AI-based model for securing cognitive IoT devices in advance communication systems

High Speed Railway (HSR) provides its customers not only safety, security, comfort and on-time commuting, but also a fast transportation alternative to air travel or regular passenger rail services. Providing these benefits would not be possible without the tremendous growth and prevalence of wireless communication technologies. Due to advances in wireless communication systems, both trains and passengers are connected through high speed wireless networks to the Internet, data centers and railroad control centers. Railroad communities, academia, related industries and standards bodies, even the European Space Agency, are involved in advancing developments of HSR for highly connected train communication systems. The goal of these efforts is to provide the capabilities for uninterrupted high-speed fault-tolerant communication networks for all possible geographic, structural and weather conditions. This survey provides an overview of the current state-of-the-art and future trends for wireless technologies aiming to realize the concept of HSR communication services. Our goal is to highlight the challenges for these technologies, including GSM-R, Wi-Fi, WIMAX, LTE-R, RoF, LCX & Cognitive Radio, the offered solutions, their performance, and other related issues. Currently, providing HSR services is the goal of many countries across the globe. Europe, Japan & Taiwan, China, as well as North & South America have increased their efforts to advance HSR technologies to monitor and control not only the operations but also to deliver extensive broadband solutions to passengers. This survey determined a trend of the industry to transition control plane operations towards narrowband frequencies, i.e. LTE400/700, and to utilize concurrently other technologies for broadband access for passengers such that services of both user and train control systems are supported. With traditional technologies, a tradeoff was required and often favored train control services over passenger amenities. However, with the advances in communication systems, such as LTE-R and cognitive radios, it is becoming possible for system designers to offer rich services to passengers while also providing support for enhanced train control operations such as Positive Train Control.

BERKOM: The first broadband isdn exchange and transmission system in Berlin

In advanced wireless communication systems, a rapid increase in the mobile data traffic and broad information bandwidth requirement can lead to the use of complex spectrally efficient modulation schemes such as orthogonal frequency-division multiplexing (OFDM). Generally, complex non-constant envelope modulated signals have very high peak-to-average ratios (PAPR). Doherty Power Amplifier (DPA) is the most commonly used power amplifier (PA) architecture for meeting high efficiency requirement in advanced communication systems, in the presence of high PAPR signals. However, limited bandwidth of the conventional DPA is often identified as a bottleneck for widespread deployment in base-station application for multi-standard communication signals. The research in this thesis focuses on the development of new designs to overcome the bandwidth limitations of a conventional PA. In particular, the bandwidth limitation factors of a conventional DPA architecture are studied. Moreover, a novel design technique is proposed for DPA's bandwidth extension. In the first PA design, limited bandwidth and linearity problems are addressed simultaneously. For this purpose, a new Class-AB PA with extended bandwidth and improved linearity is presented for LTE 5 W pico-cell base-station over a frequency range of 1.9-2.5 GHz. A two-tone load/source-pull and bias point optimization techniques are used to extract the sweet spots for optimum efficiency and linearity from the 6 W Cree GaN HEMT device for the whole frequency band. The realized prototype presented saturated PAE higher than 60%, a power gain of 13 dB and an average output power of 36.5 dBm over the desired bandwidth. The proposed PA is also characterized by QAM-256 and LTE input communication signals for linearity characterization. Measured ACPRs are lower than -40 dBc for an input power of 17 dBm. The documented results indicate that the proposed Class-AB architecture is suitable for pico-cell base-station application. In the second PA design, an inherent bandwidth limitation of Class-F power amplifier forced by the improper load harmonics terminations at multiple harmonics is investigated and analyzed. It is demonstrated that the impedance tuning of the second and third harmonics at the drain terminal of a transistor is crucial to achieve a broadband performance. The effect of harmonics terminations on power amplifier's bandwidth up to fourth harmonics is investigated. The implemented broadband Class-F PA achieved maximum saturated drain efficiency 60-77%, and 10 W output power throughout (1.1-2.1 GHz) band. The simulated and measured results verify that the presented Class-F PA is suitable for a high-efficiency system application in wireless communications over a wide range of frequencies. In the third PA design, a single- and dual-input DPA for LTE application in the 3.5 GHz frequency band are presented and compared. The main goal of this study is to improve the performance of gallium-nitride (GaN) Doherty transmitters over a wide bandwidth in the 3.5 GHz frequency band. For this purpose, the linearity-efficiency trade-off for the two proposed architectures is discussed in detail. Simulated results demonstrate that the single- and dual-input DPA exhibited a peak drain efficiency (DE) of 72.4% and 77%, respectively. Both the circuits showed saturated output power more than 42.9 dBm throughout the designed band. Saturated efficiency, gain and bandwidth of dual-input DPA are higher than that of the single-input DPA. On the other side, dual-input DPA linearity is worse as compared to the single-input DPA. In the last PA design, a novel design methodology for ultra-wide band DPA is presented. The bandwidth limitation factors of the conventional Doherty amplifier are discussed on the ground of broadband matching with impedance variation. To extend the DPA bandwidth, three different methods are used such as post-matching, low impedance transformation ratio and the optimization of offset line for wide bandwidth in the proposed design. The proposed Doherty power amplifier was designed and realized based on two 10 W GaN HEMT devices from Cree Inc. The measured results exhibited 42-57% of efficiency at the 6-dB back-off and saturated output power ranges from 41.5 to 43.1 dBm in the frequency range of 1.15 to 2.35 GHz (68.5% fractional bandwidth). Moreover, less than -25 dBc ACPRs are measured at 42 dBm peak output power throughout the designed band. In a nutshell, all power amplifiers presented in this thesis are suitable for wideband operation and their performances are satisfying the required operational standard. Therefore, this thesis has a significant contribution in the domain of high efficiency and broadband power amplifiers.

Book reviews - Advances in communication systems, theory and applications

The rapid convergence of electronics, wireless communication, and intelligent computing is reshaping the technological landscape, demanding new approaches to circuit design and communication infrastructure. Advanced Communication Systems and Next-Gen Circuit Design: Intelligent Integration of Electronics, Wireless Infrastructure, and Smart Computing Systems addresses this transformative era by exploring the fusion of cutting-edge hardware design, adaptive software systems, and intelligent networking technologies. This book aims to bridge the gap between foundational principles and emerging innovations, offering readers a comprehensive view of how advanced communication systems are built and optimized for future needs. From low-power, high-performance integrated circuits to intelligent wireless protocols and machine-learning-assisted design methodologies, we highlight the interconnected evolution of technologies that define the next generation of systems. Whether you are a researcher, engineer, or graduate student, this book is structured to guide you through both theoretical insights and practical implementations. Each chapter provides in-depth discussions, real-world case studies, and future-oriented perspectives designed to inspire innovation and deeper inquiry. In a world increasingly driven by autonomous systems, smart environments, and ubiquitous connectivity, mastering the synergy between hardware and software is no longer optional, it is essential. We hope this book serves as both a foundational reference and a forward-looking guide for those committed to designing and deploying the intelligent systems that will power the future.

This paper presents a comprehensive performance analysis of Multiple Input Multiple Output (MIMO) channels in advanced communication systems, utilizing MATLAB for simulation and visualization. Some of the performance parameters analyzed in the study are MIMO channel capacity; EVM, LS; delay spread and Doppler distributions a given reception scenario. Data analysis starts with the MIMO initialization process where received signals that are artificial are created. The instantaneous MIMO channel capacity is calculated and in addition to this its average over a certain period of time is also calculated to allow comparison between temporal values. The Doppler spectrum is now improved by Welch method and the picture shows the spectral density of the received signals. Next, spectrogram analysis is performed to study the channel response in the time domain since channel characteristics can change with time. The power delay profile is studied to study the effects of multipath propagation, together with the fitting of the path gains with Rayleigh distribution, depicting the fading nature in MIMO systems. A correlation matrix of MIMO channels is computed to analyze the dependability of various receiving antennas. In addition, EVM is monitored with time, accompanied by indications of signal quality and changes with time. Last but least, the despising of the different performance metrics is done in the bar chart and the available mean of channel capacity, EVM & delay spread give aid into understanding the complete picture of the system performance. The results help to enhance the MIMO channel knowledge and provide crucial recommendations for the further development of modern communication systems.

This thesis considers the radio resource management (RRM) of advanced wireless communication systems. With the emerging of more advanced and more complicated systems, such as cognitive radio, nodes with energy harvesting capacities (green communications), and the application of Multiple-Input Multiple-Output (MIMO) technology, RRM problems introduce more difficulties and challenges to optimize system performances. Due to specific structure of communication systems, water-filling (WF) plays an important role in RRM. This thesis introduces the fundamental theory and development of WF algorithm. The proposed Geometric Water-Filling (GWF) is presented and compared with the conventional WF algorithms. It can break through the limitations of the conventional WF to solve the more complicated optimization problems in the advanced wireless communication systems. For the application of the proposed GWF to solve the RRM problems in the advanced MIMO communication systems, cognitive radio communication systems, green communication systems and the “dual problems”, which are the sum power minimization problems, of the throughput maximization problems is investigated in this thesis. Efficient algorithms are presented to achieve the optimal resource allocation.

This thesis considers the radio resource management (RRM) of advanced wireless communication systems. With the emerging of more advanced and more complicated systems, such as cognitive radio, nodes with energy harvesting capacities (green communications), and the application of Multiple-Input Multiple-Output (MIMO) technology, RRM problems introduce more difficulties and challenges to optimize system performances. Due to specific structure of communication systems, water-filling (WF) plays an important role in RRM. This thesis introduces the fundamental theory and development of WF algorithm. The proposed Geometric Water-Filling (GWF) is presented and compared with the conventional WF algorithms. It can break through the limitations of the conventional WF to solve the more complicated optimization problems in the advanced wireless communication systems. For the application of the proposed GWF to solve the RRM problems in the advanced MIMO communication systems, cognitive radio communication systems, green communication systems and the “dual problems”, which are the sum power minimization problems, of the throughput maximization problems is investigated in this thesis. Efficient algorithms are presented to achieve the optimal resource allocation.

This thesis considers the radio resource management (RRM) of advanced wireless communication systems. With the emerging of more advanced and more complicated systems, such as cognitive radio, nodes with energy harvesting capacities (green communications), and the application of Multiple-Input Multiple-Output (MIMO) technology, RRM problems introduce more difficulties and challenges to optimize system performances. Due to specific structure of communication systems, water-filling (WF) plays an important role in RRM. This thesis introduces the fundamental theory and development of WF algorithm. The proposed Geometric Water-Filling (GWF) is presented and compared with the conventional WF algorithms. It can break through the limitations of the conventional WF to solve the more complicated optimization problems in the advanced wireless communication systems. For the application of the proposed GWF to solve the RRM problems in the advanced MIMO communication systems, cognitive radio communication systems, green communication systems and the “dual problems”, which are the sum power minimization problems, of the throughput maximization problems is investigated in this thesis. Efficient algorithms are presented to achieve the optimal resource allocation.

This thesis considers the radio resource management (RRM) of advanced wireless communication systems. With the emerging of more advanced and more complicated systems, such as cognitive radio, nodes with energy harvesting capacities (green communications), and the application of Multiple-Input Multiple-Output (MIMO) technology, RRM problems introduce more difficulties and challenges to optimize system performances. Due to specific structure of communication systems, water-filling (WF) plays an important role in RRM. This thesis introduces the fundamental theory and development of WF algorithm. The proposed Geometric Water-Filling (GWF) is presented and compared with the conventional WF algorithms. It can break through the limitations of the conventional WF to solve the more complicated optimization problems in the advanced wireless communication systems. For the application of the proposed GWF to solve the RRM problems in the advanced MIMO communication systems, cognitive radio communication systems, green communication systems and the “dual problems”, which are the sum power minimization problems, of the throughput maximization problems is investigated in this thesis. Efficient algorithms are presented to achieve the optimal resource allocation.

Methodology for developing an advanced communications system for the Deaf in a new domain

In contemporary times, communication systems have become the major drivers of globalization and trade facilitation. From its simple beginning to the more recent 5G and 6G technologies which are at various stages of development and applications, capable of entrenching the era of the Internet of Things (IoT), advancing Machine-to Machine (M-2-M) integration, and further revolutionizing the speed of seamless communication between smart devices. Significant advancements have also been achieved in the area of auxiliary technology interfaces incorporated into mobile communication systems such as the wireless LAN (Wi-Fi), Bluetooth, Infra-Red (IR), and sundry communication systems operating at the higher frequency bands of the electromagnetic spectrum. Against this backdrop, this work reviewed some communication systems highlighting their technology and developmental trends. Furthermore, it attempts to accurately forecast the probable direction of future advancements in communication systems, based on a painstaking trend and pattern analysis of the technological improvements of Bluetooth, Radar, and Wi-Fi technologies and some other communication systems in the past decade.

With advancements in communication systems and measurement technologies, smart grids have become more observable and controllable, evolving into cyber-physical-power systems (CPPS). The impact of network security and secondary equipment on power system stability has become more evident. To support the existing grid toward a smart grid scenario, smart metering plays a vital role at the customer end side. Cyber-Physical systems are vulnerable to cyber-attacks and various techniques have been evolved to detect a cyber attack in the smart grid. Weighted trust-based models are suggested as one of the most effective security mechanisms. A hardware-in-loop CPPS co-simulation platform is established to facilitate the theoretical study of CPPS and the formulation of grid operation strategies. This paper examines current co-simulation platform schemes and highlights the necessity for a real-time hard-ware-in-the-loop platform to accurately simulate cyber-attack processes. This consideration takes into account the fundamental differences in modeling between power and communication systems. The architecture of the co-simulation platform based on RT-LAB and OPNET is described, including detailed modeling of the power system, communication system, and security and stability control devices. Additionally, an analysis of the latency of the co-simulation is provided. The paper focuses on modeling and implementing methods for addressing DDOS attacks and man-in-the-middle at-tacks in the communication network. The results from simulating a 7-bus system show the effectiveness and rationality of the co-simulation platform that has been designed.

In this paper, we demonstrated recent progress on Si based optical components for advanced optical communication systems. The polarization beam splitter with extinction ratio of more than 20dB and the optical 90° hybrid having phase deviation within ±5° were obtained using MMI structures. The 12Gb/s modulators and the 20GHz photodetectors were measured. Benefiting from the unique properties of silicon modulator, an error-free 80Km transmission of the signals generated by our silicon carrier-depletion Mach-Zehnder modulator was also demonstrated at 10Gb/s and the power penalty was as low as 1.15dB. These results show that silicon photonics has a great potential in advanced optical communication systems.

Recent progress on Si-based optical components for advanced optical communication systems has been demonstrated. The polarization beam splitter with extinction ratio of more than 20 dB and the optical 90-deg hybrid having phase deviation within ±5-deg were obtained using multimode interference structures. The 12 Gb/s modulators and the 20 GHz photodetectors were measured. Benefiting from the unique properties of silicon modulator, an error-free 80 Km transmission of the signals generated by our silicon carrier-depletion Mach-Zehnder modulator was also demonstrated at 10 Gb/s and the power penalty was as low as 1.15 dB. These results show that silicon photonics has a great potential in advanced optical communication systems.