Victor Fernandes

Integrated sensing and communication (ISAC) is a cornerstone of the 6G vision, particularly when integrated with cell-free (CF) architectures. However, conventional centralized processing designs face prohibitive fronthaul overhead due to the massive volume of data fusion required. To address this, this letter proposes a signaling-efficient access point selection framework for distributed sensing in CF-ISAC, validated under the 3GPP UMa channel model with environmental clutter. By deriving selection metrics from local detector states and transmitting only scalar statistics, the framework minimizes signaling while mitigating noise accumulation. Simulation results demonstrate that our strategy ensures scalable, accurate sensing, outperforming state-of-the-art geometric and communication-centric baselines by up to 3 dB in realistic, cluttered environments.

New digital television standards are emerging to meet the demand for new services from TV broadcasters, as well as to support new high-resolution audio and video formats available on the market. In Brazil, the Brazilian Digital TV System (SBTVD) Forum defines the standard to be adopted. Among the currently available physical layer technologies, the Advanced Television Systems Committee (ATSC) 3.0 standard offers great flexibility in operating modes, depending on the broadcasters’ requirements and propagation conditions, for both fixed and mobile reception. This allows the system to be configured to balance robustness and transmission efficiency. This paper presents the performance test results in various mobile reception scenarios in the city of Rio de Janeiro, using an ATSC 3.0 signal with a transmission rate of 32.3 Mbps in a $2\times 2$ Multiple-Input Multiple-Output (MIMO) configuration. The results showed a reception success rate of 53.6%, with an increase in reception errors for Carrier-to-Noise Ratio (C/N) lower than 26 dB. Furthermore, reception errors were detected with greater intensity when the received signal level was below -70 dBm. Although the overall success rate was around 50%, the complementary metrics (C/N threshold, RSSI, and PLP0 error behavior) were consistent with theoretical expectations, demonstrating that ATSC 3.0 performs effectively under real urban mobility conditions at high spectral efficiency. ATSC 3.0 thus proved effective in broadcast transmission, meeting the needs for ultra-high-definition (UHD) audio and video broadcasting.

This study introduces a simple statistical model for the multichannel signal-to-noise ratio (mSNR) for indoor and broadband power line communication (PLC) systems. Additionally, closed-form expressions for the ergodic achievable data rate and outage probability, based on the proposed model, are presented. Relying on a real-world dataset that includes PLC channel estimates and additive noise measurements, the numerical results show that the proposed mSNR-based statistical model accurately approximates the ergodic achievable data rate and outage probability values obtained from the dataset, in comparison to a well-established channel model. Consequently, the proposed statistical model offers a simple and effective tool for evaluating indoor and broadband PLC systems.

Small Remotely Piloted Aircrafts (RPAs) are gaining an increasingly prominent role in society. However, their growing use has raised concerns due to their potential misuse for illicit activities. Consequently, the detection and accurate classification of small RPAs have become crucial. Conventional radar systems, however, struggle to distinguish these aircraft from birds, as their Radar Cross-Sections (RCS) are very similar. To address this challenge, the Micro-Doppler (MD) effect has emerged as a valuable tool, enabling the differentiation of signals between birds and small RPAs. It also facilitates the classification of these aircraft. This study analyzed the Micro-Doppler (MD) effect generated by the motion of the rotating components of quadcopter RPAs and explored how this phenomenon can be utilized to extract information, such as rotor rotation speeds and propeller sizes, for an initial classification of these aircraft. Furthermore, the MD effect produced by birds was examined to identify characteristics that can be used to differentiate RPAs from birds. Lastly, the results of MD effect measurements using a Frequency-Modulated Continuous Wave (FMCW) radar during the RPA FIMI X8 SE flight were analyzed and discussed.

Aiming to illuminate the path towards integrating energy harvesting (EH) technologies into modern electric power systems, thereby enabling more efficient and sustainable energy solutions, this paper explores energy harvesting within electric power systems and points out its potential to power data communication purposes. In this sense, we examine the overarching principles of EH in these systems, spotlighting both the merits and limitations associated with energy extraction across varying voltage levels and electric signal frequency bands. Central components of EH devices, alongside a spectrum of harvesting methodologies, are thoroughly reviewed. Also, we showcase a case study that provides a quantitative assessment of EH potential in electric power systems. The manuscript culminates in a forward-looking analysis of EH, considering emerging technologies that promise to redefine the landscape. These include integrating hybrid power line and wireless systems, strategies for optimal power allocation, enhancements in physical layer security, the innovative concept of negawatts, advancements in harvesting circuit designs and applying non-orthogonal multiple access techniques

In this work, we investigated the path loss (PL) profile of the outdoor radio channel in the 800 MHz band for the Icaraí region in the city of Niterói. This frequency band has recently been reserved by the brazilian National Telecommunications Agency (ANATEL) for utilization in Public Protection and Disaster Relief (PPDR) wireless networks, and Icaraí constitutes a potential area to receive coverage provided by a PPDR network whose implementation is of interest to the Niterói government. The investigation relies on narrowband large scale measurements, recorded at various places throughout the neighborhood. As a theoretical framework for the analysis, we consider four log-distance PL models, which have been widely used in recent outdoor channel sounding works. Our findings seek to facilitate the successful establishment and optimization of PPDR networks in Niterói city.

This work investigates the frequency spectrum in the modulator and up-conversion outputs of a generic all-digital transmitter architecture. Considering the modulator is implemented as a pulse-width modulation (PWM), it is verified that this up-conversion process introduces a series of impulses resembling the spectrum of a unipolar return-to-zero (RZ) waveform in addition to the PWM impulses. Simulations show the minimum bit resolution of PWM signals where the impulses introduced are almost unnoticed, thus their influence is not distinguished from random background noise. An all-digital transmitter is designed on a field-programmable gate array to verify it experimentally. Experimental results show that reducing power from PWM harmonics leads to a power increase in the RZ harmonics, and vice-versa. These harmonic’s power present an energy trade-off relation, a novelty demonstrated in this paper. Finally, but not least, it is observed that filtering the carrier wave out causes a considerable amount of power to be lost.

This article focuses on the hidden benefits of harvesting the wasted energy from undesirable components of electric signals in electric power systems for powering the transceivers of Internet of Things (IoT) devices. These components, mainly harmonics and interharmonics, occupy the ultranarrowband power line communication spectrum (i.e., frequencies below 3 kHz). In this context, we introduce a mathematical formulation that allows us to quantify the number of transceivers of IoT devices that this kind of wasted energy can power. Based on a measurement campaign in a building facility, we show that the wasted energy can be modeled as a cyclostationary random process on weekdays and a stationary one on weekends, mimicking the energy consumption profile in a building facility. Numerical results also highlight achievable data rates obtained in the building facility if the wasted energy is reused. This analysis shows that this kind of harvested energy from wasted energy is suitable for powering numerous transceivers of IoT devices in practical scenarios.

This work introduces statistical models for the energy harvested from the in-home hybrid power line-wireless channel in the frequency band from 0 to 100 MHz. Based on numerical analyses carried out over the data set obtained from a measurement campaign together with the use of the maximum likelihood value criterion and the adoption of five distinct power masks for power allocation, it is shown that the log-normal distribution yields the best model for the energies harvested from the free-of-noise received signal and from the additive noise in this setting. Additionally, the total harvested energy can be modeled as the sum of these two statistically independent random variables. Thus, it is shown that the energies harvested from this kind of hybrid channel is an easy-to-simulate phenomenon when carrying out research related to energy-efficient and self-sustainable networks.