Satellite radio has attained great popularity because of its wide range of geographical coverage and high signal quality as compared to the terrestrial broadcasts. Most Satellite Digital Radio (SDR) based systems favor multi-carrier transmission schemes, especially, orthogonal frequency division multiplexing (OFDM) transmission because of high data transfer rate and spectral efficiency. It is a challenging task to find a suitable platform that supports fast data rates and superior processing capabilities required for the development and deployment of the new SDR standards. Field programmable gate array (FPGA) devices have the potential to become suitable development platform for such standards. Another challenging factor in SDR systems is the distortion of variable envelope signals used in OFDM transmission by the nonlinear RF power amplifiers (PA) used in the base station transmitters. An attractive option is to use a linearizer that would compensate for the nonlinear effects of the PA. In this research, an OFDM transmitter, according to European Telecommunications Standard Institute (ETSI) SDR Technical Specifications 2007-2008, was designed and implemented on a low-cost Xilinx FPGA platform. A weakly nonlinear PA, operating in the L-band SDR frequency (1.450-1.490GHz), was used for signal transmission. An FPGA-based, low-cost, adaptive linearizer was designed and implemented based on the digital predistortion (DPD) reference design from Xilinx, to correct the distortion effects of the PA on the transmitted signal.

Satellite radio has attained great popularity because of its wide range of geographical coverage and high signal quality as compared to the terrestrial broadcasts. Most Satellite Digital Radio (SDR) based systems favor multi-carrier transmission schemes, especially, orthogonal frequency division multiplexing (OFDM) transmission because of high data transfer rate and spectral efficiency. It is a challenging task to find a suitable platform that supports fast data rates and superior processing capabilities required for the development and deployment of the new SDR standards. Field programmable gate array (FPGA) devices have the potential to become suitable development platform for such standards. Another challenging factor in SDR systems is the distortion of variable envelope signals used in OFDM transmission by the nonlinear RF power amplifiers (PA) used in the base station transmitters. An attractive option is to use a linearizer that would compensate for the nonlinear effects of the PA. In this research, an OFDM transmitter, according to European Telecommunications Standard Institute (ETSI) SDR Technical Specifications 2007-2008, was designed and implemented on a low-cost Xilinx FPGA platform. A weakly nonlinear PA, operating in the L-band SDR frequency (1.450-1.490GHz), was used for signal transmission. An FPGA-based, low-cost, adaptive linearizer was designed and implemented based on the digital predistortion (DPD) reference design from Xilinx, to correct the distortion effects of the PA on the transmitted signal.

Στόχος της εργασίας είναι η υλοποίηση του αλγορίθμου του αυτόματου εντοπισμού ομιλίας βάση το πρότυπο ETSI. Η εργασία αυτή οργανώνεται σε 4 κεφάλαια τα οποία περιλαμβάνουν την εισαγωγή στο σήμα ομιλίας, το πρότυπο ETSI, την πειραματική διαδικασία και τα συμπεράσματα. Το πρώτο κεφάλαιο περιλαμβάνει τα βασικά χαρακτηριστικά της ομιλίας και ανάλυση των συχνοτήτων συντονισμών και της συχνότητας ταλάντωσης, την έννοια του Mel και την θεωρητική λογική του αυτόματου και προσαρμοστικού αλγόριθμου. Το δεύτερο κεφάλαιο περιλαμβάνει την διαδικασία επεξεργασίας ομιλίας με front-end αλγόριθμο βασισμένο σε τεχνικές εξαγωγής παραμέτρων Mel και Cepstral, την μείωση θορύβου βασισμένη στο Wiener φίλτρο, η επεξεργασία του σήματος, η κατηγοριοποίηση μεταξύ ηχηρής και άηχης ομιλίας. Το τρίτο και τέταρτο κεφάλαιο περιλαμβάνουν τα αποτελέσματα από την πειραματική εφαρμογή του συστήματος και τα συμπεράσματα από την σύγκριση με άλλους αλγορίθμους εντοπισμού ομιλίας. / The goal of this project is the implementation of the voice activity detection algorithm based on the ETSI standard. This project is separate in 4 chapters including: initial themes for speech, ETSI standard, the experimental procedure and the results. In the first chapter are the basics about speech, formants, pitch, Mel and the theoretic logic of automatic and robust voice activity detection algorithms. In the second chapter are the procedures of speech processing based in front-end algorithm, Mel and Cepstral procedures, noise reduction based on Wiener filter, signal processing, and the classification of voiced and unvoiced speech. The last chapters are the results of the experimental procedure and the results of the compare with other system voice activity detection.

Vehicle-to-Everything (V2X) is referred to as the technology enabling communication and data exchange between vehicles and is considered a significant milestone within automotive. By enabling inter-vehicle communication, the vehicles will be more aware of their surroundings—including things outside their current line-of-sight (LOS). The vehicles utilizing this technology are in Europe referred to as Cooperative Intelligent Transport Systems (C-ITS). A single vehicle is referred to as an ITS station (ITS-S). These are the terms presented in the European V2X standard called the ETSI ITS. This thesis considered the ETSI ITS standard since it is one of the most mature within the V2X standardization flora. This thesis investigated some significant V2X use cases and conducted a risk assessment on a selection of these use cases. These significant use cases were discovered by performing semi-structured interviews with five candidates within the field. The conducted risk assessment was performed according to a method called Threat, Vulnerability, and Risk Assessment (TVRA), which ETSI has developed. The results of this thesis work became a set of safety-functional use cases that were considered significant. The cybersecurity risk varied and spanned from critical to minor risk concerning the attacks taken into account. Since security and hardening are critical aspects of automotive connectivity, this thesis provides some future research directions at the end of this thesis. One of these topics is, for example, the privacy perspective on V2X, which was not considered in this thesis.

Στην παρούσα διατριβή προτείνονται Μηχανισμοί Ασφάλειας για την ανάπτυξη ασφαλών και αξιόπιστων διάχυτων υπηρεσιών υγείας πάνω σε Δίκτυα Επόμενης Γενιάς (Next Generation Networks – NGN). Οι προτεινόμενοι Μηχανισμοί Ασφάλειας έχουν ως στόχο να λειτουργήσουν προσθετικά στο επίπεδο ασφάλειας που προσφέρουν οι υπάρχοντες μηχανισμοί ασφάλειας που υποστηρίζονται από το NGN. Αυτό είναι αναγκαίο καθώς οι διάχυτες υπηρεσίες υγείας εμπεριέχουν ιδιαιτέρως ευαίσθητη πληροφορία. Επιπρόσθετα, στην παρούσα διατριβή προτείνεται ένα γενικό πλαίσιο εφαρμογής, το οποίο υποστηρίζει τους προτεινόμενους Μηχανισμούς Ασφάλειας, προκειμένου να επιτυγχάνεται γρήγορη και αποτελεσματική ανάπτυξη ασφαλών και αξιόπιστων διάχυτων υπηρεσιών υγείας πάνω σε NGN. Πιο συγκεκριμένα, το προτεινόμενο πλαίσιο βασίζεται στην αρχιτεκτονική του προτύπου ETSI/Parlay και επεκτείνει το σύνολο των Διεπαφών των Χαρακτηριστικών Ικανότητας Υπηρεσίας (Service Capability Features Interfaces – SCFs Interfaces) και το σύνολο των μηχανισμών που υποστηρίζει το Πλαίσιο ETSI/Parlay. Το προτεινόμενο πλαίσιο επεκτείνει το σύνολο των Διεπαφών των Χαρακτηριστικών Ικανότητας Υπηρεσίας προκειμένου αυτό να περιλαμβάνει όχι μόνο τις διεπαφές που σχετίζονται με τις υπηρεσίες του υποκείμενου δικτύου (NGN), αλλά και επιπλέον διεπαφές που δίνουν τη δυνατότητα σε διάχυτες υπηρεσίες υγείας να έχουν πρόσβαση σε ικανότητες επαίσθησης (sensing capabilities) δικτύων αισθητήρων που είναι υπεύθυνα για τη συλλογή πληροφορίας περιβάλλοντος καθώς και βιοπληροφορίας. Επίσης, το προτεινόμενο πλαίσιο επεκτείνει το σύνολο των μηχανισμών που υποστηρίζει το Πλαίσιο ETSI/Parlay προκειμένου να είναι δυνατή η παροχή σε διάχυτες υπηρεσίες υγείας όχι μόνο των βασικών μηχανισμών, που υποστηρίζονται από το προτυποποιημένο Πλαίσιο ETSI/Parlay, αλλά και των Μηχανισμών Δικτύων Αισθητήρων καθώς και των Μηχανισμών Ασφάλειας, οι οποίοι προτείνονται στην παρούσα διατριβή. Οι Μηχανισμοί Ασφάλειας, οι οποίοι προτείνονται, στοχεύουν στην παροχή ασφάλειας στα δεδομένα των τελικών χρηστών καθώς και στην ασφαλή πρόσβαση στις διάχυτες υπηρεσίες υγείας και στην ασφαλή χρήση τους. Πιο συγκεκριμένα, οι προτεινόμενοι Μηχανισμοί Ασφάλειας επικεντρώνονται στη διασφάλιση της εμπιστευτικότητας των δεδομένων, της ακεραιότητας των δεδομένων, της πιστοποίησης αυθεντικότητας καθώς και του ελέγχου πρόσβασης των οντοτήτων που συμμετέχουν σε διάχυτες υπηρεσίες υγείας. Για τη διασφάλιση της εμπιστευτικότητας των δεδομένων προτείνεται ένα γενικό σχήμα κρυπτογράφησης. Αυτό το σχήμα επιτρέπει το σχεδιασμό και την υλοποίηση ασφαλών εξατομικευμένων κρυπτογραφικών αλγορίθμων τμήματος για την κρυπτογράφηση δεδομένων διάχυτων υπηρεσιών υγείας, όπως οι ιατρικοί φάκελοι των ασθενών. Επίσης, προτείνεται ένας μηχανισμός για διασφάλιση της ακεραιότητας των δεδομένων για σύστημα ιατρικής τηλε-παρακολούθησης. Αυτό το σύστημα τηλε-παρακολούθησης λειτουργεί σε περιβάλλον έξυπνου σπιτιού και υποστηρίζει τη μεταφορά βιοσημάτων του ασθενή από τον ασθενή στη Μονάδα Παροχής Υπηρεσιών Υγείας. Επιπρόσθετα, προτείνονται δύο μηχανισμοί για διασφάλιση της πιστοποίησης αυθεντικότητας. Ο πρώτος μηχανισμός είναι ένας ευφυής μηχανισμός πιστοποίησης αυθεντικότητας για εφαρμογές e-Hospital πάνω σε WLAN μέσα σε νοσοκομείο. Ο δεύτερος μηχανισμός είναι ένας μηχανισμός συμφωνίας κλειδιού ομάδας και ανάκτησης σε ad hoc δίκτυα, που χρησιμοποιούνται κατά τη διαχείριση ιατρικών συμβάντων έκτακτης ανάγκης σε περιοχές στις οποίες δεν υπάρχει σταθερή τηλεπικοινωνιακή υποδομή. Τέλος, προτείνεται μία υποδομή PKI σε ένα ιατρικό δίκτυο μεγάλης κλίμακας που συνδέει ένα ευρύ φάσμα από Μονάδες Παροχής Υπηρεσιών Υγείας. Η προτεινόμενη υποδομή PKI εστιάζεται στη διασφάλιση της πιστοποίησης αυθεντικότητας και του ελέγχου πρόσβασης των επαγγελματιών του χώρου της υγείας που επιθυμούν να αποκτήσουν πρόσβαση σε υπηρεσίες που σχετίζονται με αυτούς καθώς και σε υπηρεσίες υγείας που σχετίζονται με τον ασθενή. / In this dissertation, Security Mechanisms are proposed for the development of secure and reliable pervasive healthcare services over Next Generation Networks (NGN). The proposed Security Mechanisms aim at increasing the security level provided by the existing security mechanisms supported by NGN. It is essential since pervasive healthcare services include extremely sensitive information. Furthermore, in this dissertation, a generic application framework is proposed supporting the proposed Security Mechanisms in order the rapid and efficient development of secure and reliable pervasive healthcare services over NGN to be achieved. In particular, the proposed framework is based on the ETSI/Parlay architecture and extends the set of the Service Capability Features Interfaces (SCFs Interfaces) as well as the set of mechanisms supported by the ETSI/Parlay Framework. The proposed framework extends the set of the SCFs Interfaces in order to integrate not only the interfaces related to the services of the underlying network (NGN), but also additional interfaces enabling pervasive healthcare services to access sensing capabilities of sensor networks which are responsible for gathering context and bio information. Moreover, the proposed framework extends the set of mechanisms supported by the ETSI/Parlay Framework to provide pervasive healthcare services not only with the basic mechanisms supported by the standardized ETSI/Parlay Framework, but also with the Sensor Networks Mechanisms and the Security Mechanisms proposed in this dissertation. The proposed Security Mechanisms aim at securing the end-user data as well as the access to the pervasive healthcare services and the use of them. In particular, the proposed Security Mechanisms focus on ensuring data confidentiality, data integrity, authentication and access control of entities participating in pervasive healthcare services. To ensure data confidentiality, a generic encryption schema is proposed. This schema enables the design and implementation of secure personalized block ciphers for encryption of data included in pervasive healthcare services such as patients’ medical records. Moreover, a data integrity mechanism for a tele-monitoring system is proposed. This tele-monitoring system operates in a smart home environment and supports transmission of patient’s biosignals from the patient to the Healthcare Center. Additionally, two authentication mechanisms are proposed. The first mechanism is an intelligent authentication mechanism for e-Hospital applications over WLAN in a hospital. The second mechanism is a group key agreement and recovery mechanism in ad hoc networks used for handling emergency medical incidents in areas without fixed telecommunications infrastructure. Finally, a PKI infrastructure in a large-scale healthcare network connecting a wide spectrum of Healthcare Centers is proposed. The proposed PKI infrastructure focuses on ensuring authentication and access control of healthcare professionals willing to access services related to them as well as healthcare services related to patient.

The diploma thesis is focused on the measurement of selected parameters of the digital TV receiver DVB T, set top box. In the introductory part the work briefly deals with the theory of compression and transmission of the digital TV signal. Main part of the thesis contains detail information about individual circuits of the selected set top box Humax F3-FOX T and the results of measurements of individual parameters obtained from the available measuring devices. The final part of the thesis deals with the design changes necessary for creation of the external output for the signals and also with the methodology of the measurement.

This thesis will research and evaluate the state of the current ETSI VAM standard. The thesis evaluates and discusses the means of improving the speed and response of ETSI VAM by reducing the load on the radio medium. The research looks to prove that fewer messages broadcasted improve VRU awareness. The thesis focuses mainly on the benefits of VRU clustering as a means of reducing radio medium load through numerical evaluation and physical implementation testing. Evaluation of basic and alternate cluster parameters is performed to find the most optimal ones; alternate clustering strategies are also discussed and proposed. The thesis aims to improve the standard by finding and evaluating alternate methods and parameters in order to propose improved options. / Projektet utvärderar och diskuterar sätten att förbättra hastigheten och responsen hos ETSI VAM genom att minska belastningen på radiomediet. Forskningen syftar till att bevisa att färre meddelanden som sänds förbättrar systemets VRU-medvetenhet. Fokuset ligger huvudsakligen på att utvärdera fördelarna med "VRU-klustring" som ett sätt att minska radiomediebelastningen genom numerisk utvärdering och fysisk testning. Utvärdering av grundläggande och alternativa klusterparametrar utförs för att hitta de mest optimala; alternativa klustringsstrategier diskuteras och föreslås också. Projektet syftar till att förbättra standarden genom att hitta och utvärdera alternativa metoder och parametrar för att föreslå förbättrade alternativ.

Wireless technologies and networks are a part of our daily lives and we are surrounded by a constant stream of wireless signals. Unfortunately, there are a lot of limitations. At Toyota Material Handling Europe, future demands and expectations are raising but the technologies available today are not adapting fast enough. Indoor factory environments, moving network nodes and rapidly changing topologies are demanding situations. In this new Internet of Things day and age, transferring information in these challenging environments, the standard master and slave configuration is not enough. This report looks at the specific challenges establishing a wireless communication link between trucks in an indoor factory and warehouse environment. There are many factors to consider. Antennas, noise, frequency bands, different network technologies, propagation and path loss modeling to mention a few. Antennas and on-the-truck antenna positioning require design choices to be made. If we want to benefit from using high gain antennas, positioning is an important factor. Noise, in the highly congested 2.4 GHz band is a problem, especially considering safety critical applications. The license free ISM frequency bands have all different advantages in range, available communication protocols and amount of other technologies sharing the spectrum. The Wi-Fi, Bluetooth, ZigBee and V2X technologies looked at, tailored to the particular case of a warehouse environment like the Toyota factory, and the final selection relates to potential use case scenarios. Prioritizing, scalability, ad hoc network topologies, low latencies and short connection times together with long range, the new V2X technology building upon the IEEE 802.11p standard stands out. This report evaluates the IEEE 802.11p wireless standard running the ETSI ITS G5 V2X protocol in an indoor factory and warehouse environment. Thanks to Kapsch and their EVK-3300 V2X Evaluation Kit it was possible to evaluate transferring information between nodes, the PSR, and looking at how useful different path loss models are for estimating relative distances between trucks.

The thesis deals with the study of communication models for cooperative intelligent transport systems and the development of the application used for testing. The ETSI ITS-G5 and IEEE 1609.x DSRC/WAVE comunication stacks were compared to standartizes layered ISO/OSI reference model. The basic principes of comunication in inteligent transport systems are described for each model. Besides that the common messages structures for defining alert messages, the intersection geometry and trafic lights signals are described in further detail. Based on these structures and other requirements, an application is created that allows easy definition of alert messages, intersection geometry and its traffic light states.

Intelligent Transport Systems (ITS) are aiming to provide innovative services related to different modes of transport and traffic management, and enable various users to be better informed and make safer, more coordinated and smarter use of transport networks. Cooperative-ITS (C-ITS) support connectivity between vehicles, vehicles and roadside infrastructure, traffic signals as well as with other road users. In order to enable vehicular communications European Telecommunication Standards Institute (ETSI) delivered ITS-G5 -- a of set of C-ITS standards. Considering the goals of C-ITS, inter-vehicle communications should be reliable and efficient. In this thesis we study the performance, efficiency, and dependability of ITS-G5 communications for Cooperative adaptive cruise control (C-ACC) and platooning C-ITS applications. We provide an overview of currently available and ongoing standardization targeting communications in C-ACC/platooning. We study the performance of ITS-G5 beaconing in a C-ACC/platooning scenario, where we show that its performance may deteriorate when implemented in cooperative driving applications due to the kinematic-dependent design of the message triggering mechanism. We explain in detail the cause of this phenomenon and test it for a wide range of parameters. Also, we study the influence of different available ITS-G5 legitimate setups on the C-ACC/platooning fuel efficiency and demonstrate that proper communication setup may enhance fuel savings. This thesis also proposes a jamming denial-of-service attack detection algorithm for platooning. The main advantage of our detector is its short learning phase that not exceed a second and low detection delay of a few hundreds of milliseconds. Under some assumptions, the proposed algorithm demonstrates the ability to detect certain types of attacks with average probability above 0.9. / ACDC