A Frequency Domain-based Detection Technique for Digital Distortion on GNSS Signals

Chao Sun, Hongbo Zhao, Chen Zhuang, Wenquan Feng

Abstract:	Global Navigation Satellite Systems (GNSS) signal distortions could threaten the position accuracy and integrity of GNSS, especially for safety critical applications. Digital distortion is an important kind of deformations caused by failure inside the baseband generation unit onboard the GNSS satellites. A TMA model in time domain was particularly presented to characterize this deformation. And the multi-correlator technique, as the prevalent Signal Quality Monitoring (SQM) method, was also developed to reliably detect this anomaly and thereby protect airborne users from this integrity threat. However, the conventional multicorrelator technique is unable to estimate the distortion degree quantitatively. While another prevalent method, chip domain observable, has a poor real-time capability so that it cannot meet the stringent TTA (Time To Alarm, for avionics applications this is 6 seconds) requirements. This paper starts with deriving a spectrum form of TMA for digital distortion and proposes a novel SQM algorithm based on IFFT processing. Simulation results show that the IFFT-based method is feasible to perform a quantitative, real-time monitoring against the digital distortion.
Published in:	Proceedings of the 29th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2016) September 12 - 16, 2016 Oregon Convention Center Portland, Oregon
Pages:	1804 - 1813
Cite this article:	Sun, Chao, Zhao, Hongbo, Zhuang, Chen, Feng, Wenquan, "A Frequency Domain-based Detection Technique for Digital Distortion on GNSS Signals," Proceedings of the 29th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2016), Portland, Oregon, September 2016, pp. 1804-1813. https://doi.org/10.33012/2016.14693
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