Receivers At1
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. MGF Methods for Fixed and Gain Saturated Optically Preamplified FSO Links Impaired by Misalignments and Atmospheric Turbulence
Abstract The Gaussian approximation is commonly used to evaluate the performance of free space optical communication systems. However, other performance evaluation methods such as the saddle point approximation, Chernoff bound and the modified Chernoff bound have also been used. This paper investigates the performance of fixed and gain saturated optically pr
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. A passive-matched 22 GHz 2.6-dB-NF CMOS front-end with a 70-800 ps delay block
This paper presents a power-efficient RF differential receiver front-end supporting transmitted-reference (TR) communication in a 90 nm CMOS technology. Particularly, it addresses the issues of designing the frontend amplifier with low-noise and passive matching circuits on a silicon process and integrating a low-power delay unit in the front-end with wideba
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-06
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3. Alternativas de tratamento da água de lastro em portos exportadores de minério de ferro. / Ballast water treatment alternatives in the iron ore ports exporting.
This thesis aims at making a technical and economic analysis of the ballast water treatment in Brazilian iron ore ports. Three distinct treatment alternatives were studied: (1) onshore ballast water treatment; (2) water desalination plant to ballast water treatment; (3) onboard ballast water treatment in shuttle tanker vessels operating in the mooring, where
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/03/2012
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4. Caracterização espectral e avaliação de desempenho para formatos avançados de modulação digital optica em 40 Gb/s / Spectral characterization and performance evaluation for advanced digital optical modulation formats at 40 Gb/s
This work compares the performance of four feedforward carrier recovery architectures in coherent QPSK and 8-PSK receivers, with polarization multiplexing and differential decoding. We focused on the scenarios showing an SNR imbalance between orthogonal polarizations, as in PDL impaired systems. Using Monte Carlo simulations, we observed that the proposed jo
Publicado em: 2009
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5. Uma anÃlise da QoS na transmissÃo em redes 802.11G sob presenÃa de interferÃncia Bluetooth
This MSc thesis deals with the interference between the IEEE 802.11g and Bluetooth wireless network systems. More specifically, it was analyzed the impact that Bluetooth transmissions causes on IEEE 802.11g data transmissions. Five parameters were analyzed: transmission time, average packet transmission rate, average data transmission rate, number of lost pa
Publicado em: 2008
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6. ProgramaÃÃo pela desnutriÃÃo perinatal do controle serotoninÃrgico da liberaÃÃo do Ãxido nÃtrico por macrÃfagos alveolares em ratos adultos
Restriction on nutritional feeding has long-term consequences on the functioning of neuroimmune systems. Receivers and serotonin transporter present in alveolar macrophages (AM) are related to its operation. In the article "Perinatal malnutrition programs sustainable alterations in nitric oxide production and cell viability in activated macrophages of the ad
Publicado em: 2008
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7. Morfologia e dinâmica das irregularidades ionosféricas de pequena escala e imageamento ionosférico por GPS / Morphology and dynamic of small-scale ionospheric irregularities and ionospheric imaging by GPS
The signals received from the Global Positioning System (GPS) satellites were used to study the behavior of three important geophysical parameters of the ionosphere: small-scale irregularities, their zonal drift velocities and the Total Electron Content (TEC). From the fluctuations (scintillations) in the amplitude of the GPS L1 signal (1575.42 MHz), detecte
Publicado em: 2008
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8. Evaluation of digital terrain model extracted from SAR data in X-Band of SAR R-99B / Avaliação do Modelo Digital do Terreno Extraído de Dados SAR Interferométricos na Banda X do SAR R-99B
In the Brazilian territory there are several areas with no topographic mapping coverage and the existent maps are not updated due to the continuous land use and land cover changes. The Sistema de Prote¸cao da Amazonia (SIPAM) uses airplanes with synthetic aperture radar which allows to image in several conditions. This radar was designed for recoinassance t
Publicado em: 2007
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9. Aplicações de antenas inteligentes e equalização concorrente em sistemas WCDMA/HSDPA / Applications of smart antennas and concurrent equalization on WCDMA/HSDPA systems
This dissertation investigates and proposes different algorithms for smart antennas and channel equalization aiming at WCDMA HSDPA downlink receivers. Considering the channel equalization issue, we propose an adaptive back-propagation algorithm with concurrent sub-systems. This equalization technique exploits particular characteristics of a WCDMA downlink si
Publicado em: 2004
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10. Estudo das irregularidades ionosféricas equatoriais utilizando sinais GPS / Global positioning system studies of equatorial ionospheric irregularities
Signals transmitted by the Global Positioning System (GPS) satellites were used to study equatorial ionospheric irregularities over Brazil. GPS (L1=1.575 GHz) scintillation data were used to infer the occurrence of ~400m scale-size irregularities and compared with equatorial Spread F (ESF) observations carried out by several other instruments like VHF cohere
Publicado em: 2003
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11. Interactions between angiotensin II, aortic and sympathetic nerve during development of coarctation hypertension. / Interações entre angiotensina II, atividade do nervo depressor aórtico e atividade simpática esplâncnina durante o desenvolvimento da hipertensão por coarctação.
In the chronic phase of coarctation hypertension (CH) we have shown both marked depression of baroreceptor reflex control of heart rate (Michelini et al, Hypertension, 1992, 19: II159-II163) and normalization of the depressed reflex control even with the persistence of hypertension in losartan-treated animals (Santos et al, Am. J. Physiol, 1995, 269: H812-H8
Publicado em: 1999