Το ραδιόφωνο είναι από τις πλέον διαδεδομένες μορφές εκπομπής δεδομένων, χρησιμοποιείται δε ακόμα και σήμερα, σε μια εποχή που οι ψηφιακές τηλεπικοινωνίες επεκτείνονται ταχύτατα. Αρχικά επέτρεπε την μετάδοση μόνο ενός καναλιού ήχου, όμως επεκτάθηκε σε στερεοφωνική (δικάναλη) εκπομπή, προσετέθησαν μέθοδοι μετάδοσης ψηφιακών πληροφοριών (RDS/RBDS, DirectBand) για την πληροφόρηση χρηστών αλλά και για μεγαλύτερη ευελιξία των δεκτών. Παράδειγμα του τελευταίου είναι η λειτουργία "AF" (εναλλακτικές συχνότητες, alternative frequencies) η οποία δίνει την δυνατότητα σε ένα δέκτη να μεταπηδήσει σε άλλη συχνότητα στην οποία εκπέμπει ο ίδιος σταθμός αλλά με ισχυρότερο ή καθαρότερο σήμα. Δεδομένου του εύρους των λειτουργιών που χρησιμοποιούνται στις ραδιοφωνικές εκπομπές, είναι πολύ καλή επιλογή για την ανάπτυξη προγραμμάτων που τις εκμεταλλεύονται, από απλές μέχρι περίπλοκες τόσο στο αναλογικό όσο και στο ψηφιακό τμήμα. Για το αναλογικό τμήμα, στο ένα άκρο έχουμε έναν απλό μονοφωνικό δέκτη ενώ στο άλλο άκρο έναν στερεοφωνικό δέκτη ο οποίος μετρώντας την καθαρότητα του λαμβανόμενου σήματος επιλέγει το ποσοστό χρήσης στερεοφωνίας ώστε να επιτύχει συμβιβασμό μεταξύ διαχωρισμού καναλιών (στερεοφωνικής εικόνας) και χαμηλού θορύβου. Στα πλαίσια της παρούσας διπλωματικής, αναπτύχθηκε πρόγραμμα σε γλώσσα C το οποίο εκτελεί λειτουργία δέκτη ραδιοφωνικού σήματος διαμορφωμένου αναλογικά κατά συχνότητα (FM radio). Στον προγραμματισμό χρησιμοποιήθηκαν τεχνικές Software Defined Radio (SDR). Επιπλέον, το πρόγραμμα εκτελεί λήψη ψηφιακού σήματος ραδιοφωνικών πληροφοριών (Radio Broadcast Data System, RBDS/RDS). Στόχος της διπλωματικής είναι η επίδειξη της εφαρμογής τεχνικών SDR στα πλαίσια της υλοποίησης τηλεπικοινωνιακών συστημάτων. Με την αύξηση της ανάγκης της βιομηχανίας αλλά και των χρηστών για ταχύτερη μετάδοση δεδομένων, επήλθε και αύξηση της περιπλοκότητας των μεθόδων διαμόρφωσης στα τηλεπικοινωνιακά συστήματα. Η περιπλοκότητα αυτή απαιτεί χρήση αλγορίθμων που είναι αδύνατη με συστήματα με διακριτά στοιχεία. Μία λύση στο πρόβλημα αυτό είναι η αξιοποίηση σύγχρονων μικροεπεξεργαστών, των οποίων η ισχύς, ειδικά αυτή των εξειδικευμένων σε DSP, έχει γνωρίσει αλματώδη εξέλιξη. Προκειμένου να καταστεί δυνατή η αξιοποίηση του κατάλληλου υλικού για τα τηλεπικοινωνιακά συστήματα, χρειάζεται κατάλληλη μέθοδος προγραμματισμού. Η ιδέα αυτή έχει ήδη χρησιμοποιηθεί σε εμπορικά συστήματα. Ένα παράδειγμα είναι modem κοινής τηλεφωνικής γραμμής (PSTN/POTS) για οικιακούς υπολογιστές που το μεγαλύτερο μέρος της αποδιαμόρφωσης και διαμόρφωσης το εκτελούσε η κεντρική μονάδα επεξεργασίας του υπολογιστή. Συνεπώς, υπάρχουν παραδείγματα εφαρμογής αυτής της τεχνικής με ήδη υπαρκτό υλικό, δεν απαιτείται εξειδικευμένο hardware. Η εξέλιξη της ιδέας και η ευκολότερη πρόσβαση σε υλικό κατάλληλο, οδήγησε στην ανάπτυξη του Software Defined Radio. Software Defined Radio είναι ένα σύστημα ασύρματης τηλέπικοινωνίας (αν και είναι απολύτως εφικτή και η εφαρμογή σε ενσύρματα συστήματα) όπου αλγόριθμοι και μέρη του συστήματος που τυπικά υλοποιούνταν με ηλεκτρονικά στοιχεία (πυκνωτές, αντιστάτες, κ.α.) πραγματοποιούνται με προγράμματα που εκτελούνται σε σύστημα με επεξεργαστή, μικροελεγκτή ή άλλο προγραμματιζόμενο σύστημα. Η ονομασία Software Defined Radio αναφέρεται, επίσης, στο πρόγραμμα που εκτελεί το ανωτέρω σύστημα. Σε αυτά τα προγράμματα, χρησιμοποιούνται κατά κύριο λόγο τεχνικές επεξεργασίας ψηφιακού σήματος (DSP). Ως παράδειγμα προς μελέτη της τεχνικής θα χρησιμοποιήσουμε ένα από τα πλέον γνωστά πρωτόκολλα, το οποίο δεν είναι τετριμμένο και χρησιμοποιείται ευρύτατα και στη σύγχρονη εποχή, το ραδιόφωνο FM. Το πρωτόκολλο FM είναι αρκετά απλό ώστε η ανάλυσή του να είναι προσβάσιμη χωρίς να απαιτεί εξειδικευμένες γνώσεις τηλεπικοινωνιακών συστημάτων, αλλά όχι τετριμμένο, ώστε να αναδεικνύει την χρησιμότητα της τεχνικής SDR. Ένας δεύτερος λόγος για αυτή την επιλογή είναι η ταυτόχρονη εκπομπή ψηφιακής πληροφορίας από τους σταθμούς. Η λήψη αυτών των πληροφοριών με τη χρήση SDR υπογραμμίζει την ευελιξία της τεχνικής, η οποία επιτρέπει τον ταυτόχρονο χειρισμό τόσο των αναλογικών πληροφοριών (ήχου, στη συγκεκριμένη περίπτωση) όσο και των ψηφιακών πληροφοριών (RBDS/RDS) από το ίδιο πρόγραμμα. Στο Κεφάλαιο 1 περιγράφεται η αρχή λειτουργίας της αναλογικής διαμόρφωσης κατά συχνότητα καθώς και η εφαρμογή της στη ραδιοφωνία. Ορίζονται οι σχετικές παράμετροι και καθορίζονται οι τιμές που λαμβάνουν στην κοινή ραδιοφωνία FM. Τέλος, περιγράφεται η μετάδοση ψηφιακών πληροφοριών με το πρωτόκολλο RDS. Στο Κεφάλαιο 2 περιγράφεται η δομή και λειτουργία ενός δέκτη FM με διακριτά στοιχεία. Αναλύεται η αρχή λειτουργίας του δέκτη, ονομάζονται μερικά από τα στοιχεία που χρησιμοποιούνται συνήθως και διαγράφονται βασικές ομοιότητες με τους δέκτες SDR. Στο Κεφάλαιο 3 περιγράφεται η αρχή λειτουργίας του SDR. Δίνονται παραδείγματα υλικού κατάλληλου για SDR και οι δυνατότητες που απαιτούνται. Δίνονται παραδείγματα λογισμικού κατάλληλου για SDR και παραδείγματα εφαρμογών του. Στο Κεφάλαιο 4 αναλύεται το υλικό που χρησιμοποιήθηκε και το πρόγραμμα που αναπτύχθηκε για την αποδιαμόρφωση σήματος FM και αποκωδικοποίηση σήματος RDS. Επίσης περιγράφεται το υλικό που χρησιμοποιήθηκε καθώς και τα κριτήρια επιλογής τους. Ορίζονται οι είσοδοι και έξοδοι του προγράμματος και περιγράφεται η δομή του. Αναλύεται η λειτουργία των επιμέρους στοιχείων του προγράμματος που αναπτύχθηκε και μελετάται η συμπεριφορά τους. Τέλος, αναλύεται η αποδιαμόρφωση και αποκωδικοποίηση του ψηφιακού σήματος (RDS) από το πρόγραμμα. Στα παραρτήματα δίδονται οι συντελεστές των ψηφιακών φίλτρων που χρησιμοποιήθηκαν στην ανάπτυξη του δέκτη, ο πλήρης κώδικας του δέκτη και οδηγίες για την δημιουργία φασματογραφημάτων με το MATLAB. / FM radio is one of the most widespread forms of data transmission, used even today, in an era where digital telecommunications are quickly spreading. Initially, it allowed transmission of only one audio channel, but it was extended to stereo (two channel) transmission, digital information methods of transmission were added (RDS/RBDS, DirectBand) for user information and for greater receiver versatility. One example of the latter is the AF ("alternative frequencies") functionality which allows a receiver to switch over to another frequency, carrying the same radio program but with better reception. Given the great width of functions that are used in radio transmissions, it is a very good choice for developing software that take advantage of them, from simple to complex, both in the analog and digital domain. For the analog domain, on one end, there may be a simple monophonic receiver and on the other end a stereo receiver which, according to the clarity of the received signal, can adjust the level of stereo separation to achieve a preferable compromise between stereo image and low noise audio. For the purposes of this project, a software program was written, in C, which functions as a frequency modulated, analog radio signal receiver (FM radio). Software Defined Radio techniques were used while developing this program. Additionally, the program performs RDS ("radio data system") signal reception. The objective of this project is to demonstrate the use of Software Defined Radio techniques in the development of telecommunication systems. The industry's, and the users', need for faster data transmission, brought an increase in modulation method complexity in telecommunication systems. This complexity requires use of algorithms that is impossible with systems with discrete components. One solution to this problem is via utilization of modern microprocessors, especially those specializing in DSP, the performance of which has increased dramatically. In order to be able to use the appropriate hardware in a telecommunication system using SDR, an appropriate method of programming them is necessary. This idea has been already used in commercial systems. One example are modems for the common copper telephone line (PSTN /POTS) for home computers, where most of the modulation and demodulation was performed by the computers central processor. Therefore, there are examples of applications of this method using common hardware. The evolution of this idea and the easier access to necessary hardware led to the development of Software Defined Radio. Software Defined Radio is a wireless telecommunication system (although a wired system is equally feasible) where algorithms and components that would, typically, be implemented with electronic elements (capacitors, resistors, etc) are realized with a software program running on a system with a microprocessor, microcontroller or other programmable device. The name Software Defined Radio is also used to refer to the program itself. In such a program, DSP techniques are commonly used. As an example for studying this method we are using one of the most widely known protocols, one that is not trivial and is widely used even in modern times, the FM radio. The FM protocol is simple enough so that its analysis is approachable without specialized knowledge of telecommunication systems, but not trivial, so that it demonstrates the usefulness of the SDR method. Another reason for this choice is the simultaneous transmission of digital information from an FM broadcast station. Reception of this signal, by the program, underlines the versatility of SDR, which allows simultaneous handling of both analog (audio, in this case) and digital (RDS) information. The first chapter presents the principle of operation of analog frequency modulation and its application in radio broadcasting. The respective parameters are defined and specific values for common FM radio broadcasting are given. Finally, digital data transmission via the RDS protocol is described. The second chapter presents the structure and functionality of an FM receiver implemented with discrete elements. Its principle of operation is analyzed, some of the more common elements used are named and similarities with SDR receivers are drawn. The third chapter presents the principle of operation of an SDR system. Examples of useful hardware and relevant requirements are given. Finally, examples of suitable software and respective applications are given. The fourth chapter presents an analysis of the hardware that was used and the software program that was developed for the demodulation of the FM signal and decoding of the RDS signal, along with the criteria for choosing them. The program structure is described and its input and output data signal formats are defined. The functionality of each component of the software program is analyzed and its behavior is studied. Finally, the demodulation and decoding process for the RDS signal by the program is analyzed. In the appendixes, the coefficients of the digital filters are listed, along with the full source code for the software program that was developed and, finally, a guide for creating spectral graphs with MATLAB, similar to those in section 4.3.2.

L’utilisation de matrice de portes logiques reconfigurables (FPGA) est une des seules solutionspour traiter des flux de plusieurs 100 MÉchantillons/seconde en temps-réel. Toutefois, ce typede composant présente une grande difficulté de mise en oeuvre : au delà d’un type langage spécifique,c’est tout un environnement matériel et une certaine expérience qui sont requis pourobtenir les traitements les plus efficaces. Afin de contourner cette difficulté, de nombreux travauxont été réalisés dans le but de proposer des solutions qui, partant d’un code écrit dans unlangage de haut-niveau, vont produire un code dans un langage dédié aux FPGAs. Nos travaux,suivant l’approche d’assemblage de blocs et en suivant la méthode du skeleton, ont visé à mettreen place un logiciel, nommé CoGen, permettant, à partir de codes déjà développés et validés,de construire des chaînes de traitements en tenant compte des caractéristiques du FPGA cible,du débit entrant et sortant de chaque bloc pour garantir l’obtention d’une solution la plus adaptéepossible aux besoins et contraintes. Les implémentations des blocs de traitements sont soitgénérés automatiquement soit manuellement. Les entrées-sorties de chaque bloc doivent respecterune norme pour être exploitable dans l’outil. Le développeur doit fournir une descriptionconcernant les ressources nécessaires et les limitations du débit de données pouvant être traitées.CoGen fournit à l’utilisateur moins expérimenté une méthode d’assemblage de ces blocsgarantissant le synchronisme et cohérence des flux de données ainsi que la capacité à synthétiserle code sur les ressources matérielles accessibles. Cette méthodologie de travail est appliquéeà des traitements sur des flux vidéos (seuillage, détection de contours et analyse des modespropres d’un diapason) et sur des flux radio-fréquences (interrogation d’un capteur sans-fils parméthode RADAR, réception d’un flux modulé en fréquence, et finalement implémentation deblocs de bases pour déporter le maximum de traitements en numérique). / Using Field Programmable Gate Arrays (FPGA) is one of the very few solution for real time processingdata flows of several hundreds of Msamples/second. However, using such componentsis technically challenging beyond the need to become familiar with a new kind of dedicateddescription language and ways of describing algorithms, understanding the hardware behaviouris mandatory for implementing efficient processing solutions. In order to circumvent these difficulties,past researches have focused on providing solutions which, starting from a description ofan algorithm in a high-abstraction level language, generetes a description appropriate for FPGAconfiguration. Our contribution, following the strategy of block assembly based on the skeletonmethod, aimed at providing a software environment called CoGen for assembling various implementationsof readily available and validated processing blocks. The resulting processing chainis optimized by including FPGA hardware characteristics, and input and output bandwidths ofeach block in order to provide solution fitting best the requirements and constraints. Each processingblock implementation is either generated automatically or manually, but must complywith some constraints in order to be usable by our tool. In addition, each block developer mustprovide a standardized description of the block including required resources and data processingbandwidth limitations. CoGen then provides to the less experienced user the means to assemblethese blocks ensuring synchronism and consistency of data flow as well as the ability to synthesizethe processing chain in the available hardware resources. This working method has beenapplied to video data flow processing (threshold, contour detection and tuning fork eigenmodesanalysis) and on radiofrequency data flow (wireless interrogation of sensors through a RADARsystem, software processing of a frequency modulated stream, software defined radio).

The recent popularity and convenience of Wireless communication and the need for integration demands the development of Software Defined Radio (SDR). First defined by Mitoal, the SDR processed the entire bandwidth using a high resolution and high speed ADC and remaining operations were done in DSP. The current trend in SDRs is to design highly reconfigurable analog front ends which can handle narrow-band and wideband standards, one at a time. Charge sampling has been widely used in these architectures due to the built in antialiasing capabilities, jitter robustness at high signal frequencies and flexibility in filter design. This work proposed a 1GHz wideband front end aimed at SDR applications using Transform Domain (TD) sampling techniques. Frequency Domain (FD) sampling, a special case of TD sampling, efficiently parallelizes the signal for digital processing, relaxing the sampling requirements and enabling parallel digital processing at a much lower rate and is a potential candidate for SDR. The proposed front end converts the RF signal into current and then it is downconverted using passive mixers. The front end has five parallel paths, each acting on a part of the spectrum effectively parallelizing the front end and relaxing the requirements. An overlap introduced between successive integration windows for jitter robustness was exploited to create a novel sinc2 downsample by two filter topology. This topology was compared to a conventional topology and found to be equivalent and area efficient by about 44%. The proposed topology was used as a baseband filter for all paths in the front end. The chip was sent for fabrication in 45nm technology. The active area of the chip was 6:6mm2. The testing and measurement of the chip still remains to be done.

Developing a flexible receiver, which can be reconfigured to multiple standards, is the key to solving the problem of embedding numerous and ever-changing functionalities in mobile handsets. Difficulty in efficiently reconfiguring analog blocks of a receiver chain to multiple standards calls for moving the ADC as close to the antenna as possible so that most of the processing is done in DSP. Different standards are sampled at different frequencies and a programmable anti-aliasing filtering is needed here. Windowed integration samplers have an inherent sinc filtering which creates nulls at multiples of fs. The attenuation provided by sinc filtering for a bandwidth B is directly proportional to the sampling frequency fs and, in order to meet the anti-aliasing specifications, a high sampling rate is needed. ADCs operating at such a high oversampling rate dissipate power for no good use. Hence, there is a need to develop a programmable discrete-time down-sampling circuit with high inherent anti-aliasing capabilities. Currently existing topologies use large numbers of switches and capacitors which occupy a lot of area.A novel technique in reducing die area on a discrete-time sinc2 ↓2 filter for charge sampling is proposed. An SNR comparison of the conventional and the proposed topology reveals that the new technique saves 25 percent die area occupied by the sampling capacitors of the filter. The proposed idea is also extended to implement higher downsampling factors and a greater percentage of area is saved as the down-sampling factor is increased. The proposed filter also has the topological advantage over previously reported works of allowing the designers to use active integration to charge the capacitance, which is critical in obtaining high linearity. A novel technique to implement a discrete-time sinc3 ↓2 filter for windowed integration samplers is also proposed. The topology reduces the idle time of the integration capacitors at the expense of a small complexity overhead in the clock generation, thereby saving 33 percent of the die area on the capacitors compared to the currently existing topology. Circuit Level simulations in 45 nm CMOS technlogy show a good agreement with the predicted behaviour obtained from the analaysis.

Software defined radio (SDR) introduces endless possibilities for future communication technologies. Instead of being limited to a static segment of the radio spectrum, SDR allows RF front-ends to be more flexible by using digital signal processing (DSP) and cognitive techniques to integrate adaptive hardware with dynamic software. We present the design and implementation of an innovative RF front-end transceiver architecture for application into a SDR test-bed platform. System-level requirements were extracted from the Space Network User Guide (SNUG). Initial system characterization demonstrated image leakage due to poor filtering and mixer isolation issues. Hence, the RF front-end design was re-implemented using the Weaver architecture for improved image rejection performance.

Inspection methods for satellites post-launch are currently expensive and/or dangerous. To address this, BYU, in conjunction with NASA, is designing a series of small satellites called CubeSATs. These small satellites are designed to be launched from a satellite and to visually inspect the launching body. The current satellite revision passively tumbles through space and is appropriately named the passive inspection cube satellite (PICS). The next revision actively maintains translation and rotation relative to the launching satellite and is named the translation, rotation inspection cube satellite (TRICS). One of the necessary sensors aboard this next revision is the means to detect distance. This work explores the feasibility of using a software defined radio as a small, low-cost front end for a ranging radar to fulfill this need. For this work, the LimeSDR-Mini is selected due to its low-cost, small form factor, full duplex operation, and open-source hardware/software. Additionally, due to the the channel characteristics of space, the linear frequency modulated continuous-wave (LFMCW) radar is selected as the radar architecture due to its ranging capabilities and simplicity. The LFMCW radar theory and simulation are presented. Two programming methods for the LimeSDR-Mini are considered: GNU Radio Companion and the pyLMS7002Soapy API. GNU Radio Companion is used for initial exploration of the LimeSDR-Mini and confirms its data streaming (RX and TX) and full duplex capabilities. The pyLMS7002Soapy API demonstrates further refined control over the LimeSDR-Mini while providing platform independence and deployability. This work concludes that the LimeSDR-Mini is capable of acting as the front end for a ranging radar aboard a small satellite provided the pyLMS7002Soapy API is used for configuration and control. GNU Radio Companion is not recommended as a programming platform for the LimeSDR-Mini and the pyLMS7002Soapy API requires further research to fine tune the SDR's performance.

Drone-mounted ground penetrating radar (GPR) has the capability to investigate terrain that is inaccessible or hazardous to humans. A linear frequency-modulated (LFM) radar with the potential for GPR applications is described based on the LimeSDR Mini software defined radio (SDR). Challenges of the LimeSDR Mini radar include the SDR's lack of support for transmitter-receiver synchronization and high bleedthrough leakage. These issues are overcome through corrective software processing techniques including deconvolution of the SDR's system impulse response and digital feed-through nulling. Feed-through nulling is effective at reducing bleedthrough leakage, achieving a 26 dB reduction in power. Although high noise can confound the identification of targets with small radar cross sections in dynamic environments, the LimeSDR Mini radar is demonstrated to display a moving target across multiple ranges. This research demonstrates the increasing accessibility of SDR radar for drone applications, as the LimeSDR Mini is lightweight and low-cost compared to high-end SDRs typically used in SDR radar.

In modern society, Global Navigation Satellite Systems (GNSSs) are ubiquitously relied upon by many systems, among others in critical infrastructure, for navigation and time synchronization. To overcome the prevailing vulnerable state of civilian GNSSs, many detection schemes for different attack types (i.e., jamming and spoofing) have been proposed in literature over the last decades. With the launch of Galileo Open Service Navigation Message Authentication (OS­NMA), certain, but not all, types of GNSS spoofing are prevented. We therefore analyze the remaining attack surface of relay/replay attacks in order to identify a suitable and effective combination of detection schemes against these. One shortcoming in the evaluation of countermeasures is the lack of available test platforms, commonly limiting evaluation to mathematical description, simulation and/or test against a well defined set of recorded spoofing incidents. In order to allow researchers to test countermeasures against more diverse threats, this degree project investigates relay/replay attacks against GNSS signals in real­world setups. For this, we consider colluding adversaries, relaying/replaying on signal­ and on message­level in real­time, over consumer grade Internet, and with Commercially off the Shelf (COTS) hardware. We thereby highlight how effective and simple relay/replay attacks can be on existent and likely on upcoming authenticated signals. We investigate the requirements for such colluding attacks and present their limitations and impact, as well as highlight possible detection points. / Det moderna samhället förlitar sig på ständigt tillgängliga satellitnavigeringssystem (GNSSs) för navigering och tidssynkronisering i bland annat kritisk infrastruktur. För att åtgärda det rådande såbara tillståndet i civila GNSSs har många detektionssystem för olika attacktyper (dvs. jamming och förfalskning) blivit förslagna i den vetenskapliga litteraturen under de senaste årtiondena. Införandet av Galileo Open Service Navigation Message Authentication (OS NMA) förhindrar vissa, men inte alla typer av förfalskningsattacker. Därför analyserar vi den övriga angreppsytan för replay attacker för att identifiera en kvalificerad och effektiv kombination av detektionssystem emot dem. Ett tillkortakommande i utvärdering av detektionssystemen är bristen på tillgängliga testplattformar, vilket får konsekvensen att utvärderingen ofta är begränsad till matematiska beskrivningar, simuleringar, och/eller testning mot ett väldefinierat set av genererad förfalskningsattacker. För att hjälpa forskarna testa detektionssystemen mot mer varierade angrepp undersöker detta examensarbete replay attacker mot GNSS signaler i realistiska situationer. För dessa syften betraktar vi kollaborerande angripare som utför replay attacker på signal ­ och meddelandennivå i realtid över konsument­kvalité Internet med vanlig hårdvara. Vi framhäver därmed hur effektiva och enkla replay attacker kan vara mot befintliga och kommande autentiserade signaler. Vi undersöker förutsättningar för sådana kollaborerande attacker och presenterar deras begränsningar och verkan, samt möjliga kännetecken.

The world of wireless communications is under constant change. Radio standards evolve and new standards emerge. More and more functionality is put into wireless terminals. E.g. mobile phones need to handle both second and third generation mobile telephony as well as Bluetooth, and will soon also support wireless LAN functionality, reception of digital audio and video broadcasting, etc. These developments have lead to an increased interest in software defined radio (SDR), i.e. radio devices that can be reconfigured via software. SDR would provide benefits such as low cost for multi-mode devices, reuse of the same hardware in different products, and increased product life time via software updates. One essential part of any software defined radio is a programmable baseband processor that is flexible enough to handle different types of modulation, different channel coding schemes, and different trade-offs between data rate and mobility. So far, programmable baseband solutions have mostly been used in high end systems such as mobile telephony base stations since the cost and power consumption have been considered too high for handheld terminals. In this work a new low power and low silicon area programmable baseband processor architecture aimed for multi-mode terminals is presented. The architecture is based on a customized DSP core and a number of hardware accelerators connected via a configurable network. The architecture offers a good tradeoff between flexibility and performance through an optimized instruction set, efficient hardware acceleration of carefully selected functions, low memory cost, and low control overhead. One main contribution of this work is a study of important issues in programmable baseband processing such as software-hardware partitioning, instruction level acceleration, low power design, and memory issues. Further contributions are a unique optimized instruction set architecture, a unique architecture for efficient integration of hardware accelerators in the processor, and mapping of complete baseband applications to the presented architecture. The architecture has been proven in a manufactured demonstrator chip for wireless LAN applications. Wireless LAN firmware has been developed and run on the chip at full speed. Silicon area and measured power consumption have proven to be similar to that of a non-programmable ASIC solution.

Dans le but d’améliorer la disponibilité des services fournis par un récepteur, la conception d’un récepteur GNSS permettant de recevoir plusieurs signaux de toutes les bandes simultanément semble être la solution. Une architecture à sous échantillonnage RF optimisée de type SDR (Software Defined Radio) comportant un étage RF intégrable et reconfigurable et un étage de traitement numérique avec une implémentation logicielle du traitement en bande de base est défini pour ce récepteur GNSS, tout en répondant aux exigences des spécifications des standards GNSS : des réseaux radio cellulaires : GPS, Glonass, Galileo, Beidou. Un choix des composants discrets suite au dimensionnement system est effectué et ceci pour installer un prototype de validation expérimental. Ensuite nous nous s’intéressons à la caractérisation de la chaine RF afin d’étudier les limitations causés par la non linéarité et d’étudier la stabilité du prototype proposé. Un étage de traitement numérique des signaux IF, capturés à la sortie de l’ADC, est implémenté sous Matlab. L’acquisition de ces données permet la détermination des satellites visible à un instant donné qui nous permet éventuellement la détermination d’une position / In order to improve the availability of services provided by a receiver, designing a GNSS receiver to collect multiple signals from all bands simultaneously seems to be the solution. An optimized software-defined RF (SDR) sub-sampling architecture with an integral and reconfigurable RF stage and a digital processing stage with a software implementation of the baseband processing is defined for this GNSS receiver, while meeting the requirements GNSS standards specifications: cellular radio networks: GPS, Glonass, Galileo, Beidou. Many discrete components are selected after system dimensioning. Thus, experimental validation prototype is installed. Then we are interested in the characterization of the RF front-end in order to determine the limitations caused by the nonlinearity and to study the stability of the proposed prototype. A stage of digital processing of the IF signals, captured at the ADC output, is implemented under Matlab software. The acquisition of these data allows the determination of satellites visible at a given instant that allows us to determine a position