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Sitemap > Bulletin Board > Diplomarbeiten, Bachelor- und Masterarbeiten > Diplomarbeit/Masterarbeit -- Estimation of Synchronization Parameters Considering Quantization Effects
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Diplomarbeit/Masterarbeit -- Estimation of Synchronization Parameters Considering Quantization Effects

23.07.2008, Diplomarbeiten, Bachelor- und Masterarbeiten

A Global Navigation Satellite System (GNSS), like GPS or the forthcoming European Galileo system, perform high accuracy time-of-arrival (TOA) ranging to determine user position. This concept entails measuring the time it takes for a signal transmitted by an emitter at a known location to reach a user receiver. At least four GNSS satellites are needed to calculate user position and the clock offset between the clock of the user receiver and the system time. Thus, the quality of the data provided by a GNSS receiver largely depends on the synchronization error with the signal transmitted by the GNSS satellite (navigation signal), that is, on the accuracy in the propagation delay estimation of the direct signal (line-of-sight signal, LOSS). Additionally to the propagation delay of the navigation signal also the Doppler frequency and the carrier phase have to be estimated by the receiver in order to perform coherent down-conversion to base-band and to achieve high accuracy navigation using carrier phase estimates. In a conventional GNSS receiver maximum likelihood (ML) estimation of synchronization parameters, time-delay, Doppler frequency and carrier phase is performed. An efficient method to implement such a ML estimator is a Delay-Lock-Loop (DLL) with a Phase-Lock-Loop (PLL). Initialization of the PLL and the DLL is achieved by a process called acquisition where rough estimates of the time-delay and the Doppler frequency are derived non-coherently. The DLL, PLL, and acquisition process are affected in their performance by quantization effects resulting from analog-to-digital conversion (ADC) of the received signal. In this thesis work the mentioned quantization effects shall be studied in detail and their effect on the accuracy of the estimation of the synchronization parameters shall be quantified. The tasks addressed in this thesis are part of a current project between the Lehrstuhl fuer Netzwerktheorie und Signalverarbeitung (NWS, Institute for Circuit Theory and Signal Processing) with the Institute for Communications and Navigation within the Deutsches Zentrum fuer Luft- und Raumfahrt (DLR, German Aerospace Center).

Kontakt: Dipl.-Ing. Amine Mezghani / M.Sc. Mario Castaneda (NWS, Room N1129) Email: amine.mezghani@nws.ei.tum.de / mario.castaneda@nws.ei.tum.de, Dipl.-Ing. Felix Antreich (DLR), Email: felix.antreich@dlr.de