A5009698144- Advanced MIMO Systems Optimization
- Wireless Communication Networks Research
- Advanced Wireless Network Optimization
- Wireless Networks and Protocols
- Telecommunications and Broadcasting Technologies
- Power Line Communications and Noise
- Advanced Wireless Communication Techniques
- Power System Optimization and Stability
- Optimal Power Flow Distribution
- Cooperative Communication and Network Coding
- Energy Harvesting in Wireless Networks
- IoT Networks and Protocols
- IPv6, Mobility, Handover, Networks, Security
- Multimedia Communication and Technology
- Noise Effects and Management
- Speech and Audio Processing
- Software-Defined Networks and 5G
- Electric Power System Optimization
- Indoor and Outdoor Localization Technologies
- IoT and Edge/Fog Computing
- Advanced Adaptive Filtering Techniques
- Underwater Vehicles and Communication Systems
- Millimeter-Wave Propagation and Modeling
- Satellite Communication Systems
- Vehicle Noise and Vibration Control
Universidade Federal do Rio Grande do Norte
2016-2025
Universidade Federal de Juiz de Fora
2023
Coordenação de Aperfeicoamento de Pessoal de Nível Superior
2023
Munster Technological University
2023
Universidade Federal do Ceará
2002-2020
Centro Universitário de Volta Redonda
2018
Universidade Federal de São Carlos
2008-2011
University of KwaZulu-Natal
2011
Universidade de São Paulo
2004-2010
Universidade Federal do Pará
2009
The expansion of wireless broadband access network deployments is resulting in increased scarcity available radio spectrum. It very likely that the near future, cellular technologies and local area networks will need to coexist same unlicensed bands. However, two most prominent technologies, LTE Wi-Fi, were designed work different bands not a shared band. In this article, we discuss issues arise from concurrent operation Wi-Fi point view resource management. We show severely impacted by...
It is essential to monitor the radiation levels which general population may be exposed and compare them limits established by national international standards. This especially true in residential environments, where there a consolidated use of microwave ovens Wi-Fi access points, addition short distances devices can from user, as well prolonged periods user exposure. The objective this work measure exposure for daily oven scenarios measured with standards verify possible relation...
LoRaWAN has become popular as an IoT enabler. The low cost, ease of installation and the capacity fine-tuning parameters make this network a suitable candidate for deployment smart cities. In northern Sweden, in region Skellefteå, we have deployed to enable applications assist lives citizens. As Skellefteå subarctic climate, investigate how extreme changes weather happening during year affect real terms SNR, RSSI use SF when ADR is enabled. Additionally, evaluate two propagation models...
The Internet of Things (IoT) paradigm gains more importance each day, as the number and variety connected devices grows. To answer specific needs IoT, many wireless network standards have been developed. An example is LoRaWide Area Network (LoRaWAN), which has gained popularity thanks to affordable costs its gateways, well wide range, low energy consumption flexibility. Considering challenges that exist with testing researching on real LoRaWAN systems, development accurate simulators...
Cellular broadband Internet of Things (IoT) applications are expected to keep growing year-by-year, generating demands from high throughput services. Since some these deployed over licensed mobile networks, as long term evolution (LTE), one already common problem is faced: the scarcity spectrum cope with increasing demand for data rate. The LTE-Unlicensed (LTE-U) forum, aiming tackle this problem, proposed LTE-U operate in 5 GHz unlicensed spectrum. However, Wi-Fi consolidated technology...
LoRa has emerged as a prominent technology for the Internet of Things (IoT), with Wide Area Network (LoRaWAN) emerging suitable connection solution smart things. The choice best location installation gateways, well robust network server configuration, are key to deployment LoRaWAN. In this paper, we present an evaluation Received Signal Strength Indication (RSSI) values collected from real-life LoRaWAN deployed in Skellefteå, Sweden, when compared calculated by Radio Frequency (RF) planning...
Vehicular acoustic noise evaluations are a concern of researchers due to health and comfort effects on humans fundamental for anyone interested in mitigating audio noise. This paper focuses the evaluation level inside vehicle by using statistical tools. First, an experimental setup was developed with microphones microcomputer located strategically car's panel, measurements were carried out different conditions such as car window position, rain, traffic, speed. Regression analysis performed...
Electroencephalography (EEG) is a fundamental tool for understanding the brain's electrical activity related to human motor activities. Brain-Computer Interface (BCI) uses such develop assistive technologies, especially those directed at people with physical disabilities. However, extracting signal features and patterns still complex, sometimes delegated machine learning (ML) algorithms. Therefore, this work aims ML based on Random Forest algorithm classify EEG signals from subjects...
Although the 5G New Radio standard empowers mobile communication networks with diverse technologies such as Massive MIMO, mmWave deployments, and much more, some network functionalities still do not explore potential of assembling Artificial Intelligence to their methodologies. The handover procedure is planned very similarly in older 3GPP networks, based on simple power measurement comparisons rudimentary parameter tuning, Time-To-Trigger Hysteresis. This work develops evaluates simulations...
This article presents a new approach to minimize the losses in electrical power systems. considers application of primal-dual logarithmic barrier method voltage magnitude and tap-changing transformer variables, other inequality constraints are treated by augmented Lagrangian method. The function aggregates all constraints. first-order necessary conditions reached Newton's method, updating dual variables penalty factors. Test results presented show good performance this approach.
The default medium access mechanism for Wi-Fi, Distributed Coordination Function (DCF), is a simple contention based protocol aimed at providing fair distribution of resources among Wi-Fi nodes. However, DCF suffers from significant performance degradation in the presence dense deployments. Hence, improving MAC layer essential efficient spectrum sharing overlapping Basic Subscriber Set (OBSS) next generation wireless networks. In this context, paper, we compare with an existing mechanisms,...
In general, acoustic channels are not Gaussian distributed neither second-order stationary. Considering them for signal processing methods designed assumptions is inadequate, consequently yielding in poor performance of such methods. This paper presents an analysis audio corrupted by impulsive noise using non-Gaussian models. Audio samples compared to the Gaussian, α -stable and mixture models, evaluating fitting graphical numerical We discuss properties as window length overlap, finally...
It is crucial to monitor the levels of Non-Ionizing Radiation (NIR) which general population may be exposed and compare them limits defined in current standards, view rapid rise communication services prospects a connected society. A high number people visits shopping malls since these locations usually have several indoor antennas close public, it therefore kind place that must evaluated. Thus, this work presents measurements electric field mall located Natal, Brazil. We proposed set six...
This article presents a study with feasibility and performance analysis of machine learning (ML) techniques using supervised for anomaly detection problems in 5G communication network. The proposed ML models (Multilayer Perceptron, Decision Tree, Support Vector Machine) were used to classify data into or non-anomaly based on two Open Radio Access Network (O-RAN) datasets various key indicators (KPIs). Furthermore, we propose strategy that devotes labeling anomalous situations, leveraging the...
Modern wireless systems employ adaptive techniques to provide high throughput while observing desired coverage, Quality of Service (QoS) and capacity. An alternative further enhance data rate is apply cognitive radio concepts, where a system able exploit unused spectrum on existing licensed bands by sensing the opportunistically access portions. Techniques like Automatic Modulation Classification (AMC) could help or be vital for such scenarios. Usually, AMC implementations rely some form...
3GPP has been working in establishing a new network infrastructure based on unlicensed spectrum known as LTE Secondary Cell (SCell) carrier aggregation scenario which user terminals would still be anchored to an Primary (PCell) over licensed spectrum. On this scenario, best-effort content delivered the band SCell, while QoS traffic and control signaling PCell responsibility. This work makes performance analysis of 3GPP's solution, named License Assisted Access (LTE-LAA), allows system...
The use of unmanned aerial vehicles (UAV) to provide services such as the Internet, goods delivery, and air taxis has become a reality in recent years. these aircraft requires secure communication between control station UAV, which demands characterization channel. This paper aims present measurement setup using an acquire data for radio frequency channel propagation environment with particular vegetation (Caatinga) lake. presents following contributions: identification model that best...
The O-RAN Alliance conceived an open architecture model that aims at driving new levels of openness in the radio access network (RAN). defines RAN Intelligent Controller (RIC) as a microservices-based platform for implementing monitoring and control techniques form xApps. This paper uses open-source to exercise accessibility versatility aspects implement xApps with strategies over simplified based on GNU Radio. A spectrum sensing algorithm is proposed use case demonstrate how SDR platforms,...
This paper presents a new approach that improves the performance of Newton's method for optimal reactive dispatch problem. In this inequality constraints are divided into two groups: treated by penalty function, which added to objective function through factors, and barrier grouped with set active (power flow equations). The first order necessary conditions optimality reached method, updating terms. factorization is carried out on elements instead structures in blocks. main advantage not...