10 research outputs found

    RĂ©cepteur Sans-Fil Ă  Basse Consommation et Ă  Modulation Mixte FSK-ASK pour les Dispositifs MĂ©dicaux

    Get PDF
    RÉSUMÉ Les Ă©metteurs-rĂ©cepteurs radiofrĂ©quences (RF) offrent le lien de communications le plus commun afin de mettre au point des dispositifs mĂ©dicaux implantables dĂ©diĂ©s aux interfaces homme-machines. La surveillance en continu des paramĂštres biologiques des patients nĂ©cessite un module de communication sans-fil capable de garantir un Ă©change de donnĂ©es rapide, en temps rĂ©el, Ă  faible puissance tout en Ă©tant implĂ©mentĂ© dans un espace physique rĂ©duit. La consommation de puissance des dispositifs implantables joue un rĂŽle important dans les durĂ©es de vie des batteries qui nĂ©cessitent une chirurgie pour leur remplacement, Ă  moins qu’une technique de transfert de puissance sans-fil soit utilisĂ©e pour recharger la batterie ou alimenter l’implant a travers les tissus humains. Dans ce projet, nous avons conçu, implĂ©mentĂ© et testĂ© un rĂ©cepteur RF Ă  faible puissance et haut-dĂ©bit de donnĂ©es opĂ©rant entre 902 et 928 MHz qui est la bande industrielle-scientifiquemĂ©dicale (Industrial, Scientific and Medical) d’AmĂ©rique du Nord. Ce rĂ©cepteur fait partie d’un systĂšme de communication bidirectionnel dĂ©diĂ© Ă  l’interface sans-fil des dispositifs Ă©lectroniques implantables et bĂ©nĂ©ficie d’une nouvelle technique de conversion de modulation par dĂ©placement de frĂ©quence (FSK) en Modulation par dĂ©placement d’amplitude (ASK). Toutes les phases de conception et d’implĂ©mentation de la topologie adoptĂ©e pour les rĂ©cepteurs RF sont survolĂ©es et discutĂ©es dans cette thĂšse. Les diffĂ©rents Ă©tages de circuits sont conçus selon une Ă©tude analytique fondĂ©e de la modulation FSK et ASK utilisĂ©es, ce qui permettra une amĂ©lioration des performances notamment le dĂ©bit de transmission des donnĂ©es et la consommation de puissance. Tous les circuits sont rĂ©alisĂ©s de façon Ă  ce que la consommation totale et la surface de silicium Ă  rĂ©server soient le minimum possible. Un oscillateur avec verrouillage par injection (Injection-Looked Oscillator - ILO) de faible puissance est rĂ©alisĂ© pour assurer la conversion des signaux ASK en FSK. Une combinaison des avantages des deux architectures de modulation d’amplitude et de frĂ©quence, pour les circuits d’émetteurrĂ©cepteur sans fil, a Ă©tĂ© rĂ©alisĂ© avec le systĂšme proposĂ©. Un module incluant un rĂ©cepteur de rĂ©veil (Wake up) est ajoutĂ© afin d’optimiser la consommation totale du circuit en mettant tous les blocs Ă  l’arrĂȘt. Nous avons rĂ©alisĂ© un rĂ©cepteur de rĂ©veil RF compact et Ă  faible coĂ»t, permettant de trĂšs faible niveaux de consommation d’énergie, une bonne sensibilitĂ© et une meilleure tolĂ©rance aux interfĂ©rences. Le design est basĂ© sur une topologie homodyne Ă  dĂ©tection d’enveloppe permettant une transposition directe du signal RF modulĂ© en amplitude en un signal en bande de base. Cette architecture nĂ©cessite une architecture peu encombrante Ă  intĂ©grer qui Ă©limine le problĂšme des frĂ©quences image pour la mĂȘme topologie avec une modulation de frĂ©quence.---------- ABSTRACT ISM band transceiver using a wake-up bloc for wireless body area networks (WBANs) wearable and implantable medical devices is proposed. The system achieves exceptionally low-power consumption and allows a high-data rate by combining the advantages of Frequency-Shift-Keying (FSK) and Amplitude-Shift- Keying (ASK) modulation techniques. The transceiver employs FSK modulation at a data rate of 8 Mbit/s to establish RF link among the medical device and a control unit. Transmitter (Tx) includes a new efficient FSK modulation scheme which offer up to 20 Mb/s of data-rate and dissipates around 0.084 nJ/b. The design of the proposed oscillator achieves variable frequency from 300 kHz to 8 MHz by adjusting the transistors geometry, the on-chip control signal and the tuning capacitors. In the transmitter path, the high-quality LOs Inand Quadrature-phase (I and Q) outputs are produced using a very low-power fully integrated integer-N frequency synthesizer. The architecture of the receiver is inspired from the super-regenerative receiver (SRR) topology which can be used to design a transceiver that is suitable for ASK modulation. In fact, this architecture is based mainly on envelope detection scheme which remove the need to process the carrier phase to reduce the complexity of integrated design. It has been shown too, that the envelope detection scheme is more robust to phase noise than the coherent scheme. The integrated receiver uses on a new FSK-to-ASK conversion technique. The conversion feature that we adopt in the main receiver design is based on the fact that the incident frequency of converter could be differentiated by the amplitude of output signal, which conducts to the frequency-to-amplitude conversion. Thanks to the injection locking oscillator (ILO). the new design of converter is located between the LNA as first part and the envelope detector as second part to benefit from the injection-locking isolation. On-Off-keying (OOK) fully passive wake-up circuit (WuRx) with energy harvesting from Radio Frequency (RF) link is used to optimize the power issipation of the RF transceiver in order to meet the low power requirement. The WuRx operates at the ISM 902–928 MHz. A high efficiency differential rectifier behaves as voltage multiplier. It generates the envelope of the input signal and provides the supply voltage for the rest of blocks including a low-power comparator and reference generators

    RF Integrated Circuits for Energy Autonomous Sensor Nodes.

    Full text link
    The exponential growth in the semiconductor industry has enabled computers to pervade our everyday lives, and as we move forward many of these computers will have form factors much smaller than a typical laptop or smartphone. Sensor nodes will soon be deployed ubiquitously, capable of capturing information of their surrounding environment. The next step is to connect all these different nodes together into an entire interconnected system. This “Internet of Things” (IoT) vision has incredible potential to change our lives commercially, societally, and personally. The backbone of IoT is the wireless sensor node, many of which will operate under very rigorous energy constraints with small batteries or no batteries at all. It has been shown that in sensor nodes, radio communication is one of the biggest bottlenecks to ultra-low power design. This research explores ways to reduce energy consumption in radios for wireless sensor networks, allowing them to run off harvested energy, while maintaining qualities that will allow them to function in a real world, multi-user environment. Three different prototypes have been designed demonstrating these techniques. The first is a sensitivity-reduced nanowatt wake-up radio which allows a sensor node to actively listen for packets even when the rest of the node is asleep. CDMA codes and interference rejection reduce the potential for energy-costly false wake-ups. The second prototype is a full transceiver for a body-worn EKG sensor node. This transceiver is designed to have low instantaneous power and is able to receive 802.15.6 Wireless Body Area Network compliant packets. It uses asymmetric communication including a wake-up receiver based on the previous design, UWB transmitter and a communication receiver. The communication receiver has 10 physical channels to avoid interference and demodulates coherent packets which is uncommon for low power radios, but dictated by the 802.15.6 standard. The third prototype is a long range transceiver capable of >1km communication range in the 433MHz band and able to interface with an existing commercial radio. A digitally assisted baseband demodulator was designed which enables the ability to perform bit-level as well as packet-level duty cycling which increases the radio's energy efficiency.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/110432/1/nerobert_1.pd

    Asic Design of RF Energy Harvester Using 0.13UM CMOS Technology

    Get PDF
    Recent advances in wireless sensor nodes, data acquisition devices, wearable and implantable medical devices have paved way for low power (sub 50uW) devices. These devices generally use small solid state or thin film batteries for power supply which need replacement or need to be removed for charging. RF energy harvesting technology can be used to charge these batteries without the need to remove the battery from the device, thus providing a sustainable power supply. In other cases, a battery can become unnecessary altogether. This enables us to deploy wireless network nodes in places where regular physical access to the nodes is difficult or cumbersome. This thesis proposes a design of an RF energy harvesting device able to charge commercially available thin film or solid-state batteries. The energy harvesting amplifier circuit is designed in Global Foundry 0.13um CMOS technology using Cadence integrated circuit design tools. This Application Specific Integrated Circuit (ASIC) is intended to have as small a footprint as possible so that it can be easily integrated with the above-mentioned devices. While a dedicated RF power source is a direct solution to provide sustainable power to the harvesting circuit, harvesting ambient RF power from TV and UHF cellular frequencies increases the possibilities of where the harvesting device can be placed. The biggest challenge for RF energy harvesting technology is the availability of adequate amount of RF power. This thesis also presents a survey of available RF power at various ultra-high frequencies in San Luis Obispo, CA.The idea is to determine the frequency band which can provide maximum RF power for harvesting and design a harvester for that frequency band

    Transceiver architectures and sub-mW fast frequency-hopping synthesizers for ultra-low power WSNs

    Get PDF
    Wireless sensor networks (WSN) have the potential to become the third wireless revolution after wireless voice networks in the 80s and wireless data networks in the late 90s. This revolution will finally connect together the physical world of the human and the virtual world of the electronic devices. Though in the recent years large progress in power consumption reduction has been made in the wireless arena in order to increase the battery life, this is still not enough to achieve a wide adoption of this technology. Indeed, while nowadays consumers are used to charge batteries in laptops, mobile phones and other high-tech products, this operation becomes infeasible when scaled up to large industrial, enterprise or home networks composed of thousands of wireless nodes. Wireless sensor networks come as a new way to connect electronic equipments reducing, in this way, the costs associated with the installation and maintenance of large wired networks. To accomplish this task, it is necessary to reduce the energy consumption of the wireless node to a point where energy harvesting becomes feasible and the node energy autonomy exceeds the life time of the wireless node itself. This thesis focuses on the radio design, which is the backbone of any wireless node. A common approach to radio design for WSNs is to start from a very simple radio (like an RFID) adding more functionalities up to the point in which the power budget is reached. In this way, the robustness of the wireless link is traded off for power reducing the range of applications that can draw benefit form a WSN. In this thesis, we propose a novel approach to the radio design for WSNs. We started from a proven architecture like Bluetooth, and progressively we removed all the functionalities that are not required for WSNs. The robustness of the wireless link is guaranteed by using a fast frequency hopping spread spectrum technique while the power budget is achieved by optimizing the radio architecture and the frequency hopping synthesizer Two different radio architectures and a novel fast frequency hopping synthesizer are proposed that cover the large space of applications for WSNs. The two architectures make use of the peculiarities of each scenario and, together with a novel fast frequency hopping synthesizer, proved that spread spectrum techniques can be used also in severely power constrained scenarios like WSNs. This solution opens a new window toward a radio design, which ultimately trades off flexibility, rather than robustness, for power consumption. In this way, we broadened the range of applications for WSNs to areas in which security and reliability of the communication link are mandatory

    Design of a 2.4 Ghz BAW-Based CMOS Transmitter

    Get PDF
    In recent years, bulk acoustic wave resonators (BAW) in combination with RF circuits have shown a big potential in achieving the low-power consumption and miniaturization level required to address wireless sensor nodes (WSN) applications. A lot of work has been focused on the receiver side, by integrating BAW resonators with low noise amplifiers (LNA) and in frequency synthesis with the design of BAW-based local oscillators, most of them working at fixed frequency due to their limited tuning range. At the architectural level, this has forced the implementation of several single channel transceivers. This thesis aims at exploring the use of BAW resonators in the transmitter, proposing an architecture capable of taking full advantage of them. The main objective is to develop a transmitter for WSN multi-channel applications able to cover the whole 2.4 GHz ISM band and enable the compatibility with wide-spread standards like Bluetooth and Bluetooth Low Energy. Typical transmissions should thus range from low data rates (typically tens of kb/s) to medium data rates (1 Mb/s), with FSK and GFSK modulation schemes, should be centered on any of the channels provided by these standards and cover a maximum transmission range of some tens of meters. To achieve these targets and circumvent the limited tuning range of the BAW oscillator, an up-conversion transmitter using wide IF is used. The typical spurs problems related to this transmitter architecture are addressed by using a combined suppression based on SSB mixing and selective amplification. The latter is achieved by cointegration of a high efficiency power amplifier with BAW resonators, which allows performing spurs filtering while preserving the efficiency. In particular the selective amplifier is designed by including in the PA analysis the BAW resonator parameters, which allows integrating the BAW filter into the passive network loading the amplifier, participating in the drain voltage shaping. Finally, the frequency synthesis section uses a fractional division plus LC PLL filtering and further integer division to generate the IF signals and exploit the very-low BAW oscillator phase noise. The transmitter has been integrated in a 0.18 ”m standard digital CMOS technology. It allows addressing the whole 80 MHz wide 2.4 GHz ISM band. The unmodulated RF frequency carrier demonstrates a very-low phase noise of –136 dBc/Hz at 1 MHz offset. The IF spurs are maintained lower than –48 dBc, satisfying the international regulations for output power up to 10 dBm without the use of any quadrature error compensation in the transmitter. This is achieved thanks to the rejection provided by the SSB mixer and the selective amplifier, which can reach drain efficiency of up to 24% with integrated inductances, including the insertion losses of the BAW filter. The transmitter consumes 35.3 mA at the maximum power of 5.4 dBm under 1.6 V (1.2 V for the PA), while transmitting a 1 Mb/s GFSK signal and complying with both Bluetooth and Bluetooth Low Energy relative and absolute spectrum requirements

    Toward Brain Area Sensor Wireless Network

    Get PDF
    RÉSUMÉ De nouvelles approches d'interfaçage neuronal de haute performance sont requises pour les interfaces cerveau-machine (BMI) actuelles. Cela nĂ©cessite des capacitĂ©s d'enregistrement/stimulation performantes en termes de vitesse, qualitĂ© et quantitĂ©, c’est Ă  dire une bande passante Ă  frĂ©quence plus Ă©levĂ©e, une rĂ©solution spatiale, un signal sur bruit et une zone plus large pour l'interface avec le cortex cĂ©rĂ©bral. Dans ce mĂ©moire, nous parlons de l'idĂ©e gĂ©nĂ©rale proposant une mĂ©thode d'interfaçage neuronal qui, en comparaison avec l'Ă©lectroencĂ©phalographie (EEG), l'Ă©lectrocorticographie (ECoG) et les mĂ©thodes d'interfaçage intracortical conventionnelles Ă  une seule unitĂ©, offre de meilleures caractĂ©ristiques pour implĂ©menter des IMC plus performants. Les avantages de la nouvelle approche sont 1) une rĂ©solution spatiale plus Ă©levĂ©e - en dessous dumillimĂštre, et une qualitĂ© de signal plus Ă©levĂ©e - en termes de rapport signal sur bruit et de contenu frĂ©quentiel - comparĂ© aux mĂ©thodes EEG et ECoG; 2) un caractĂšre moins invasif que l'ECoG oĂč l'enlĂšvement du crĂąne sous une opĂ©ration d'enregistrement / stimulation est nĂ©cessaire; 3) une plus grande faisabilitĂ© de la libre circulation du patient Ă  l'Ă©tude - par rapport aux deux mĂ©thodes EEG et ECoG oĂč de nombreux fils sont connectĂ©s au patient en cours d'opĂ©ration; 4) une utilisation Ă  long terme puisque l'interface implantable est sans fil - par rapport aux deux mĂ©thodes EEG et ECoG qui offrent des temps limitĂ©s de fonctionnement. Nous prĂ©sentons l'architecture d'un rĂ©seau sans fil de microsystĂšmes implantables, que nous appelons Brain Area Sensor NETwork (Brain-ASNET). Il y a deux dĂ©fis principaux dans la rĂ©alisation du projet Brain-ASNET. 1) la conception et la mise en oeuvre d'un Ă©metteur-rĂ©cepteur RF de faible consommation compatible avec la puce de capteurs de rĂ©seau implantable, et, 2) la conception d'un protocole de rĂ©seau de capteurs sans fil (WSN) ad-hoc Ă©conome en Ă©nergie. Dans ce mĂ©moire, nous prĂ©sentons un protocole de rĂ©seau ad-hoc Ă©conome en Ă©nergie pour le rĂ©seau dĂ©sirĂ©, ainsi qu'un procĂ©dĂ© pour surmonter le problĂšme de la longueur de paquet variable causĂ© par le processus de remplissage de bit dans le protocole HDLC standard. Le protocole adhoc proposĂ© conçu pour Brain-ASNET prĂ©sente une meilleure efficacitĂ© Ă©nergĂ©tique par rapport aux protocoles standards tels que ZigBee, Bluetooth et Wi-Fi ainsi que des protocoles ad-hoc de pointe. Le protocole a Ă©tĂ© conçu et testĂ© par MATLAB et Simulink.----------ABSTRACT New high-performance neural interfacing approaches are demanded for today’s Brain-Machine Interfaces (BMI). This requires high-performance recording/stimulation capabilities in terms of speed, quality, and quantity, i.e. higher frequency bandwidth, spatial resolution, signal-to-noise, and wider area to interface with the cerebral cortex. In this thesis, we talk about the general proposed idea of a neural interfacing method which in comparison with Electroencephalography (EEG), Electrocorticography (ECoG), and, conventional Single-Unit Intracortical neural interfacing methods offers better features to implement higher-performance BMIs. The new approach advantages are 1) higher spatial resolution – down to sub-millimeter, and higher signal quality − in terms of signal-to-noise ratio and frequency content − compared to both EEG and ECoG methods. 2) being less invasive than ECoG where skull removal Under recording/stimulation surgery is required. 3) higher feasibility of freely movement of patient under study − compared to both EEG and ECoG methods where lots of wires are connected to the patient under operation. 4) long-term usage as the implantable interface is wireless − compared to both EEG and ECoG methods where it is practical for only a limited time under operation. We present the architecture of a wireless network of implantable microsystems, which we call it Brain Area Sensor NETwork (Brain-ASNET). There are two main challenges in realization of the proposed Brain-ASNET. 1) design and implementation of power-hungry RF transceiver of the implantable network sensors' chip, and, 2) design of an energy-efficient ad-hoc Wireless Sensor Network (WSN) protocol. In this thesis, we introduce an energy-efficient ad-hoc network protocol for the desired network, along with a method to overcome the issue of variable packet length caused by bit stuffing process in standard HDLC protocol. The proposed ad-hoc protocol designed for Brain-ASNET shows better energy-efficiency compared to standard protocols like ZigBee, Bluetooth, and Wi-Fi as well as state-of-the-art ad-hoc protocols. The protocol was designed and tested by MATLAB and Simulink

    Wake-up radio systems : design, development, performance evaluation and comparison to conventional medium access control protocols for wireless sensor networks

    Get PDF
    During the recent years, the research related to Wake-up Radio (WuR) systems has gained noticeable interest. In WuR systems, a node initiating a communication first sends a Wake-up Call (WuC) by means of its Wake-up Transmitter (WuTx), to the Wake-up Receiver (WuRx) of a remote node to activate it in an on-demand manner. Until the reception of the WuC, the node's MCU and main data transceiver are in sleep mode. Hence, WuR drastically reduce the power required by wireless nodes. This thesis provides a complete analysis of several WuR designs vs. conventional MAC protocols for Wireless Sensor Networks (WSN). The research is performed in an incremental fashion and includes hardware, softwar and simulation topics. WuR systems enable energy savings in plenty of different applications, e.g., retrieving information from environmental pollution sensors placed in a city by a mobile collector node, or activating a sleeping wireless AP. They are easy to program in and provide implicit synchronization. However, achieving a good WuRx design may become a challenge because power amplifiers cannot be used for the sake of energy. The system proposed in chapter 2 is a successful WuR system prototype. The so-called S”A-WuRx is less complex than commercial WuR systems, it is cheaper from the monetary point of view, requires several times less energy and allows for up to 15 meters of communication, an adequate value for WuR systems. However, the system can be improved by including several desirable features, such as longer operational ranges and/or addressing mechanisms. The so-called Time-Knocking (TicK) addressing strategy, analyzed in chapter 3, enables energy efficient node addressing by varying the time between WuCs received by a MCU. TicK allows for variable length addresses and multicast. A WuR system may not fit any possible application. Thus, while the S”A-WuRx and TicK efficiently solved many of the requirements of single-hop and data-collector applications, they lack of flexibility. Instead, SCM-WuR systems in chapter 4 feature an outstanding trade-off between hardware complexity, current consumption and operational range, and even enable multi-hop wake-up for long remote sensor measure collection. To contextualize the WuR systems developed, chapter 5 provides an overview of the most important WuR systems as of 2014. Developing a MAC protocol which performs acceptably in a wide range of diverse applications is a very difficult task. Comparatively, SCM-WuR systems perform properly in all the use cases (single and multi-hop) presented in chapter 6. Bluetooth Low Energy, or BLE, appears as a duty-cycled MAC protocol mainly targeting single-hop applications. Because of its clearly defined use cases and its integration with its upper application layers, BLE appears as an extremely energy-efficient protocol that cannot be easily replaced by WuR. Because of all these aspects, the performance of BLE is analyzed in chapter 7. Finally, chapter 8 tries to solve one of the issues affecting WuR systems, that is, the need for extra hardware. While this issue seems difficult to solve for WuRx, the chapter provides ideas to use IEEE 802.11-enabled devices as WuTx.Durant els Ășltims anys, la investigaciĂł relativa als sistemes de RĂ dios de Wake-up (de l'anglĂšs Wake-up Radio, WuR) ha experimentat un interĂšs notable. En aquests sistemes, un node inicia la comunicaciĂł inal.lĂ mbrica transmetent una Wake-up Call (WuC), per mitjĂ  del seu transmissor de Wake-up (WuTx), dirigida al receptor de Wake-up (WuRx) del node remot. Aquesta WuC activa el node remot, el microcontrolador (MCU) i la rĂ dio principals del qual han pogut romandre en mode "sleep" fins el moment. AixĂ­ doncs, els sistemes WuR permeten un estalvi drĂ stic de l'energia requerida pels nodes sense fils. Aquesta tesi proposa diferents sistemes WuR i els compara amb protocols MAC existents per a xarxes de sensors sense fils (Wireless Sensor Networks, WSN). La investigaciĂł es realitza de forma progressiva i inclou hardware, software i simulaciĂł. Els sistemes WuR permeten un estalvi energĂštic notable en moltes aplicacions: recolÂżlecciĂł d'informaciĂł ambiental, activaciĂł remota de punts d'accĂ©s wi-fi, etc. SĂłn fĂ cils de programar en software i comporten una sincronitzaciĂł implĂ­cita entre nodes. Malauradament, un consum energĂštic mĂ­nim impossibilita l'Ășs d'amplificadors de potĂšncia, i dissenyar-los esdevĂ© un repte. El sistema presentat en el capĂ­tol 2 Ă©s un prototip exitĂłs de sistema WuR. De nom S”A-WuR, Ă©s mĂ©s senzill que alternatives comercials, Ă©s mĂ©s econĂČmic, requereix menys energia i permet distĂ ncies de comunicaciĂł WuR majors, de fins a 15 metres. L'estratĂšgia d'adreçament Time-KnocKing, presentada en el capĂ­tol 3, permet dotar l'anterior S”A-WuR d'una forma d'especificar el node adreçat, permetent estalvi energĂštic a nivell de xarxa. TicK opera codificant el temps entre diferents WuC. Depenent del temps entre intervals, es desperten el/s node/s desitjats d'una forma extremadament eficient. Tot i els seus beneficis, hi ha aplicacions no implementables amb el sistema S”A-WuR. Per a aquest motiu, en el capĂ­tol 4 es presenta el sistema SCM-WuR, que ofereix un rang d'operaciĂł de 40 a 100 metres a canvi d'una mĂ­nima complexitat hardware afegida. SCM-WuR cobreix el ventall d'aplicacions del sistema S”A-WuRx, i tambĂ© les que requereixen multi-hop a nivell WuR. El capĂ­tol 5 de la tesi compara els dos sistemes WuR anteriors vers les propostes mĂ©s importants fins el 2014. El capĂ­tol 6 inclou un framework de simulaciĂł complet amb les bases per a substituir els sistemes basats en duty-cycling a WuR. Degut a que desenvolupar un protocol MAC que operi acceptablement bĂ© en multitud d'aplicacions esdevĂ© una tasca prĂ cticament impossible, els sistemes WuR presentats amb anterioritat i modelats en aquest capĂ­tol representen una soluciĂł versĂ til, interessant i molt mĂ©s eficient des del punt de vista energĂštic. Bluetooth Low Energy, o Smart, o BLE, representa un cas d'aplicaciĂł especĂ­fica on, degut a la gran integraciĂł a nivell d'aplicaciĂł, la substituciĂł per sistemes de WuR esdevĂ© difĂ­cil Per a aquesta raĂł, i degut a que es tracta d'un protocol MAC extremadament eficient energĂšticament, aquesta tesi contĂ© una caracteritzaciĂł completa de BLE en el capĂ­tol 7. Finalment, el capĂ­tol 8 soluciona un dels inconvenients del sistemes WuR, el disseny de WuTx especĂ­fics, presentant una estratĂšgia per a transformar qualsevol dispositiu IEEE 802.11 en WuTx

    60 GHz photonic millimeter-wave communication systems

    Get PDF
    Currently available copper-based Internet access technologies like xDSL and DOCSIS cover data transmission speeds in the range of some 10 Mb/s. With new applications, an increase in bandwidth demand up to the Gb/s-range is expected for the next years. Therefore, an evolution of access networks by gradual replacement of copper-based by fiber-optic infrastructure is presently ongoing. A similar development can be predicted for wireless access technology operating within the classical microwave range. Due to regulatory requirements and a lack of bandwidth alternatives need to be developed in the millimeter-wave band. In this regard, the frequency range around 60 GHz has a special importance due to a worldwide available unlicensed spectrum of several GHz of bandwidth. In this context, the integration of wireless networks in fiber-optic networks by the fiber-optic transport of the radio signal (radio-over-fiber, RoF) is of particular importance. Besides the low-loss optical transport of a 60 GHz radio signal RoF technology furthermore allows to shift complexity from base stations to a central office by a centralized provision of the millimeter-wave carrier. This work deals with the modeling, realization and characterization of 60 GHz RoF systems providing data rates within the multi-Gb/s range. On the theoretical side, a system model has been developed comprising relevant electrical and optical noise sources and the transmission properties of fiber-optic and wireless links as well. This allows for instance to make reliable predictions of the expected system performance in the run-up to RoF system planning and thus to identify optimization potential. Using innovative approaches and technologies, 12.5 Gb/s data transmission has been realized via fiber and wirelessly for the first time over technical relevant distances. Also, if compared to conventional RoF systems the dispersion-limited fiber-optic range has been multiplied. Another RoF system in the frame of this work aimed for an uncompressed HDTV transmission, for instance for video conferencing with high resolution (1080p) and extremely low latency (telemedicine). The wireless transmission of an uncompressed HDTV signal has been successfully demonstrated. Including the previously achieved results and experiences, the system complexity has been significantly reduced
    corecore