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Discrete Dynamics in Nature and Society
Volume 2011, Article ID 329535, 11 pages
http://dx.doi.org/10.1155/2011/329535
Research Article

Design and Simulation of a Fully Digitized GNSS Receiver Front-End

School of Electronic and Information Engineering, Beihang University (BUAA), Beijing 100191, China

Received 6 April 2011; Accepted 24 May 2011

Academic Editor: Jinde Cao

Copyright © 2011 Yuan Yu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In the near future, RF front-ends of GNSS receivers may become very complicated when multifrequency signals are available from at least four global navigation systems. Based on the direct RF sampling technique, fully digitized receiver front-ends may solve the problem. In this paper, a direct digitization RF front-end scheme is presented. At first, a simplified sampling rate selection method is adopted to determine the optimal value. Then, the entire spectrum of GNSS signal is directly digitized through RF sampling at a very fast sampling rate. After that, the decimation and filtering network is designed to lower the sampling rate efficiently. It also realizes the digital downconversion of the signal of interest and the separation of narrow band signals from different navigation systems. The scheme can be flexibly implemented in software. Its effectiveness is proved through the experiment using simulated and true signals.