Map-matching algorithms integrate positioning data with spatial road network data (roadway centrelines) to identify the correct link on which a vehicle is travelling and to determine the location of a vehicle on a link. A map-matching algorithm could be used as a key component to improve the performance of systems that support the navigation function of intelligent transport systems (ITS). The required horizontal positioning accuracy of such ITS applications is in the range of 1 m to 40 m (95%) with relatively stringent requirements placed on integrity (quality), continuity and system availability. A number of map-matching algorithms have been developed by researchers around the world using different techniques such as topological analysis of spatial road network data, probabilistic theory, Kalman filter, fuzzy logic, and belief theory. The performances of these algorithms have improved over the years due to the application of advanced techniques in the map matching processes and improvements in the quality of both positioning and spatial road network data. However, these algorithms are not always capable of supporting ITS applications with high required navigation performance, especially in difficult and complex environments such as dense urban areas. This suggests that research should be directed at identifying any constraints and limitations of existing map matching algorithms as a prerequisite for the formulation of algorithm improvements. The objectives of this paper are thus to uncover the constraints and limitations by an in-depth literature review and to recommend ideas to address them. This paper also highlights the potential impacts of the forthcoming European Galileo system and the European Geostationary Overlay Service (EGNOS) on the performance of map matching algorithms. Although not addressed in detail, the paper also presents some ideas for monitoring the integrity of map-matching algorithms. The map-matching algorithms considered in this paper are generic and do not assume knowledge of ‘future’ information (i.e. based on either cost or time). Clearly, such data would result in relatively simple map-matching algorithms.

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Current map-matching algorithms for transport applications: State-of-the art and future research directions

The availability of location information has become a key factor in today's communications systems allowing location based services. In outdoor scenarios, the mobile terminal position is obtained with high accuracy thanks to the global positioning system (GPS) or to the standalone cellular systems. However, the main problem of GPS and cellular systems resides in the indoor environment and in scenarios with deep shadowing effects where the satellite or cellular signals are broken. In this paper, we survey different technologies and methodologies for indoor and outdoor localization with an emphasis on indoor methodologies and concepts. Additionally, we discuss in this review different localization-based applications, where the location information is critical to estimate. Finally, a comprehensive discussion of the challenges in terms of accuracy, cost, complexity, security, scalability, etc. is given. The aim of this survey is to provide a comprehensive overview of existing efforts as well as auspicious and anticipated dimensions for future work in indoor localization techniques and applications.

Recent Advances in Indoor Localization: A Survey on Theoretical Approaches and Applications

This newly revised and greatly expanded edition of the popular Artech House book Principles of GNSS, Inertial, and Multisensor Integrated Navigation Systems offers you a current and comprehensive understanding of satellite navigation, inertial navigation, terrestrial radio navigation, dead reckoning, and environmental feature matching . It provides both an introduction to navigation systems and an in-depth treatment of INS/GNSS and multisensor integration. The second edition offers a wealth of added and updated material, including a brand new chapter on the principles of radio positioning and a chapter devoted to important applications in the field. Other updates include expanded treatments of map matching, image-based navigation, attitude determination, acoustic positioning, pedestrian navigation, advanced GNSS techniques, and several terrestrial and short-range radio positioning technologies. The book shows you how satellite, inertial, and other navigation technologies work, and focuses on processing chains and error sources. In addition, you get a clear introduction to coordinate frames, multi-frame kinematics, Earth models, gravity, Kalman filtering, and nonlinear filtering. Providing solutions to common integration problems, the book describes and compares different integration architectures, and explains how to model different error sources. You get a broad and penetrating overview of current technology and are brought up to speed with the latest developments in the field, including context-dependent and cooperative positioning. DVD Included: Features eleven appendices, interactive worked examples, basic GNSS and INS MATLAB simulation software, and problems and exercises to help you master the material.

Principles of GNSS, Inertial, and Multisensor Integrated Navigation Systems, Second Edition

Assisted GPS (A-GPS) has been developed to provide greatly improved capabilities, helping GPS work better and faster in almost any location. Offering a detailed look at all the technical aspects and underpinnings of A-GPS, this unique book places emphasis on practical implementation. The book reviews standard GPS design, helping you understand why GPS requires assistance in the first place. You discover how A-GPS enables the computing of a position from navigation satellites in the absence of precise time - a topic not covered in any other book. Moreover, you learn how to design and analyze a high sensitivity GPS receiver and determine the achievable sensitivity. The book provides detailed worksheets that show how to compute, analyze, and improve the processing gain from the input signal at the antenna to the signal after the correlators. These worksheets are used in the book to generate families of curves that completely characterize receiver sensitivity, parameterized in terms of front end noise figure, coherent and noncoherent integration times. From this work a law of achievable sensitivity is derived and explained in the book. This cutting-edge volume discusses special forms of assistance data, industry standards for A-GPS, and government mandates for location of mobile phones. You also find coverage of future global navigation satellite systems and how they can be designed specifically for instant-fixes and high sensitivity. The book features numerous tables, worksheets, and graphs that illustrate key topics and provide the equivalent of a technical handbook for engineers who design or use A-GPS.

A-GPS: Assisted GPS, GNSS, and SBAS

A Software-Defined GPS and Galileo Receiver

This article presents a new tracking technique for sine-BOC(n,n) (or Manchester encoded) ranging signals, which is most likely to be a part of the new European Global Navigation Satellite System (GNSS), Galileo, signal plan. When traditional sine-BOC(n,n) tracking is considered, although offering excellent performance compared with current signals, it has the main drawback of potentially giving biased measurements. The new method presented herein allows the removal of this threat while maintaining the same level of performance. An adapted version of this technique can also be used for acquisition purposes

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ASPeCT: Unambiguous sine-BOC(n,n) acquisition/tracking technique for navigation applications

Automatic Gain Control (AGC) is a very important component in a Global Navigation Satellite System (GNSS) receiver. Such functionality is required anytime multibit quantization is implemented so as to lower quantization losses. In GNSS receivers, where the signal power is below that of the thermal noise floor, the AGC is driven by the ambient noise environment rather than the signal power. As a result, AGC can be a valuable tool for assessing the operating environment of a GNSS receiver. AGC and its functionality are investigated throughout this paper. Behavior of this system, both in the nominal thermal noise environment as well as when the AGC circuit will be subjected to various types of interference, are examined. Its usefulness as an interference detection and estimation tool is highlighted through several tests using simulated and real signals. Moreover, the frequency assignment of the proposed GPS L5 signal is expected to face a significant interference environment as a result of other aviation systems operate in or near band. A specific AGC and analog-to-digital converter (ADC) design performing digital pulse blanking and dedicated to L5 receivers is also studied.

https://hal-enac.archives-ouvertes.fr/hal-01021721/document

Automatic gain control (AGC) as an interference assessment tool

The combined use of proposed GALILEO signals and current and also future GPS signals will help users to greatly improve positioning accuracy, continuity of service, availability and integrity. The performances brought by all these signals are degraded by the same perturbations such as multipath, effects of ionosphere or jamming. However, differences in signal designs and environments imply differences in protection against these perturbations. One type of critical criterion is the set of the key operations thresholds in receivers such as acquisition, tracking and data demodulation. The aim of the submitted paper is to propose required signal power to noise spectral density ratio to perform acquisition, tracking and data demodulation given desired performances. Some of the considered performances are acquisition false alarm, detection probabilities, mean acquisition time and bit error rate. These thresholds are computed for GPS L5 and Galileo E5a/E5b signals. The paper starts with a brief review of studied signal relevant characteristics such as central frequency, code frequency and period, data rate and used coding and minimum received C/N0. After this, the second part is dedicated to the presentation of the different methods that can be used for acquisition, tracking and data demodulation thresholds computation. These thresholds take into account some degradations originating from the front end bandwidth, the tracking errors and acquisition times. Intrasystem and intersystem interference are considered through the use of the interference coefficient. Benefits from pilot channels and data coding are also highlighted. Obtained results enable to estimate C/N0 margins with respect to minimal available C/N0 for different GNSS signals

https://hal-enac.archives-ouvertes.fr/hal-01021712/document

Analysis of L5/E5 acquisition, tracking and data demodulation thresholds

Positioning in urban or indoor environments is a hot topic, due to both regulations such as the E911 and extension of location-based services targeting the mass market concentrated in metropolitan areas. In deep urban or indoor areas, it is generally recognized that satellite-based positioning systems are not suitable (alone) to provide a continuous, reliable, and accurate position to the user. Therefore, alternative positioning techniques may be useful to complement or replace satellite positioning in these environments. This paper investigates the possibility of using a mobile TV system based on the DVB-SH standard as a system of opportunity for positioning. A system-level modification is used in order to make emitter discrimination possible in the synchronized emitter network. Then, the signal processing steps required for pseudorange estimation are detailed. The proposed method is simulated using realistic channel sounding measurements and provides a mean positioning error around 40 m.

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Positioning Using Mobile TV Based on the DVB-SH Standard

A method and apparatus for acquiring and tracking a BOC signal in a satellite navigation receiver includes a synthesized acquisition test function or a discriminator for code delay provided by combining a BOC autocorrelation function and a BOC/PRN cross-correlation function.

Christophe Macabiau

Papers

ASPeCT: Unambiguous sine-BOC(n,n) acquisition/tracking technique for navigation applications

Automatic gain control (AGC) as an interference assessment tool

Analysis of L5/E5 acquisition, tracking and data demodulation thresholds

Positioning Using Mobile TV Based on the DVB-SH Standard

BOC signal acquisition and tracking method and apparatus