Robust GNSS signal demodulation

Centre National d'Etudes Spatiales CNES - 10/18/2016


Method and device for spread spectrum radio navigation signal demodulation comprising a data channel modulated by a navigation message and an unmodulated pilot channel. After combining these channels and performing despreading, the demodulation of the despread data signal enables obtainment of the navigation message (with a bit error rate of up to 10%).


Optimal performance - Modernized reception of GPS and GALILEO signals under difficult conditions - Does not necessarily require changes to the ASIC: depending on receiver architecture, a software modi cation may suffice


More robust demodulation - Demodulating the navigation message is no longer dependent on the search threshold of a phase-locked loop (PLL) - Demodulation can be performed in code-only mode A simplified receiver architecture - Because carrier phase recovery is no longer necessary, there is no need to use a phase-locked loop - The receiver can simply use an FLL loop to search for the carrier - Simplified receiver architecture and greater robustness than with a PLL. - It is possible to estimate the symbol of the message received for data wiping purposes, even when the signal-to-noise spectral density ratios are lower than the PLL dropout threshold

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