Impact of NLOS propagation upon ranging precision in UWB systems

Denis, B.; Keignart, J.; Daniele, N.

doi:10.1109/uwbst.2003.1267868

Cited by 129 publications

(84 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results were compared to an indirect approach in which TOA estimates are obtained by the ML-TOA estimator and a least squares technique is then used to localize the MS. The direct ML location estimation is shown to From (14) and the well-known identity tr(AB) = tr (BA), the elements of the Fisher's information matrix are given by …”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Indoor positioning based on statistical multipath channel modeling

Yen

Voltz

2011

J Wireless Com Network

View full text Add to dashboard Cite

In order to estimate the location of an indoor mobile station (MS), estimated time-of-arrival (TOA) can be obtained at each of several access points (APs). These TOA estimates can then be used to solve for the location of the MS. Alternatively, it is possible to estimate the location of the MS directly by incorporating the received signals at all APs in a direct estimator of position. This article presents a deeper analysis of a previously proposed maximum likelihood (ML)-TOA estimator, including a uniqueness property and the behavior in nonline-of-sight (NLOS) situations. Then, a ML direct location estimation technique utilizing all received signals at the various APs is proposed based on the ML-TOA estimator. The Cramer-Rao lower bound (CRLB) is used as a performance reference for the ML direct location estimator.

show abstract

Section: Discussionmentioning

confidence: 99%

“…The effects of the NLOS situations are also discussed. The NLOS situation is another major challenge for indoor positioning for it can cause large TOA estimation bias that in turn result in large location estimation errors [14]. There are optimization methods which can be used to mitigate the error due to NLOS.…”

Section: Introductionmentioning

confidence: 99%

Indoor positioning based on statistical multipath channel modeling

Yen

Voltz

2011

J Wireless Com Network

View full text Add to dashboard Cite

show abstract

“…Thus, the NLOS range measurement is much larger than the LOS range one. It was observed that the NLOS bias errors of the range measurements are much larger than the range measurement errors of the LOS scenarios [32].…”

Section: Source Localization Under Los/nlos Environmentsmentioning

confidence: 98%

TDOA-Based Source Collaborative Localization via Semidefinite Relaxation in Sensor Networks

Yan

Wang

Shen

et al. 2015

International Journal of Distributed Sensor Networks

View full text Add to dashboard Cite

The time delay of arrival-(TDOA-) based source localization using a wireless sensor network has been considered in this paper. The maximum likelihood estimate (MLE) is formulated by taking the correlated TDOA noise into account, which is caused by the difference with the TOA of the reference sensor. The global optimal solution is difficult to obtain due to the nonconvex nature of the ML function. We propose an alternative semidefinite programming method, which transforms the original ML problem into a convex one by relaxing nonconvex equalities into convex matrix inequalities. In addition, the source localization algorithm in the presence of sensor location errors and non-line-of-sight (NLOS) observations is developed. Our simulation results demonstrate the potential advantages of the proposed method. Furthermore, the proposed source localization algorithm by taking the NLOS TOA measurements as the constraints of the convex problem can provide a good estimate.

show abstract

“…The transceivers in this study had an LOS path, whereas signals in our study had non-line-ofsight (NLOS) harsher propagation conditions because of travel through building materials. Attempts to reduce the localization error in the NLOS case were made, e.g., [2], [3], [4], but excessive propagation delay in the NLOS condition was a limiting factor of precise ranging [3]. Wylie and Holtzman [2] used statistical information of the difference in the variance of time of arrival (TOA) in the line-of-sight (LOS) case and in the NLOS case.…”

Section: Introductionmentioning

confidence: 99%

“…Wylie and Holtzman [2] used statistical information of the difference in the variance of time of arrival (TOA) in the line-of-sight (LOS) case and in the NLOS case. Algorithms that detects the first path under a multipath condition were developed, e.g., [3], [4]. Our algorithm estimates location of a transmitter with very small error even with the considerable ranging error caused by excessive propagation delay in the NLOS case overcoming ranging limitation.…”

Section: Introductionmentioning

confidence: 99%

Using UWB Radios as Sensors for Disaster Recovery

Lee

Singh

2007

2007 IEEE International Conference on Ultra-Wideband

View full text Add to dashboard Cite

Abstract-This paper considers the problem estimating the interior structure of a collapsed building by using embedded UWB radios as sensors. We created an extensive database of UWB propagation data through various building materials. Then, using this data and a novel algorithm, we demonstrate that we can indeed determine material type, thickness and cavity dimensions using UWB radios. This paper presents the algorithm and the evaluation results. As we show, for most common building materials such as concrete and reinforced concrete, the presented algorithm has a very small estimation error.

show abstract

Impact of NLOS propagation upon ranging precision in UWB systems

Cited by 129 publications

References 1 publication

Indoor positioning based on statistical multipath channel modeling

Indoor positioning based on statistical multipath channel modeling

TDOA-Based Source Collaborative Localization via Semidefinite Relaxation in Sensor Networks

Using UWB Radios as Sensors for Disaster Recovery

Contact Info

Product

Resources

About