel, brute force attack and some statistical attacks have shown that the proposed encryption scheme exhibited a high level of security, could maintain the confidentiality and integrity of the transmitted information and the original signal can be accurately recovered even in the presence of noise.A comparitive study between different methods is given to show the advantages and the drawbacks of the proposed communication system.

Low-loss MIMO antenna wireless communication system for 5G cardiac pacemakers

Cardiovascular diseases (CVDs) are one of the leading causes of death globally. The Internet of things (IoT) enabled with industrial, scientific, and medical (ISM) bands (2.45 and 5.8 GHz) facilitates pacemakers to remotely share heart health data to medical professionals. For the first time, communication between a compact dual-band two-port multiple-input-multiple-output (MIMO) antenna (integrated inside the leadless pacemaker) and an outside-body dual-band two-port MIMO antenna in the ISM 2.45 and 5.8 GHz frequency bands is demonstrated in this work. The proposed communication system offers an attractive solution for cardiac pacemakers as it can operate on a 5G IoT platform while also being compatible with existing 4G standards. The experimental verification of the proposed MIMO antenna low-loss communication capability is also presented by comparing it to the existing single–input–single–output communication between the leadless pacemaker and outside body monitoring device.

Wireless Communication System Performance in M2M Nakagami-m Fading Channel

In this paper, we investigate a wireless mobile communication system with a cooperative network operating over a mobile-to-mobile (M2M) fading channel in the presence of co-channel interference. Since there is no direct line of sight between the source (S) and the destination (D) due to various obstacles, the signal transmission takes place by using a relay (R). We modeled and represented the desired signal and co-channel interference by using the Nakagami-m fading distribution from the source (S) to the relay (R), as well as from the relay (R) to the destination (D). As the popularity of M2M communication has increased in 5G cellular networks, the performance analysis of the proposed system is of great importance. We derived closed-form expressions for the probability density function (PDF) and cumulative distribution function (CDF) of the signal-to-interference ratio (SIR) at the input of the destination station. Based on the cumulative distribution function (CDF), we also evaluated the outage probability (Pout) of the proposed communication system. In addition, we derived a closed-form approximate expression for the level crossing rate (LCR) by using the Laplace approximation formula for the three-fold integral. Validity of the derived theoretical results we approved by Monte Carlo simulations.

Communication System Based on Magnetic Coils for Underwater Vehicles

In this work, a wireless communication system based on magnetic coils for underwater vehicles is presented. Firstly, the mathematical model of magnetic field induction using magnetic coils is discussed. Then, a description of the proposed communication system is presented, including the main components of the transmitter and receiver module. The experimental results show that due to the properties of the magnetic field, the proposed communication system can work properly in different environments such as air or water with the same efficiency. Underwater tests were carried out in different water circumstances: varying the temperature in a range from 10 °C to 35 °C, varying concentrations of clay in a range from 0% to 10%, and varying the salinity concentration in a range from 1000 ppm ( parts per million) to 35,000 ppm. It was observed that these conditions do not affect the information transfer. Finally, the advantages of using the proposed system compared to existing submarine communication systems are discussed.

Space-frequency-polarization-division multiplexed wireless communication system using anisotropic space-time-coding digital metasurface.

In the past few years, wireless communications based on digital coding metasurfaces have gained research interest owing to their simplified architectures and low cost. However, in most of the metasurface-based wireless systems, a single-polarization scenario is used, limiting the channel capacities. To solve the problem, multiplexing methods have been adopted, but the system complexity is inevitably increased. Here, a space-frequency-polarization-division multiplexed wireless communication system is proposed using an anisotropic space-time-coding digital metasurface. By separately designing time-varying control voltage sequences for differently oriented varactor diodes integrated on the metasurface, we achieve frequency-polarization-division multiplexed modulations. By further introducing different time-delay gradients to the control voltage sequences in two polarization directions, we successfully obtain space-frequency-polarization-division multiplexed modulations to realize a wireless communication system with a new architecture. The new communication system is designed with compact dual-polarized meta-elements, and can improve channel capacity and space utilization. Experimental results demonstrate the high-performance and real-time transmission capability of the proposed communication system, confirming its potential application in multiple-user collaborative wireless communications.

Artificial Intelligence-Based Energy Efficient Communication System for Intelligent Reflecting Surface-Driven VANETs

The ever-increasing traffic, various delay-sensitive services, and energy consumption-constrained requirements have brought huge challenges to the current communication networks in the vehicular ad-hoc networks (VANETs). These challenges motivate academia and industry to investigate novel architectures with powerful data transmission and processing capabilities for low-latency and high energy-efficiency vehicular communication. In this paper, we propose an artificial intelligence (AI) and intelligent reflecting surface (IRS) empowered energy-efficiency communication system for VANETs. First, we design a smart and efficient hybrid vehicular communication framework, where IRS-aided dedicated short-range communication and long term evolution-based cellular communication are combined for data transmission in VANETs. Secondly, an IRS-aided data transmission is proposed to improve vehicular communication, in which the head vehicles selection method is designed. Based on the direct and IRS-reflecting signal propagation, fine-grained beamforming is achieved for directional vehicular transmission. Thirdly, a deep reinforcement learning (DRL) empowered network resource control and allocation scheme is proposed. In this scheme, we formulate an energy efficiency-maximizing model under the given transmission latency for VANETs and jointly optimize the settings of all participants to achieve efficient and low-latency communication. Finally, experimental results verify the effectiveness of our proposed communication system for VANETs.

СТАТИСТИЧЕСКИЕ ХАРАКТЕРИСТИКИ СИСТЕМЫ ОТНОСИТЕЛЬНОЙ ПЕРЕДАЧИ ИНФОРМАЦИИ НА ОСНОВЕ ХАОТИЧЕСКИХ ИМПУЛЬСОВ В КАНАЛЕ С ГАУССОВСКИМ ШУМОМ

The purpose of this paper is to analyze the statistical characteristics of a differentially coherent communication scheme based on the use of chaotic pulses in the presence and absence of thermal noise for various distributions of chaotic signal instantaneous values. To achieve this goal, a numerical simulation for the performance of direct chaotic differentially coherent communication scheme is carried out in the work by a computer simulation. A numerical simulation was carried out, confirming the previously obtained analytical bit error probability estimates vs energy per bit to gaussian noise power spectral density ratio. The minimum energy per bit to gaussian noise power spectral density ratio values, which provide the given error probabilities, are obtained. It is shown that the proposed communication system works effectively at high values of processing gain(the behavior of the communication system was studied for various values of processing gain), and in the case of high values of processing gain, the results obtained do not depend on the choice of a specific discrete chaotic signal distribution.

SISTEM DE COMUNICAȚIE MOBIL, GSM-WIFI, PENTRU VEHICULELE AGRICOLE

The research carried out in this paper aimed to create a communication network for a fleet of agricultural vehicles by means of which to transmit and receive information on the status of work, working time, processed areas, number of machines used and much more necessary information. Communication is based on GSM and WiFi standards, which bring the most secure security standards in data protection to this network. The major advantage of the solution presented is that all the important information is concentrated in one place. The proposed communication system consists of a mobile device that routes the WiFi network on a GSM network that has a minimum 3G standard but also works with 5G, depending on the GSM operator and the devices that are mounted on vehicles, which communicate over the WiFi network. The communication device was mounted on an electric tractor, where it was powered by the tractor's power source. In this communication architecture, the vehicle transmitted information to a control centre and also to other vehicles in the vicinity. The system was able to receive data from other devices, authorized in the system, which could be fixed in the field. The collected data were transmitted to a server in a remote location. The obtained results showed a decrease of signal strength while getting further away from the tractor, with good results up to 100 m radius.

Reliable Semantic Communication System Enabled by Knowledge Graph.

Semantic communication is a promising technology used to overcome the challenges of large bandwidth and power requirements caused by the data explosion. Semantic representation is an important issue in semantic communication. The knowledge graph, powered by deep learning, can improve the accuracy of semantic representation while removing semantic ambiguity. Therefore, we propose a semantic communication system based on the knowledge graph. Specifically, in our system, the transmitted sentences are converted into triplets by using the knowledge graph. Triplets can be viewed as basic semantic symbols for semantic extraction and restoration and can be sorted based on semantic importance. Moreover, the proposed communication system adaptively adjusts the transmitted contents according to channel quality and allocates more transmission resources to important triplets to enhance communication reliability. Simulation results show that the proposed system significantly enhances the reliability of the communication in the low signal-to-noise regime compared to the traditional schemes.

Capacity Enhancement of Multiuser Wireless Communication System through Adaptive Non-Linear Pre coding

Multiuser multiple-input multiple-output (MIMO) nonlinear pre coding techniques face the issue of poor computational scalability of the size of the network. But by this nonlinear pre coding technique the interference is pre-cancelled automatically and also provides better capacity. So in order to reduce the computational burden in this paper, a definitive issue of MU-MIMO scalability is tackled through a non-linear adaptive optimum vector perturbation technique. Unlike the conventional (Vector Perturbation) VP methods, here a novel anterograde tracing is utilized which is usually recognized in the nervous system thus reducing complexity. The tracing of distance can be done through an iterative-optimization procedure. By this novel non-linear technique the capacity is improved to a greater extend which is explained practically. By means of this, the computational complexity is managed to be in the cubic order of the size of MUMIMO, and this mainly derives from the inverse of the channel matrix. The proposed signal processing system has been implemented in the working platform of MATLAB/SIMULINK. The simulation results of proposed communication system and comparison with existing systems shows the significance of the proposed work.

A Heterogeneous Unmanned Ground Vehicle and Blimp Robot Team for Search and Rescue using Data-driven Autonomy and Communication-aware Navigation

This paper describes the architecture and implementation of a heterogeneous team comprising unmanned ground vehicles and blimp robots capable of navigating unknown subter- ranean environments for search and rescue missions. The ground vehicles are equipped with a range of sensors for accurate perception, localization, and mapping. The blimps feature a long flight duration and collision tolerance when traversing uneven terrain. The design of the system was meant to satisfy the requirements of the Defense Advanced Research Projects Agency (DARPA) Subterranean Challenge in terms of perception capability and autonomy. To facilitate navigation through smoke-filled spaces, we employed novel millimeter wave radar to enable cross-modal representations for integration via deep reinforcement learning. The autonomy of the proposed scheme was augmented using simulations to train deep neural networks, thereby allowing the system to perform sequential decision-making for collision avoidance and navigation toward a specific goal. The navigation system was evaluated in the DARPA SubT Urban Circuit, and quantitative localization results and recovery strategy from failures was discussed. The proposed communication system comprises mesh WiFi with XBee (ZigBee network with XBee radios) and ultra-wideband (UWB) communication modules as well as spherical nodes that can be shot out like a cannonball and miniature cars deployed as mobile nodes. The propagation and radio signal strength index of various modules were evaluated using data collected during field tests in order to overcome the uncertainties of subterranean environments, including non-line-of-sight propagation, multipath propagation, and fading reception. We also discuss the lessons learned during this project and reflect on future plans.

Reliable and Low-Power Communications System Based on IR-UWB for Offshore Wind Turbines

In this paper, we propose the design of a low-power wireless sensor network architecture that enables robust communications inside offshore wind turbines. This research work is in the scope of the WATEREYE EU Project, where we have designed a corrosion monitoring solution to work unattended. The architecture is composed of several fixed sensor nodes, one mobile sensor node, several anchors and the WATEREYE Computer (WEC). Our approach is based on Impulse Radio Ultra wideband (IR-UWB) technology offering reliable and low-power communications in these harsh environments. On top of that, we propose a double star network using two UWB channels for the following purposes: one network for communications to send the sensor data and another one for ranging estimations to calculate the indoor positioning of the mobile sensor node. The power strategies applied to our system, at Hardware (HW) and Firmware (FW) levels, are described in detail. Furthermore, we present power consumption measurements obtaining the power profiles and the autonomy of the most important components of the proposed architecture supplied by battery. On the other hand, we describe the methodology to analyze the range, reliability and continuity of the two UWB links providing the packet loss and gaps as a function of distance. The proposed communications system has been validated in three different scenarios considering two of them very hostile environments. Furthermore, one of the scenarios is a real offshore wind turbine.

Free-space optical link optimization in visible light communication system

Abstract Free space optical communication is a potential technology that exploits the visible light frequency band for communication. In this paper, a free-space optical link (FSOL) optimization in visible light communication (VLC) is used to improve the channel performance for signal strength and analyze the effect of signal failures in a communication system. The data transmission and reception phenomenon are established using a light-emitting diode (LED) as a carrier at transmitter and photodiode as a detector at the receiver, respectively. The OptiSystem tool uses to optimize the component parameters of this proposed communication system. The bit error rate (BER) analyzer displays the signals as an eye diagram with the challenges of components uncertainty for better signal performance. The optimized components solve the problem encountered transmitting improve and enhance the signals strength. The acceptable eye diagram displayed from the BER analyzer has been resolved as a result of component optimizations by adding and removing noise to ascertain the behavior of the channel. A better signal retrieve by the display of the acceptable eye diagram from the OptiSystem software used. The FSOL components optimization improve the loss of data, weak signal, loss of power, signal failure, and signal errors which guarantee multi-mobile users with the shared signal. OptiSystem software package used to fully characterize the FSOL system.

IEC 61850 modeling of an AGC dispatching scheme for mitigation of short-term power flow variations

High penetration of renewable energy-based generators increases variability in power systems. To prevent transmission lines from overloading due to such variations, advanced power flow management system should be developed. This paper proposes an Automatic Generation Control (AGC) design that mitigates power flow increase on heavy load lines. The developed method optimizes dispatching of control order from AGC so as not to increase power flow of these lines. This is achieved by considering how the output change of each control unit effects power flow in the system. The performance of the proposed method is examined by simulation study with 10-machine power system model. Furthermore, the communication infrastructure of the developed AGC system and its components are developed according to IEC 61850 communication standard. Operational instructions are mapped onto IEC 61850 messages. Simulations are performed with network emulators to validate the developed communication models and their operation. The benefit of the proposed communication system with IEC 61850 is achieving plug and play capability with universal models. The results of both simulations show that communication infrastructure is successfully developed and AGC prevents power flow increase in heavily loaded lines by making use of remained capacity of light loaded lines as proposed.

Message Queuing Telemetry Transport Communication Infrastructure for Grid-Connected AC Microgrids Management

In a context with an increasing number of non-traditional power sources, smart inverters function as the main interfaces between distributed energy resources (DERs) and the power bus. This role is even more prominent in microgrids (MGs), where numerous DERs must be controlled and coordinated. For this aim, MGs need to implement suitable communication links since, even in distributed control, the system must compensate voltage and frequency deviations caused by local controllers. Likewise, a communication system is required to optimize its operation. This paper aims to apply the technological advances brought by the Internet of Things (IoT) to the issue of communication within an MG. The work proposes a wireless communication architecture based on the message queuing telemetry transport (MQTT) protocol, accompanied by a set of requirements and specifications to establish a multi-directional information flow between DERs in an MG, and potential energy management system (EMS) or secondary controllers. A laboratory-scale testbed was implemented to demonstrate the operation of an EMS in the proposed architecture. The experimental results showed how current control structures seamlessly integrate with the proposed communication system. Furthermore, it was demonstrated that communication latencies or failures did not comprise the stability of the MG, but only decreased the optimality of the EMS control strategy.