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Author Roudier, M. ♦ Grelier, T. ♦ Ries, L. ♦ Poulliat, C. ♦ Boucheret, M.-L. ♦ Garcia-Pena, A. ♦ Julien, O. ♦ Kubrak, D.
Sponsorship IEEE Aerosp. Electron. Syst. Soc.
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©2014
Language English
Subject Domain (in DDC) Technology ♦ Engineering & allied operations ♦ Military & nautical engineering
Subject Keyword Decoding ♦ Global Positioning System ♦ Receivers ♦ Urban areas ♦ Channel models ♦ AWGN channels ♦ Fading ♦ GNSS demodulation performance ♦ GNSS ♦ channel decoding ♦ soft input decoders ♦ Channel State Information ♦ urban propagation channel model
Abstract Nowadays, the majority of new GNSS applications targets dynamic users in urban environments; therefore the decoder input in GNSS receivers needs to be adapted to the urban propagation channel to avoid mismatched decoding when using soft input channel decoding. The aim of this paper consists thus in showing that the GNSS signals demodulation performance is significantly improved integrating an advanced soft detection function as decoder input in urban areas. This advanced detection function takes into account some a priori information on the available Channel State Information (CSI). If no CSI is available, one has to blindly adapt the detection function in order to operate close to the perfect CSI case. This will lead to avoid mismatched decoding due to, for example, the consideration by default of the Additive White Gaussian Noise (AWGN) channel for the derivation of soft inputs to be fed to soft input decoders. As a consequence the decoding performance will be improved in urban areas. The expressions of the soft decoder input function adapted for an urban environment is highly dependent on the available CSI at the receiver end. Based on different model of urban propagation channels, several CSI contexts will be considered namely perfect CSI, partial statistical CSI and no CSI. Simulation results will be given related to the GPS L1C demodulation performance with these different advanced detection function expressions in an urban environment. The results presented in this paper are valid for any kind of soft input decoders, such as Viterbi decoding for trellis based codes, the MAP/BCJR decoding for turbo-codes and the Belief Propagation decoding for LDPC codes.
Description Author affiliation: INPT-ENSEEIHT/IRIT, Univ. of Toulouse, Toulouse, France (Poulliat, C.; Boucheret, M.-L.) || SIGNAV Res. Group, ENAC, Toulouse, France (Garcia-Pena, A.; Julien, O.) || Thales Alenia Space, Toulouse, France (Kubrak, D.) || Radionavigation Signals & Equipments, CNES, Toulouse, France (Roudier, M.; Grelier, T.; Ries, L.)
ISSN 21533598
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research ♦ Reading
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2014-05-05
Publisher Place USA
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
e-ISBN 9781479933204
Size (in Bytes) 2.23 MB
Page Count 8
Starting Page 581
Ending Page 588


Source: IEEE Xplore Digital Library