scholarly journals Plataforma educativa para desarrollo de sistemas de software radio mediante modulación QPSK en Octave y Arduino

2020 ◽  
pp. 22-31
Author(s):  
Eric Mario Silva-Cruz ◽  
Franco Gabriel Caballero-Julián ◽  
Miguel Ángel Pérez-Solano ◽  
Cristian Pérez-Ojeda
Keyword(s):  
Software Radio ◽  
Quadrature Modulation ◽  
Radio System ◽  
High Speeds ◽  
Front End ◽  
Modulation Techniques ◽  
Analog Approach ◽  
Radio Systems ◽  
Web Platform

Nowadays, the development of software radio based systems has allowed the transmission of data at high speeds and frequencies in the order of Gigahertz (Jovanovic, 2018). For this, the digital system is characterized by using digital modulation techniques in software through transmission symbols in the DigitalEnd stage, applying digital-analog (DAC) and analogdigital (ADC) converters to vary the sampling frequency and transmit the data in the Front End, (Chien, 2001). This work presents a digital educational platform to simulate the characteristics of a Software Radio system and not a web platform. The present investigation is focused on the characterization of signals modulated by Octave considering in the first instance the quadrature modulation QPSK, where the transmission of the modulated signal is carried out by means of the Arduino board in a digital port, with a digital-analog approach (DAC) using PWM modulation a RC filter and an amplifier circuit, which synthesize the signal considering the limitations of the Arduino board. The proposed design presents an electronic platform that will allow the understanding of software-based radio systems.

scholarly journals Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory

2021 ◽  
Vol 16 (01) ◽  
pp. P01026-P01026
Author(s):  
A. Aab ◽  
P. Abreu ◽  
M. Aglietta ◽  
J.M. Albury ◽  
I. Allekotte ◽  
...  
Keyword(s):  
Pierre Auger Observatory ◽  
Silicon Photomultiplier ◽  
Front End

scholarly journals A Collision Dynamics Model of a Multi-Level Train

2006 ◽  
Author(s):  
Michelle Priante ◽  
David Tyrell ◽  
Benjamin Perlman
Keyword(s):  
Three Dimensional ◽  
Design Parameters ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Single Level ◽  
High Speeds ◽  
Front End ◽  
Multi Level ◽  
Low Speeds ◽  
Vertical Accelerations

In train collisions, multi-level rail passenger vehicles can deform in modes that are different from the behavior of single level cars. The deformation in single level cars usually occurs at the front end during a collision. In one particular incident, a cab car buckled laterally near the back end of the car. The buckling of the car caused both lateral and vertical accelerations, which led to unanticipated injuries to the occupants. A three-dimensional collision dynamics model of a multi-level passenger train has been developed to study the influence of multi-level design parameters and possible train configuration variations on the reactions of a multi-level car in a collision. This model can run multiple scenarios of a train collision. This paper investigates two hypotheses that could account for the unexpected mode of deformation. The first hypothesis emphasizes the non-symmetric resistance of a multi-level car to longitudinal loads. The structure is irregular since the stairwells, supports for tanks, and draglinks vary from side to side and end to end. Since one side is less strong, that side can crush more during a collision. The second hypothesis uses characteristics that are nearly symmetric on each side. Initial imperfections in train geometry induce eccentric loads on the vehicles. For both hypotheses, the deformation modes depend on the closing speed of the collision. When the characteristics are non-symmetric, and the load is applied in-line, two modes of deformation are seen. At low speeds, the couplers crush, and the cars saw-tooth buckle. At high speeds, the front end of the cab car crushes, and the cars remain in-line. If an offset load is applied, the back stairwell of the first coach car crushes unevenly, and the cars saw-tooth buckle. For the second hypothesis, the characteristics are symmetric. At low speeds, the couplers crush, and the cars remain in-line. At higher speeds, the front end crushes, and the cars remain in-line. If an offset load is applied to a car with symmetric characteristics, the cars will saw-tooth buckle.

Characterization of Frontal Crash Pulses

2000 ◽  
Author(s):  
Hikmat F. Mahmood ◽  
Fadhel Aouadi
Keyword(s):  
Pulse Duration ◽  
Test Data ◽  
Frontal Crash ◽  
Design Information ◽  
Injury Criteria ◽  
Front End ◽  
Time Zones

Abstract This paper presents test data of more than 30 vehicles of different manufacturer, weight and front-end length. The relationships between the vehicle frontal NCAP pulse, the dummy response and the vehicle characteristics are shown in many figures. Vehicle frontal pulses were characterized and analyzed by considering different time zones within the pulse duration: bumper effect zone (0 ms. to 5 ms.), engine effect zone (18 ms. to 35 ms.), dummy engagement zone (48 ms. to 68 ms.). Also, ratios and delays between rocker pulse and the dummy chest and head pulses are computed and analyzed. The purpose of this study is not to develop a crash pulse but to generate design information that can assist in the design of front-end structure to meet injury criteria.

DEVELOPMENT OF A SOFTWARE COMPLEX FOR INTELLIGENT TUNING OF OPERATING FREQUENCIES FOR COGNITIVE RADIO SYSTEMS

2021 ◽  
Author(s):  
Е.О. КАНДАУРОВА ◽  
Д.С. ЧИРОВ
Keyword(s):  
Cognitive Radio ◽  
Software Defined Radio ◽  
Experimental Studies ◽  
Spectrum Utilization ◽  
Radio System ◽  
Cognitive Radio System ◽  
Software Complex ◽  
Cognitive Radio Systems ◽  
Software Modules ◽  
Radio Systems

Представлено описание разработанных программных модулей интеллектуальной перестройки рабочих частот для системы когнитивного радио, в которых применяется ранее предложенный алгоритм анализа использования радиочастотного спектра. Также разработаны программные модули для взаимодействия с программно-определяемыми радиосистемами, такими как LimeSDR. Экспериментально показано, что использование алгоритма предсказания занятости частотных каналов позволяет сократить время оперативного сканирования спектра. A description of the developed software modules for intelligent tuning of operating frequencies for the cognitive radio system is presented. These software modules use the previously proposed algorithm of RF spectrum utilization analysis. Also, software modules have been developed for interacting with software-defined radio such as LimeSDR. Experimental studies have shown that the use of an algorithm for predicting the occupancy of frequency channels allows reducing the time of operational scanning of the spectrum.

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