Preliminary Studies on the Large Intelligent Surfaces Efficiencies Under Different Channels

Michelle Soares Pereira Facina, Gustavo Fraidenraich

DOI: 10.14209/SBRT.2020.1570656693

Keywords:

Abstract

This work investigates the impact of the channel model, and power allocation on the performance of a system employing Large Intelligent Surfaces (LIS). Most of the previous studies have considered the energy efficiency of such systems under the influence of Rayleigh channels and Zero-Forcing (ZF) precoding. We present results for Rice channels and Matched Filter (MF) receiver showing a surprising reduction in energy efficiency. We also derive an accurate approximation for spectral efficiency when the equal power allocation strategy is employed. According to our simulations, a loss of 6 dB is observed when the symbols are transmitted with the same power.

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Simulador Radar baseado no software Blender

Raíssa Andrade, Rômulo Fernandes da Costa, Renato Machado

DOI: 10.14209/SBRT.2020.1570656801

Keywords: SABER modelagem 3D equação radar path tracing

Abstract

This article demonstrates the validation of some elementary concepts of radar theory using a simulator based on the open-source 3D modeling software Blender. From a simply built 3D scene, it is possible to verify target detection, fading of the simulated radar signal, and features related to the system's spatial resolution, as it is provided by the theoretical model.

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Antena Multibanda Semi-Espiral CPW para Aplicações no 5G sub-6 GHz

Valdemir Praxedes da Silva Neto, Jose Garibaldi Duarte Jr.

DOI: 10.14209/SBRT.2020.1570656813

Keywords: Multiband Spiral CPW 5G sub-6 GHz

Abstract

Modern wireless communication systems increasingly need radio frequency devices capable of meeting their operating specifications. In this work, an antenna with multiband characteristics based on semi-spiral geometry and coplanar waveguide feed line is proposed for applications in the 5G sub-6 GHz standards. A study is done on the physical parametersof the spiral patch and feed line geometry. The prototype built was subjected to measurement where four operating bands were obtained, which were centered at 1.36, 1.71, 2.47 and 3.65 GHz, therefore, possibly applicable in the specified standards

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Sistema Fuzzy para Detecção de Novidades em Inspeção Não Destrutiva por Ultrassom

Geiza M. de Barros, Moises A Oliveira, Eduardo Simas Filho, Maria Cléa Albuquerque, Ivan Silva, Cláudia Teresa Farias

DOI: 10.14209/SBRT.2020.1570656856

Keywords: Inspeção Não-Destrutiva Processamento de Sinais Detecção de Novidades Lógica Nebulosa

Abstract

In this paper, Fuzzy decision rules, in the context of novelty detection, aims to increase efficiency and reliability related to defect identification associated with a set of A-Scan signals, obtained from a welded test piece in a non-destructive inspection using the Time-of-Flight Diffraction (ToFD) ultrasound technique. The training process only required samples without defects, and the result consisted in assigning a probability that a given analyzed signal was related to some non-conformity. ToFD ultrasonic signals from five types of defects indicated the method's efficiency.

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Redução da Complexidade do Max-Log-MPA em Sistemas SCMA

Luis Mataveli

DOI: 10.14209/SBRT.2020.1570657286

Keywords: SCMA Max-Log-MPA Redução de Complexidade

Abstract

For detection in SCMA (Sparse Code Multiple Access) systems the optimal algorithm is MAP (Maximum a Posteriori). Although it has the best performance, MAP has high complexity for cases where there are a large numbers of users. Thus, the MPA (Message Passing Algorithm) has been studied as an option for detection in these systems. Even though it is smaller, MPA's complexity is also high and can be reduced. One way is to use mathematical approximations, such as is done in Max-Log-MPA. Based on this algorithm, we propose in this work a method that eliminates some calculations within the iterative part of Max-Log-MPA. This is done by comparing the values of some variables with decision thresholds.

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Transformada RAHT com Predição Inter-Quadros para Compressão de Nuvem de Pontos

André L Souto, Ricardo L de Queiroz

DOI: 10.14209/SBRT.2020.1570657479

Keywords:

Abstract

This work studies the use of region adaptive hierarchical transform (RAHT) with predictive approaches for attribute compression of dynamic point clouds. An intra-frame predictive RAHT, where the intra-frame prediction residuals are encoded instead of the voxel attributes themselves, was shown to deliver large gains over conventional RAHT. We extend the scheme to inter-frame prediction and show that an adaptive combination of zero-motion-vector (ZMV) inter-frame and intra-frame predictions may achieve large gains over convetional RAHT and intra-frame predictive RAHT when compressing attributes of dynamic point clouds. The use of the low computational cost ZMV technique suits as an alternative for high computational cost motion estimation algorithms for point clouds.

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Blind Source Separation based on Semblance Beamforming

Alexandre Miccheleti Lucena, Kenji Nose Filho, Ricardo Suyama

DOI: 10.14209/SBRT.2020.1570657503

Keywords: source separation beamforming semblance source cancellation

Abstract

The source separation task has been tackled from different approaches, including beamforming. The idea of exploiting geometric information of the sensors may contribute in convolutive mixture separation context, usually assumed in real scenario. This work proposes a beamformer algorithm for source separation based on the semblance coherence function. The performance of the algorithm for artificially mixed signals is evaluated using a objective intelligibility metric throughout Monte Carlo simulations in two scenarios and different SNR levels. Results are compared with classic techniques: GSS and Delay and Sum, where the proposed algorithm achieves the best performance under no influence of additive noise.

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Fusão de Dados com Sensores com Geometria e Granularidade Distintas em Ambiente de Alta Taxa de Eventos

Dayane Oliveira Gonçalves, Mariana de Souza Oliveira, Luciano Andrade, Augusto S Cerqueira, José de Seixas

DOI: 10.14209/SBRT.2020.1570657577

Keywords: Estimação de Parâmetros Calorimetria Processamento de Sinais Fusão de Dados

Abstract

One of the biggest challenges faced in multiple sensors systems is to provide an efficient combining data method to obtain information of interest as accurately as possible. This work presents a linear technique to combine the information from redundant sensors, in order to minimize the effects of noise. Results obtained using sensors from the Hadronic Calorimeter of the ATLAS Experiment (CERN, Switzerland), to detect muon particles, have shown a reduction of 6% in the noise from the combination of neighboring channels. The method is also very effective in detecting and removing bad channels, increasing the robustness of the system.

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A Robust ToA and Pulse Width Estimator for Electronic Warfare Applications

Aline de Oliveira Pinto Silva, Rafael de Figueirêdo, Luiz Eugênio Segadilha, Sergio Neves, Jean Marc-Lopez

DOI: 10.14209/SBRT.2020.1570657578

Keywords: Electronic Warfare ToA Estimation Pulse Width Estimation ELINT

Abstract

We propose a robust Time of Arrival (ToA) and Pulse Width (PW) estimator for Electronic Intelligence (ELINT) and Electronic Support Measures (ESM) systems in Electronic Warfare (EW) applications. Robust ToA and PW measurements of the intercepted radar pulse are assets in EW algorithms and are worthy to be pursued. The proposed estimation method is based on Autoconvolution (AC) and Model Change Detection (MCD) theory. Computer simulations show the superior performance of the proposed method in the presence of AWGN and spurious signals when compared to a Histogram and Mean-Based Threshold methods and a Autoconvolutional method. A comparison of the methods with a recorded radar pulse confirms the robustness of the proposed method in a real scenario.

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Comparações de modelo epidêmico suscetível-infectado em redes reais e aleatórias

Rodrigo M Malagutti, Marcio Eisencraft

DOI: 10.14209/SBRT.2020.1570657814

Keywords: Epidemic models Complex networks Susceptible-infected Random networks

Abstract

This paper aims to relay the results from computer simulations of mechanisms for gradual transmission of epidemics with the susceptible-infected model over real networks in comparison to random ones. In particular, networks from the models of Erdos-Renyi, Watts-Strogatz (small world) and Barabási-Albert (scale free) are analyzed. By changing contamination parameters and network properties, it is possible to notice an increase in contamination potential as the networks approach human patterns of organization.

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