Chip Transition-Edge Based Signal Tracking for Ultra-Precise GNSS Monitoring Applications

Sanjeev Gunawardena, John Raquet, Frank van Graas

Abstract:	This paper introduces the concept of tracking GNSS signals using their underlying spreading sequence chip transition edges. An empirical chip rising edge-based tracking technique is first used to observe the underlying chip shapes of the live sky GPS-SPS constellation at high fidelity. The results reveal positive versus negative chip asymmetries that are characteristic to each satellite. This asymmetry is due to various types of natural signal deformation that is known to occur within the satellite’s signal generation and transmission hardware. Hence, the novel concept of monitoring chip asymmetry that is introduced in this paper has potential to extend the state-of-the-art in the areas of GNSS signal quality monitoring and authentication. A technique to directly monitor chip asymmetry within a specially designed ChipShape GNSS receiver architecture is introduced. This method employs separate code discriminators that align themselves to the chip rising-edge and falling-edge zero crossings. The paper describes the procedure for calibrating these discriminators and also presents their multipath error envelopes.
Published in:	Proceedings of the ION 2015 Pacific PNT Meeting April 20 - 23, 2015 Marriott Waikiki Beach Resort & Spa Honolulu, Hawaii
Pages:	100 - 106
Cite this article:	Gunawardena, Sanjeev, Raquet, John, van Graas, Frank, "Chip Transition-Edge Based Signal Tracking for Ultra-Precise GNSS Monitoring Applications," Proceedings of the ION 2015 Pacific PNT Meeting, Honolulu, Hawaii, April 2015, pp. 100-106.
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