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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
421

Sidokanalattack mot knappsats för elektroniskt passersystem / Side-channel attack against electronic entry system keypad

Alasjö, Alexander January 2017 (has links)
Genom ett undersökande experiment med elektromagnetisk sidokanalattack mot en knappsats för ett kommersiellt passersystem påvisas att informationsläckage i sidokanaler är ett fortsatt aktuellt problem och hur det gör fysisk åtkomstkontroll sårbart genom avlyssning och kopiering av användaruppgifter. Med enkel radioutrustning kan knapptryckningar registreras och avkodas genom oönskad elektromagnetisk strålning och teoretiskt är det möjligt att genomföra avlyssningen på en längre distans med särskilt utformad antenn och anpassad mottagare. Rapporten diskuterar problematiken med emission security hos konsumentprodukter som i militära sammanhang benämns Tempest eller RÖS (röjande signaler) och kräver kostsamma tester för att detekteras och hanteras. I regelverk för EMC (elektromagnetisk kompatibilitet) behandlas elektriska apparaters och näts utstrålning och påverkan av elektromagnetiska vågor, men inte direkt hur information kan läcka från informationsteknologisk utrustning vilket denna rapport vill problematisera. / Through an exploratory experiment using electromagnetic side-channel attack against a keypad for a commercial entry system it is demonstrated that information leakage through side-channels are an ongoing issue and may make entry systems vulnerable by recording of user data. Using simple radio equipment, keypresses can be recorded and decoded by undesired electromagnetic radiation and theoretically it is possible to carry out the attack on a longer distance with a specially designed antenna and a custom recieiver. The report discusses emission security in consumer products which in military context is termed Tempest or compromising emanations (Swedish: RÖS) and requires expensive tests to be detected and handled. The EMC regulations (electromagnetic compatibility) handles radiation and influence of electromagnetic waves in electronic apparatus and nets, but not directly how information can leak from information technology equipment which this report wants to problematize.
422

Conception d’un crypto-système reconfigurable pour la radio logicielle sécurisée

Grand, Michaël 02 December 2011 (has links)
Les travaux de recherche détaillés dans ce document portent sur la conception et l’implantation d’un composant matériel jouant le rôle du sous-système cryptographique d’une radio logicielle sécurisée.A partir du début des années 90, les systèmes radios ont peu à peu évolué de la radio classique vers la radio logicielle. Le développement de la radio logicielle a permis l’intégration d’un nombre toujours plus grand de standards de communication sur une même plateforme matérielle. La réalisation concrète d’une radio logicielle sécurisée amène son concepteur à faire face à de nombreuses problématiques qui peuvent se résumer par la question suivante : Comment implanter un maximum de standards de communication sur une même plateforme matérielle et logicielle ? Ce document s’intéresse plus particulièrement à l’implantation des standards cryptographiques destinés à protéger les radiocommunications.Idéalement, la solution apportée à ce problème repose exclusivement sur l’utilisation de processeurs numériques. Cependant, les algorithmes cryptographiques nécessitent le plus souvent une puissance de calcul telle que leur implantation sous forme logicielle n’est pas envisageable. Il s’ensuit qu’une radio logicielle doit parfois intégrer des composants matériels dédiés dont l'utilisation entre en conflit avec la propriété de flexibilité propre aux radios logicielles.Or depuis quelques années, le développement de la technologie FPGA a changé la donne. En effet, les derniers FPGA embarquent un nombre de ressources logiques suffisant à l’implantation des fonctions numériques complexes utilisées par la radio logicielle. Plus précisément, la possibilité offerte par les FPGA d'être reconfiguré dans leur totalité (voir même partiellement pour les derniers d’entre eux) fait d’eux des candidats idéaux à l’implantation de composants matériels flexibles et évolutifs dans le temps. À la suite de ces constatations, des travaux de recherche ont été menés au sein de l’équipe Conception des Systèmes Numériques du Laboratoire IMS. Ces travaux ont d’abord débouché sur la publication d’une architecture de sous-système cryptographique pour la radio logicielle sécurisée telle qu’elle est définie par la Software Communication Architecture. Puis, ils se sont poursuivis par la conception et l’implantation d’un cryptoprocesseur multi-cœur dynamiquement reconfigurable sur FPGA. / The research detailed in this document deal with the design and implementation of a hardware integrated circuit intended to be used as a cryptographic sub-system in secure software defined radios.Since the early 90’s, radio systems have gradually evolved from traditional radio to software defined radio. Improvement of the software defined radio has enabled the integration of an increasing number of communication standards on a single radio device. The designer of a software defined radio faces many problems that can be summarized by the following question: How to implement a maximum of communication standards into a single radio device? Specifically, this work focuses on the implementation of cryptographic standards aimed to protect radio communications.Ideally, the solution to this problem is based exclusively on the use of digital processors. However, cryptographic algorithms usually require a large amount of computing power which makes their software implementation inefficient. Therefore, a secure software defined radio needs to incorporate dedicated hardware even if this usage is conflicting with the property of flexibility specific to software defined radios.Yet, in recent years, the improvement of FPGA circuits has changed the deal. Indeed, the latest FPGAs embed a number of logic gates which is sufficient to meet the needs of the complex digital functions used by software defined radios. The possibility offered by FPGAs to be reconfigured in their entirety (or even partially for the last of them) makes them ideal candidates for implementation of hardware components which have to be flexible and scalable over time.Following these observations, research was conducted within the Conception des Systèmes Numériques team of the IMS laboratory. These works led first to the publication of an architecture of cryptographic subsystem compliant with the security supplement of the Software Communication Architecture. Then, they continued with the design and implementation of a partially reconfigurable multi-core cryptoprocessor intended to be used in the latest FPGAs.
423

Fully Integrated CMOS Transmitter and Power Amplifier for Software-Defined Radios and Cognitive Radios

Raja, Immanuel January 2017 (has links) (PDF)
Software Defined Radios (SDRs) and Cognitive Radios (CRs) pave the way for next-generation radio technology. They promise versatility, flexibility and cognition which can revolutionize communications systems. However they present greater challenges to the design of radio frequency (RF) front-ends. RF front-ends for the radios in use today are narrow-band in their frequency response and are optimized and tuned to the carrier frequency of interest. SDRs and CRs demand front-ends which are versatile, configurable, tunable and be capable of transmitting and receiving signals with different bandwidths and modulation schemes. Integrating power amplifiers (PAs) with transmitters in CMOS has many advantages and challenges. This thesis deals with the design of an RF transmitter front-end for SDRs and CRs in CMOS. The thesis begins with an introduction to SDRs and the requirements they place on transmitters and the challenges involved in designing them in CMOS. After a brief overview of the existing techniques, the proposed architecture is presented and explained. A digitally intensive transmitter solution is proposed. The transmitter covers a wide frequency range of 750 MHz to 2.5 GHz. The inputs to the proposed transmitter are in-phase and quadrature (I & Q) data bit streams. Multiple stages of up-sampling and filtering are used to remove all spurs in the spectrum such that only the harmonics of the carrier remain. Differential rail-to-rail quadrature clocks are generated from a continuous wave signal at twice the carrier frequency. The clocks are corrected for their duty cycle and quadrature impairments. The heart of the transmitter is an integrated reconfigurable CMOS power amplifier (PA). A methodology to design reconfigurable Class E PAs with a series fixed inductor has been presented. A CMOS power amplifier that can span a wide frequency range with sufficient output power and efficiency, supporting varying envelope complex modulation signals, with good linearity has been designed. Digital pre-distortion (DPD) is used to linearize the PA. The full transmitter and the clock correction blocks have been designed and fabricated in a commercial 130-nm CMOS process and experimentally characterized. The PA delivers a maximum power of 13 dBm with an efficiency of 27% at 1 GHz. While transmitting a 16-QAM signal at 1 GHz, the measured EVM is 4%. It delivers a maximum power of around 11-13 dBm from 750 MHz to 1.5 GHz and up to 6.5 dBm of power till 2.5 GHz. Comparing the proposed system with recently published literature, it can be seen that the proposed design is one of the very few transmitters which has an integrated matching network, tunable across the frequency range. The proposed PA produces the highest output power and with largest efficiency for systems with on-chip output networks.
424

Software defined radio for cognitive wireless sensor networks : a reconfigurable IEEE 802.15.4 reconfigurable / Radio logicielle pour des réseaux de capteurs sans fil cognitifs : un standard IEEE 802.15.4 reconfigurable

Zitouni, Rafik 14 October 2015 (has links)
Le nombre croissant d'applications des Réseaux de Capteurs Sans Fils (RCSFs) a conduit les industriels à concevoir ces réseaux avec une couche Physique (PHY) suivant le standard IEEE 802.15.4. Actuellement, cette couche est implémentée en matériel souffrant d'un manque de flexibilité du changement des paramètres radio, telles que bandes de fréquences et modulations. Ce problème est accentué par la rareté du spectre radio fréquences. La Radio Logiciel (RL) est une nouvelle solution pour reconfigurer plus facilement ces paramètres. A partir d'une RL, il est possible de développer une radio cognitive permettant une écoute de spectre et un Accès Dynamique au Spectre (ADS). Ces deux possibilités sont utiles pour surmonter le problème de la rareté du spectre. Cette thèse propose une nouvelle solution Radio logicielle pour un RCSF basé sur le standard IEEE 802.15.4. Notre objectif est de caractériser une plate-forme RL qui implémente à la fois deux couches PHY standardisées et une radio cognitive pour des RCSFs. Dans cette thèse, nous avons réalisé des implémentations RL en utilisant une plateforme composée de la solution Universal Software Peripheral Radio (USRP) d'Ettus Research et de GNU Radio. Nous avons choisi cette plateforme particulière puisqu'elle est parmi les outils les plus performants et les plus pratiques d'après notre état de l'art. Une étude minutieuse a été effectuée pour analyser l'architecture logicielle de la GNU Radio avant son utilisation. Des USRPs avec leurs cartes filles ont été aussi analysés à travers des mesures expérimentales radio fréquences. L'analyse de cette plate-forme a apporté une description détaillée de son architecture et de ses performances. Nous avons prouvé que les performances mesurées sont plus faibles que ceux attendus pour certaines cartes filles d'USRP. Malgré ces résultats, certaines cartes ont de nombreuses caractéristiques intéressantes, comme de grandes bandes de fréquences couvertes et une puissance de sortie linéaire. Un modèle empirique a été introduit pour caractériser avec précision la puissance de sortie moyenne d'une carte fille particulière. Nous avons ensuite implémenté une nouvelle couche PHY standardisée pour la bande de fréquence 868/915 MHz basée sur le standard 802.15.4. Un processus de rétro-ingénierie d'une autre implémentation développée pour la bande 2.4GHz a été effectué. Ces deux couches ont été décrites par des chaines de communications ou des graphes de flux. Nous avons finalement proposé une nouvelle radio cognitive par une reconfiguration de ces graphes de flux dans les deux bandes de fréquences correspondantes. La particularité de notre radio cognitive est de reconfigurer les graphes de flux en fonction de la fréquence sélectionnée. Cette sélection est effectuée par un ADS et une écoute de spectre basé sur une détection d'énergie, validés tous les deux au travers des réelles communications sans fil. Nous avons introduit un algorithme à base de messages afin de reconfigurer les graphes de flux et de synchroniser la sélection sur une fréquence porteuse. Les deux couches physiques en RL pour les bandes 2.4 GHz et 868/915 MHz ont été testées et sont fonctionnelles. La première a été testée en échangeant des paquets de données avec des nœuds capteurs réels. La deuxième a été expérimentée par l'échange de paquets, à travers une communication entre deux radios logicielles USRP/GNU Radio. Nous avons réussi à mesurer deux paramètres réels d'une communication sans fil : le taux d'erreur binaire et le taux de succès des paquets. Les couches PHY résultantes ont servi à la réalisation et à l'expérimentation d'un ADS de notre radio cognitive. Un ADS a amélioré significativement le taux de succès de paquets par rapport à celui obtenu avec un accès statique dans un environnement indoor. Les résultats de cette thèse conduisent à expérimenter une radio cognitive avec une RL non seulement pour un RCSF, mais pour d'autres réseaux sans fil et standards radio / The Increasing number of Wireless Sensor Networks (WSNs) applications has led industries to design the physical layer (PHY) of these networks following the IEEE 802.15.4 standard. The traditional design of that layer is on hardware suffering from a lack of flexibility of radio parameters, such as changing both frequency bands and modulations. This problem is emphasized by the scarcity of the radio-frequency spectrum. Software Defined Radio (SDR) is an attracting solution to easily reconfigure radio parameters. In addition to SDR, a cognitive radio concept can be proposed by spectrum sensing and Dynamic Spectrum Access (DSA) both to overcome the spectrum scarcity problem. This thesis proposes a new SDR solution for WSNs based on the IEEE 802.15.4 standard. Our aim is to characterize an SDR platform that implements two standardized PHY layers and cognitive radio for WSNs. In this thesis, we carried out SDR implementations using a GNU Radio and Universal Software Peripheral Radio (USRP) platform. We chose this particular platform because it is one of the most practical and well-performed ones. A thorough study was performed to analyze GNU Radio software architecture before its usage. USRPs and their daughter boards were also analyzed through experimental radio-frequency measurements. The analysis of the GNU Radio USRP platform brought a detailed description of its architecture and performances as well as the way to implement an SDR. This description particularly assists researchers to quickly develop efficient SDR receivers and transmitters. We show through our experiments that the measured performances of daughter boards mounted on a USRP are lower than expected ones. Despite these results, some daughter boards have many interesting features such as large covered frequency bands and with a linear output power. An empirical model was introduced to accurately characterize the average output power of a particular daughter board. Then, we implemented a new possible standardized PHY layer for the 868/915 MHz frequency band. A reverse engineering process of another implementation was performed for the 2450 MHz frequency band. These two PHY layers were described by communication chains or flow graphs. We suggested a new Cognitive Radio by a reconfiguration of these flow graphs within the corresponding frequency bands. The particularity of our cognitive radio is to reconfigure flow graphs in function to the selected frequency. This selection is performed by DSA and spectrum sensing based on energy detection both through real wireless communications. We introduced a message based algorithm in order to reconfigure the flow graphs and to synchronize the selection of a carrier frequency. Our two implemented PHY layers for the 2450 MHz and the 868/915 frequency bands were found functional. The first one was tested by exchanging data packets with real sensor nodes. The second was also experienced by a packet exchange, but via GNURadio/USRP communications. Both tests were carried out through real communications. We were also able to measure two wireless communication parameters: Bit Error Rate (BER) and the Packet Success Rate (PSR). The result of functional PHY layers was beneficial for realization and experiments of our cognitive radio. We found that our DSA significantly improves the packet success rate compared to that obtained with static spectrum access in an indoor environment. The results of this thesis lead to experiment a cognitive radio with an SDR not only for a WSN, but for other wireless networks and radio standards
425

Telemetrický archiv družic / Satellite Telemetry Archive

Vorálek, Jan January 2020 (has links)
This thesis deals with a design of telemetry archive of PSAT, PSAT-2 and BRICSat sattelites. This telemetry data need to be extracted from SDR IQ records. The thesis contains a Doppler effect theory and description of structure of telemetry data. Then it presents a design of a program for Doppler effect correction, demodulation and decoding of these records and saving the data to telemetry archive. Thesis also deals with analysis of decoded data.
426

Simmulating and prototyping software definednetworking (SDN) using Mininet approach to optimise host communication in realistic programmable networking environment

Zulu, Lindinkosi Lethukuthula 11 1900 (has links)
In this project, two tests were performed. On the first test, Mininet-WiFi was used to simulate a Software Defined Network to demonstrate Mininet-WiFi’ s ability to be used as the Software Defined Network emulator which can also be integrated to the existing network using a Network Virtualized Function (NVF). A typical organization’s computer network was simulated which consisted of a website hosted on the LAMP (Linux, Apache, MySQL, PHP) virtual machine, and an F5 application delivery controller (ADC) which provided load balancing of requests sent to the web applications. A website page request was sent from the virtual stations inside Mininet-WiFi. The request was received by the application delivery controller, which then used round robin technique to send the request to one of the web servers on the LAMP virtual machine. The web server then returned the requested website to the requesting virtual stations using the simulated virtual network. The significance of these results is that it presents Mininet-WiFi as an emulator, which can be integrated into a real programmable networking environment offering a portable, cost effective and easily deployable testing network, which can be run on a single computer. These results are also beneficial to modern network deployments as the live network devices can also communicate with the testing environment for the data center, cloud and mobile provides. On the second test, a Software Defined Network was created in Mininet using python script. An external interface was added to enable communication with the network outside of Mininet. The amazon web services elastic computing cloud was used to host an OpenDaylight controller. This controller is used as a control plane device for the virtual switch within Mininet. In order to test the network, a webserver hosted on the Emulated Virtual Environment – Next Generation (EVENG) software is connected to Mininet. EVE-NG is the Emulated Virtual Environment for networking. It provides tools to be able to model virtual devices and interconnect them with other virtual or physical devices. The OpenDaylight controller was able to create the flows to facilitate communication between the hosts in Mininet and the webserver in the real-life network. / Electrical and Mining Engineering
427

Link failure detection in OSPF network using OpenFlow protocol

Pamulapati, Santhan 21 May 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The study of this thesis is focused on reducing the link failure detection time in OSPF network. When a link failure occurs, OSPF protocol detects it using RouterDeadInterval time. This timer is fired only after a predefined time interval, thus increasing the time of convergence after the link failure. There are previous studies to reduce the RouterDeadInterval time, but they introduce other effects which are discussed later in the thesis. So, a novel approach is proposed in this thesis to reduce the link failure detection time with the help of emerging network architecture Software Defined Networking (SDN) and OpenFlow Protocol.
428

A Calibration Method for a Controlled Reception Pattern Antenna and Software Defined Radio Configuration

Bauer, Zachary Obenour 12 June 2013 (has links)
No description available.
429

Ultra-wideband Spread Spectrum Communications using Software Defined Radio and Surface Acoustic Wave Correlators

Gallagher, Daniel 01 January 2015 (has links)
Ultra-wideband (UWB) communication technology offers inherent advantages such as the ability to coexist with previously allocated Federal Communications Commission (FCC) frequencies, simple transceiver architecture, and high performance in noisy environments. Spread spectrum techniques offer additional improvements beyond the conventional pulse-based UWB communications. This dissertation implements a multiple-access UWB communication system using a surface acoustic wave (SAW) correlator receiver with orthogonal frequency coding and software defined radio (SDR) base station transmitter. Orthogonal frequency coding (OFC) and pseudorandom noise (PN) coding provide a means for spreading of the UWB data. The use of orthogonal frequency coding (OFC) increases the correlator processing gain (PG) beyond that of code division multiple access (CDMA); providing added code diversity, improved pulse ambiguity, and superior performance in noisy environments. Use of SAW correlators reduces the complexity and power requirements of the receiver architecture by eliminating many of the components needed and reducing the signal processing and timing requirements necessary for digital matched filtering of the complex spreading signal. The OFC receiver correlator code sequence is hard-coded in the device due to the physical SAW implementation. The use of modern SDR forms a dynamic base station architecture which is able to programmatically generate a digitally modulated transmit signal. An embedded Xilinx Zynq ™ system on chip (SoC) technology was used to implement the SDR system; taking advantage of recent advances in digital-to-analog converter (DAC) sampling rates. SDR waveform samples are generated in baseband in-phase and quadrature (I & Q) pairs and upconverted to a 491.52 MHz operational frequency. The development of the OFC SAW correlator ultimately used in the receiver is presented along with a variety of advanced SAW correlator device embodiments. Each SAW correlator device was fabricated on lithium niobate (LiNbO3) with fractional bandwidths in excess of 20%. The SAW correlator device presented for use in system was implemented with a center frequency of 491.52 MHz; matching SDR transmit frequency. Parasitic electromagnetic feedthrough becomes problematic in the packaged SAW correlator after packaging and fixturing due to the wide bandwidths and high operational frequency. The techniques for reduction of parasitic feedthrough are discussed with before and after results showing approximately 10:1 improvement. Correlation and demodulation results are presented using the SAW correlator receiver under operation in an UWB communication system. Bipolar phase shift keying (BPSK) techniques demonstrate OFC modulation and demodulation for a test binary bit sequence. Matched OFC code reception is compared to a mismatched, or cross-correlated, sequence after correlation and demodulation. Finally, the signal-to-noise power ratio (SNR) performance results for the SAW correlator under corruption of a wideband noise source are presented.
430

Improving fairness, throughput and blocking performance for long haul and short reach optical networks

Tariq, Sana 01 January 2015 (has links)
Innovations in optical communication are expected to transform the landscape of global communications, internet and datacenter networks. This dissertation investigates several important issues in optical communication such as fairness, throughput, blocking probability and differentiated quality of service (QoS). Novel algorithms and new approaches have been presented to improve the performance of optical circuit switching (OCS) and optical burst switching (OBS) for long haul, and datacenter networks. Extensive simulations tests have been conducted to evaluate the effectiveness of the proposed algorithms. These simulation tests were performed over a number of network topologies such as ring, mesh and U.S. Long-Haul, some high processing computing (HPC) topologies such as 2D and 6D mesh torus topologies and modern datacenter topologies such as FatTree and BCube. Two new schemes are proposed for long haul networks to improve throughput and hop count fairness in OBS networks. The idea is motivated by the observation that providing a slightly more priority to longer bursts over short bursts can significantly improve the throughput of the OBS networks without adversely affecting hop-count fairness. The results of extensive performance tests have shown that proposed schemes improve the throughput of optical OBS networks and enhance the hop-count fairness. Another contribution of this dissertation is the research work on developing routing and wavelength assignment schemes in multimode fiber networks. Two additional schemes for long haul networks are presented and evaluated over multimode fiber networks. First for alleviating the fairness problem in OBS networks using wavelength-division multiplexing as well as mode-division multiplexing while the second scheme for achieving higher throughput without sacrificing hop count fairness. We have also shown the significant benefits of using both mode division multiplexing and wavelength division multiplexing in real-life short-distance optical networks such as the optical circuit switching networks used in the hybrid electronic-optical switching architectures for datacenters. We evaluated four mode and wavelength assignment heuristics and compared their throughput performance. We also included preliminary results of impact of the cascaded mode conversion constraint on network throughput. Datacenter and high performance computing networks share a number of common performance goals. Another highly efficient adaptive mode wavelength- routing algorithm is presented over OBS networks to improve throughput of these networks. The effectiveness of the proposed model has been validated by extensive simulation results. In order to optimize bandwidth and maximize throughput of datacenters, an extension of TCP called multipath-TCP (MPTCP) has been evaluated over an OBS network using dense interconnect datacenter topologies. We have proposed a service differentiation scheme using MPTCP over OBS for datacenter traffic. The scheme is evaluated over mixed workload traffic model of datacenters and is shown to provide tangible service differentiation between flows of different priority levels. An adaptive QoS differentiation architecture is proposed for software defined optical datacenter networks using MPTCP over OBS. This scheme prioritizes flows based on current network state.

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