High Resolution Delay Estimation in Urban GNSS Vehicular Navigation

Negin Sokhandan, Ali Broumandan, James T. Curran and Gerard Lachapelle

Abstract:	Multipath propagation causes major impairments to satellite based navigation systems and is often the dominant source of accuracy degradation and a major issue for high precision Global Navigation Satellite System (GNSS) applications. Most of the commonly used time-of-arrival estimation techniques cannot provide the required estimation accuracy in severely dense multipath environments such as urban canyons. In this paper, the Doppler spectrum broadening (Doppler spread) of the fast fading channel (where the rate of the variations of the channel is faster than the symbol rate of the signal) resulting from the motion of the receiver or surrounding objects is employed for the purpose of signal decorrelation for the high-resolution estimation of multipath delays through the subspace-based Multiple Signal Classification (MUSIC) technique. Specifically, delay-domain correlator outputs at different Doppler frequencies will be combined to enhance the rank of the signal autocorrelation matrix. Theoretical simulation and processing results of real data collected in downtown Calgary are presented to compare the performance of the proposed method with the spatial-temporal-diversity based MUSIC technique and a widely available algorithm in commercial GNSS receivers, namely the double-delta correlator technique. The performance metrics are based upon pseudorange and positioning errors. The pseudoranges and positions computed by the proposed techniques are compared to the reference trajectory established using a high precision Inertial Measurement Unit (IMU).
Published in:	Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012) September 17 - 21, 2012 Nashville Convention Center, Nashville, Tennessee Nashville, TN
Pages:	1417 - 1427
Cite this article:	Sokhandan, Negin, Broumandan, Ali, Curran, James T., Lachapelle, Gerard, "High Resolution Delay Estimation in Urban GNSS Vehicular Navigation," Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Nashville, TN, September 2012, pp. 1417-1427.
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