The navigation systems are widely diffused in various fields of application. The most popular navigation system is well known as Global Positioning System (GPS): it is used essentially in an outdoor environment, due to the fact that the buildings introduce an extremely high attenuation to the satellite signals. In order to provide a navigation service inside the buildings, it is necessary to implement a communication system capable to retrieve the user’s position and to deliver the navigation data in an appropriate format. This thesis describes the architecture of a navigation system for people that need to be guided through indoor environments, e.g., public buildings, hospitals, where orientation is very critical. The system has to provide both navigation and context aware information to people that may be in difficult emotive state as it happens to patients and visitors in a hospital. As it is widely explained in the whole thesis, the communication system uses an InfraRed (IR) optical link, thus a general overview to the IR light, and the modulations used in the optical communication systems is given. Moreover, one of the main topic of this thesis is to illustrate a complete study of the optimized architecture suitable to navigate an user inside a building. The IR navigation system developed in this thesis has stemmed out from a first reverse engineering step where an existing IR analog solution suited to transmit only voice signals has been analyzed. A number of tests have been carried out to characterize the existing analog solution, the modulation used (FM) and its main parameters. The need to have a new digital communication system is suggested by the possibility to improve the performance, developing a numerical transmission architecture: this allows to identify and, consequently, to locate an user. In this thesis a complete study on the feasibility of the digital architecture is proposed. All the technical details and justifications will be illustrated and discussed, including the study made upon the analog solution, keeping always in mind the need to maintain the compatibility with the analog solution. The thesis will also illustrate the development of the analog blocks that compose both transmission Front End and reception Front End. A particular attention will be paid to the Front End implemented on the receiver device, where the Received Signal Strength (RSS) value is needed. In fact, the user must point the receiver device to the transmitter illuminator as directly as possible (the : to do it correctly, a visual (or audible) indication of the RSS could be useful. Since the receiver device must be pointed in direction of the illuminator, it should be useful to understand if the system’s performance in an indoor environment could be corrupted by the reflections of the IR beams: these reflections are caused by the walls, windows or any other reflective surfaces. This effect, called multipath is taken into account: a generic analytical expression of the total received signal will be derived, and a simulation of the performance degeneration will be shown. Finally, the implementation of a working prototype is presented, with the focus on the user interface. The navigation system has been installed at the Oncology Reference Center (CRO) hospital in Aviano (Italy), in the framework of the EasyMob project. The EasyMob project will be introduced in this thesis, giving an overview about the entire set of technologies used to navigate an user into a confined space (e.g., colored visible light path guides and Thin Film Transistor (TFT) displays). Moreover a deep study on a number of IR navigation architectures is given, illustrating pros and cons of the infrastructure chosen and explained in the whole thesis.

INFRARED COMMUNICATION SYSTEMS FOR THE NAVIGATION IN INDOOR ENVIRONMENTS / Marco De Piante - Udine. , 2014 Apr 04. 26. ciclo

INFRARED COMMUNICATION SYSTEMS FOR THE NAVIGATION IN INDOOR ENVIRONMENTS

De Piante, Marco
2014-04-04

Abstract

The navigation systems are widely diffused in various fields of application. The most popular navigation system is well known as Global Positioning System (GPS): it is used essentially in an outdoor environment, due to the fact that the buildings introduce an extremely high attenuation to the satellite signals. In order to provide a navigation service inside the buildings, it is necessary to implement a communication system capable to retrieve the user’s position and to deliver the navigation data in an appropriate format. This thesis describes the architecture of a navigation system for people that need to be guided through indoor environments, e.g., public buildings, hospitals, where orientation is very critical. The system has to provide both navigation and context aware information to people that may be in difficult emotive state as it happens to patients and visitors in a hospital. As it is widely explained in the whole thesis, the communication system uses an InfraRed (IR) optical link, thus a general overview to the IR light, and the modulations used in the optical communication systems is given. Moreover, one of the main topic of this thesis is to illustrate a complete study of the optimized architecture suitable to navigate an user inside a building. The IR navigation system developed in this thesis has stemmed out from a first reverse engineering step where an existing IR analog solution suited to transmit only voice signals has been analyzed. A number of tests have been carried out to characterize the existing analog solution, the modulation used (FM) and its main parameters. The need to have a new digital communication system is suggested by the possibility to improve the performance, developing a numerical transmission architecture: this allows to identify and, consequently, to locate an user. In this thesis a complete study on the feasibility of the digital architecture is proposed. All the technical details and justifications will be illustrated and discussed, including the study made upon the analog solution, keeping always in mind the need to maintain the compatibility with the analog solution. The thesis will also illustrate the development of the analog blocks that compose both transmission Front End and reception Front End. A particular attention will be paid to the Front End implemented on the receiver device, where the Received Signal Strength (RSS) value is needed. In fact, the user must point the receiver device to the transmitter illuminator as directly as possible (the : to do it correctly, a visual (or audible) indication of the RSS could be useful. Since the receiver device must be pointed in direction of the illuminator, it should be useful to understand if the system’s performance in an indoor environment could be corrupted by the reflections of the IR beams: these reflections are caused by the walls, windows or any other reflective surfaces. This effect, called multipath is taken into account: a generic analytical expression of the total received signal will be derived, and a simulation of the performance degeneration will be shown. Finally, the implementation of a working prototype is presented, with the focus on the user interface. The navigation system has been installed at the Oncology Reference Center (CRO) hospital in Aviano (Italy), in the framework of the EasyMob project. The EasyMob project will be introduced in this thesis, giving an overview about the entire set of technologies used to navigate an user into a confined space (e.g., colored visible light path guides and Thin Film Transistor (TFT) displays). Moreover a deep study on a number of IR navigation architectures is given, illustrating pros and cons of the infrastructure chosen and explained in the whole thesis.
4-apr-2014
Navigation system; Infrared; Communication system; Frequency Modulation; FPGA; VHDL; Correlator Bank;
INFRARED COMMUNICATION SYSTEMS FOR THE NAVIGATION IN INDOOR ENVIRONMENTS / Marco De Piante - Udine. , 2014 Apr 04. 26. ciclo
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11390/1132344
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