Quantization Effects in GNSS Receivers in the Presence of Interference

M. Abdizadeh, J.T. Curran, G. Lachapelle

Abstract:	The signal quantization process in a receiver can introduce loss of signal quality, especially in the presence of interference. The carrier-to-noise density ratio (C/N0) is often used to describe the GPS receiver performance and, so, this signal quality loss is typically expressed in terms of a C/N0 loss. This paper aims to provide a comprehensive analysis of the quantization loss incurred in a conventional GNSS receiver in presence of Continuous Wave (CW) interference in terms of C/N0. This work seeks to extend the analysis of interference free case to further consider the interference characteristics and received interference power level. Simulation results show that traditional techniques used to estimate carrier-to-noise ratio are unreliable when interference is present. To avoid this problem, the bit error rate metric is employed in this work. By examining an increase in BER in the presence of quantization and interference relative to the interference and quantization free case, the corresponding loss in C/N0 can be deduced. It will be shown that a receiver needs to adaptively adjust the quantizer gain both in the presence and absence of interference to minimize the total processing losses. This reduced processing loss can provide an associated improvement in both acquisition and tracking performance. Index Terms—Global Navigation Satellite System (GNSS), quantization, interference.
Published in:	Proceedings of the 2012 International Technical Meeting of The Institute of Navigation January 30 - 1, 2012 Marriott Newport Beach Hotel & Spa Newport Beach, CA
Pages:	742 - 779
Cite this article:	Abdizadeh, M., Curran, J.T., Lachapelle, G., "Quantization Effects in GNSS Receivers in the Presence of Interference," Proceedings of the 2012 International Technical Meeting of The Institute of Navigation, Newport Beach, CA, January 2012, pp. 742-779.
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