Maximum Likelihood Estimation of Position in GNSS

Closas, Pau; Fernández‐Prades, Carles; Fernandez–Rubio, Juan A.

doi:10.1109/lsp.2006.888360

Cited by 125 publications

(98 citation statements)

References 3 publications

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“…The first one consists on self positioning of a receiver by the signal coming from different synchronized transmitters at known locations. This is the case of the Global Navigation Satellite System (GNSS) where the DPE approach, based on Maximum Likelihood Estimation (MLE), has been considered in [3]. In this scenario, higher accuracy, compared with the two steps approach, has been proved given by the Cramer-Rao Bound (CRB) [4].…”

Section: Introductionmentioning

confidence: 99%

Assessment of Direct Positioning for IR-UWB in IEEE 802.15.4a channels

Navarro

Closas

Nájar

2013

2013 IEEE International Conference on Ultra-Wideband (ICUWB)

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Abstract-This paper assesses the problem of localization in IR-UWB under realistic channel models for Direct Position Estimation (DPE) approaches. DPE schemes have been proposed for positioning and localization for well developed systems like GNSS, where it has been analytically proved that the Maximumlikelihood single-step estimator outperforms two-step procedures. The extension to wideband systems and less favorable scenarios like indoor UWB channels is less explored. We derive a DPE algorithm and analyze its performance against two-step TOA based localization for an IR-UWB system. Numerical results are provided for IEEE 802.15.4a channel model showing positioning performance of the two approaches and highlighting the tradeoffs.

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Section: Introductionmentioning

confidence: 99%

Assessment of Direct Positioning for IR-UWB in IEEE 802.15.4a channels

Navarro

Closas

Nájar

2013

2013 IEEE International Conference on Ultra-Wideband (ICUWB)

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“…Additionally, using the information contained in the in-built street maps to correct the current location of the receptor (e.g., avoiding impossible positions inside of buildings) helps to reduce the mean error to just 5 meters. Moreover, Closas et al (2007) focused on statistical computation to improve the positioning accuracy, generating maximum likelihood estimators under multipath conditions which are able to reduce the maximum error to 10 meters. Hence, even if the current location of the vehicle may present some degree of error, it is possible to achieve a good performance of the system.…”

Section: The Enhanced Street Broadcast Reduction Scheme In Real Mapsmentioning

confidence: 99%

Evaluating the impact of a novel message dissemination scheme for vehicular networks using real maps

Fogue

Garrido

Martínez

et al. 2012

Transportation Research Part C: Emerging Technologies

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In traffic safety applications for Vehicular ad hoc networks (VANETs), some warning messages have to be urgently disseminated in order to increase the number of vehicles receiving the traffic warning information. In those cases, redundancy, contention, and packet collisions due to simultaneous forwarding (usually known as the broadcast storm problem) are prone to occur. In the past, several approaches have been proposed to solve the broadcast storm problem in multi-hop wireless networks such as Mobile ad hoc Networks (MANETs). Among them we can find counter-based, distance-based, location-based, cluster-based, and probabilistic schemes, which have been mainly tested in non-realistic simulation environments. In this paper, we present the enhanced Street Broadcast Reduction (eSBR), a novel scheme specially designed to increase the percentage of informed vehicles and reduce the notification time; at the same time, it mitigates the broadcast storm problem in real urban scenarios. We evaluate the impact that our scheme has on performance when applied to VANET scenarios based on real city maps, and the results show that it outperforms previous schemes in all situations.

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“…The positioning approach omitting the intermediate step is known in the literature as Direct Position Estimation (DPE) [6], [7]. DPE has been applied to GNSS [8], narrowband emitters localization [6], passive geolocation [9], and UWB [10], [11] among others.…”

Section: Introductionmentioning

confidence: 99%

Spatial sparsity based direct positioning for IR-UWB in IEEE 802.15.4a channels

Lagunas

Nájar

Navarro

et al. 2014

2014 IEEE International Conference on Ultra-WideBand (ICUWB)

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Abstract-In this paper, we focus on the application of Compressive Sensing (CS) techniques to Impulse Radio (IR) UltraWideBand (UWB) positioning systems under indoor propagation environments. Direct Position Estimation (DPE) approaches can potentially improve the position estimation accuracy of conventional two-step techniques by directly estimating the position coordinates from the observed signal in a single step. Furthermore, DPE does not require a threshold selection upon which accuracy of two-step approaches depend on. Although in the presence of multipath the actual gains are not straight forward, recent evaluation of DPE positioning in IR-UWB system proved accurate positioning estimate gains. However it comes at a cost of higher computational complexity. This paper exploits the sparseness of the problem to reduce the computational load of the positioning estimation process and relax the requirements of the Analog to Digital Converter (ADC) when sampling UWB signals. Based on the fact that the number of unknown targets is small in the discrete spatial domain, this paper incorporates the multiple location hypotheses into an overcomplete basis, which highlights the sparseness of the spatial domain. This fact motivates the use of CS-based sampling and sparsity-based reconstruction techniques to jointly evaluate all possible hypotheses, thus avoiding the traditional position-by-position scanning where the multiple location hypotheses are evaluated independently. In so doing, we not only achieve a significant reduction in computational time but also we relax the sampling requirements.

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Maximum Likelihood Estimation of Position in GNSS

Cited by 125 publications

References 3 publications

Assessment of Direct Positioning for IR-UWB in IEEE 802.15.4a channels

Assessment of Direct Positioning for IR-UWB in IEEE 802.15.4a channels

Evaluating the impact of a novel message dissemination scheme for vehicular networks using real maps

Spatial sparsity based direct positioning for IR-UWB in IEEE 802.15.4a channels

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