Sistema e processo para geração, sincronização remota e comparação de sinais temporais precisos / System and process for the generation, remote synchronization and comparison of precise time signals

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

05/07/2010

RESUMO

This thesis present new proposals for time dissemination systems, which were analyzed and implemented as complete solutions providing high resolution in radio links focusing in the requirements of the new geolocation system known as GEOLOCAL. The solutions found are useful for other applications equiring time synchronization. The work has been developed in different areas that include high precision counters; nanosecond resolutions clocks; radio links for time dissemination and measurements of distance; coded sequence generators for detection and identification of counting fields, digital jitter suppressors using samples averaging and clock synchronizers for quartz based oscillators. High precision counters have been investigated for the purpose to construct a high resolution clock. As a result it has been obtained a unique solution using delay lines with independent counters. This configuration allows the obtaining high count resolution with the use of low frequency reference oscillators, without increasing the system uncertainties due to interpolation non-linearity errors. The radio links were constructed with synchronous interface between the transmission and reception bases using FSK (Frequency Shift Keying) modulation. The measurements errors due to jitter in circuit propagation were minimized by calculating the average of samples taken every count set. In order to implement a low cost system, it has been developed an innovative clock synchronization technique between quartz oscillator elements to the type OCXO (Oven Controlled Crystal Oscillator). This synchronization technique produced stabilities equivalent to those obtained with rubidium-referred oscillators. The digital systems have been constructed using FPGA (Field Programmable Gate Array).

ASSUNTO(S)

relógios distância - medição osciladores osciladores de base de tempo watches distance measurements oscillators time base generators

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