The thesis is mainly in algorithm design and implementation of hardware circuit of baseband signal processing at the transceiver of 2450 MHz band chirp spread spectrum in IEEE 802.15.4a ¡V 2007 Low Rate-Wireless Personal Area Network (LR-WPAN). Due to the characteristic of LR-WPAN such as low cost, low power consumption, small size and easy to implementation, we have to take the complexity and the system performance into consideration. In this thesis, we study on the algorithm design of baseband signal, and analysis the simulation result. At the transmitter, following the specification and realize it. At the receiver, designing the algorithm including the packet detection, energy detection and down-sampling, carrier frequency offset estimation and compensation, timing synchronization, and bi-orthogonal demapper. The system performance after quantizing is 3dB better than the receiver sensitivity we expected. After finishing the algorithm design of the transceiver, we implement the baseband signal circuit by using Verilog Code. Finally, we make an application to National Chip Implementation Center (CIC), and will measure the circuit after the chip tape out. The circuit is fabricated in a 0.18-£gm CMOS technology.

The necessity of interconnecting objects more and more, possibly with high mobility, has pushed the telecommunications industry to recently develop new wireless standards in order to guarantee tracking of devices and to provide integration with well-known worldwide networks such as the Internet. Within these standards the role played by power consumption is implicit, hence power consumption needs to be as low as possible in order to fulfill long-life requirements and to offer the opportunity of locating and moving smart objects in the coverage area while relying only on batteries as the device's power source.  Considering the importance of identifying and tracking these smart objects with high accuracy and high precision, this document propose an implementation of an IEEE 802.15.4a MAC layer, exploiting ultra-wideband wireless technology, with a time synchronization algorithm included for precise Time Difference of Arrival indoor positioning. Nevertheless, this thesis demonstrates the advantages of using UWB for indoor wireless communication, due to its accuracy in localization and its robustness against interference. A demonstration network has been analyzed consisting of four main base stations optimistically displaced at the corners of a room gathering timestamps from a central tag moving within the space where the UWB signal is within range. These timestamps are collected in one of the base station which plays the role of the coordinator and sends this information to a server which computes the position of the tag using TDOA formulation. The main focus of this work is the synchronization algorithms used to synchronize the four base stations and secondly to synchronize the coordinator with the tag. Particular interest is placed on the protocol, the kind of messages exchanged, and the procedure used to maintain a good level of synchronization and to avoid unwanted clock drifts. Moreover the thesis gives some hints of potential future improvements and proposes a possible solution for large-scale scenarios involving the installation of additional base stations for higher coverage and integration of a larger number of tags, with a focus on synchronization, collision avoidance, and routing procedures to better Fit the situation of a larger network and more tags.  As a result, all the assumptions and the methodologies applied give evidence of how difficult it is to meet contemporary requirements for position accuracy, low power consumption, limited memory, and small message exchange when utilizing low-power and lossy networks and to address problems which need to be further studied in the future. The results of this thesis project offer a good proof of the possibility to reach high accuracy in terms of localization when exploiting UWB radio technology and redundant time synchronization algorithms with the help of TDOA measurements. / Nödvändigheten av sammankopplade objekt mer och mer, eventuellt med hög rörlighet, har drivit telekombranschen till nyligen utveckla nya tråadlösa standarder för att garantera spåarning av enheter och att ge integration med välkända världsomspännande nätverk som Internet. Inom dessa standarder roll strömförbrukningen är implicit, måaste därför strömförbrukningen ska vara såa låag som möjligt för att uppfylla låang livslängd krav och erbjuda möjligheten att lokalisera och flytta smarta objekt i täckningsområadet medan enbart med hjälp av batterier som enhetens strömkälla. Med tanke påa vikten av att identiera och spåara dessa smarta objekt med hög noggrannhet och hög precision, detta dokument föreslåa ett genomförande av en IEEE 802.15.4a MAC-lager, utnyttja ultrabredbandsteknik tråadlös teknik, med en tidssynkronisering algoritm ingåar för exakt tidsskillnaden för ankomst inomhus positionering. Ändåa visar denna avhandling fördelarna med att använda UWB för inomhus tråadlös kommunikation, påa grund av dess noggrannhet i lokalisering och robusthet mot störningar. En demonstration nätverk har analyserats beståar av fyra huvudsakliga basstationer optimistiskt förskjutna i hörnen av ett rum samla tidsstämplar fråan en central tagg flyttar inom utrymme där UWB signalen är inom räckhåall.  Dessa tidsangivelser samlas i en av basstationen som spelar rollen av samordnare och skickar denna information till en server som beräknar position taggen med TDOA formulering. Tyngdpunkten i detta arbete är att synkronisering algoritmer som används för att synkronisera de fyra basstationer dels att synkronisera samordnaren med taggen. Särskilt intresse läggs vid protokollet, den typ av utbytta meddelanden och det förfarande som används för att upprätthåalla en god nivåa av synkronisering och för att undvika oönskade klocka drivor. Dessutom avhandlingen ger nåagra tips om potentiella framtida förbättringar och föreslåar en möjlig lösning för storskaliga scenarier som innebär installation av ytterligare basstationer för högre täckning och integration av ett större antal taggar, med fokus påa synkronisering, att undvika kollision och routing förfaranden för att bättre passa situationen i ett större nätverk och fler taggar.  Som ett resultat, som tillämpas alla antaganden och metoder vittnar om hur svåart det är att uppfylla dagens krav påa positionsnoggrannhet, låag strömförbrukning, begränsat minne, och småa utbyte av meddelanden vid användning med låag effekt och förstörande nätverk och att ta itu med problem som måaste studeras vidare i framtiden. Resultaten fråan denna avhandling projekt erbjuder en bra bevis påa möjligheten att nåa hög noggrannhet vad gäller lokalisering vid utnyttjande UWB radioteknik och redundanta tid algoritmer synkronisering med hjälp av TDOA mätningar.

In recent years, the requirement of application such as wireless sensor networks and short-range wireless controllers caused the growing of ZigBee technology. ZigBee is a communication technology developed specifically for short-range, low rate, low-cost wireless transmission.There are some characteristic such as short-range, low rate, low cost, and low power. The ZigBee Aliance group developed the specifications of software, and IEEE 802.15.4 group developed the specifications of hardware. IEEE 802.15.4a impulse radio UWB physical layer is one of the ZigBee physical layers. In our study, we designed a baseband signal processing algorithm meeting the specifications of IEEE 802.15.4a. The data processing flow in transmitter followed the specifications. In receiver, we designed baseband algorithms based-on the non-coherent energy detection scheme. Our algorithm including packet detection, synchronization and demodulation, and considering the implementation of algorithm, reducing the complexity of hardware as possible and improving the efficiency. Finally, the system performance is 3.9dB better than the receiver sensitivity.

Depuis quelques années, la thématique de la localisation a connu un regain d’intérêt,motivé en grande partie par le développement des réseaux de capteurs sans fil. Lespropositions ayant pour objectif d’apporter une réponse à cette problématique peuvent êtreclassées en deux catégories : les méthodes range-based, retenues pour cette thèse, dont lacaractéristique est de se fonder sur des mesures en temps réel du signal pour générer uneestimation relativement fiable de la distance, et les solutions range-free, économes enressources car se limitant à l’exploitation d’hypothèses concernant la connectivité des noeudsdans le réseau. Les contributions peuvent se focaliser sur l’un des trois aspects fondamentauxde la question : le développement d’une couche physique performante, la proposition d’unalgorithme de calcul permettant des résultats plus précis, et la mise en place d’un protocole decollecte de mesures.La contribution de cette thèse est par conséquent multiple : en premier lieu, nousproposons un nouveau protocole de mesure du temps de vol, nommé Parallel SymmetricDouble-Sided Two-Way Ranging (PSDS-TWR), dont l’objectif est la réduction de la chargeprotocolaire du service. Deuxièmement, nous avons mis en place un algorithme de calcul dela position désigné par interRing Localization Algorithm (iRingLA). Basé sur une recherchelinéaire, iRingLA accepte des données inexactes et en extrait une estimation de la positiondont l’erreur est inférieure à 2m dans 70% des cas, ceci en s’exécutant directement sur unnoeud mobile léger. Les données concernant l’algorithme ont été collectées grâce à unprototype utilisant la technologie Chirp Spread Spectrum tandis que l’étude de performancedu protocole a impliqué la conception d’un simulateur nommé DokoSim / The development of Wireless Sensor Networks has given a new life to research in thefield of localization. Many proposals have been made which can be classified as either rangefreeor range-based solutions. The range-free category relies on a priori knowledge of thenetwork while the latter uses the available hardware to measure signal characteristics fromwhich distance information can be derived. Although the information origin can vary, allproposals either introduce a new protocol, a novel algorithm or a new and improved physicallayer.Our work led to the definition of a new protocol and an efficient algorithm. Aside fromallowing the nodes to collect Time Of Flight related data, the Parallel Symmetric Double-Sided Two-Way Ranging protocol (PSDS-TWR) reduces overhead and energy consumption,making the localization service affordable for the network. The performance of this protocol,in terms of duration, has been studied using a homemade simulator named DokoSim. We alsointroduce an algorithm based on rings and linear search. This inter-Ring LocalizationAlgorithm (iRingLA) achieves a localization error of less than 2m in 70% of the cases whilebeing tested on our Chirp Spread Sprectrum based prototype

The aim of this work is study the standard for wireless sensor networks IEEE 802.15.4a. Design and implementation of a packet analyzer for ultra wideband technology com- pliant with IEEE 802.15.4a standard. Integrate packet analyzer to inspection software Wireshark and implement dissector for view packets. Finally, analyze and evaluate the parameters of the proposed packet analyzer.

Wireless Sensor Networks are the main representative of pervasive computing in large-scale physical environments. These networks consist of a large number of small, wireless devices embedded in the physical world to be used for surveillance, environmental monitoring or other data capture, processing and transfer applications. Ultra wideband has emerged as one of the newest and most promising concepts for wireless technology. Considering all its advantages it seems a likely communication technology candidate for future wireless sensor networks. This paper considers the viability of ultra wideband technology in wireless sensor networks by employing an IEEE 802.15.4a low-rate ultra wideband physical layer model in the OMNET++ simulation environment. An elaborate investigation into the inner workings of the IEEE 802.15.4a UWB physical layer is performed. Simulation experiments are used to provide a detailed analysis of the performance of the IEEE 802.15.4a UWB physical layer over several communication distances. A proposal for a cognitive, adaptive communication approach to optimize for speed and distance is also presented. AFRIKAANS : Draadlose Sensor Netwerke is die hoof verteenwoordiger vir deurdringende rekenarisering in groot skaal fisiese omgewings. Hierdie tipe netwerke bestaan uit ’n groot aantal klein, draadlose apparate wat in die fisiese wêreld ingesluit word vir die doel van bewaking, omgewings monitering en vele ander data opvang, verwerk en oordrag applikasies. Ultra wyeband het opgestaan as een van die nuutste en mees belowend konsepte vir draadlose kommunikasie tegnologie. As al die voordele van dié kommunikasie tegnologie in ag geneem word, blyk dit om ’n baie goeie kandidaat te wees vir gebruik in toekomstige draadlose sensor netwerke. Hierdie verhandeling oorweeg die vatbaarheid van die gebruik van die ultra wyeband tegnologie in draadlose sensor netwerke deur ’n IEEE 802.15.4a lae-tempo ultra wyeband fisiese laag model in die OMNET++ simulasie omgewing toe te pas. ’n Breedvoerige ondersoek word geloots om die fyn binneste werking van die IEEE 802.15.4a UWB fisiese laag te verstaan. Simulasie eksperimente word gebruik om ’n meer gedetaileerde analiese omtrent die werkverrigting van die IEEE 802.15.4a UWB fisiese laag te verkry oor verskillende kommunikasie afstande. ’n Voorstel vir ’n omgewings bewuste, aanpasbare kommunikasie tegniek word bespreek met die doel om die spoed en afstand van kommunikasie te optimiseer. / Dissertation (MEng)--University of Pretoria, 2011. / Electrical, Electronic and Computer Engineering / unrestricted

Dans ce travail nous nous intéressons à la modélisation des couches MAC et PHY dans le cadre des réseaux sans fil à faible, portée. Il présente les techniques de modélisation utilisées pour l'intégration des couches MAC-PHYs (Medium Access Control and Physical layer) de type IR-UWB (Impulse Radio Ultra Wideband) d'une part, et des nouvelles techniques de transmission à 60GHz incluant le beamforming d'autre part, dans le simulateur GloMoSim/QualNet. La modélisation de IR-UWB est basée sur la prise en compte directe des collisions d'impulsions et de l'interférence multi-utilisateur au niveau de la couche PHY par l'introduction du concept de séquences de réception et la notion d'orthogonalité en réception. L'architecture de modélisation proposée est basée sur l'utilisation d'une matrice d'interférence, elle a été développée en deux étapes : une première modélisation basée sur des trains d'impulsions uniformément espacées et une deuxième modélisation plus complète prenant en compte l'utilisation des séquences de sauts aléatoires également appelés séquences de time hopping. L'évaluation de performances de cette partie est basée sur une application typique des réseaux de capteurs dans le cadre d'une application de détection d'intrusion sur une surface protégée. La modélisation à 60 GHz à pour but la prise en compte des nouvelles techniques d'amélioration du débit, notamment l'agrégation et le beamforming. La prise en compte du beamforming est basée sur la définition, des diagrammes de rayonnement des antennes ainsi que de l'interface MAC-PHY/Antenne. La modélisation des deux protocoles de beamforming définis dans le standard 802.15.3c est également effectuée. L'évaluation de performances de cette partie est basée sur un système de distribution de contenu multimédia.