Location Fingerprinting for Ultra-Wideband Systems
The Key to Efficient and Robust Localization
Christoph Steiner
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Christoph Steiner, Location Fingerprinting for Ultra-Wideband Systems (2010), Logos Verlag, Berlin, ISBN: 9783832599348
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Beschreibung / Abstract
In this thesis, a novel radio frequency based position location concept is proposed and studied, which provides accurate position estimates in dense multipath and non-line-of-sight propagation environments. The main idea is to apply the location fingerprinting paradigm of position location to channel impulse responses with ultra-wide bandwidth. The large bandwidth enables a fine temporal resolution of the multipath propagation channel, which in turn acts as a unique location fingerprint of the positions of transmitter and receiver.
At first a location fingerprinting framework is developed from a communication theoretic perspective. Then location fingerprinting with two ultra-wideband receiver structures is studied. The first receiver is able to perform channel estimation and the second receiver is a low complexity generalized energy detection receiver. Their position location performance is analyzed theoretically and experimentally with measured data and it is shown that decimeter accuracy is achievable with both receiver structures in dense multipath and non-line-of-sight propagation environments.
However, this experimental performance analysis reveals also a major shortcoming of the proposed method: In order to achieve high position location accuracy, a large amount of training data is required. In order to increase the efficiency of the training phase two promising techniques are proposed in this thesis. The first method is based on the idea of joint localization and training. The second technique is based on a geometrical channel model and utilizes a priori knowledge about the geometry of the propagation environment
The thesis concludes with a summary of the major findings and with a list of interesting future research topics in the field of location fingerprinting for ultra-wideband systems.
At first a location fingerprinting framework is developed from a communication theoretic perspective. Then location fingerprinting with two ultra-wideband receiver structures is studied. The first receiver is able to perform channel estimation and the second receiver is a low complexity generalized energy detection receiver. Their position location performance is analyzed theoretically and experimentally with measured data and it is shown that decimeter accuracy is achievable with both receiver structures in dense multipath and non-line-of-sight propagation environments.
However, this experimental performance analysis reveals also a major shortcoming of the proposed method: In order to achieve high position location accuracy, a large amount of training data is required. In order to increase the efficiency of the training phase two promising techniques are proposed in this thesis. The first method is based on the idea of joint localization and training. The second technique is based on a geometrical channel model and utilizes a priori knowledge about the geometry of the propagation environment
The thesis concludes with a summary of the major findings and with a list of interesting future research topics in the field of location fingerprinting for ultra-wideband systems.
Inhaltsverzeichnis
- BEGINN
- 1 Introduction
- 1.1 Motivation
- 1.2 Ultra-Wideband Wireless Communication
- 1.3 Ultra-Wideband Positioning Systems
- 1.4 Contributions
- 2 Location Fingerprinting: A Communication Theoretic Perspective
- 2.1 Problem Formulation
- 2.2 Deterministic Location Fingerprints
- 2.3 Novel Position Location Concept - "Geo-Regioning"
- 2.4 Location Fingerprinting as Hypothesis Testing Problem
- 3 Channel Measurement Campaign
- 3.1 Measurement Setup
- 3.2 Measurement Scenario
- 3.3 Impact of Antennas
- 3.4 Measurement Signal-to-Noise Ratio
- 3.5 Energy Normalization
- 3.6 Temporal Alignment
- 4 Location Fingerprinting with a Coherent Receiver
- 4.1 Choice of the Location Fingerprints
- 4.2 Regional Channel Model
- 4.3 Distortions of the Location Fingerprints
- 4.4 Position Location and Clustering Systems
- 4.5 Analytical Pairwise Error Probabilities
- 4.6 Theoretical and Experimental Performance Analysis
- 4.7 Summary and Conclusions
- 5 Location Fingerprinting with a Generalized Energy Detection Receiver
- 5.1 Generalized Energy Detection Receiver
- 5.2 Exact Distribution of Energy Samples for a Gaussian Channel Model
- 5.3 Stochastic Modeling of Energy Samples
- 5.4 Correlation among Energy Samples
- 5.5 Position Location and Clustering Systems
- 5.6 Accuracy of Closed Form Approximations
- 5.7 Experimental Performance Analysis
- 5.8 Summary and Conclusions
- 6 Combination of Training Phase and Localization Phase
- 6.1 Location Fingerprinting via Parameter Estimation of Mixture Densities
- 6.2 Expectation Maximization Algorithm
- 6.3 Position Location and Clustering Systems
- 6.4 Experimental Performance Analysis
- 6.5 Summary and Conclusions
- 7 Efficient Training Phase
- 7.1 Electromagnetic Wave Propagation
- 7.2 Input Output Relations in Passband and Equivalent Baseband
- 7.3 Analysis of Path Delays
- 7.4 Linearization of Path Gains
- 7.5 Simplified Input Output Relation
- 7.6 Estimation of Linear Model Parameters
- 7.7 Experimental Analysis of Prediction Accuracy
- 7.8 Parameter Estimation based on Predicted Channel Responses
- 7.9 Summary and Conclusions
- 8 Conclusions and Outlook
- 8.1 Conclusions
- 8.2 Outlook on Future Research