Accurate and Integrated Localization System for Indoor Environments Based on IEEE 802.11 Round-Trip Time Measurements

Bahillo, Alfonso; Mazuelas, Santiago; Lorenzo, Rubén M.; Fernández, Patricia; Prieto, Javier; Durán, Ramón J.; Abril, Evaristo J.

doi:10.1155/2010/102095

Cited by 21 publications

(30 citation statements)

References 15 publications

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“…We will assume that each anchor collects one measurement (M 1 = M 2 = ... = M N = 1) from all the other anchors, then N = L ·(L − 1). Each measurement is the average value of 100 TOA measurements to guarantee the assumptions in the models of Sections II and III [6], [19]. After collecting the N averaged measurements (simulated or empirical), α and β are estimated by considering two different cases depending on whether the bias is Gaussian or Uniform:…”

Section: Simulations and Measurements Resultsmentioning

confidence: 99%

“…However, the technical difÀculty and the involved cost of synchronizing devices can shift researchers' attention to RSSbased systems. In order to solve the synchronization issue, techniques based on measuring round-trip-times are frequently employed [6], [15]. In this case, the relationship between TOA measurements, z, and distance, d, can be assumed to be…”

Section: Relationship Between Toa and Distancementioning

confidence: 99%

“…As mentioned above, systems based on dynamically estimating ranges from TOA-measurements do not require an arduous off-line phase storing measurements. However, α and β parameters in (1) have to be estimated, for instance, by means of a linear regression of LOS measurements previously obtained, which requires an off-line phase of calibration [6], [15]. Other techniques obtain these parameters from processingtime knowledge, however, this is not possible with low-cost devices [18].…”

Section: Relationship Between Toa and Distancementioning

confidence: 99%

See 2 more Smart Citations

Self-calibration of TOA/distance relationship for wireless localization in harsh environments

Prieto

Bahillo

Mazuelas

et al. 2012

2012 IEEE International Conference on Communications (ICC)

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The success of location-based services in open areas, mainly driven by Global Navigation Satellite Systems (GNSS), has pushed the research community towards the development of robust systems that provide a similar localization accuracy in harsh environments, where there is no line-of-sight (LOS) to satellites. Techniques based on time-of-arrival (TOA) measurements are the most promising since they can offer an appropriate balance between accuracy and complexity. However, their performance is commonly compromised by the knowledge of an accurate model relating TOA measurements and distance, which can involve an arduous task of calibration. In this paper, we present a method for real-time self-calibration of the model relating TOA and distance, based on TOA measurements exchanged among the anchors in the wireless network. Simulation and empirical results show the appropriateness of the derived models for a TOA-based localization system, since the obtained errors are remarkably close to the ones achieved with pre-calibrated parameters.

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Section: Simulations and Measurements Resultsmentioning

confidence: 99%

Section: Relationship Between Toa and Distancementioning

confidence: 99%

Section: Relationship Between Toa and Distancementioning

confidence: 99%

See 1 more Smart Citation

Self-calibration of TOA/distance relationship for wireless localization in harsh environments

Prieto

Bahillo

Mazuelas

et al. 2012

2012 IEEE International Conference on Communications (ICC)

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“…In [51], the team added real-time location capabilities, achieving a precision of better than 3.51 m in 50% of cases in a hard multipath and NLOS indoor environment. A detailed overview of their work is provided in [52] and [53].…”

Section: Mac Layer Hardware Methodsmentioning

confidence: 99%

Survey of WiFi positioning using time-based techniques

et al. 2015

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Estimating the position of mobile devices with high accuracy in indoor environments is of interest across a wide range of applications. Many methods and technologies have been proposed to solve the problem but, to date, there is no "silver bullet". This paper surveys research conducted on indoor positioning using time-based approaches in conjunction with the IEEE 802.11 Wireless Local Area Network standard (WiFi). Location solutions using this approach are particularly attractive due to the wide deployment of WiFi and because prior mapping is not needed. This paper provides an overview of the IEEE 802.11 standards and summarizes the key research challenges in 802.11 time-based positioning. The paper categorizes and describes the many proposals published to date, evaluating their implementation complexity and positioning accuracy. Finally, the paper summarizes the state-of-the-art and makes suggestions for future research directions.

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“…The former group uses an estimation of distances or angles from three or more sites, to derive user location. The distance information is extracted from received signal strength (RSS) and/or propagation time measures from their neighbor base stations [5], whereas angles can be estimated if antenna arrays are available. However, most critics to these techniques come from the fact that received power suffers from large-scale and small-scale fading phenomena and hence is not reliable for positioning.…”

Section: Introductionmentioning

confidence: 99%

Localization in Wireless Networks: The Potential of Triangulation Techniques

Osa

Matamales

Monserrat

et al. 2012

Wireless Pers Commun

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User localization is one of the key service-enablers in broadband mobile communications. Moreover, from a different point of view, next steps towards automatic network optimization also depend upon the capability of the system to perform real-time user localization, in order to obtain the traffic distribution. The aim of this paper is to get deeper into the feasibility and accuracy of different localization mechanisms ranging from triangulation to database correlation. Call tracing data extracted from a real operating mobile network have been used to assess these algorithms after the execution of an extensive measurements campaign. Results show that enhanced triangulation offers the best performance even outperforming other more sophisticated mechanisms like fingerprinting, without introducing any change in the network and without requiring any special characteristic of the user equipment. Indeed, the lack of precision of channel estimates, which for the same position could differ up to 10 dB, introduces a large uncertainty that harms localization mechanisms based on database correlation. Finally, this paper identifies the areas for improvement in triangulation to reach its maximum potential, provides details for its implementation and analyzes the performance of the different proposed enhancements.

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Accurate and Integrated Localization System for Indoor Environments Based on IEEE 802.11 Round-Trip Time Measurements

Cited by 21 publications

References 15 publications

Self-calibration of TOA/distance relationship for wireless localization in harsh environments

Self-calibration of TOA/distance relationship for wireless localization in harsh environments

Survey of WiFi positioning using time-based techniques

Localization in Wireless Networks: The Potential of Triangulation Techniques

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