Signal Constellation
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. GENERATION AND PERFORMANCE ANALYSIS OF GPS AND GLONASS VIRTUAL DATA FOR POSITIONING UNDER DIFFERENT IONOSPHERIC CONDITIONS
Abstract Several approaches concerning the use in positioning of GNSS (Global Navigation Satellite Systems) can be considered: systems, applied methods and errors that can affect the signals. Following the GLONASS (GLObal NAvigation Satellite System) constellation reestablishment (2011), there was renewed interest in its use with GPS (Global Positioning Syst
Bol. Ciênc. Geod.. Publicado em: 10/07/2019
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2. Estudos de sistemas OFDM para comunicações ópticas / Studies OFDM systems for optical communications
The development of digital modulation formats in optical communications systems is considered to be a promising way to increase the spectral efficiency and to combat the effects of signal degradation in optical fiber without changing the infrastructure already deployed. In this context, the technique called OFDM (orthogonal frequency division multiplexing) e
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 03/10/2012
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3. Brazilian Portugueses nasal diphthongation: an acoustic and aerodynamic analysis of speech / A ditongação nasal no português brasileiro: uma análise acústico-aerodinâmica da fala
There are several studies that characterize the nasal vowels. However, there are few studies about the nasal diphthongation. This phenomenon emerges from the articulatory gestures constellation. This can be noted by analyzing of the acousticaerodynamics parameters. The aim of this work is study the gesture configuration between the thong movement and the vel
Publicado em: 2010
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4. Modulação quantizada para sistemas com codificação wavelet sujeitos ao desvanecimento rayleigh
Wavelet coding is an efficient technique to overcome the multipath fading effects, which are characterized by fluctuations in the intensity of the transmitted signals over wireless channels. Since the wavelet symbols are non-equiprobable, modulation schemes play a significant role in the overall performance of wavelet systems. Thus the development of an effi
Publicado em: 2009
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5. Proposal of signal constellations for the genetic code / Proposta de constelações de sinais para o codigo genetico
A proposta deste trabalho é apresentar uma abordagem aos processos genéticos e moleculares, utilizando a teoria de comunicações e codificação na modelagem do dogma central da biologia molecular. A partir desta modelagem associamos o código genético a um modulador de um sistema de comunicação. Mais especificamente, tal procedimento consiste em const
Publicado em: 2008
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6. Uma analise da influencia da curvatura do espaço em sistemas de comunicações / An analysis of the influence of the space curvature in communication systems
Em geral, o espaço EucIidiano é utilizado no projeto e na análise de desempenho da maior parte dos sistemas de comunicações atuais. Nesta tese, verificamos que o modelo de um sistema de comunicação não necessariamente está restrito ao espaço Euclidiano, mas sim a uma variedade Riemanniana. Com isso, os sistemas de comunicaçoes podun ser analisados
Publicado em: 2008
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7. Frequency domain concurrent channel equalization for multicarrier systems
Receivers for wireless Orthogonal Frequency Division Multiplexing (OFDM) systems usually perform the channel estimation based on pilot carriers in known positions of the channel spectrum. Interpolation between pilot carriers is applied to determine the channel transfer function in all carrier frequencies. Channel variations along time are compensated by mean
Journal of the Brazilian Computer Society. Publicado em: 2007-03
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8. Realizações de constelações de sinais hiperbolicas densas associadas a sistemas lineares atraves das funções automorfas
In this work we have introduced a transmission line as a hyperbolic modeling; we have constructed a signal constellation in the hyperbolic plane from regular tessellations such as the ones generated by {12g - 6, 3} ; we have established a procedure for couting the number of points of the constellations mentioned above. We have also presented the automorphic
Publicado em: 2005
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9. Altered transcription of a defective measles virus genome derived from a diseased human brain.
Measles virus (MV) is a negative strand RNA virus which usually causes acute disease, but in rare cases its persistence in the human brain induces the lethal disease subacute sclerosing panencephalitis (SSPE). The transcription of MV and of a defective MV derived from autopsy material of a SSPE case was studied in cultured cells. In the lytic infection the l