scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A Novel Multipath Mitigation Technique for GNSS Signals in Urban Scenarios

01 Mar 2020-IEEE Transactions on Vehicular Technology (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 69, Iss: 3, pp 2649-2658
TL;DR: It is shown that the proposed technique provides significant improvements over the current state of the art techniques like high resolution correlator/double delta correlator and narrow correlator on general multipath scenarios encountered in the urban settings.
Abstract: In typical urban or suburban environments, multipath poses a serious threat to the accuracy of position determined by a global navigation satellite system (GNSS) receiver. In this paper, a novel multipath mitigation technique is proposed for general multipath scenarios encountered in the urban settings. In the proposed technique, a double differentiated correlation function based histogram output is used to estimate the code delay. It is shown that the proposed technique provides significant improvements over the current state of the art techniques like high resolution correlator/double delta correlator and narrow correlator. The results hold for general multipath models for the mobile-satellite channels. The performance guarantees include closed form expressions for the probability of correct delay estimate and simulation results for the average range error variation with respect to carrier to noise ratio (CNR), signal bandwidth and different channel settings.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, the influence of GNSS satellite orbit parameters on multipath fading frequency and established a multipath signal model related to satellite orbital parameters for the ground multipath reflection model.
Abstract: In the Global Navigation Satellite System (GNSS), the multipath error affected by many aspects is the main error source that affects satellite navigation, and it is difficult to establish a much more accurate model to analyze it. Based on the ground multipath reflection model, it firstly deeply studies the influence of GNSS satellite orbit parameters on multipath fading frequency and establishes a multipath signal model related to satellite orbit parameters. Secondly, the influence of carrier phase cycle slip, receiver clock adjustment, and GNSS satellite orbit on multiparameter- (MP-) combined observations is analyzed in detail based on the measured data. Finally, aiming at the common phenomenon of code-carrier divergence in the Beidou system, the elevation-based pseudorange correction model and a sidereal filtering are built to correct the MP errors; experiments with measured data show that there is a fluctuation range reduction of 35.7% after sidereal filtering when the receiver reaches a steady state.

4 citations

Journal ArticleDOI
TL;DR: A framework that exploits joint multipath-Doppler diversity is proposed to reduce multipath errors and improve the measurement accuracy, and has a significant performance improvement over existing multipath mitigation methods.
Abstract: Radio frequency (RF) relative measurement provides an effective means of communication and autonomous navigation for the spacecraft formation flying. Multipath and Doppler are two main factors that affect the accuracy of RF relative measurement. In this study, a framework that exploits joint multipath-Doppler diversity is proposed to reduce multipath errors and improve the measurement accuracy. The proposed framework first utilizes an Extended Kalman Filter (EKF) estimator to estimate the parameters of Doppler and multipath. Different from existing research, the proposed framework reconstructs the received signal according to the estimated parameters, so as to mitigate multipath signals and enhance the direct signal. Numerical results demonstrate that the framework is suitable for both multipath and multipath-Doppler scenarios, and has a significant performance improvement over existing multipath mitigation methods.

3 citations

Journal ArticleDOI
09 Jun 2022
TL;DR: In this article , a real-time multipath estimation and mitigation technique was proposed to compensate for the time offset between constellations in urban areas, which can be effectively utilized for automobiles in a deep urban environment without any help from sensors other than GNSS.
Abstract: Multipath and non-line-of-sight (NLOS) signals are the major causes of poor accuracy of a global navigation satellite system (GNSS) in urban areas. Despite the wide usage of the GNSS in populated urban areas, it is difficult to suggest a generalized method because multipath errors are user-specific and cannot be eliminated by the differential GNSS (DGNSS) or a real-time kinematic technique (RTK). This paper introduces a real-time multipath estimation and mitigation technique which considers compensation for the time offset between constellations. It also presents a mode-switching algorithm between the DGNSS and multipath mitigating mode and shows that this technique can be effectively utilized for automobiles in a deep urban environment without any help from sensors other than GNSS. The availability is improved from 64% to 100% and the error RMS is reduced from 11.1 m to 1.2 m on Teheran-ro, Seoul, Korea. Because this method does not require prior information or additional sensor implementation for high-positioning performance in deep urban areas, it is expected to gain wide usage in not only the automotive industry but also future intelligent transportation systems.

2 citations

Journal ArticleDOI
TL;DR: In this article, a superresolution multipath estimation method based on waveform replacement and adaptive-filtering is proposed, where the continuous pseudorandom noise code autocorrelation waveform of the matched filtering output is first replaced by a designed triangular pulse waveform, and a reiterative minimum mean-square error adaptive filtering approach is applied to realize superresolution estimation of multipath parameters.
Abstract: In direct sequence spread spectrum systems, the multipath interference is known to be one of the most important factors in degrading the measurement accuracy. To resolve this problem, we propose a superresolution multipath estimation method based on waveform replacement and adaptive-filtering. In this method, the continuous pseudorandom noise code autocorrelation waveform of the matched filtering output is first replaced by a designed triangular pulse waveform. Subsequently, a reiterative minimum mean-square error adaptive filtering approach is applied to realize superresolution estimation of multipath parameters. The proposed method can achieve accurate multipath estimation even in complex multipath scenarios containing short-delay multipaths and make a good balance between the computational complexity and the estimation performance of multipath parameters. Simulation results verify the effectiveness of the proposed method.

2 citations

References
More filters
Journal ArticleDOI

6,899 citations


"A Novel Multipath Mitigation Techni..." refers background or result in this paper

  • ...The result stated in (17) is a standard result for generalization of Bernoulli trials derived in [33]....

    [...]

  • ...From the theory of random variables [33], it is known that the operation of double differentiation will make the noise power four times the original power in case of AWGN....

    [...]

Book
01 Jan 1996
TL;DR: In this paper, the authors discuss the effects of RF interference on GPS Satellite Signal Receiver Tracking (GSRSR) performance and the integration of GPS with other Sensors, including the Russian GLONASS, Chinese Bediou, and Japanese QZSS systems.
Abstract: Fundamentals of Satellite Navigation. GPS Systems Segments. GPS Satellite Signal Characteristics and Message Formats. Satellite Signal Acquisitions and Tracking. Effects of RF Interference on GPS Satellite Signal Receiver Tracking. Performance of Standalone GPS. Differential GPS. Integration of GPS with other Sensors. Galileo. The Russian GLONASS, Chinese Bediou, and Japanese QZSS Systems. GNSS Markets and Applications.

4,475 citations

Journal ArticleDOI
TL;DR: This paper presents the derivation of these narrow correlator spacing improvements, verified by simulated and tested performance.
Abstract: Historically, conventional GPS receivers have used 1.0 chip early-late correlator spacing in the implementation of delay lock loop s (DLLs), However, there are distinct advantages to narrowing this spacing, especially in C/A-code tracking applications. These advantages are the reduction of tracking errors in the presence of both noise and multipath. The primary disadvantage i s that a wider precorrelation bandwidth is required, coupled with higher sample rates and higher digital signal processing rates. However, with current CMOS technology, this is easily achievable and well worth the price. Noise reduction is achieved with narrower spacing because the noise components of the early and late signals are correlated and ten d to cancel, provided that early and late processing are simultaneous (not dithered). Multipath effects are reduced because the DLL discriminator is less distorted by the delayed multipath signal. This paper presents the derivation of these narrow correlator spacing improvements, verified by simulated and tested performance.

749 citations

Journal ArticleDOI
TL;DR: A statistical model for a land mobile satellite link that assumes that the amplitude of the line-of-sight component under foliage attenuation (shadowing) is lognormally distributed and the received multipath interference has a Rayleigh distribution is described.
Abstract: A statistical model for a land mobile satellite link is described. The model assumes that the amplitude of the line-of-sight component under foliage attenuation (shadowing) is lognormally distributed and the received multipath interference has a Rayleigh distribution. Expressions for the level crossing rate and average fade duration are given. Comparison between results calculated from the model and from measurements show reasonably good agreement. The model should be useful for designing communications systems and for simulating propagation effects in the laboratory.

678 citations


Additional excerpts

  • ...In the standard multipath channel model by [25], [26], [28]; channel coefficients are Rayleigh distributed and given as:...

    [...]