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This paper presents a novel frequency modulated continuous wave radar with imaging capability, purposely designed for river monitoring applications. Radar images are obtained using a fixed antenna whose beam can be steered according to the excitation frequency. This is achieved by means of a planar array of slots with a custom feeding network featuring marked frequency squint effects. The radar prototype is experimentally validated in significant scenarios such as those related to static object detection and river water level estimation. The prototype operates in the 24 GHz frequency band and can produce real-time 2D radar maps with a simple signal processing and hardware, the latter implemented in a Raspberry Pi single board computer. The proposed architectures open new prospectives in the field of river monitoring with non-contact sensors, proving how it is possible to properly detect water level, an essential parameter used to estimate the river discharge.

Undesired conversion between common-mode (CM) and differential-mode (DM) noise often occurs in modern electronic and electrical systems, posing challenges in terms of Electromagnetic Compatibility (EMC). Modal analysis represents a crucial tool in EMC investigation and provides insight into the mechanism underlying mode conversion. By inspecting CM and DM behaviors and their interconversion, it allows for understanding of conducted emission propagation mechanisms, drives electromagnetic interference (EMI) filter design towards optimal/tailored solutions, and enables the possibility to identify the main contributors to the radiated emission phenomenon. This paper offers a comprehensive review of mathematical methodologies and modelling strategies for EMC-oriented modal analysis, with particular emphasis on mode conversion phenomena. To this end, modal decomposition techniques and standard parameters for quantifying mode conversion are summarized and compared. Additionally, the paper provides an overview and in-depth discussion of different scenarios and test cases in which mode conversion occurs, with the final goal to achieve a systematic comprehension of its root causes and consequences within power and communication systems. Eventually, a survey of circuit modelling approaches for mode conversion is presented, offering insights into addressing this phenomenon effectively.

Nowadays, the integration of smart systems within the modern industrial scenario is a continuously growing paradigm. Computer Numerical Control (CNC) machinery can heavily benefit from the introduction of Artificial Intelligence (AI) based monitoring applications. In this paper, we present an industrial condition and fault prevention monitoring system for CNC tools. The developed system is the result of an industrial project aimed at realizing a multi-purpose machine which is currently in pre-commercial stage. The results of this work represent the base platform for the further commercial development, which will be carried on from the industrial partners in accordance with clients feedbacks and specifications. This work presents the hardware architecture of the system, the web-based monitoring platform for remote management, and the AI framework used for fault monitoring. The multi-purpose machine is equipped with accelerometer units to monitor the vibration in multiple points of the structure. The control unit of the machine is connected to the sensing nodes and is used to communicate the actual machine state to a remote web platform. The accelerometric data are analyzed through an AI algorithm to perform fault detection. The fault detection algorithm was trained with the measurements performed on the machine under controlled environment faulty operation. The Internet of Things (IoT) based architecture has proven to be effective to facilitate the supervision of the machining processes, and the AI-based classification shows good classification performances for the fault detection tests.

In this paper, the prototypical deployment of a Multiple-Input-Multiple-Output (MIMO) antennas system, denoted as Smart Selective Antennas System (SSAS), aiming at mitigating inter-cell interference effects of cellular networks for in-flight Unmanned Aerial Vehicles (UAVs), is discussed. In detail, the proposed SSAS is beneficial to increase the communication reliability over existing cellular networks, especially with regard to complex Beyond Visual Line of Sight (BVLOS) drones’ missions and applications. Its deployment is motivated as existing 4G Long Term Evolution (LTE) cellular networks (as well as 5G networks) are mainly designed and optimized for terrestrial utilization, thus not taking into account interference effects on flying connected devices. The prototypical implementation of the SSAS has been expedient to conduct multiple experimental flights with a drone at different altitudes, collecting performance results and validating the proposed SSAS as a viable solution for inter-cell interference mitigation.

Electric vehicles (EVs) are pivotal in the global shift towards sustainable energy systems. As EV adoption rises, effective integration into the power grid becomes vital. Vehicle-to-grid (V2G) operations, enabling bidirectional power flow between EVs and the grid, enhance grid resilience and leverage EVs as distributed energy resources. This article presents a comprehensive framework addressing gaps in EV integration. It combines EV travel energy forecasts and electricity market engagement, coordinating forecast-based optimization with real-time management. Our approach introduces a novel prioritization mechanism, optimizing power allocation based on forecasted state-of-charge for upcoming trips. The optimization follows a multi-objective function that aims to minimize the operational costs and maximize both the upward and downward flexibility to provide ancillary services. The study assesses EV participation in Replacement Reserve, Secondary Reserve, and energy arbitrage. Simulations compare scenarios, unveiling optimal performances. The framework showcases EVs' potential to bolster grid stability, yielding economic value for EV owners and the power system. This article pioneers a holistic approach to EV integration, bridging current limitations, and emphasizing economic and technical benefits.

Automation systems within nuclear laboratories are intended to work under harsh operating conditions. Selective Production of Exotic Species (SPES) is a nuclear research facility currently under construction by the Istituto Nazionale di Fisica Nucleare, dedicated to the production and study of radioactive ion beams. Isotopes are produced within the target ion source unit, a vacuum vessel that must be replaced on a regular basis. The highly radioactive environment necessitates the deployment of a set of automated systems dedicated to the unit's remote management. To meet high-level security standards, the design of such instrumentation and control systems must include extensive verification. Based on specific safety requirements, model checking can be used to assess the systems' correctness. This article describes how to employ an integrated toolchain to design, simulate, formally verify, and deploy the control software for the Horizontal Handling Machine, a safety-critical remote handling system in operation at SPES. The IEC 61499 standard's adoption led to a redesign of the control logic. Following a preliminary online simulation, the closed-loop system has been formally verified using the NuSMV symbolic model checker, with the help of the FB2SMV converter. In addition, the Function Blocks Modeling Environment tool was used for automating verification and analyzing counterexamples.

In recent years, edge computing has become an essential technology for real-time application development by moving processing and storage capabilities close to end devices, thereby reducing latency, improving response time and ensuring secure data exchange. In this work, we focus on a Smart Agriculture application that aims to protect crops from ungulate attacks, and therefore to significantly reduce production losses, through the creation of virtual fences that take advantage of computer vision and ultrasound emission. Starting with an innovative device capable of generating ultrasound to drive away ungulates and thus protect crops from their attack, this work provides a comprehensive description of the design, development and assessment of an intelligent animal repulsion system that allows to detect and recognize the ungulates as well as generate ultrasonic signals tailored to each species of the ungulate. Taking into account the constraints coming from the rural environment in terms of energy supply and network connectivity, the proposed system is based on IoT platforms that provide a satisfactory compromise between performance, cost and energy consumption. More specifically, in this work, we deployed and evaluated various edge computing devices (Raspberry Pi, with or without a neural compute stick, and NVIDIA Jetson Nano) running real-time object detector (YOLO and Tiny-YOLO) with custom-trained models to identify the most suitable animal recognition HW/SW platform to be integrated with the ultrasound generator. Experimental results show the feasibility of the intelligent animal repelling system through the deployment of the animal detectors on power efficient edge computing devices without compromising the mean average precision and also satisfying real-time requirements. In addition, for each HW/SW platform, the experimental study provides a cost/performance analysis, as well as measurements of the average and peak CPU temperature. Best practices are also discussed and lastly, this article discusses how the combined technology used can help farmers and agronomists in their decision making and management process.

In this paper, a systematic approach for electromagnetic compatibility (EMC) modelling of hand-assembled, complex cable bundles is presented. The first part of the article focuses on bundles laid out above a ground plane, with layout approximately parallel to the reference ground. In order to generate smooth and physics-based trajectories, polynomial curves are used to represent the conductors in the bundle. A suitable process for the generation of bundle samples is developed, which allows for controlling the degree of randomness and avoiding conductors overlapping. Parametric representation of more general bundle structures with arbitrary orientation is then addressed, and the modeling approach is extended to more complex bundle structures, such as bundles involving twisted-wire pairs. To assess the ability of Transmission Line (TL) theory to deal with complex and locally highly non-uniform bundle shapes, a fictitious bundle trajectory shaped as a trefoil knot is introduced. All the generated bundle geometries are used in combination with TL-based EMC models in order to predict the disturbances induced in the bundle terminal units due to crosstalk or coupling with external electromagnetic fields. Prediction accuracy is assessed by comparison versus full-wave electromagnetic simulation of the same bundle structures. Suitable examples are presented to show the high numerical efficiency and good accuracy of the proposed modeling approach, as well as the need for accurate and physics-based representation of the bundle geometry in order to achieve solid EMC prediction in a wide frequency range.

Matching filter (MF)-free digital filter multiplexed (DFM) single sideband (SSB) OFDM intensity modulation and direct detection (IMDD) dual-channel transmissions of 51.25Gbit/s over 25km SSMFs are experimentally demonstrated. It is shown that both transmission system impairments and digital filter characteristic variations can only lead to

We study support for unmanned aerial vehicle (UAV) communications through a cell-free massive MIMO architecture, wherein a large number of access points (APs) is deployed in place of large co-located massive MIMO arrays. We consider also a variation of the pure cell-free architecture by applying a user-centric association approach, where each user is served only from a subset of APs in the network. Under the general assumption that the propagation channel between the mobile stations, either UAVs or ground users (GUEs), and the APs follows a Ricean distribution, we derive closed form spectral efficiency lower bounds for uplink and downlink with linear minimum mean square error channel estimation. We consider several power allocation and user scheduling strategies for such a system, and, among these, also minimum-rate maximizing power allocation strategies to improve the system fairness. Our numerical results reveal that cell-free massive MIMO architecture and its low-complexity user-centric alternative may provide better performance than a traditional multi-cell massive MIMO network deployment.

In this paper we apply a novel approach to near-infrared subcutaneous palm vascular pattern authentication. The proposed method relies on a recursive algorithm based on a positive linear dynamical system whose evolution depends on the two matrices representing the vein patterns to be compared. The output of the system reaches a high value when a good matching between the two matrices is observed, otherwise it converges rapidly to zero, even in presence of noise. With respect to another algorithm we recently introduced, this approach achieves not only a better authentication performance but also a drastic reduction in terms of computation time. These improvements are demonstrated by means of extensive experiments conducted on challenging datasets.

This work investigates the performance of RF immunity procedures exploiting semi-rigid coaxial test probes as coupling devices to inject continuous wave (CW) RF power into the outlets of Integrated Circuits (ICs). Two solutions are presented, both offering the advantage with respect to the traditional direct power injection method, to run the test without removing the IC from its actual PCB. The first procedure resorts to near-field coupling to inject the noise into an interconnecting trace. The second procedure requires metallic contact between the probe tip and the injection point (e.g., a via or an IC pin). Specific figures of merit, such as coupling and power efficiency, test repeatability and intrusiveness, sensitivity to setup parameters and lateral spatial resolution, are introduced and used to ascertain the effectiveness of the proposed procedures. To this end, both numerical simulations and measurements were carried out on several PCBs. Feasibility of the proposed immunity procedures is eventually proven by an application example, involving a thermal sensor as device under test.

This paper proposes a Ka-band receiver front-end for future CubeSats Low-Earth Orbit (LEO) to Geostationary (GEO) inter-satellite links. The receiver is able to support very high data rates (up to 100 Mbit/s) in Quadrature Phase-Shift Keying (QPSK) when in the line of sight of a GEO satellite that is equipped with a steerable 70-cm antenna and transmitting a 25-W signal. The originality of the proposed approach is twofold. First we will demonstrate the receiver feasibility based on a class of miniaturized and low-cost microwave integrated circuits, currently available on the market. In particular, our receiver is based on a novel combination of integrated Low-Noise Amplifiers (LNA) with an image rejection filter, the latter exploiting the Substrate Integrated Waveguide (SIW) technology. An optimization of the via placement proved to be able to reduce the need for shielding apparatuses, thus simplifying the mechanics and reducing mass, volume and hardware costs. Secondly, we will propose a noise injection circuit capable of measuring and calibrating the receiver gain, also during in-orbit operation. Self testing capabilities are particularly relevant for CubeSats because the usage of commercial components poses serious reliability issues.

In the development of alternative test methods for pre-compliance radiated-susceptibility (RS) investigations, it is proven that a special test setup, involving an additional wire placed in proximity of the cable under test and fed by two radio-frequency generators, can reproduce through crosstalk (XT) the same terminal voltages/currents induced in the standard RS test setup, on condition that those generators are properly controlled in magnitude and phase. Such a test setup does not require expensive facilities like anechoic chambers and powerful amplifiers to feed antennas, therefore it represents a fast and cheap alternative to get feedback on radiated immunity in the early-design stage, before the formal RS assessment carried out according to standards. While in past literature works the equivalence between XT and RS was demonstrated for some simple cables like a single bare wire or a differential pair, this paper presents a new XT-based test setup suitable for the practically relevant case of a complex bundle of dielectric-covered wires. To this aim, two different formulations of feeding conditions are proposed, one more rigorous, based on multiconductor-transmission-line modeling, and one approximate, based on bundle-reduction techniques. The performance of both the equivalence schemes is assessed and discussed in the frequency range between 1 MHz and 1 GHz.

This paper presents a method to assess intentional electromagnetic interference (IEMI) in a linear multiport system, due to coupling with a high-power electromagnetic (HPEM) field. First, an approach based on the Lorentz reciprocity theorem is proposed to model field coupling for the arbitrary direction of incidence and polarization, which minimizes the number of required full-wave numerical simulations. Afterward, three constrained-optimization problems are identified to describe the worst-case scenarios related to different radiated-susceptibility effects at the system's ports. Namely, under the assumption of limited bandwidth and finite energy density, the spectrum and the waveform of the HPEM field are found so to maximize the dissipated energy, the peak, and the rectified impulse of the induced voltage waveform. It is shown analytically that in the worst-case energy scenario, the HPEM field shall be a properly tuned narrowband field, whereas in the worst-case voltage peak scenario a wideband field properly matched to the frequency response of the system is needed. In addition, it is shown that the rectified impulse of the induced voltage can be made arbitrarily large by reducing the impinging field bandwidth. A typical printed-circuit board interconnect for low-voltage differential signaling is used to exemplify and validate the proposed approach. Furthermore, uncertainty-quantification techniques are exploited to cope with the lack of knowledge about the incidence and polarization parameters of the HPEM field, as well as to account for uncertain geometrical parameters of the victim system.

By performing in-network caching, Internet Service Providers (ISPs) allow Content Providers (CPs) to serve contents from locations closer to users. In this way, the pressure of content delivery on ISPs' network is alleviated, and the users' Quality-of-Experience (QoE) improved. Due to its impact on QoE, caching has been recently considered as a form of traffic prioritization in the debate on Network Neutrality (NN). A possible approach to perform NN-compliant caching consists in assigning the same portion of cache storage to all the CPs. However, this static subdivision does not consider the different popularities of the CPs' contents and is therefore inefficient. Alternatively, the cache can be subdivided among the CPs proportionally to the popularity of their contents. However, CPs consider this information private and are reluctant to disclose it. In this work, we propose a protocol to perform a popularity-driven subdivision of the caches' storage in a privacy-preserving and network-neutral fashion. The protocol is based on the Shamir Secret Sharing (SSS) scheme and is designed to ensure a NN-compliant subdivision of the caches while preserving the privacy of both CPs and ISP (i.e., contents' popularity and caches' size are not disclosed). Through dynamic simulation, we show that the popularity-driven cache subdivision (enforced by using our protocol) outperforms several baseline approaches in terms of overall network Resource Occupation (RO) and caching Hit-Ratios. Thanks to our numerical results, we observe that the frequency of execution of the protocol has a significant impact on the RO, and that the ISP can tune this frequency to minimize its RO while introducing an acceptable data overhead. Because of this tuning, several CPs may experience a loss with respect to the hit-ratio that they would obtain by independently choosing the frequency of execution. This loss is very limited, and the employment of the protocol is therefore beneficial to all the involved parties, especially since, by using it, CPs are guaranteed that the ISP behaves in a network-neutral manner.

The purpose of this paper is to bestow the reader with a timely study of UAV cellular communications, bridging the gap between the 3GPP standardization status quo and the more forward-looking research. Special emphasis is placed on the downlink command and control (C&C) channel to aerial users, whose reliability is deemed of paramount technological importance for the commercial success of UAV cellular communications. Through a realistic side-by-side comparison of two network deployments – a present-day cellular infrastructure versus a next-generation massive MIMO system – a plurality of key facts are cast light upon, with the three main ones summarized as follows: 1) UAV cell selection is essentially driven by the secondary lobes of a base station’s radiation pattern, causing UAVs to associate to far-flung cells; 2) over a 10 MHz bandwidth, and for UAV heights of up to 300 m, massive MIMO networks can support 100 kbps C&C channels in 74% of the cases when the uplink pilots for channel estimation are reused among base station sites, and in 96% of the cases without pilot reuse across the network; and 3) supporting UAV C&C channels can considerably affect the performance of ground users on account of severe pilot contamination, unless suitable power control policies are in place.

Long-term evolution (LTE) is a broadband wireless cellular system currently available in about 200 countries. From the mobile network operator point of view, one of the most appealing characteristics of LTE is the possibility of providing the users with mobile broadband services like voice over LTE and video over LTE (ViLTE), with strict quality of service (QoS) guarantees. The success of such services, which usually require a subscription fee, is obviously tightly bound to the users' quality of experience (QoE), that must be significantly better than the quality perceived in case of free services. This paper attempts to evaluate the perceived quality of the ViLTE service. In more detail, we present the results of an experimental test-bed realised at one of the most popular italian MNO, aimed at evaluating the impact of several network layer QoS parameters on the QoE of the ViLTE service.

Internet of Things (IoT) devices play a crucial role in the overall development of IoT in providing countless applications in various areas. Due to the increasing interest and rapid technological growth of sensor technology, which have certainly revolutionized the way we live today, a need to provide a detailed analysis of the embedded platforms and boards is consequential. This paper presents a comprehensive survey of the recent and most-widely used commercial and research embedded systems and boards in different classification emphasizing their key attributes including processing and memory capabilities, security features, connectivity and communication interfaces, size, cost and appearance, operating system support, power specifications, and battery life and listing some interesting projects for each device. Through this exploration and discussion, readers can have an overall understanding on this area and foster more subsequent studies.