XXXVIII Simpósio Brasileiro de Telecomunicações e Processamento de Sinais

Acoustic waves captured by passive sonar systems are analyzed by human operators, aiming to identify possible threats in the subsea environment. Automatic Classification Systems can aid in the work of this professional, however requiring mechanisms to deal with the presence of unknown classes. This article proposes the use of a hierarchical committee of...

This work presents a hardware architecture for the extraction of fetal electrocardiogram (FECG), based on the adaptive algorithm NLMS (Normalized Least Mean Square). Sensors positioned in the abdomen and maternal chest, capture the signals processed by hardware, seeking to identify the fetal heartbeat, canceling the interferences from the maternal...

The impact of deleterious effects resulting from the insertion of optical noise and limitations of the electro-optical modulator in channels with transmission rates of 1 Tb/s are studied based on numerical simulations, considering the systemic transmission of such signals. The results indicate that channels are impacted by limitations in the...

This work presents the design of a low noise amplifier (LNA) targeted to be used in 1.09 GHz ADS-B receivers. The design aims to satisfy the communication standard requirements, using low cost components. In order to reduce the amplifier variability under temperature and voltage variations, a closed-loop active bias is used. The circuit was designed and...

Physical-layer Key generation for wireless networks has been considered a promising alternative to traditional techniques based on pseudorandom number generators. This work evaluates key generation in a Long Range Wide Area (LoRaWAN) based on Received Signal Strength Indicator (RSSI) values, measured during the reception of LoRaWAN packets. This work...

We have implemented a technique for nonlinear compensation in optical transmission based on neural network optimization applied to digital back-propagation and evaluated its performance with experimental data from an unrepeatered link, sweeping the parameters most relevant to computational complexity. This technique enabled mutual information gains over...

Space-division multiplexing (SDM) is currently the only solution to cope with the exponential growth of data traffic in optical transmission networks. The performance of long-haul SDM transmission is fundamentally limited by mode-dependent loss (MDL) and mode-dependent gain (MDG) generated in components and amplifiers. To enable the study of MDL/MDG...

Redes IoT são heterogêneas no que se refere aos dispositivos presentes, incluindo assim dispositivos sem capacidade de se comunicar com a pilha de protocolos TCP/IP integral. Para permitir que sensores e atuadores dessa classe enviem dados através da Internet, é necessário utilizar o denominado gateway IoT, que atua na interconexão dos dispositivos...

Bi-level images are used in many fields to represent binary masks for object and region of interest coding, enhancement layers of color images and point cloud occupancy maps as geometry slices. Compression of bi-level images is usually performed using context adaptive arithmetic coding. In this paper, we propose a low complexity context selection...

This work advances the study of indoor hybrid PLC-wireless channels when the frequency band delimited by 1.7 MHz and 100 MHz is taken into account. In this sense, a measurement campaign was carried out in a building facility to investigate the wireless signal propagation of these kind of channels. Based on the collected measures of PLC-wireless channels...